U.S. Department of the Interior

U.S. Fish & Wildlife Service

Ridgefield National Wildlife Refuge

28908 NW Main Ave.

Ridgefield, WA 98642-0457

Phone: 360/887-4106

Fax: 360/887-4109

http://www.fws.gov

National Wildlife Refuge System Information

1 800/344 WILD

September 2010

The mission of the U.S. Fish & Wildlife Service

is working with others to conserve, protect, and

enhance fish, wildlife, and plants and their habitats

for the continuing benefit of the American people.

Cover Photo:

Cackling geese

©Dave Renwald
Comprehensive Conservation Plans provide long-term guidance for 

management decisions and set forth goals, objectives, and strategies needed 

to accomplish refuge purposes and identify the U.S. Fish and Wildlife Service’s 

best estimates of future needs. These plans detail program planning levels that are 

sometimes substantially above current budget allocations, and as such, are primarily 

used for strategic planning and program prioritization purposes. The plans do not 

constitute a commitment for staffing increases, operational and maintenance increases, 

or funding for future land acquisition.

Ridgefield National Wildlife Refuge is a place where people of all abilities can experience nature 

and share their outdoor traditions with others. This island of habitat with its rich diversity 

of floodplain forests, freshwater marshes, and meadows, will continue to sustain thriving 

populations of wintering dusky Canada geese, migrating waterfowl, and other wildlife. 

With collaboration from our conservation partners, the Refuge will apply sound, 

scientific principles to sustain the long-term ecological health and integrity of 

Lower Columbia River floodplain habitats; expand environmental education; 

encourage participation in wildlife-dependent recreational opportunities; 

protect and interpret unique cultural resources; and foster natural and 

cultural resources stewardship. As the rural character of the landscape 

changes, the Refuge will become even more important to wildlife and 

those seeking to understand our natural and cultural heritage.

Our Vision for the Future

Sandhill crane

©Roger Windemuth


Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

iii

Finding of No Significant Impact

for the 

Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Clark County, Washington 

The U.S. Fish and Wildlife Service (Service) has completed a Comprehensive Conservation Plan 

(CCP) and Environmental Assessment (EA) for Ridgefield National Wildlife Refuge (Refuge). 

The CCP will guide management of the Refuge for 15 years. The CCP/EA describes our 

proposals for managing the Refuge and their effects on the human environment under four 

alternatives, including the no action alternative.

Decision

Based on our comprehensive review and analysis in the CCP/EA, we selected Alternative 2 for 

implementation, because it will guide management of the Refuge in a manner that: 

• Achieves the mission of the National Wildlife Refuge System, and the purposes, vision, 

and goals of the Refuge. 

• Maintains and restores the ecological integrity of the Refuge’s habitats and populations. 

• Addresses the important issues identified during the CCP scoping process. 

• Addresses the legal mandates of the Service and the Refuge.

• Is consistent with the scientific principles of sound wildlife management and endangered 

species recovery.

• Facilitates priority public uses appropriate and compatible with the Refuge’s purposes 

and the Refuge System mission.

Summary of the Actions to be Implemented

Implementing the selected alternative will have no significant impacts on the environmental 

resources identified in the CCP/EA. Refuge management under the selected alternative will 

protect, maintain, and enhance habitat for priority species and resources of concern, and improve 

the Refuge’s capability to provide food for migrating and wintering waterfowl. Improving the 

Refuge’s floodplain/riparian forest, oak woodland, instream, and wetland habitats will increase the 

value of lands and waters for a wide variety of native fish and wildlife. 

The availability and quality of wildlife-dependent recreation on the Refuge will improve under 

the selected alternative, but within a regional context, the cumulative change would be small. 

Implementing the Refuge hunt programs will result in no significant, adverse cumulative 

population level impacts to hunted or nonhunted wildlife species. A summary of the CCP 

actions we will implement follows.

Under Alternative 2, the Refuge will: 

• Protect, maintain, and where feasible, restore habitat for priority species, including dusky 

Canada geese and other waterfowl, and imperiled Federal and State listed species. 

• Meet Pacific Flyway management plan goals for dusky Canada geese and cackling geese.

• Maintain high-quality green forage for geese in improved pastures and wet meadows, and 

increase cropland and wet meadow acreage. 

Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

v 

Supporting References

U.S. Fish and Wildlife Service. June 2010. Ridgefield National Wildlife Refuge, Draft 

Comprehensive Conservation Plan and Environmental Assessment. 

U.S. Fish and Wildlife Service. 2010. Ridgefield National Wildlife Refuge Comprehensive 

Conservation Plan. 

Note: This Finding of No Significant Impact and supporting references are available for public 

review at Ridgefield National Wildlife Refuge Complex, 28908 NW Main Avenue, Ridgefield, 

Washington 98642, and U.S. Fish and Wildlife Service, Division of Planning, Visitor Services, 

and Transportation, 911 NE 11th Avenue, Portland, Oregon, 97232. These documents can also 

be found on the Internet at http://pacific.fws.gov/planning/. Interested and affected parties are 

being notified of our decision. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

vi

 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Table of Contents v 

Table of Contents

Chapter 1. Introduction and Background ............................................................................................ 1-1 

1.1 Introduction ......................................................................................................................................... 1-1 

1.2 Proposed Action .................................................................................................................................. 1-1 

1.3 Purpose and Need for the CCP ........................................................................................................... 1-2 

1.4 Content and Scope of the CCP ............................................................................................................ 1-7 

1.5 Refuge Planning and Management Guidance ..................................................................................... 1-8 

1.5.1 The U.S. Fish and Wildlife Service .......................................................................................... 1-8 

1.5.2 National Wildlife Refuge System ............................................................................................. 1-8 

1.5.3 Biological Resource Protection Acts ...................................................................................... 1-12 

1.5.4 Historic Preservation Acts ...................................................................................................... 1-13 

1.6 Refuge Establishment and Refuge Purposes ..................................................................................... 1-14 

1.6.1 Refuge Acquisition History and Authorities .......................................................................... 1-15 

1.6.2 Summary of Purposes and Management Direction for the Refuge ........................................ 1-21 

1.7 Relationship to Ecosystem Management Goals ................................................................................ 1-22 

1.7.1 Regional Setting ..................................................................................................................... 1-22 

1.7.2 Regional Conservation Plans .................................................................................................. 1-24 

1.7.3 Pacific Flyway Management Plans ......................................................................................... 1-27 

1.7.4 Partners in Flight Landbird Conservation Plans ..................................................................... 1-30 

1.7.5 Recovery Plans ....................................................................................................................... 1-31 

1.8 Issues, Concerns and Opportunities .................................................................................................. 1-32 

1.8.1 Major Issues to be Addressed in the CCP............................................................................... 1-32 

1.8.2 Issues Outside the Scope of the CCP ...................................................................................... 1-33 

1.9 Refuge Vision ................................................................................................................................... 1-35 

1.10 Refuge Goals ................................................................................................................................... 1-35 

1.10.1 Wildlife and Habitat Goals ................................................................................................... 1-35 

1.10.2 Cultural Resources Goal ....................................................................................................... 1-35 

1.10.3 Public Use Goals .................................................................................................................. 1-35 

1.11 Planning Process ............................................................................................................................. 1-36 

1.12 References ....................................................................................................................................... 1-37 

Chapter 2. Management Direction ........................................................................................................ 2-1 

2.1 Overview ............................................................................................................................................. 2-1 

2.2 Management Directions Considered but Not Developed .................................................................... 2-1 

2.3 Description of Management Direction ................................................................................................ 2-3 

2.3.1 Summary of Management Direction......................................................................................... 2-3 

2.3.2 Summary of Management Direction......................................................................................... 2-8 

2.4 Goals, Objectives, and Strategies ...................................................................................................... 2-25 

2.4.1 Goal 1: Provide and manage a mixture of secure, diverse, productive grassland habitats for 

foraging migratory waterfowl and grassland-dependent wildlife. .................................................... 2-26 

2.4.2 Goal 2: Provide agricultural crops as forage for migratory waterfowl and sandhill cranes 

annually. ........................................................................................................................................... 2-31 

2.4.3 Goal 3: Provide, manage, and enhance a diverse assemblage of wetland habitats 

characteristic of the historic lower Columbia River. ........................................................................ 2-32 

2.4.4 Goal 4: Protect, manage, and restore a natural diversity of native floodplain forests 

representative of the historic lower Columbia River ecosystem. ..................................................... 2-40 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

vi Table of Contents

2.4.5 Goal 5: Protect, manage, and restore a natural diversity of native upland forests 

representative of the historic lower Columbia River ecosystem. ..................................................... 2-44 

2.4.6 Goal 6: Protect, enhance and where feasible restore riverine habitat and tidal wetlands 

representative of the historic lower Columbia River ecosystem, to benefit salmonids and other 

native aquatic species. ...................................................................................................................... 2-47 

2.4.7 Goal 7: Collect scientific information (inventories, monitoring, and research) necessary to 

support adaptive management decisions on the refuge associated with Goals 1-6. ......................... 2-51 

2.5 Ridgefield Refuge Cultural Resources Goal and Objectives ............................................................. 2-64 

2.5.1 Goal 1: The Refuge will protect and manage its cultural resources for their educational, 

scientific, and cultural values for the benefit of present and future generations of Refuge users 

and communities. .............................................................................................................................. 2-64 

2.6 Ridgefield Refuge Public Use Goals and Objectives ......................................................................... 2-66 

2.6.1 Goal 1: Waterfowl hunters of all abilities will enjoy a quality, safe hunting program that 

provides a variety of waterfowl hunting experiences, promotes youth hunting, balances hunt 

program needs with other public use program needs, and reduces impacts to nontarget species..... 2-66 

2.6.2 Goal 2. Visitors of all abilities have the opportunity to participate in safe, quality wildlifedependent recreation programs, including wildlife observation, photography, interpretation, and 

fishing, consistent with the needs of other public use programs, with limited wildlife disturbance 

in the face of increasing Refuge visitation........................................................................................ 2-70 

2.6.3 Goal 3: The refuge’s cultural resources and the Cathlapotle Plankhouse will be interpreted 

to enlighten visitors about the refuge’s unique natural and cultural history. .................................... 2-79 

2.6.4 Goal 4: Through Refuge outreach efforts local residents will have the opportunity to gain 

an understanding of and appreciation for the refuge and Refuge System mission. .......................... 2-81 

2.6.5 Goal 5: Students from southwest Washington will participate in quality environmental 

education programs on the refuge that meet State educational requirements and provide safe and 

memorable experiences that foster a connection with nature and the refuge. .................................. 2-83 

2.7 References .......................................................................................................................................... 2-86 

Chapter 3. Physical Environment.......................................................................................................... 3-1 

3.1 Climate ................................................................................................................................................ 3-1 

3.1.1 Temperature .............................................................................................................................. 3-1 

3.1.2 Precipitation .............................................................................................................................. 3-2 

3.1.3 Climate Cycles in the Pacific Northwest .................................................................................. 3-2 

3.1.4 Floods ....................................................................................................................................... 3-3 

3.1.5 Wind and Severe Weather Events ............................................................................................ 3-4 

3.2 Climate Change ................................................................................................................................... 3-5 

3.2.1 Predicted Future Ecological Trends .......................................................................................... 3-5 

3.2.2 Detailed Future Climate Change in the Pacific Northwest ....................................................... 3-7 

3.2.3 Potential Changes to the Refuge ............................................................................................... 3-8 

3.3 Hydrology ........................................................................................................................................... 3-9 

3.3.1 Columbia River and Changes due to Hydropower Operations ................................................. 3-9 

3.3.2 Wetlands Hydrology ............................................................................................................... 3-10 

3.3.3 Gee Creek and Campbell Slough ............................................................................................ 3-12 

3.4 Topography and Bathymetry ............................................................................................................ 3-13 

3.5 Geology and Geomorphology ........................................................................................................... 3-14 

3.5.1 Physical Setting ...................................................................................................................... 3-14 

3.5.2 Geomorphology ...................................................................................................................... 3-14 

3.5.3 Geologic History ..................................................................................................................... 3-15

3.6 Soils ................................................................................................................................................. 3-17 

3.7 Environmental Contaminants ............................................................................................................ 3-18 

3.7.1 Air Quality .............................................................................................................................. 3-18 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Table of Contents vii

3.7.2 Water Quality and Contaminants ............................................................................................ 3-19 

3.8 Surrounding Land Uses ..................................................................................................................... 3-24 

3.9 References ......................................................................................................................................... 3-26 

Chapter 4. Refuge Biology and Habitat ................................................................................................ 4-1 

4.1 Historic Wildlife and Habitat Conditions and Changes Since 1800 ................................................... 4-1 

4.1.1 Historic Descriptions of Habitat and Wildlife .......................................................................... 4-1 

4.1.2 Changes to Lower Columbia River Wildlife and Habitats Since 1850 .................................... 4-5 

4.1.3 History of Refuge Management ................................................................................................ 4-9 

4.1.4 Changes in Wildlife Populations after Refuge Establishment ................................................ 4-12 

4.1.5 Influx of Exotic and Invasive Species .................................................................................... 4-14 

4.2 Selection of Priority Resources of Concern ...................................................................................... 4-20 

4.2.1 Selection Process .................................................................................................................... 4-20 

4.2.2 Analysis of Priority Resources of Concern............................................................................. 4-22 

4.3 Waterfowl and Supporting Habitat-Improved Pasture and Croplands .............................................. 4-23 

4.3.1 Description and Location ........................................................................................................ 4-23 

4.3.2 Condition and Trends ............................................................................................................. 4-23 

4.3.3 Habitats Utilized ..................................................................................................................... 4-26 

4.3.4 Key Ecological Attributes....................................................................................................... 4-28 

4.3.5 Threats .................................................................................................................................... 4-29 

4.4 Native Grasslands ............................................................................................................................. 4-30 

4.4.1 Description and Location ........................................................................................................ 4-30 

4.4.2 Condition and Trends ............................................................................................................. 4-31 

4.4.3 Associated Wildlife ................................................................................................................ 4-31 

4.4.4 Key Ecological Attributes....................................................................................................... 4-32 

4.4.5 Threats .................................................................................................................................... 4-34 

4.5 Wetlands and Deepwater Habitats .................................................................................................... 4-35 

4.5.1 Description and Location ........................................................................................................ 4-35 

4.5.2 Condition and Trends ............................................................................................................. 4-39 

4.5.3 Associated Wildlife ................................................................................................................ 4-42 

4.5.4 Key Ecological Attributes....................................................................................................... 4-43 

4.5.5 Threats .................................................................................................................................... 4-46 

4.6 Riparian and Floodplain Forests ....................................................................................................... 4-46 

4.6.1 Description and Location ........................................................................................................ 4-46

4.6.2 Condition and Trends ............................................................................................................. 4-47 

4.6.3 Associated Wildlife ................................................................................................................ 4-48 

4.6.4 Key Ecological Attributes....................................................................................................... 4-50 

4.6.5 Threats .................................................................................................................................... 4-52 

4.7 Oregon White Oak Woodlands, Upland Mixed Woodlands ............................................................. 4-53 

4.7.1 Description and Location ........................................................................................................ 4-53 

4.7.2 Condition and Trends ............................................................................................................. 4-54 

4.7.3 Associated Wildlife ................................................................................................................ 4-55 

4.7.4 Key Ecological Attributes....................................................................................................... 4-55 

4.7.5 Threats .................................................................................................................................... 4-57 

4.8 Instream Habitat ................................................................................................................................ 4-58 

4.8.1 Description and Location ........................................................................................................ 4-58 

4.8.2 Condition and Trends ............................................................................................................. 4-58 

4.8.3 Associated Wildlife ................................................................................................................ 4-59 

4.8.4 Key Ecological Attributes....................................................................................................... 4-60 

4.8.5 Threats .................................................................................................................................... 4-61 

4.9 Threatened, Endangered, and Sensitive Species ............................................................................... 4-62 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

viii Table of Contents

4.9.1 State or Federally Listed Species Known to Occur on the Refuge ......................................... 4-62 

4.9.2 Condition and Trends of Washington State and Federally Listed Species and Habitats 

Utilized on the Refuge ...................................................................................................................... 4-66 

4.9.3 Condition and Trends of Sensitive Species and Habitats Utilized on the Refuge .................. 4-71 

4.9.4 Key Ecological Attributes and Threats ................................................................................... 4-72 

4.10 Wildlife and Habitat Research and Monitoring Efforts .................................................................. 4-73 

4.10.1 Waterfowl Surveys ............................................................................................................... 4-73 

4.10.2 Surveys for Listed Species and Other Species of Management Concern ............................. 4-74 

4.10.3 Habitat and Vegetation Inventories, Surveys, and Monitoring ............................................. 4-74 

4.10.4 Habitat Restoration and Monitoring (Multi-agency coordination projects) ......................... 4-75 

4.10.5 Invasive Species Monitoring and Studies of Control Techniques ........................................ 4-75 

4.10.6 Baseline Inventories of Major Fish and Wildlife Groups ..................................................... 4-76 

4.10.7 Experimental Reintroductions .............................................................................................. 4-76 

4.10.8 Other Research Projects ........................................................................................................ 4-77 

4.10.9 Contaminants Studies ........................................................................................................... 4-77 

4.10.10 Other Monitoring ................................................................................................................ 4-79 

4.11 References ....................................................................................................................................... 4-79 

Chapter 5. Refuge Facilities and Public Use Programs ....................................................................... 5-1 

5.1 Infrastructure and Administrative Facilities ....................................................................................... 5-1 

5.1.1 Boundary Fences and Markers ................................................................................................. 5-1 

5.2 Recreation Overview .......................................................................................................................... 5-6 

5.2.1 Open and Closed Areas ............................................................................................................ 5-6 

5.2.2 Annual Recreation Visitors ....................................................................................................... 5-6 

5.2.3 Annual Recreation Visits .......................................................................................................... 5-7 

5.2.4 Recreation and Entrance Fee Program...................................................................................... 5-8 

5.2.5 Accessibility of Recreation Sites and Programs for People with Disabilities .......................... 5-9 

5.2.6 Law Enforcement...................................................................................................................... 5-9 

5.3 Waterfowl Hunting ........................................................................................................................... 5-10 

5.4 Fishing .............................................................................................................................................. 5-21 

5.4.1 Number of Visits .................................................................................................................... 5-21 

5.4.2 Facilities .................................................................................................................................. 5-22 

5.5 Wildlife Viewing and Photography .................................................................................................. 5-22 

5.5.1 Number of Visits .................................................................................................................... 5-22 

5.5.2 Facilities .................................................................................................................................. 5-22 

5.6 Environmental Education .................................................................................................................. 5-23 

5.6.1 Number of Visitors ................................................................................................................. 5-23 

5.6.2 Facilities .................................................................................................................................. 5-23 

5.6.3 Environmental Education Program Details ............................................................................ 5-23 

5.7 Interpretation/Outreach ..................................................................................................................... 5-24 

5.8 Cultural Resources Interpretation ..................................................................................................... 5-24 

5.9 Nonwildlife-Dependent Recreation .................................................................................................. 5-25 

5.9.1 Recreational Boating and Waterskiing ................................................................................... 5-25 

5.9.2 Camping, Beach Use, and Swimming .................................................................................... 5-25 

5.9.3 Horseback Riding, Bicycling, Jogging, and Dog Walking. .................................................... 5-26 

5.10 Illegal Uses...................................................................................................................................... 5-26 

5.11 Area Outdoor Recreational Opportunities and Trends .................................................................... 5-26 

5.11.1 Nearby Recreational Opportunities ...................................................................................... 5-26 

5.11.2 Outdoor Recreation Rates and Trends .................................................................................. 5-26 

5.12 References ....................................................................................................................................... 5-29 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Table of Contents ix

Chapter 6. Special Designation Lands, Cultural Resources, and Social/Economic Environment .. 6-1 

6.1 Special Designation Lands .................................................................................................................. 6-1 

6.1.1 National Register of Historic Places ......................................................................................... 6-1 

6.1.2 Important Bird Areas (IBA) ...................................................................................................... 6-1 

6.1.3 Research Natural Area .............................................................................................................. 6-2 

6.2 Archaeological and Cultural Resources .............................................................................................. 6-3 

6.2.1 Pre-recorded History ................................................................................................................. 6-4 

6.2.2 Pre-contact Native American Traditions .................................................................................. 6-5 

6.2.3 Post-Contact Traditions ............................................................................................................ 6-6 

6.2.4 Recent Settlement and Economic Development Period ......................................................... 6-13 

6.3 Social/Economic Environment ......................................................................................................... 6-20 

6.3.1 Population, Housing, and Income ........................................................................................... 6-20 

6.3.2 Employment and Business ...................................................................................................... 6-22 

6.3.3 Refuge Impact on Local Economies ....................................................................................... 6-25 

6.4 References ......................................................................................................................................... 6-26 

Maps

Map 1. Location map for refuges of the Ridgefield National Wildlife Refuge Complex. ......................... 1-3 

Map 2. Ridgefield National Wildlife Refuge and vicinity. ........................................................................ 1-5 

Map 3. Refuge Tracts ............................................................................................................................... 1-17 

Map 4. Future Management Wetlands and Habitat for the River ‘S’ Unit .............................................. 2-11 

Map 5. Future Management Wetlands and Habitat for the Bachelor Unit .............................................. 2-13 

Map 6. Future Management Wetlands and Habitat for the Carty Unit .................................................... 2-15 

Map 7. Future Management Wetlands and Habitat for the Roth and Ridgeport Dairy Units .................. 2-17 

Map 8. Public Use for the River ‘S’ Unit ................................................................................................ 2-19 

Map 9. Current Public Use Facilities, Access, and Regulations .............................................................. 5-11 

Tables

Table 1.1 Land purchases and purchase authorities for Ridgefield Refuge ............................................ 1-19 

Table 1.2 Protected Bottomland Habitat in the Portland Basin (Oregon and Washington) Area ........... 1-23 

Table 2.1 Summary of CCP Actions, By Alternative ............................................................................. 2-21 

Table 3.1 Projected Changes in the Pacific Northwest Climate (Data from CIG 2008) ........................... 3-8 

Table 4.1 Priority Resources of Concern for the CCP ............................................................................ 4-20 

Table 4.2 Habitat Attributes, Indicators, and Condition Parameters for Waterfowl* ............................. 4-28 

Table 4.3 Habitat Attributes, Indicators, and Condition Parameters for Improved Pasture (managed 

for dusky and cackling geese). ................................................................................................ 4-29 

Table 4.4a Upland (Dry) Prairie Ecological Attributes, Indicators, and Condition Parameters ............. 4-32 

Table 4.4b Bottomland (Wet) Prairie Ecological Attributes, Indicators, and Condition Parameters ..... 4-33 

Table 4.5 Old Field Ecological Attributes, Indicators, and Condition Parameters ................................. 4-34 

Table 4.6a Wetland Ecological Attributes, Indicators, and Condition Parameters ................................. 4-43 

Table 4.6b Ecological Attributes, Indicators, and Condition Parameters for Ephemeral Ponds 

(Howellia ponds) ..................................................................................................................... 4-45 

Table 4.7 Focal Species for Riparian Woodland and Shrub Habitat in Western Oregon and 

Washington (adapted from Altman and Holmes 2000) ........................................................... 4-48 

Table 4.8 Mean annual capture rates of target landbird species at Bachelor Point MAPS Station, 

1993-2003. ............................................................................................................................... 4-49 

Table 4.9 Early Successional Floodplain Forest Ecological Attributes, Indicators, and Condition 

Parameters ............................................................................................................................... 4-50 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

x Table of Contents

Table 4.10 Mid-late Successional Floodplain Forest Ecological Attributes, Indicators, and Condition 

Parameters. .............................................................................................................................. 4-51 

Table 4.11 Oregon Ash Floodplain Forest Ecological Attributes, Indicators, and Condition 

Parameters. .............................................................................................................................. 4-52 

Table 4.12 Oregon White Oak Woodland Ecological Attributes, Indicators, and Condition 

Parameters ............................................................................................................................... 4-55 

Table 4.13 Upland Mixed Forest Ecological Attributes, Indicators, and Condition Parameters. ........... 4-56 

Table 4.14 Instream Ecological Attributes, Indicators, and Condition Parameters (Gee Creek, 

Campbell Slough) .................................................................................................................... 4-60 

Table 4.15 Special Status Bird Species Known to Occur or Likely to Have Occurred on the Refuge 

Historically .............................................................................................................................. 4-62 

Table 4.16 Special Status Mammals Known or Likely to have Occurred on the Refuge Historically ... 4-63 

Table 4.17 Special Status Reptiles and Amphibians Known to Occur or Likely to Have Occurred on 

the Refuge Historically ............................................................................................................ 4-64 

Table 4.18 Special Status Fishes Occurring on the Refuge and in Surrounding Waters ........................ 4-64 

Table 4.19 Special Status Plants Known to Occur or Likely to have Occurred on the Refuge 

Historically .............................................................................................................................. 4-65 

Table 4.20 Ecological Attributes, Indicators, and Condition Parameters for Great Blue Heron Nesting 

Colonies and Associated Foraging Areas ................................................................................ 4-72 

Table 5.1 Participation Frequency for Selected Outdoor Recreational Activities in Washington State. 5-27 

Table 5.2 Projected Future Changes in Participation for Selected Outdoor Recreation Activities ......... 5-29 

Table 6.1 Significant Concentrations of Birds Noted to Identify the Ridgefield Refuge as a 

Washington State Important Bird Area ..................................................................................... 6-2 

Table 6.2 Tribal Affiliations With Lands Now Part of Ridgefield Refuge ............................................. 6-13 

Table 6.3 Selected Population and Associated Social Statistics, Local Counties ................................... 6-21 

Table 6.4 Clark County Business Statistics ............................................................................................ 6-23 

Table 6.5 Clark County Output, Employment, Labor Income, and Other Value Added, 2004 .............. 6-23 

Table 6.6 Ridgefield Refuge Visitor Recreation-related Expenditures (2004) ....................................... 6-26 

Table 6.7 Ridgefield Refuge Economic Effects Associated with Visitation .......................................... 6-26 

Figures

Figure 3.1 Historic and current hydrograph of the Columbia River ....................................................... 3-11 

Figure 4.1 General Land Office map of Bachelor Island, Gee Creek, Sauvie Island, and the 

Scappoose Flats, 1854. Source: Bureau of Land Management, Oregon State Office, Land 

Status and Cadastral Records, Willamette Meridian-Oregon and Washington. ........................ 4-4 

Figure 4.2 Midwinter Waterfowl Populations at Ridgefield Refuge. Source: Midwinter Waterfowl 

Survey data, 1985–2007 .......................................................................................................... 4-25 

Figure 5.1 Average annual visitation to Ridgefield Refuge, 1965-2007 .................................................. 5-7 

Figure 5.2 Recreational visits to Ridgefield Refuge in fiscal year 2007, by type of visit ........................ 5-8 

Figure 5.3 Annual number of hunter visits to the refuge, 1965-2007. .................................................... 5-14 

Figure 5.4. Annual harvest of birds per hunter at Ridgefield Refuge, 1965-2007. ................................. 5-16 

Figure 5.5 Annual number of ducks harvested at the Ridgefield Refuge, 1965-2007. ........................... 5-16 

Figure 5.6 Species composition of ducks harvested at Ridgefield Refuge, 1966-2007. ......................... 5-17 

Figure 5.7 Annual number of geese harvested at Ridgefield Refuge, 1966-2007. ................................ 5-18 

Figure 5.8 Subspecies composition of Canada geese harvested on Ridgefield Refuge, 1966-2007. ..... 5-19 

Figure 6.1 William Clark’s map of the “Wapato Valley,” including the site of the “Quathlapotle 

nation” ..................................................................................................................................... 6-10 

Figure 6.2 Haying on the John Burrow Ranch on Bachelor Island, 1912. (Clark County Historical 

Society, Image No. P03.5.1) .................................................................................................... 6-17 

Figure 6.3 Farm house built by Simeon Reed and William Ladd on Bachelor Island in the 1870s. ...... 6-18 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Table of Contents xi

Appendices

Appendix A: Appropriate Use Determinations......................................................................................................... A-1 

Appendix B: Compatibility Determinations............................................................................................................. B-1 

Appendix C: Wildlife and Plants .............................................................................................................................. C-1 

Appendix D: Implementation ................................................................................................................................... D-1 

Appendix E: Wilderness Review ............................................................................................................................. E-1 

Appendix F: Biological Resources of Concern ....................................................................................................... F-1 

Appendix G: Statement of Compliance....................................................................................................................G-1 

Appendix H: Glossary .............................................................................................................................................. H-1 

Appendix I: CCP Team Members ............................................................................................................................ I-1 

Appendix J: Public Involvement .............................................................................................................................. J-1 

Appendix K: Integrated Pest Management Plan ....................................................................................................... K-1 

Appendix L: Federal Highway Administration Transportation Access Analysis ..................................................... L-1 

Appendix M: Land Protection Plan ........................................................................................................................... M-1 

Appendix N: Comments and Responses.................................................................................................................... N-1 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

xii Table of Contents
Chapter 1. Introduction and Background

A dusky Canada goose spreads its wings/Roger Windemuth

Above: Pied-billed grebe/Jim Cruce

Right: An old Oregon white oak on

the Carty Unit/USFWS
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 1. Introduction and Background 1-1 

Chapter 1. Introduction and Background 

1.1 Introduction

The fertile bottomlands of the lower Columbia River have long been vital to both wildlife and 

people. Over the millennia, the river’s floodwaters altered the landscape by braiding new channels, 

refreshing marshes, and depositing sediments which created a mosaic of bottomland forests, 

meadows, and marshes, teeming with a rich diversity of fish and wildlife. Native people chose this 

strategic place to sustain a thriving population and trade goods among Indian tribes along the river. 

The wealth and prosperity resulting from these abundant natural resources were represented in their 

magnificent cedar plank houses and canoes. When the Lewis and Clark expedition visited the town 

of the Cathlapotle nation in 1805 and 1806, they noted this prosperity, as well as the abundant 

wildlife in the lower reaches of the Columbia River (Moulton 1990, 1991). 

The Corps of Discovery’s reports of the West’s vast natural resources brought new immigrants to the 

land. The fertile river bottoms were sought out for agricultural uses to feed the burgeoning 

population. The cities of Portland and Vancouver grew at the confluence of the Columbia and 

Willamette rivers. Dams and dikes provided power and controlled floods, driving the development 

of agriculture and industry, but also removing the influence of the river from certain habitats. Today, 

only remnants remain of the diverse floodplain habitats that once covered the bottomlands of the 

lower Columbia River. 

Today, the Ridgefield National Wildlife Refuge (refuge) preserves both habitat for wildlife, and 

evidence of the people who once lived here. This island of habitat with its rich diversity of 

floodplain forests, freshwater marshes, and meadows, continues to sustain thriving populations of 

wintering dusky Canada geese, migrating waterfowl, and other wildlife. The refuge also preserves 

the most intact archaeological site on the lower Columbia River, and evidence of at least 2,300 years 

of continuous human occupation. The refuge is a place where people can share a bond with nature, 

and each other, by passing on outdoor traditions to new generations. As the population of the region 

increases, the refuge will become even more important to wildlife and those seeking to connect with 

nature. 

The Ridgefield Refuge’s boundary encompasses 6,170 acres of Columbia River bottomlands and 

uplands in Clark County, Washington (see maps 2 and 3). Of that, the refuge manages 5,217.7 acres, 

owned in fee title, or managed per agreements or leases. The refuge was established in 1965 for the 

conservation of dusky Canada geese and other waterfowl. It contains over 5,000 acres of pastures, 

wetlands, riparian and bottomland forest, and oak woodlands. Ridgefield Refuge is part of the 

Ridgefield National Wildlife Refuge Complex, which also includes Steigerwald Lake, Pierce, and 

Franz Lake National Wildlife Refuges. 

1.2 Proposed Action

We, the U.S. Fish and Wildlife Service (Service), manage the Ridgefield Refuge as part of the 

National Wildlife Refuge System. This document is the refuge’s CCP. A CCP sets forth 

management guidance for a refuge for a period of 15 years, as required by the National Wildlife 

Refuge System Administration Act (16 U.S.C. 668dd et seq.) as amended by the National Wildlife 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

1-2 Chapter 1. Introduction and Background

Refuge System Improvement Act of 1997 (Public Law 105-57). The Administration Act requires 

CCPs to identify and describe: 

• The purposes of the refuge; 

• The fish, wildlife and plant populations, their habitats, and the archaeological and cultural 

values found on the refuge; 

• Significant problems that may adversely affect wildlife populations and habitats and ways to 

correct or mitigate those problems; 

• Areas suitable for administrative sites or visitor facilities; and 

• Opportunities for fish and wildlife dependent recreation. 

National Wildlife Refuge System (Refuge System) planning policy (Service Manual Part 602, 602 

FW3, June 21, 2000) states that the purpose of CCPs is to: “describe the desired future conditions of 

a refuge and provide long-range guidance and management direction to achieve refuge purposes; 

help fulfill the National Wildlife Refuge System mission; maintain and, where appropriate, restore 

the ecological integrity of each refuge and the Refuge System; . . . and meet other mandates.” 

The Service developed and examined alternatives for future management of Ridgefield Refuge 

through the CCP process. These were presented in the Draft Comprehensive Conservation Plan and 

Environmental Assessment (USFWS 2010). The various alternatives addressed the major issues and 

relevant mandates identified during the process and are consistent with the principles of sound fish 

and wildlife management. We evaluated four alternatives for the refuge’s CCP and selected 

Alternative 2 as the preferred alternative. 

The preferred alternative represents the most balanced approach for: Achieving the refuge’s 

purposes, vision, and goals; contributing to the Refuge System’s mission; addressing relevant issues 

and mandates; and managing the refuge consistent with the sound principles of fish and wildlife 

management. The preferred alternative was slightly modified between the draft and final documents 

based upon comments received from the public, other agencies, and organizations. The Service’s 

Regional Director for the Pacific Region made the final decision about the alternative to be 

implemented. 

1.3 Purpose and Need for the CCP

The purpose of the CCP is to provide the Service, the Refuge System, partners, and the public with a 

15-year management plan for improving the refuge’s habitat conditions and infrastructure, for fish, 

wildlife, and public use. An approved CCP will ensure that the Service manages the refuge to 

achieve its purposes, vision, goals, and objectives; and help fulfill the mission of the Refuge System. 

The CCP will provide reasonable, scientifically grounded guidance for the long-term conservation of 

native plants and animals, with emphasis on migratory birds and improving the refuge’s grassland, 

wetland, riparian, and woodland habitats. The CCP will identify appropriate actions for protecting 

and sustaining the cultural and biological features of the refuge; its wintering waterfowl populations 

and habitats; the migratory landbird and waterbird populations that use the refuge; and threatened, 

endangered, or rare species. A final purpose of the CCP is to provide guidance and evaluate the 

priority public use programs on the refuge, including hunting, fishing, wildlife observation, 

photography, environmental education and interpretation. 
CAPE MEARES

NWR

Salem

Eugene

Tacoma

Seattle

Olympia

Portland

OREGON

ISLANDS

NWR

COPALIS

NWR

QUILLAYUTE

NEEDLES

NWR

FLATTERY

ROCKS

NWR

LEWIS AND CLARK NWR

WILLAPA

NWR

RIDGEFIELD

NWR

WILLIAM L. FINLEY NWR

ANKENY NWR

NISQUALLY

NWR

BASKETT SLOUGH NWR

GRAYS

HARBOR

NWR

NESTUCCA

BAY NWR

DUNGENESS 

NWR

STEIGERWALD LAKE NWR

JULIA BUTLER HANSEN

REFUGE FOR THE COLUMBIAN

WHITE-TAILED DEER

BANDON

MARSH

NWR

SAN JUAN 

ISLANDS 

NWR

THREE ARCH

ROCKS NWR

PROTECTION

ISLAND

NWR

TUALATIN

RIVER 

NWR

SILETZ BAY

NWR

FRANZ LAKE NWR

PIERCE NWR

Map 1 Regional Context

Data Sources: Highways, State and Country Boundaries from ESRI; Cities from USGS; USFWS Ecoregions and Refuge Boundaries from USFWS/R1

§ ̈¦90

C A L I F O R N I A

W A S H I N G T O N

O R E G O N

I D A H O

P a c i f i c O c e a n

Area

Enlarged

Pacific

Flyway

0 Miles 100

0 Kilometers 100

§ ̈¦90

§ ̈¦82

§ ̈¦84

§ ̈¦5

§ ̈¦5

File: 10-035-11

Legend

National Wildlife Refuge

North Pacific Coast Ecoregion UTM ZONE 10N

NAD 83

Chapter 1. Introduction and Background

_____________________________________________________________________________________________

1-3 ______________________________________________________________________________________________ Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

1-4 Chapter 1. Introduction and Background

To preserve the quality of our map, this side was left blank intentionally.
Bachelor

Island

Unit River S

Unit

Roth

Unit

Ridgeport

Dairy

Unit

Wigeon

Lake

S a u v i e

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( O R )

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Green

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Ridgefield

(WA)

S. Hillhurst Road

SR 501 - Pioneer Street

N. Main Ave.

Auto

Tour

Route

River S

Entrance

122°45'0"W

45°45'0"N 45°45'0"N

T 4 N

T 3 N

T 4 N

T 3 N

R 1 W R 1 E

Produced in the D ivision of R ealty & R efuge Inform ation

Portland, O regon

Data C urrent to: 03/09/09

M ap D ate: 03/18/10

Basem ap: 2006 N AIP

M eridian: W ILLA M E TTE

File: 10-035-9.M XD

0 1 2 0.5

M iles

0 2 1

Kilometers UT M ZO N E 10

NA D 83

1:42,000

Legend

FWS Approved Acquisition Boundary

Lands Not Managed by FWS

"@ Refuge Headquarters

1-5
_________________________________________________________________________________________________________________________________________________

1-6
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 1. Introduction and Background 1-7 

The CCP is needed for a variety of reasons. Primary among these is the need to provide migration 

and wintering habitat for dusky Canada geese and other waterfowl in the lower Columbia River 

region. There is a need to improve habitat conditions on the refuge’s grassland, wetland, riparian, 

bottomland forest, and oak woodland habitats, many of which are degraded by invasive plants and 

animals. There is a need to address the refuge’s contributions to the recovery of Federal and State 

listed species native to the lower Columbia River and the Willamette Valley-Puget Trough 

ecoregion, including Columbian white-tailed deer, water howellia, and western pond turtle. There is 

a need to protect and restore habitat values for other sensitive, rare, and declining species of the 

lower Columbia River. 

There is a need to analyze refuge public use programs for the Refuge System’s wildlife-dependent 

priority public uses and to determine what improvements or alterations should be made in the pursuit 

of compatible, higher quality programs, and to accommodate increasing numbers of visitors while 

providing for the needs of wildlife. The refuge also includes important archaeological sites, and 

there is a need to address both protection of cultural resources and cultural resources education. 

1.4 Content and Scope of the CCP

This CCP provides guidance for management of refuge habitats and wildlife and administration of 

public uses on refuge lands and waters. This CCP is intended to comply with both the Refuge 

System Administration Act and the National Environmental Policy Act (NEPA), as amended (42 

U.S.C. 4321-4347). The CCP includes the following information. 

• An overall vision for the refuge and its role in the local ecosystem (Chapter 1). 

• Goals and objectives for specific habitats, research, inventory, monitoring, and public use 

programs, as well as strategies for achieving the objectives (Chapter 2). 

• A description of the refuge’s physical environment (Chapter 3). 

• A description of the refuge’s wildlife species and species groups identified as priority 

resources of concern and their habitats; their condition and trends on the refuge and within 

the local ecosystem; the desired ecological conditions for sustaining them, and a short 

analysis of threats to resources of concern and their habitats (Chapter 4). 

• A description of the refuge’s administrative and public use facilities, and public use programs 

(Chapter 5). 

• A description of the refuge’s historic and cultural resources, socioeconomic environment and 

special designation areas (Chapter 6). 

• Evaluations of existing and proposed public uses for appropriateness and compatibility with 

the refuge’s purposes (Appendices A and B). 

• A comprehensive list of plants and vertebrate species known or suspected to occur on the 

refuge (Appendix C). 

• An outline of the projects, staff and facilities needed to support the CCP’s implementation 

(Appendix D). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

1-8 Chapter 1. Introduction and Background

1.5 Refuge Planning and Management Guidance

The refuge is managed as part of the Refuge System within a framework provided by legal and 

policy guidelines. This CCP is primarily guided by the provisions of the mission and goals of the 

Refuge System, the purposes of the refuge as described in its acquisition authority, Service policy, 

and Federal laws. The following summaries are provided as background for the CCP. 

1.5.1 The U.S. Fish and Wildlife Service

The refuge is managed by the Service, an agency within the Department of the Interior. The Service

is the principal Federal agency responsible for conserving, protecting and enhancing the Nation’s fish 

and wildlife populations, and their habitats. 

The mission of the Service is “working with others, to conserve, protect and enhance fish and 

wildlife and their habitats for the continuing benefit of the American people.” Although we share 

this responsibility with other Federal, state, tribal, local, and private entities, the Service has specific 

trust responsibilities for migratory birds, endangered and threatened species, and certain anadromous 

fish and marine mammals. The Service has similar trust responsibilities for the lands and waters we

administer to support the conservation and enhancement of fish, wildlife, plants, and their habitats. 

The Service also enforces Federal wildlife laws and international treaties for importing and exporting 

wildlife, assists with state fish and wildlife programs, and helps other countries develop wildlife 

conservation programs. 

1.5.2 National Wildlife Refuge System

The Service manages the 150-million acre Refuge System. The Refuge System is the world’s largest 

network of public lands and waters set aside specifically for conserving wildlife and protecting 

ecosystems. From its inception in 1903, the Refuge System has grown to encompass more than 550 

national wildlife refuges; thousands of small wetlands and other special management areas; and 

millions of acres of islands and their surrounding marine environments in remote areas of the Pacific 

Ocean. The needs of wildlife and their habitats come first on refuges, in contrast to other public 

lands that are managed for multiple uses. 

National Wildlife Refuge System Mission and Goals. The mission of the Refuge System is:

“to administer a national network of lands and waters for the conservation, 

management, and where appropriate, restoration of the fish, wildlife, and plant 

resources and their habitats within the United States for the benefit of present and 

future generations of Americans” (National Wildlife Refuge System Administration 

Act of 1966, as amended)(16 U.S.C. 668dd et seq.) 

Wildlife conservation is the fundamental mission of the Refuge System. The goals of the Refuge 

System, as articulated in the Mission Goals and Purposes Policy (Service Manual Part 601 (601 

FW1)) are to: 

• Conserve a diversity of fish, wildlife, and plants and their habitats, including species that are 

endangered or threatened with becoming endangered. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 1. Introduction and Background 1-9 

• Develop and maintain a network of habitats for migratory birds, anadromous and interjurisdictional fish, and marine mammal populations that is strategically distributed and 

carefully managed to meet important life history needs of these species across their ranges. 

• Conserve those ecosystems, plant communities, wetlands of national or international 

significance, and landscapes and seascapes that are unique, rare, declining, or 

underrepresented in existing protection efforts. 

• Provide and enhance opportunities to participate in compatible wildlife-dependent recreation 

(hunting, fishing, wildlife observation and photography, and environmental education and 

interpretation). 

• Foster understanding and instill appreciation of the diversity and interconnectedness of fish, 

wildlife, and plants and their habitats. 

Law and Policy Pertaining to the Refuge System. Refuges are guided by various Federal laws and 

executive orders, Service policies, and international treaties. Fundamental to the management of every 

refuge are the mission and goals of the Refuge System and the designated purposes of the refuge unit as 

described in establishing legislation, executive orders, or other documents establishing, authorizing, or 

expanding a refuge. 

Key concepts and guidance of the Refuge System derive from the National Wildlife Refuge System 

Administration Act of 1966 (Administration Act) as amended (16 U.S.C. 668dd-668ee); the Refuge 

Recreation Act of 1962 as amended (16 U.S.C. 460k-460k-4); Title 50 of the Code of Federal 

Regulations; and the Service Manual. The Administration Act is implemented through regulations 

covering the Refuge System, published in Title 50, subchapter C of the Code of Federal Regulations 

and policies contained in the Service Manual. These regulations and policies govern general 

administration of units of the Refuge System. 

Many other laws apply to the U.S. Fish and Wildlife Service and management of Refuge System 

lands. Examples include the Endangered Species Act of 1973, as amended, and the National Historic 

Preservation Act of 1966, as amended. Brief descriptions of laws pertinent to Ridgefield Refuge are 

included in this chapter. A complete list of laws pertaining to the Fish and Wildlife Service and the 

Refuge System can be found at http://laws.fws.gov.

Refuge Recreation Act of 1962 (16 U.S.C. 460k-460k-4). The Refuge Recreation Act authorized 

the Secretary of the Interior to administer refuges, hatcheries, and other conservation areas for 

recreational use, when such uses do not interfere with the area’s primary purposes. It provided for 

public use fees and permits, and penalties for violating regulations. It also authorized the acceptance 

of donated funds and real and personal property, to assist in carrying out its purposes. Enforcement 

provisions were amended in 1978 and 1984 to make violations misdemeanors in accordance with the 

uniform sentencing provisions of 18 U.S.C. 3551-3586. 

National Wildlife Refuge System Administration Act (16 U.S.C. 668dd et seq.) as amended by the 

National Wildlife Refuge System Improvement Act* (Public Law 105-57). Of all the laws governing 

activities on national wildlife refuges, the Refuge Administration Act exerts the greatest influence. The 

National Wildlife Refuge System Improvement Act of 1997 (Refuge Improvement Act) amended the 

Administration Act by defining a unifying mission for all refuges, including a new process for 

determining compatible uses on refuges, and requiring that each refuge be managed under a 

comprehensive conservation plan. Key provisions of the Refuge Administration Act follow. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

1-10 Chapter 1. Introduction and Background

• Comprehensive conservation planning. A CCP must be completed for each refuge by the year 

2012, as is required by the Refuge Administration Act. Each CCP will be revised every 15 years 

or earlier if monitoring and evaluation determine that changes are needed to achieve the refuge’s

purposes, vision, goals, or objectives. The Refuge Administration Act also requires that CCPs be 

developed with the participation of the public. Public comments, issues, and concerns are

considered during the development of a CCP, and together, with the formal guidance, can play a 

role in selecting the preferred alternative. The CCP provides guidance in the form of goals, 

objectives, and strategies for refuge programs, but may lack some of the specifics needed for 

implementation. Therefore, step-down management plans will be developed for individual 

program areas as needed, following completion of the CCP. The step-down plans are founded on 

management goals, objectives and strategies outlined in a CCP, and require appropriate NEPA 

compliance. 

• Wildlife conservation; biological diversity, integrity and environmental health. The Refuge 

Administration Act expressly states that the conservation of fish, wildlife and plants, and 

their habitats is the priority of Refuge System lands, and that the Secretary of the Interior 

shall ensure that the biological integrity, diversity, and environmental health of refuge lands 

are maintained. House Report 105–106 accompanying the Improvement Act states “... the 

fundamental mission of our System is wildlife conservation: wildlife and wildlife 

conservation must come first.” 

• Refuge purposes. Each refuge must be managed to fulfill the Refuge System mission and the 

specific purpose(s) for which the refuge was established. The purposes of a refuge are 

specified in or derived from the law, proclamation, executive order, agreement, public land 

order, donation document, or administrative memorandum establishing, authorizing, or 

expanding a refuge, refuge unit, or refuge subunit. When a conflict exists between the 

Refuge System mission and the purpose of an individual refuge, the refuge purpose may 

supersede the mission.

• Priority public uses on refuges. The Administration Act superseded some key provisions of 

the Refuge Recreation Act regarding compatibility, and also provided significant additional 

guidance regarding recreational and other public uses on units of the Refuge System. The 

Refuge Administration Act identifies six priority wildlife-dependent recreational uses. These 

uses are hunting, fishing, wildlife observation and photography, and environmental education 

and interpretation. The Service is to grant these six wildlife-dependent public uses special 

consideration during planning for, management of, and establishment and expansion of units 

of the Refuge System. When determined compatible on a refuge-specific basis, these six 

uses assume priority status among all uses of the refuge in question. The Service is to make 

extra efforts to facilitate priority wildlife-dependent public use opportunities. 

Compatibility and Appropriate Refuge Uses Policies (603 FW 2 and 1). With few exceptions, 

lands and waters within the Refuge System are different from multiple-use public lands in that they 

are closed to all public access and use unless specifically and legally opened. No refuge use may be 

allowed or continued unless it is determined to be appropriate and compatible. Generally, an 

appropriate use is one that contributes to fulfilling the refuge purpose(s), the Refuge System mission, 

or goals or objectives described in a refuge management plan. A compatible use is a use that in the 

sound professional judgment of the refuge manager will not materially interfere with or detract from 

the fulfillment of the mission of the Refuge System or the purposes of the refuge. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 1. Introduction and Background 1-11

The six wildlife-dependent recreational uses described in the Refuge Administration Act (hunting, 

fishing, wildlife observation and photography, and environmental education and interpretation) are 

defined as appropriate. When determined to be compatible, they receive priority consideration over 

other public uses in planning and management. Other nonwildlife-dependent uses on a refuge are 

reviewed by the refuge manager to determine if the uses are appropriate. If a use is determined 

appropriate, then a compatibility determination is completed. 

When preparing a CCP, refuge managers must re-evaluate all general public, recreational, and 

economic uses (even those occurring to further refuge habitat management goals) occurring or 

proposed on a refuge for appropriateness and compatibility. Updated appropriate use and 

compatibility determinations for existing and proposed uses for the Ridgefield Refuge are in 

Appendices A (Appropriateness) and B (Compatibility) of this CCP. 

Biological Integrity, Diversity, and Environmental Health Policy (601 FW 3). The Refuge 

Administration Act directs the Service to “ensure that the biological integrity, diversity, and 

environmental health of the National Wildlife Refuge System are maintained for the benefit of 

present and future generations of Americans...” The policy is an additional directive for refuge 

managers to follow while achieving refuge purpose(s) and the Refuge System mission. It provides 

for the consideration and protection of a broad spectrum of native fish, wildlife, and habitat resources 

found on refuges and associated ecosystems. When evaluating the appropriate management direction 

for refuges (e.g., in compatibility determinations), refuge managers will use sound professional 

judgment to determine their refuge’s contribution to biological integrity, diversity, and environmental 

health at multiple landscape scales. Sound professional judgment incorporates field experience, 

knowledge of refuge resources, an understanding of the refuge’s role within an ecosystem, applicable 

laws, and best available science, including consultation with others both inside and outside the

Service. The policy states that “the highest measure of biological integrity, diversity, and 

environmental health is viewed as those intact and self-sustaining habitats and wildlife populations 

that existed during historic conditions.” 

Wildlife-dependent Recreation Policies (605 FW 1-7). The Refuge Administration Act states that

“compatible wildlife-dependent recreation is a legitimate and appropriate general public use of the 

System.” A series of recreation policies provide additional guidance and requirements to consider 

after a recreational use has been determined to be compatible. These policies also establish a quality 

standard for visitor services on national wildlife refuges. Through these policies, we are to 

simultaneously enhance wildlife-dependent recreational opportunities, provide access to quality 

visitor experiences, and manage refuge resources to conserve fish, wildlife, plants, and their habitats. 

New and ongoing recreational uses should help visitors focus on wildlife and other natural resources, 

and provide an opportunity to display resource issues, management plans, and how the refuge 

contributes to the Refuge System and the Service’s mission. The policies also require development 

of a visitor services plan. 

Research Natural Area Policy (8 RM 10). The refuge contains one Research Natural Area (RNA), 

the 129-acre Blackwater Island RNA, established December 1972 (Wiberg and Green 1981). 

Research Natural Areas have special status on lands managed by the Service. Guidance for the 

operation of RNAs is provided in Section 8 RM 10 of the Service’s Refuge Manual, the purposes of 

RNAs are:
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

1-12 Chapter 1. Introduction and Background

(1) “...to preserve adequate examples of all major ecosystem types or other outstanding physical 

or biological phenomena;” 

(2) “To provide research and educational opportunities for scientists and others in the 

observation, study, and monitoring of the environment;” and 

(3) “...to preserve a full range of genetic and behavioral diversity for native plants and animals, 

including endangered or threatened species...” 

The Manual states that “activities on RNAs are limited to research, study, observation, monitoring, 

and educational activities that are non-destructive, non-manipulative, and maintain unmodified 

conditions . . . public uses which contribute to modification of a Research Natural Area should be 

discontinued or expressly prohibited if such uses threaten serious impairment of research and 

education values” (USFWS 1981). 

1.5.3 Biological Resource Protection Acts

The refuge’s plant and animal species are protected under several Federal laws, including the 

following. 

Endangered Species Act of 1973 (16 U.S.C. 1531-1544). Through Federal action and by 

encouraging the establishment of state programs, the 1973 Endangered Species Act (ESA) provided 

for the conservation of ecosystems upon which threatened and endangered species of fish, wildlife, 

and plants depend. The ESA: 

• Authorizes the determination and listing of species as endangered and threatened; 

• Prohibits unauthorized taking, possession, sale, and transport of endangered species; 

• Provides authority to acquire land for the conservation of listed species, using land and water 

conservation funds; 

• Authorizes establishment of cooperative agreements and grants-in-aid to States that establish 

and maintain active and adequate programs for endangered and threatened wildlife and 

plants; 

• Authorizes the assessment of civil and criminal penalties for violating the act or regulations; 

and 

• Authorizes the payment of rewards to anyone furnishing information leading to arrest and 

conviction for any violation of the act or any regulation issued there under. 

Both the Service and the National Marine Fisheries Service (NMFS) implement and enforce the 

ESA. The Service has primary responsibility for terrestrial and freshwater organisms, while NMFS 

has jurisdiction over most marine and anadromous fish listed under the ESA. Under the ESA, the 

Service has primary responsibility for the federally threatened water howellia, and NMFS has 

primary responsibility for listed anadromous fish, including the Lower Columbia River 

Evolutionarily Significant Units (ESU) of Chinook and coho salmon. Listed species and species of 

concern found on the refuge are described in Chapter 4, Section 4.9. 

Section 7 of the ESA requires Federal agencies to ensure that actions authorized, funded, or carried 

out by them are not likely to jeopardize the continued existence of listed species, or modify critical 

habitat. The Service will consult with NMFS regarding potential impacts of visitor use on listed 

anadromous fish species found within the refuge and consult internally regarding terrestrial species. 

For candidate species and species of concern, refuge management activities are focused on protecting 

habitat and reducing threats so that these species do not need the protection of the ESA. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 1. Introduction and Background 1-13

Migratory Bird Treaty Act of 1918 (16 U.S.C. 703-712). The framers of the Migratory Bird Treaty 

Act were determined to put an end to the commercial trade in birds, and their feathers, that by the 

early years of the 20th century had wreaked havoc on the populations of many native bird species. 

The Migratory Bird Treaty Act decreed that all migratory birds and their parts (including eggs, nests, 

and feathers) were fully protected. It is the domestic law that affirms or implements the United 

States’ commitment to four international conventions (with Canada, Japan, Mexico, and Russia) for 

the protection of a shared migratory bird resource. Each of the conventions between two nations 

protect selected species of birds that are common to both countries (i.e., they occur in both countries 

at some point during their annual life cycle). All of the refuge’s bird species are protected under this 

act, with the exception of nonnative species (European starling, house sparrow, and rock dove). 

1.5.4 Historic Preservation Acts

The refuge’s historic resources are protected under several Federal laws. 

Archaeological Resources Protection Act of 1979, as amended (16 U.S.C. 470aa-470ll). The 

Archaeological Resources Protection Act largely supplanted the resource protection provisions of the 

Antiquities Act of 1906 for archaeological items. This act established detailed requirements for 

issuance of permits for any excavation for or removal of archaeological resources from Federal or 

Indian lands. It also established civil and criminal penalties for the unauthorized excavation, 

removal, or damage of any such resources; for any trafficking in such resources removed from 

Federal or Indian land in violation of any provision of Federal law; and for interstate and foreign 

commerce in such resources acquired, transported, or received in violation of any State or local law. 

Public Law 100-588, approved November 3, 1988, (102 Stat. 2983) lowered the threshold value of 

artifacts triggering the felony provisions of the act from $5,000 to $500, made attempting to commit 

an action prohibited by the act a violation, and required the land managing agencies to establish 

public awareness programs regarding the value of archaeological resources to the Nation.

Archeological and Historic Preservation Act of 1960, as amended (16 U.S.C. 469-469c). To 

carry out the policy established by the Historic Sites Act, this Archeological and Historic 

Preservation Act directed Federal agencies to notify the Secretary of the Interior whenever they find 

that a Federal or federally assisted, licensed, or permitted project may cause loss or destruction of 

significant scientific, prehistoric, or archaeological data. The act authorized use of appropriated, 

donated, and/or transferred funds for the recovery, protection, and preservation of such data. 

Historic Sites, Buildings and Antiquities Act of 1935 (16 U.S.C. 461-462, 464-467). This act 

declared it a national policy to preserve historic sites and objects of national significance, including 

those located on refuges. It provided procedures for designation, acquisition, administration, and 

protection of such sites. National Historic and Natural Landmarks are designated under authority of 

this act.

National Historic Preservation Act of 1966 (16 U.S.C. 470-470b, 470c-470n). This act provided 

for preservation of significant historical features (buildings, objects, and sites) through a grant-in-aid 

program to the States. It established a National Register of Historic Places and a program of 

matching grants under the existing National Trust for Historic Preservation (16 U.S.C. 468-468d). 

The act established an Advisory Council on Historic Preservation, which was made a permanent 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

1-14 Chapter 1. Introduction and Background

independent agency in Public Law 94-422, approved September 28, 1976 (90 Stat. 1319). That act 

also created the Historic Preservation Fund. Federal agencies are directed to take into account the 

effects of their actions on items or sites listed or eligible for listing in the National Register. As of 

September 2004, 157 historic sites on national wildlife refuges had been placed on the National 

Register, and an additional 229 sites have been identified as eligible for listing. The Basalt 

Cobblestone Quarries at Ridgefield Refuge were listed on the National Register of Historic Places in 

1981. The refuge’s Cathlapotle town site is eligible for listing. 

Native American Graves Protection and Repatriation Act of 1990 (25 U.S.C. 3001-13) 

This Act establishes requirements for the treatment of Native American human remains and sacred or 

cultural objects found on Federal land. In any case where human remains or funerary objects can be 

associated with specific Tribes or groups of Tribes, the agency is required to provide notice of the 

item in question to the Tribe or Tribes. Upon request, each agency is required to return any such item 

to any lineal descendant or specific Tribe with whom such item is associated.

Executive Order 11593 Protection and Enhancement of the Cultural Environment. Signed May 

6, 1971, Executive Order 11593 requires that the Federal government provide leadership in 

preserving, restoring, and maintaining the historic and cultural environment of the Nation. Agencies 

of the executive branch of the government must: 

1. Administer the cultural properties under their control in a spirit of stewardship and trusteeship 

for future generations; 

2. Initiate measures necessary to direct their policies, plans, and programs in such a way that 

federally owned sites, structures, and objects of historical, architectural, or archaeological 

significance are preserved, restored, and maintained for the inspiration and benefit of the 

people; and 

3. In consultation with the Advisory Council on Historic Preservation, institute procedures to 

assure that Federal plans and programs contribute to the preservation and enhancement of 

nonfederally owned sites, structures, and objects of historical, architectural, or archaeological 

significance.

1.6 Refuge Establishment and Refuge Purposes

The Refuge Administration Act directs the Service to manage refuges to achieve their purposes. The 

purposes for which a refuge is established form the foundation for planning and management 

decisions. Refuge purposes are the driving force in the development of the refuge vision statements, 

goals, objectives, and strategies in a CCP and are critical to determining the compatibility of existing 

and proposed refuge uses. 

The purposes of a refuge are specified in or derived from the law, proclamation, executive order, 

agreement, public land order, donation document, or administrative memorandum establishing, 

authorizing, or expanding a refuge, refuge unit, or refuge subunit. Unless these documents indicate 

otherwise, purposes dealing with the conservation, management, and restoration of fish, wildlife, and 

plants, and the habitats on which they depend take precedence over other purposes in the 

management and administration of any unit. 

Where a refuge has multiple purposes related to fish, wildlife, and plant conservation, the more 

specific purpose will take precedence in instances of conflict. When an additional unit is acquired 

under an authority different from the authority used to establish the original unit, the addition takes 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 1. Introduction and Background 1-15

on the purpose(s) of the original unit, but the original unit does not take on the purpose(s) of the 

newer addition. When a conflict exists between the Refuge System mission and the purpose of an 

individual refuge, the refuge purpose may supersede the mission. The purposes for Ridgefield 

Refuge are described below.

1.6.1 Refuge Acquisition History and Authorities

In January 1964, the Service completed a Consolidated Report of the Proposed Ridgefield National 

Wildlife Refuge. The report was considered at a meeting of the Migratory Bird Commission 

(MBCC) on February 17, 1964. The report proposed the purchase of 6,538.53 acres of private land 

in Clark County, Washington, under the funding authority of the Migratory Bird Conservation Act 

(MBCA) of 1929 (45 Stat. 1222), as amended, to create the Ridgefield Refuge. 

The justification for creating the refuge was that “The Western Canada goose has an extremely 

limited winter range, concentrated along the Willamette and Lower Columbia rivers. This subspecies 

is limited in numbers and requires protection and habitat to insure its continued existence.” (In the 

later 1965 memorandum establishing the refuge, “western Canada goose” was amended to read 

“dusky Canada goose.”) The report also noted that the human population of the Portland-Vancouver 

area was rapidly expanding and river bottom lands were being developed for industry and intensive 

farming. “This process will continue inevitably until all waterfowl habitat is gone unless the land is 

preserved in public ownership.” 

Other justifications for establishment of the refuge included providing winter food for waterfowl, 

providing public hunting, and reducing or insuring against crop depredation by geese and “the large 

numbers of mallards, pintails, and wigeon which winter in this area.” During this time, most of the 

acreage within the proposed refuge was used for cattle production, except tracts 23 and 23a on 

Bachelor Island, which were used for potato farming, and tracts 14, 14a, and 24, which were private 

hunting clubs (see Map 3 for refuge tracts). 

The Service’s proposed management included creating 1,600 acres of permanent ponds and marsh by 

placing water control structures on Gee Creek, and by diking existing lakes; creating an additional 

300 acres of seasonal ponds within diked areas; farming within diked areas; fall planting of alfalfa 

and grain which, supplemented by native pasture, would provide winter food for geese and wigeon; 

and controlling weed on overgrazed pasture land. Grazing would initially be reduced “until pastures 

recover from present over-use” but presumably, would be resumed in the future. 

On May 18, 1965, the MBCC under the authority of the MBCA, approved the establishment of 

Ridgefield Refuge and identified a 6,130.8-acre refuge acquisition boundary. From the MBCC’s 

Memorandum #1, the purpose of the new refuge was to “Provide wintering habitat for dusky Canada 

goose and other waterfowl.” The memorandum also specified peak populations of migratory 

waterfowl, including 3,000 geese and 125,000 ducks, and that the refuge would also provide 

“breeding and migration use” for waterfowl. The importance of the refuge to dusky Canada geese 

was explicitly recognized: “The dusky Canada goose has an extremely limited winter range, 

concentrated along the Willamette and lower Columbia rivers. This subspecies is limited in numbers 

and requires protection and habitat to insure its continued existence.” The memorandum also 

specifically mentioned that the refuge would provide “substantial public shooting.” “A portion of the 

area in line with management findings but not to exceed 40 percent will be considered for waterfowl 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

1-16 Chapter 1. Introduction and Background

hunting in the future.” A number of tracts on the River ‘S’ and Carty units, totaling 2,483.03 acres, 

were acquired under this purchasing authority using MBCA funds. Tract 21-I on the Carty Unit 

(24.99 acres) was also donated to the Service under authority of the MBCA. 

Subsequent MBCC memoranda (Memorandum #4 of August 5, 1965; Memorandum #6 of January 

22, 1974; Memorandum #8 of February 5, 1985) reapproved the purchase price of remaining acreage 

within the acquisition boundary, due to increased land values. In all of these memoranda, the 

justification for acquisition was “To provide resting and wintering area for migratory waterfowl.” 

Tracts on the Roth Unit totaling 510.4 acres were acquired under this purchasing authority using 

MBCA funds. 

The Environmental Impact Statement (EIS), Land Acquisition—Zimmerly Tract for Addition to 

Ridgefield National Wildlife Refuge, Washington, dated March 1980, covered the acquisition of 

1,610 acres of Bachelor Island within the approved refuge boundary. In the EIS, the Service stated 

that its objective for the acquisition was “To preclude uses that would be incompatible with wildlife 

use, such as industrial, commercial, or residential development, and to gain the capability to manage 

the land for increased wildlife benefits.” The EIS mentioned the following species and species 

groups as priorities for management: wintering waterfowl, bald eagle, sandhill crane, and great blue 

heron. 

The Environmental Assessment (EA), Acquisition of Remaining Tracts, Ridgefield National Wildlife 

Refuge, Clark County, Washington, dated December 1983, applied to 1,609.97 acres of Bachelor 

Island, and 589.31 acres of the Ridgeport Dairy Unit (the remaining tracts within the approved refuge 

boundary). In the EA, the Service stated that its objectives for the acquisition were “To preclude 

activities, such as industrial, commercial, and residential development, that would be incompatible 

with wildlife use; to prevent changes in the present pattern of land use; and to gain authority to 

manage the lands for increased wildlife benefits . . . To increase overwintering carrying capacity for 

dabbling ducks . . . To maintain current capacity in support of existing overwintering use by Canada 

geese, swans, and diving ducks.” 

The Land Protection Plan (LPP) for Proposed Acquisitions to the Ridgefield National Wildlife 

Refuge, dated November 1984, covered the same areas identified in the December 1983 EA. In the 

LPP, the Service stated that its objectives for the acquisition were “to preclude human activities that 

would be incompatible with wildlife use; to prevent major changes in the present pattern of land use; 

and to manage added refuge lands for increased wildlife benefits.” The LPP mentioned the following 

species and species groups as priorities for management: wintering waterfowl, bald eagle, sandhill 

crane, and great blue heron. On February 11, 1985, Tracts 23 and 23a (1,609.97 acres) on Bachelor 

Island were purchased from Bachelor Island Ranch, Inc. with MBCA funds. 

The Preliminary Project Proposal (May 1989) and the Decision Document (Categorical Exclusion), 

Acquisition of Port of Vancouver Tract, Ridgefield National Wildlife Refuge, Clark County, 

Washington (October 12, 1989) applied to 520.81 acres (Tract 12) of the Ridgeport Dairy Unit. 

Described in the Categorical Exclusion for the property transfer, the Service stated its objectives for 

the acquisition: “To preclude human activities, such as land development and commercial enterprise, 

(both with potential for altering habitat and polluting areas) that would be incompatible with wildlife 

use; to prevent major changes in the present pattern of wildlife use; and to manage added refuge land 

for increased wildlife benefits.” The Categorical Exclusion mentioned the following species and 

species groups as priorities for management: “over 20 species of waterfowl wintering along the lower 

Columbia River including mallard, pintail, and blue winged teal . . .; six subspecies of Canada geese 
!@

19 UV

23 V 21 V

25 V

23a V

21-I UV

2M-1

V

E1 V

E1 V

17 V 2M V

20 UV

10R

UV10M

UV21a UV

26 UV17-I UV E1 UV 10R-1

UV2M-3

UV

17R-1

UV 10E

UV

11 V

11b V

122°45'0"W122°50'0"W

45°50'0"N 45°50'0"N

T 5 N

T 4 N

R 1 W R 1 E

T 4 N

T 3 N

T 4 N

T 3 N

T 5 N

T 4 N

Map 3 Land Status
_________________________________________________________________________________________________________________________________________________

1-18 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 1. Introduction and Background 1-19

(Taverner’s, dusky, western, cackling, lesser, and the endangered Aleutian); bald eagle; peregrine 

falcon; tundra swan; sandhill crane; shorebirds; marshbirds; and songbirds.” Tract 12 on the 

Ridgeport Dairy Unit was purchased from the Port of Vancouver on March 1, 1991, using Land and 

Water Conservation Funds (LWCF), under the authority of the Fish and Wildlife Act of 1956. This 

is the only portion of the refuge for which we used this funding source, for all other tracts being 

purchased, we used MBCA funds. 

The MBCC Memorandum #10, dated March 21, 1995, approved the purchase price for 68.5 acres 

(Tracts 14 and 14a) of the Ridgeport Dairy Unit. The purpose of this acquisition was “To preserve a 

major wintering area for migratory waterfowl along the Pacific Coast.” These tracts were purchased 

from the Campbell Lake Rod and Gun Club on September 5, 1995, with MBCA funds. 

The Decision Document (Categorical Exclusion), Roth Lowlands Addition to the Ridgefield National 

Wildlife Refuge (April 24, 2007) expanded the refuge’s acquisition boundary by 42 acres, to include 

tracts between Campbell Lake and Lake River. The Service stated that its objectives for the 

boundary expansion were to: “reduce disturbance to roosting sandhill cranes (a State-endangered 

species) on Campbell Lake; reduce disturbance to dusky Canada geese and other waterfowl using 

adjacent pastures and wetlands; provide wintering habitat for dusky Canada geese and other 

migratory birds.” 

Table 1.1 Land purchases and purchase authorities for Ridgefield Refuge 

Date

Legal 

Document Direction

May 18, 

1965 

MBCC 

Memo #1 

The MBCC, acting under authority of the MBCA, authorized the Service to 

acquire 14 tracts in Clark County, WA, totaling 6,130.08 acres at a price of 

$2.2 million, “to provide wintering habitat for dusky Canada geese and 

other waterfowl. Will also provide breeding and migration use and 

substantial public shooting in area. Estimated peak population: 125,000 

ducks and 3,000 geese.” 

January 

27, 1966

Warranty 

Deed

Tracts 21 and 21a (655.73 acres) purchased from Mary E. Carty et al. under 

authority of the MBCA. Purpose derived from MBCC Memo #1. 

January 

31, 1966 

Warranty 

Deed

Tracts 17, 17-I, 17R, 17R-1 (total 1,739.23 acres) purchased from West 

Coast Farms Company under authority of the Migratory Bird Hunting and 

Conservation Stamp Act of 1934 (16 U.S.C. 718-718j). Purpose derived 

from MBCC Memo #1. 

February 

14, 1966

Warranty 

Deed

Tract 19 (23.83 acres) purchased from James E. Carty with MBCA funds. 

Purpose derived from MBCC Memo #1. 

March 29, 

1966 

Warranty 

Deed

Tract 20 (11.47 acres) purchased from William E. Carty with MBCA funds. 

Purpose derived from MBCC Memo #1. 

September 

23, 1966 

Warranty 

Deed

Tract 25 (49.14 acres) purchased from Albert L. Kunz with MBCA funds. 

Purpose derived from MBCC Memo #1. 

November 

17, 1966

Warranty 

Deed

Tract 26 (3.63 acres) purchased from Fred and Elizabeth Laws with MBCA

funds. Purpose derived from MBCC Memo #1.

November 

29, 1967 

Quitclaim 

Deed

Tract 21-I (24.99 acres) donated to the Service by Constance and Aubrey 

Morgan under the authority of the MBCA of 1929. Purpose derived from 

MBCC Memo #1. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

1-20 Chapter 1. Introduction and Background

Date

Legal 

Document Direction

February 

22, 1968 

Quitclaim 

Deed

Tract 21-I (24.99 acres) donated to the Service by Mary E. Carty et al. under 

the authority of the MBCA of 1929. Purpose derived from MBCC Memo 

#1. 

August 5, 

1969

MBCC 

Memo #4

Re-approved purchase of Tracts 11, 12, 14a “to provide resting and 

wintering area for migratory waterfowl.” 

October 

21, 1969 

Agreement 

Purchase of 

Lands

Tract 11 (153.78 acres) purchased from Rosa Roth under the authority of 

the MBCA of 1929 as described within MBCC Memo #1 and #4. 

*Agreement for Purchase of Lands dated June 16, 1969.

January 

13, 1970

Warranty 

Deed

Tracts 11a, b, (356.62 acres) purchased from Rosa Roth under the authority 

of the MBCA as described within MBCC Memo #1 and #4. 

March 

1972 

MBCC 

Memo 

(no#)

Re-approved purchase “to provide resting and wintering area for migratory 

waterfowl.” 

January 

22, 1974

MBCC 

Memo #6

Re-approved purchase “to provide resting and wintering area for migratory 

waterfowl.” 

March 

1980 

EIS, Land 

Acquisition 

Zimmerly 

Tract

Described acquisition of 1,610 acres of Bachelor Island within the 

acquisition boundary “to preclude uses that would be incompatible with 

wildlife use, such as industrial, commercial, or residential development, and 

to gain the capability to manage the land for increased wildlife benefits.” 

Species or species groups specifically mentioned were wintering waterfowl, 

bald eagle, sandhill crane, and great blue heron. 

December 

1983 

EA, 

Acquisition 

of 

Remaining 

Tracts, 

Ridgefield 

Refuge

Covered acquisition of remaining tracts (12, 14, 18, 22, 23, 23a, 24, 27, 42, 

41) within the approved refuge boundary “to preclude activities, such as 

industrial, commercial, and residential development, that would be 

incompatible with wildlife use; to prevent changes in the present pattern of 

land use; and to gain authority to manage the lands for increased wildlife 

benefits . . . to increase overwintering carrying capacity for dabbling ducks . 

. . to maintain current capacity in support of existing overwintering use by 

Canada geese, swans, and diving ducks.” 

November 

1984 

LPP, 

Proposed 

Acquisitions

to the 

Ridgefield 

Refuge

Covered acquisition of tracts 12 (tract 41 is a part of this tract), 14, 18, 22, 

23, 23a, 24, 27 and 42 within the approved refuge boundary under authority 

of the MBCA “to preclude human activities that would be incompatible 

with wildlife use; to prevent major changes in the present pattern of land 

use; and to manage added refuge lands for increased wildlife benefits.” 

Species and species groups specifically mentioned were wintering 

waterfowl, bald eagles, sandhill cranes, great blue heron. 

February 

5, 1985

MBCC 

Memo #8

Reapproved purchase “to provide resting and wintering area for migratory 

waterfowl.”

February 

11, 1985 

Warranty 

Deed

Bachelor Island tracts (23 and 23a with 1,609.97 acres) purchased from 

Bachelor Island Ranch Inc. under the authority of the MBCA. Attachment 

to deed states acquisition authority for the tract as “Section 5 of the Act of 

February 18, 1929 (45 Stat. 1222) as amended by the Improvement Act of 

1978 (92 Stat 3110), Section 6 of the Act of February 18, 1929 as amended 

by the Section 301 of the Act of June 15, 1935 (49 Stat 381) and the 

Migratory Bird Hunting Stamp Act of March 16, 1934 as amended.” MBCC 

Memos #1, #4, #6, #8 and memo of March 1972; EIS of 1980, and EA of 

1983.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 1. Introduction and Background 1-21

Date

Legal 

Document Direction

October 

12, 1989 

CatEx 

(Decision 

Document, 

Acquisition

of Port of 

Vancouver 

Tract)

Purpose of acquisition of Tract 12 “to preclude human activities, such as 

land development and commercial enterprise, (both with potential for 

altering habitat and polluting areas) that would be incompatible with 

wildlife use; to prevent major changes in the present pattern of wildlife use; 

and to manage added refuge land for increased wildlife benefits.” Species or 

species groups specifically mentioned were “over 20 species of waterfowl 

wintering along the lower Columbia River including mallard, pintail, and 

blue winged teal which are listed in the North American Waterfowl 

Management Plan;” six subspecies of Canada geese (Taverner’s, dusky, 

western, cackling, lesser, and the endangered Aleutian); bald eagle; 

peregrine falcon; tundra swan; sandhill crane; shorebirds; marshbirds; and 

songbirds. 

March 1, 

1991 

Warranty 

Deed

Ridgeport Dairy tract (Tract 12 with 520.81 acres, also called the Port of 

Vancouver Tract) purchased from the Port of Vancouver using LWCF

funding under authority of the Fish and Wildlife Act of 1956. The purposes 

of lands purchased with LWCF funding are “for the development, 

advancement, management, conservation and protection of fish and wildlife 

resources” (Fish and Wildlife Act of 1956, 16 U.S.C 742f(a)(4)). MBCC 

Memos #1, #4, #6, #8 and memo of March 1972; EA of 1983; CatEx of 

October 12, 1989.

March 21, 

1995

MBCC 

Memo #10

Price approval for Tracts 14 and 14a (69 acres “to preserve a major 

wintering area for migratory waterfowl along the Pacific coast”).

September 

5, 1995 

Warranty 

Deed

Tracts 14 and 14a (68.5 acres) purchased from Campbell Lake Rod and Gun 

Club under the authority of the MBCA. MBCC Memos #1, #4, #6, #8, #10 

and memo of March 1972; EA of 1983. 

April 24, 

2007 

CatEx 

(Decision 

Document, 

Roth 

Lowlands 

Addition) 

42-acre expansion of acquisition boundary between Campbell Lake and 

Lake River (Tracts 40 and 40a). Purpose of addition would be to reduce 

disturbance to roosting sandhill cranes (a State-endangered species) on 

Campbell Lake; reduce disturbance to dusky Canada geese and other 

waterfowl using adjacent pastures and wetlands; provide wintering habitat 

for dusky Canada geese and other migratory birds. 

1.6.2 Summary of Purposes and Management Direction for the Refuge

The purposes for Ridgefield Refuge have been identified in legal documentation establishing and 

adding refuge lands. Because the refuge was originally established to “Provide wintering habitat for 

dusky Canada goose and other waterfowl,” “provide breeding and migration use [by waterfowl],” 

and “provide substantial public shooting opportunities . . . A portion of the area in line with 

management findings but not to exceed 40%, will be considered for waterfowl hunting in the future” 

(MBCC Memorandum 1), these represent the priority for management to achieve refuge purposes. 

In accordance with Director’s Order No.132, all lands acquired since the original establishment of 

the refuge retain this purpose. 

Along with managing for dusky Canada geese and other migratory waterfowl to achieve refuge 

purposes, legal documentation for including additional lands to the refuge identified the following 

purposes for specific refuge units: 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

1-22 Chapter 1. Introduction and Background

• “to preclude uses that would be incompatible with wildlife use, such as industrial, 

commercial, or residential development, and to gain the capability to manage the land for 

increased wildlife benefits.” (Bachelor Island, Ridgeport Dairy Units, Tract 14, Roth Unit) 

• “to prevent major changes in the present pattern of wildlife use . . .” (Ridgeport Dairy Unit) 

• “for the development, advancement, management, conservation and protection of fish and 

wildlife resources” (Fish and Wildlife Act of 1956) (Ridgeport Dairy Unit) 

• “to preserve a major wintering area for migratory waterfowl along the Pacific coast.” (Roth 

Unit, Tracts 14, 14a) 

In addition to dusky Canada geese and other migratory waterfowl, the following species or species 

groups were identified as management priorities for the Bachelor Island and Ridgeport Dairy units, 

and Tract 14 of the Roth Unit: bald eagle, sandhill crane, great blue heron, peregrine falcon, 

shorebirds, marshbirds, and songbirds. 

1.7 Relationship to Ecosystem Management Goals

1.7.1 Regional Setting

The lower Columbia River, defined as the river and adjacent bottomlands from Bonneville Dam (at 

river mile 145) to the mouth of the Columbia west of Astoria, contains approximately 64,000 acres of 

secure habitat, of which more than half is protected by the following national wildlife refuges (see 

map 1): Lewis and Clark Refuge (38,000 acres, including 12,167 land acres), Julia Butler Hansen 

Refuge (6,270 acres), Ridgefield Refuge (5, 218 acres), Franz Lake Refuge (552 acres), Steigerwald 

Lake Refuge (1,046 acres), and Pierce Refuge (329 acres). 

Within the lower Columbia region, the lowlands of the Portland Basin (called the “Wapato Valley” 

by Lewis and Clark) comprise a unique setting of fertile bottomlands, most of which are now greatly 

altered by urban, industrial, and agricultural development. The 900-square-mile basin is generally 

defined as the area of low topography at the confluence of the Willamette and Columbia rivers, 

including the region along the Columbia River from the Sandy River downstream to the Cowlitz 

River, and the Willamette River north (downstream) from its falls at Oregon City to its confluence 

with the Columbia River (Ames 1999). Geologically, the Portland Basin proper begins roughly at 

the Sandy River and extends downstream to the confluence of the Lewis and Columbia rivers (Evarts 

et al. 2009). The Basin is considered part of the Willamette Valley-Puget Trough ecoregion, lying 

between the Willamette Valley to the south, and the Puget Basin to the north. Historically, the 

Portland Basin was an ecologically rich and productive environment, a complex of riparian and 

bottomland forests, sloughs, and wetlands that supported a wide diversity of wildlife and the region’s 

densest human population prior to Euro-American contact. 

Today much of the Basin is occupied by the Portland-Vancouver metropolitan areas. Outside of 

these areas, much of the Columbia River bottomlands, including the larger river islands, have been 

diked and converted to farmland, and in some cases, industrial uses. Approximately 28,000 acres of 

bottomland habitat of the Portland Basin are natural areas under Federal, State or local ownership, 

including the Ridgefield National Wildlife Refuge and Shillapoo Wildlife Area in Washington; and 

the Sauvie Island Wildlife Area, Smith and Bybee Wetlands Natural Area, Government Island, West 

Hayden Island, and the Sandy River Delta in Oregon (see Table 1.2 below). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 1. Introduction and Background 1-23

Other areas of special biological significance include Burlington Bottoms Wildlife Mitigation Area; 

McGuire Island; Gary, Flag, and Chatham islands in the Columbia River northeast of the Sandy 

River Delta; and the Rooster Rock State Park wetlands. Most of these natural areas have a land use 

history of diking, farming, and/or grazing, therefore, habitat has changed significantly from historic 

conditions. However, they still have high value to wildlife, including migrating and wintering 

waterfowl and sandhill cranes, nesting great blue herons, bald eagle, osprey, and anadromous fish. 

Other smaller habitat areas in the Portland-Vancouver metro area are protected as state and regional 

parks and green spaces that are managed primarily for recreational use, but also for their scenic and 

wildlife values. Figure 1.2 displays the refuge and other conservation areas of the Portland Basin. 

Table 1.2 Protected Bottomland Habitat in the Portland Basin (Oregon and Washington) 

Area Acres Ownership

Ridgefield National Wildlife Refuge (WA) 5,218 U.S. Fish and Wildlife Service

Steigerwald Lake NWR (WA) 1,046 U.S. Fish and Wildlife Service

Shillapoo Wildlife Area (WA) 2,371 (Includes 477-acre

Vancouver Lake Unit)

Washington Dept. of Fish and 

Wildlife

Sauvie Island Wildlife Area (OR) 11,500 Oregon Dept. of Fish and 

Wildlife

Sandy River Delta (OR) 1,400 U.S. Forest Service/Columbia 

River Gorge National Scenic 

Area

Burlington Bottoms Wildlife Mitigation 

Site

417 Bonneville Power 

Administration

Reed Island State Park (WA) 508 Washington State Parks

Rooster Rock State Park (OR) 570 Oregon Dept. of Parks and Rec.

Wapato Access Greenway State Park 

(Virginia Lakes, OR)

280 Oregon Dept. of Parks and Rec.

Vancouver Lake Regional Park (WA) 234 Clark County Parks

Oaks Bottom Wildlife Refuge (OR) 160 City of Portland

Big Four Corners Natural Area (OR) 165 City of Portland

West Hayden Island (OR) 370* acres proposed to 

be maintained as natural 

area (of 820 total acres)

(Port of Portland 2009)

Port of Portland

Vanport Wetlands Mitigation Area (OR) 70 Port of Portland

Government Island, Lemon Island, 

McGuire Island (OR)

2,000 (includes 432-acre

Jewett Lake mitigation 

area)

Port of Portland (leased to 

Oregon Dept. of Parks and 

Rec.)

Smith and Bybee Wetlands Natural Area 

(OR)

2,000 Metro Regional Parks and 

Greenspaces

East Government Island (OR) 224 Metro Regional Parks and 

Greenspaces

Total 28,163 acres 

*Proposed site not 

included in total.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

1-24 Chapter 1. Introduction and Background

1.7.2 Regional Conservation Plans

A brief summary of the major regional conservation plans we considered in the development of this 

CCP follows. 

Washington Comprehensive Wildlife Conservation Strategy (2005) and Oregon 

Comprehensive Wildlife Conservation Strategy (2006). The Washington and Oregon 

Departments of Fish and Wildlife prepared Comprehensive Wildlife Conservation Strategies 

(CWCS) (WDFW 2005, and ODFW 2006) in response to two Federal programs−the Wildlife 

Conservation and Restoration Program and the State Wildlife Grant Program. The CWCS provide a 

strategic framework for the conservation of each State’s wildlife species and their habitats. They 

include information on the distribution and abundance of priority wildlife and habitats; provide 

strategies for conserving and monitoring wildlife and habitat; and provide for coordination with the 

public and Federal, state, tribal, and local agencies. The CWCS emphasize proactive measures to 

conserve declining species and habitats, and to keep common species common; to “help conserve 

wildlife and vital natural areas before they become too rare and costly to protect” (WDFW 2005). 

A number of species that were identified as Species of Greatest Conservation Need (SGCNs) in the 

Washington CWCS occur on the refuge, including the great blue heron, northern pintail, lesser scaup, 

bald eagle, peregrine falcon, Vaux’s swift, purple martin, and slender-billed white-breasted nuthatch. 

The Pacific Townsend’s big-eared bat may occur on the Refuge but has not been confirmed. Other 

priority species that were historically present on the refuge include Columbian white-tailed deer, 

western pond turtle, western gray squirrel, Mazama pocket gopher, and gray-tailed vole. 

Washington Natural Heritage Plan (2007) and Oregon Natural Heritage Plan (2003). The 

Washington Natural Heritage Plan (WDNR 2007) addresses the State’s rare plants, plant associations 

and landscape features. This program provides the framework for a statewide system of state-owned 

natural areas that provide habitat for rare and declining species and places for healthy, functioning 

ecosystems. The primary tool used to develop priorities for individual species is the global and state 

ranking system used by NatureServe and its member Natural Heritage programs. Global and state 

ranks have also been assigned to all terrestrial ecosystems and some of the wetland and aquatic 

ecosystems. The Oregon Natural Heritage Plan (Oregon Natural Heritage Program 2003) is similar 

in scope and methodology to the Washington Plan. 

The refuge hosts two Washington Priority 1 vertebrate species−slender-billed white-breasted 

nuthatch, streaked horned lark, and Oregon vesper sparrow−although the latter two species are rare; 

one Priority 2 species−sandhill crane; one Priority 1 ecological community−overflow plain; and one 

Priority 2 ecological community−Oregon white oak/oval-leaf viburnum/poison oak plant community. 

Both priority communities occur on the Carty Unit’s Blackwater Island RNA. 

Willamette Valley–Puget Trough–Georgia Basin Ecoregional Assessment (2004). The Nature 

Conservancy, the Washington Department of Fish and Wildlife (WDFW), the Nature Conservancy of 

Canada, the Washington Department of Natural Resources (WDNR), and other partners have 

developed Ecoregional Assessments for each of Washington’s nine ecoregions. The refuge lies 

within the area covered by the Willamette Valley–Puget Trough–Georgia Basin Ecoregional 

Assessment (Floberg et al. 2004). Ecoregional assessments identify ecologically significant areas for 

conservation action with a goal of protecting representative biodiversity. They are the result of 

rigorous scientific analyses, incorporating an extensive expert review. They represent the most 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 1. Introduction and Background 1-25

comprehensive effort to set conservation priorities at a regional scale to date. The assessments have 

resulted in a series of products useful to those working to conserve biodiversity in the Pacific 

Northwest, including: 

• A portfolio of priority conservation areas highlighting the most important and suitable areas 

for conservation of ecoregional biodiversity; 

• Maps of relative conservation value of all lands and waters in each ecoregion; and 

• A compilation of the comprehensive biodiversity information and data that were used to 

develop the assessment. 

Lower Columbia Salmon Recovery and Fish and Wildlife Subbasin Plan (2004). The Northwest 

Power and Conservation Council (NPCC) was formed by the states of Washington, Oregon, Idaho 

and Montana to protect and mitigate fish and wildlife that are affected by development and operation 

of the Columbia River hydropower system while assuring an adequate power supply. The council 

established the Columbia River Fish and Wildlife Program to guide efforts to protect, mitigate, and 

enhance fish and wildlife resources. Through the Fish and Wildlife Program, the Columbia basin 

was divided into 62 subbasins for planning purposes. A plan was then developed for each subbasin. 

These plans contain the strategies that drive the implementation of the Council’s Fish and Wildlife 

Program (NPCC 2004). Two subbasin plans apply to the refuge, the Mainstem and Estuary Subbasin 

Plan (vol. II.A) and the Lewis Subbasin Plan (vol. II.G) which includes Gee Creek.

The Lewis Subbasin Plan identifies fall Chinook, chum, coho, and summer and winter steelhead as 

focal species. Gee Creek, part of which lies on the refuge, provides some rearing habitat for native 

salmonids. The Mainstem Lower Columbia River and Columbia Estuary Subbasin Plan identifies the 

following focal species: fall Chinook salmon, spring Chinook salmon, chum salmon, coho salmon, 

winter and summer steelhead, Pacific lamprey, white and green sturgeon, northern pikeminnow, 

Pacific smelt (eulachon), river otter, Columbian white-tailed deer, Caspian tern, bald eagle, osprey, 

sandhill crane, yellow warbler, and red-eyed vireo. The focal fish species primarily use waters 

adjacent to the refuge as migration habitat, although the refuge provides some rearing habitat for 

Chinook salmon. The refuge is an important habitat for the focal bird species listed in the plan.

Lower Columbia River Estuary Partnership Comprehensive Conservation and Management 

Plan (1999). The Lower Columbia River Estuary Partnership (LCREP) is part of the National 

Estuary Program (NEP). The NEP was established to coordinate protection of estuaries of national 

significance that are threatened with ecological degradation resulting from human activities. The 

NEP focuses its efforts on the tidally influenced portion of the Columbia–from the river’s mouth to 

Bonneville Dam. 

In response to an agreement between the governors of Oregon and Washington, and the 

Environmental Protection Agency (EPA), the LCREP prepared the Comprehensive Conservation and 

Management Plan for the estuary (LCREP 1999). The goals of the estuary plan include: increasing 

habitat and habitat functions; preventing toxic and conventional pollution; improving land use 

practices to protect ecosystems; monitoring the health of the river and evaluating the impact of 

actions; strengthening coordination between the states in water quality and species issues; and 

enhancing educational opportunities about the lower river and estuary to build stewardship among all 

citizens.
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1-26 Chapter 1. Introduction and Background

For each of the estuary plan’s goals, there are specific actions that may be taken to accomplish the 

goal. The refuge plays a significant role in achieving the recommended actions, including the 

following: 

• Protect, conserve and enhance identified habitats, particularly wetlands, on the mainstem of 

the lower Columbia River. 

• Preserve and/or restore buffer areas in appropriate locations along tributaries and the 

mainstem to a condition that is adequate to maintain a healthy, functioning riparian zone for 

the lower river and estuary. 

• Maintain public information and education efforts about the lower river and estuary that 

focus on endangered species, habitat loss and restoration, biological diversity, and lifestyle 

practices and connections to the river. 

North American Waterfowl Management Plan-Pacific Coast Joint Venture, Lower Columbia 

River Focus Area (1994): The North American Waterfowl Management Plan is an international 

action plan, signed by the United States, Canada, and Mexico, to conserve migratory birds 

throughout the continent. The goal of the plan is to return waterfowl populations to their 1970s 

levels by conserving wetland and upland habitats. Transforming the goals into on-the-ground actions 

is accomplished through partnerships called joint ventures. Joint ventures are comprised of 

individuals, corporations, conservation organizations, and local, state, provincial, and Federal 

agencies. Habitat joint ventures restore and enhance wetlands and associated upland habitats. 

The refuge falls under a focus area plan for the lower Columbia River developed by the Oregon 

Habitat Joint Venture (1994). It is one of a series of Oregon “focus area” plans developed in the 

1990s to provide a broad overview of wetland and wildlife resources, and describe conservation 

needs and opportunities in general areas identified as “target areas” for Joint Venture action. The 

plan included objectives to protect low lying pastureland in private ownership to provide waterfowl 

feeding areas; and to permanently protect, create, restore, and enhance tidal wetlands, freshwater 

wetlands, and associated uplands. 

The plan notes that population goals for most wildlife species are not well defined and are better 

addressed in terms of habitat goals. The overall objective for waterfowl is to maintain populations 

equal to the greatest population since 1970. However the plan did state that the lower Columbia 

River focus area should maintain habitat capable of supporting peak populations of 6,500 tundra 

swans, 50,000 Canada geese, 90,000 ducks, and 150,000 shorebirds. Nesting populations of colonial 

birds (for example, great blue herons) should be maintained at or above their present numbers. 

In addition to the overall objectives, several of the plan’s recommended actions for wetland habitats 

are pertinent to the refuge, for example, restoring diked former tidelands where feasible and 

appropriate; encouraging public use of publicly owned, wetland habitat areas at levels consistent with 

protection of resource values; and supporting “coordinated resource management planning” and other 

efforts to control purple loosestrife and other invasive, nonnative species. The plan specifically 

recommended that the refuge “block-up public ownership with Washington Department of Wildlife 

in Vancouver lowlands to protect and enhance existing habitat values.” 

Northern Pacific Coast Regional Shorebird Management Plan (2000). The United States 

Shorebird Conservation Plan (Brown et al. 2001) includes 11 regional plans reflecting major 

shorebird flyways and habitats within the United States. The Northern Pacific Regional Working 

Group was formed under the auspices of the national plan to formulate shorebird management goals 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 1. Introduction and Background 1-27

for the Northern Pacific Region (NPR), which represents western Washington and Oregon. The 

purpose of this management plan is to address shorebird management needs on a regional basis while 

considering Pacific Flyway and national levels of need (Drut and Buchanan 2000). 

Shorebirds are a minor component of the bird species and populations at the refuge; however, drying 

and shallow wetlands do provide some foraging opportunities for spring and fall migrating 

shorebirds, especially dunlin, long-billed dowitcher, yellowlegs, western sandpipers, and least 

sandpipers. Changes in wetland management will create increased shallow water conditions and 

moist soil which will provide foraging habitat for shorebirds. 

1.7.3 Pacific Flyway Management Plans

The Pacific Flyway Council is an administrative body that forges cooperation among public wildlife 

agencies for the purpose of protecting and conserving migratory game birds in western North 

America. The Council has prepared numerous management plans to date for most populations of 

swans, geese, and sandhill cranes in the Pacific Flyway (www.pacificflyway.gov). These plans 

typically focus on populations, which are the primary unit of management, but may be specific to a 

species or subspecies. Management plans serve to: 

• Identify common goals; 

• Coordinate collection and analysis of biological data; 

• Establish the priority of management actions and responsibility for them; and 

• Emphasize research needed to improve management. 

The Council creates flyway management plans to help state and Federal agencies cooperatively 

manage migratory game birds under common goals. Management strategies are recommendations, 

but do not commit agencies to specific actions or schedules. Fiscal, legislative, and priority 

constraints influence the level and timing of implementation. Pacific Flyway plans generally guide 

management and research for a 5-year planning horizon. Several of these plans pertain to species 

found on the refuge. A brief summary of the flyway management plans we considered in the 

development of this CCP follows. 

Pacific Flyway Management Plan for the Dusky Canada Goose (2008). The Pacific Flyway 

Management Plan for the Dusky Canada Goose (Branta canadensis occidentalis) (March 2008) was 

adopted by the Pacific Flyway Council and is a revision of earlier plans adopted by the Council 

(1973, 1985, 1992, and 1997). This Management Plan identifies a set of goals and objectives to 

assist in maintaining and enhancing the dusky Canada goose population. 

Dusky Canada geese nest on Alaska’s Copper River Delta and Middleton Island, and primarily 

winter in the Willamette Valley, lower Columbia River, and select coastal sites in both Oregon and 

Washington. The population declined steeply in the early 1980s, falling from 26,000 in 1975 to less 

than 10,000 in 1984 and 1985, as effects of the 1964 Alaska earthquake accelerated changes to 

breeding ground habitats on the Copper River Delta. An increase in elevation allowed shrubs and 

trees to establish rapidly, creating conditions favorable to brown bears and other mammalian 

predators. As a result, predation on nests and adult geese increased significantly. 

During the 1990s, the population was moderately stable, at about 15,000. In 2009 the population fell 

below 10,000, and Action Level 2 (see below) and appropriate management actions were initiated. 
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1-28 Chapter 1. Introduction and Background

With ongoing forest succession on the Copper River Delta and associated predation on geese, 

impaired production will likely limit the population of dusky geese for the long term. Objectives of 

this Management Plan are to: 

• Manage the number of dusky geese to sustain the population within a range of 10,000 to 

20,000 geese, as measured by indices of geese on the Copper River Delta and Middleton 

Island, with primary consideration to: Maintain the breeding population on Copper River 

Delta; and maintain the dusky goose population to withstand an incidental harvest of duskys, 

when harvests of abundant subspecies are desired to assist in depredation control. 

• Maintain and enhance breeding ground habitat conditions to achieve average annual 

production of 20 percent young, measured as the most recent 10-year average. 

• Manage and enhance wintering and migration habitat for dusky and other geese, with an 

emphasis on habitat objectives outlined in the Northwest Oregon/Southwest Washington 

Canada Goose Agricultural Depredation Control Plan (Pacific Flyway Council 1998). 

This Management Plan also identifies three action levels for increasingly intensive management 

efforts to benefit the population status of dusky Canada geese. These levels are designed to ensure 

adequate time for management actions to take effect, based on biological constraints and the 

expected response times of dusky Canada geese to the proposed management actions. The three 

action levels listed below are population based. Management procedures that relate to the levels are 

described in the Management Plan: 

• Action Level 1: 20,000–10,000 

• Action Level 2: 9,999−5,000 

• Action Level 3: Below 5,000 

In the event that Action Level 3 is reached, the agencies will initiate a thorough population risk 

assessment, review the conservation status of dusky geese, and re-evaluate all feasible and practical 

intensive management options. 

As a cooperating wildlife agency for the welfare and management of the dusky Canada goose 

population, refuge management actions for the benefit of duskys will adhere to the recommendations 

prescribed in the Pacific Flyway Management Plan for the Dusky Canada Goose.

Pacific Flyway Management Plan for the Cackling Canada Goose (1999). The cackling Canada 

goose, now called the cackling goosea

 

a In this CCP the term “cackling goose” refers specifically to the subspecies B. hutchinsii minima.

 (Branta hutchinsii minima), is unique to the Pacific Flyway. 

This subspecies primarily nests in the Yukon-Kuskokwim Delta of Alaska and winters from 

California to Washington. Between the late 1960s and the late 1970s, cackler populations declined 

from more than 400,000 birds, to less than 50,000. A record low count of less than 26,000 cacklers 

was tallied in the fall of 1984. The steady decline likely resulted from the combined effects of spring 

subsistence hunting in Alaska, and sport harvest primarily in California. Cooperative conservation 

efforts restored the cackling goose population to about 250,000 by the time the cackler plan was 

written. However, there was a major shift in wintering areas. Historically, nearly all cackling geese 

wintered in the Central Valley of California. Since the early 1990s, the majority of cacklers have 

wintered in western Oregon and southwest Washington. Today cacklers are by far the most abundant 

goose wintering in the Willamette Valley and lower Columbia River. Over the past decade, the 

cackler population declined and is well below the restoration goal. The fall estimate for 2009 was 

160,000, 17 percent lower than the 2008 estimate (USFWS 2009). 
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Chapter 1. Introduction and Background 1-29

The major objectives of the cackler plan are to achieve a population of 250,000 cackling geese on 

breeding grounds. The plan targets a 5 to 10 percent average annual population increase toward the 

population objective. Additional objectives include a distribution of no more than 20 percent of the 

population to be wintering in the Willamette Valley and lower Columbia River. Where feasible, 

nesting, migration, and wintering habitat will be maintained, managed, and enhanced to meet 

population and public use goals. Management of habitat and harvest for cackling geese will 

minimize agricultural depredation complaints. 

Pacific Flyway Management Plan for the Pacific Population of Western Canada Geese (2000).

The Pacific population of western Canada geese (Branta canadensis moffitti) nest in central and 

southern British Columbia, northwestern Alberta, northern and southwestern Idaho, western 

Montana, northwestern Nevada, northern California, and throughout Washington and Oregon. A 

large segment of this population is nonmigratory and resident throughout the year. In response to 

human activities, such as transplants and artificial nesting structures, the population has expanded its 

historic distribution. Agricultural practices, residential expansion, and park development has further 

expanded this population. In some urbanized areas, the geese have become acclimated to human 

interaction and reside in parks. 

The goals for the Pacific population of western Canada geese are to maintain a level and distribution 

that will optimize recreation opportunities and minimize depredation and/or nuisance problems in 

agricultural and urban areas. A management plan for the Pacific population of lesser Canada geese 

(B. canadensis parvipes) and Taverner’s cackling geese (B. hutchinsii taverneri) was in draft in 1994 

but was not finalized. 

Pacific Flyway Management Plan for the Pacific Coast Population of Sandhill Cranes (1983). 

The plan objective is to maintain the wintering population in California at the mid-1980s level of 

20,000 to 25,000 birds, and habitat to support that population. These birds have benefited from 

measures taken to manage migratory birds in general; however, their management is complicated 

because the relationships between the birds’ breeding areas, migration routes, and wintering areas are 

poorly defined. 

Pacific Flyway Management Plan for the Western Population of Tundra Swans (2001). The 

goal of the tundra swan plan is to ensure the maintenance of the western population of tundra swans, 

at a size and distribution that will provide for all their benefits to society (Pacific Flyway Council 

2001). Objectives of the plan include maintaining a population of at least 60,000 swans in their 

current geographic distribution to provide suitable public benefits. For the most part, swans use 

lands which will continue to be managed for waterfowl in general with consideration being given to 

swans and other waterfowl species that are more dependent upon natural and managed wetlands than 

agricultural areas. Refuge wetlands provide wintering habitat for up to 3,000 tundra swans. The 

management practices in the CCP will ensure the continuation of that habitat. 

Northwest Oregon/Southwest Washington Canada Goose Agricultural Depredation Plan 

(1998). This is a comprehensive nine-point plan developed by the Service, ODFW, WDFW, Animal 

and Plant Health Inspection Service–Wildlife Services, and the Oregon and Washington Farm 

Bureaus to establish a systematic and comprehensive approach for minimizing depredation losses 

caused by Canada geese in the Willamette Valley–Lower Columbia River (WV-LCR) area. Major 

objectives of the plan include the stabilization and eventual reduction in the number of wintering 
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1-30 Chapter 1. Introduction and Background

Canada geese in the WV-LCR. The plan proposes the development and implementation of 

techniques to assess the population, distribution, and survival rates of Canada geese on both the 

wintering and breeding grounds. 

Additionally, public lands in the WV-LCR were to be managed to provide abundant, high quality 

goose forage while reducing public use disturbances to increase the amount of geese on public lands, 

while subsequently decreasing the amount of geese on private lands. Other key components include 

increasing Canada goose hunting opportunities within the harvest guidelines of other Pacific Flyway 

population management plans and increased efforts to haze geese from private agricultural lands 

within the WV-LCR. Specifically, the Federal lands within the WV-LCR are to support the plan’s 

objectives:

• To increase the amount of Canada goose use on public lands, while subsequently decreasing 

the amount of Canada goose occurrence on private lands; 

• To review habitat management programs on refuges and wildlife areas to develop programs 

to increase and improve goose forage; and 

• To decrease disturbance to wintering Canada geese and increase goose use of public lands by 

implementing public use restrictions. 

Strategies identified for the refuge include: 

• Implement habitat improvements projects funded as part of the Lower Columbia River-North 

American Wetlands Conservation Act (NAWCA) grant. 

• Implement farming and grazing modifications to provide forage for Canada geese. 

1.7.4 Partners in Flight Landbird Conservation Plans

Partners in Flight (PIF) is an international coalition of government agencies, conservation groups, 

academic institutions, private organizations, and citizens dedicated to the long-term maintenance of 

healthy populations of native landbirds. Partners in Flight focuses their resources toward goals of 

improving monitoring and inventory, research, management, and education programs involving birds 

and their habitats. The PIF strategy is to stimulate cooperative public and private sector efforts in 

North America and the Neotropics to meet these goals. Specific strategies for accomplishing the 

goals are contained in regional landbird conservation plans. These plans describe priority habitats 

and species, and provide recommended management actions to conserve priority habitats and 

species. 

The regional plan applicable to the refuge is the Conservation Strategy for Landbirds in Lowlands 

and Valleys of Western Oregon and Washington (Altman and Holmes 2000). This plan identifies 

four priority habitats: grassland-savanna (including agricultural grasslands), oak woodland, riparian, 

and chaparral. Three of these habitats (riparian, oak woodland and agricultural grasslands) are found 

on the refuge. Eleven riparian focal species, eight oak woodland species, and four grassland species 

identified in the plan occur on the refuge (see Chapter 4). Refuge grasslands are heavily altered by 

past grazing and cropping practices, and are dominated by introduced pasture grasses and reed 

canarygrass. Most are managed as pastures for the benefit of Canada and cackling geese. However, 

even in areas dominated by nonnative grasses, suitable habitat for grassland birds exists. Mowing in 

managed pastures is generally delayed until July 15 after the young of grassland nesting birds have 

fledged. In addition, unmowed buffer areas provide considerable benefit to grassland birds. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 1. Introduction and Background 1-31

1.7.5 Recovery Plans

Recovery plans are prepared by the Service for most endangered species. These plans specify 

actions that are believed to be necessary to protect and recover the species. States also prepare plans 

for state listed species. A brief description of Federal and state recovery plans follows. 

Water Howellia (Howellia aquatilis) Recovery Plan (public and agency review draft 1996). Water 

howellia (Howellia aquatilis) was federally listed as threatened in 1994. Critical habitat was not 

designated, because the Service was concerned about the publication of site-specific maps of critical 

habitat (USFWS 1994). A recovery plan has not yet been published for this species; however, a draft 

recovery plan was released for public review and comment in 1996. Several small ponds containing 

water howellia occur on the Carty Unit (see Chapters 2, 4). 

Columbian White-tailed Deer Recovery Plan (1983). The Columbian white-tailed deer (CWT 

deer) was federally listed as endangered in 1968. The Recovery Plan for the Columbian White-tailed 

Deer (USFWS 1983) states that the Columbia River population of the deer may be considered 

recovered if a minimum of 400 individuals can be maintained in at least three viable subpopulations 

distributed in suitable secure habitat. General guidelines for accomplishing this goal are: 

• Maintain overall viability of 400 deer; 

• Increase the subpopulation on Tenasillahe Island to a minimum viable herd of 50; and 

• Secure the habitat of one additional subpopulation. 

Listed stepwise under the general guidelines are specific actions that are recommended to accomplish 

the deer’s recovery. One action that is potentially applicable to management of the refuge is 

“Transplant CWTD to establish new subpopulations within their historical range.” Ridgefield is 

within the historic range of CWT deer and has been proposed as a potential transplantation site. A 

feasibility study required for establishing a population of CWT deer on the refuge is included as a 

strategy in the CCP (see Chapter 2). 

Washington State Recovery Plan for the Sandhill Crane (2002). All subspecies of sandhill cranes 

are listed as endangered in Washington State. While some argue that the true “endangered” 

population in Washington is breeding greater sandhills (G. canadensis tabida), the Canadian sandhill 

(G. c. rowani) is of conservation concern due to its limited numbers, distinct coastal migration path, 

and habitat issues at breeding, staging, and wintering areas (Ivey et al. 2005). The lower Columbia 

River region is the only major stopover site for Canadian sandhill cranes between their northern 

breeding areas and wintering sites in California’s Central Valley. In recent years, up to 4,273 cranes 

have been counted on the lower Columbia during early fall (Littlefield and Ivey 2002). Staging 

counts may represent the entire population nesting in coastal B.C. and southeast Alaska. The refuge

provides important roosting habitat for approximately 30 percent of this population. Protection of 

sandhill crane roosts are, therefore, an important management issue.

Washington State Recovery Plan for the Western Pond Turtle (1999). The western pond turtle 

was listed as a sensitive species by WDFW in 1981. This status was changed to threatened in 1983, 

and endangered in November 1993. The Columbia Gorge National Scenic Area Management Plan 

has placed a number of identified pond turtle habitats in categories which will protect them from 

development and alteration. Wetland protection regulations, such as Section 404 of the Clean Water 

Act that regulates the discharge of fill, also applies to wetland habitat of pond turtles (Hays et al. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

1-32 Chapter 1. Introduction and Background

1999). The refuge lies within the historic range of the western pond turtle. A single individual was 

found on the refuge in 2005; however, subsequent surveys failed to locate more individuals. 

In 1992, the Service conducted a status review for the western pond turtle in response to a petition 

(USFWS 1992) to list the species as threatened or endangered under the Endangered Species Act

(ESA). This petition to list the species was denied, because although the turtle has declined and is 

affected by human activity, it still occurs in 90 percent of its historic range and is not in danger of 

extinction or likely to become so in the foreseeable future (USFWS 1993a). Though the western 

pond turtle is not protected under the Federal ESA, it is a species of special concern for the Service.

1.8 Issues, Concerns and Opportunities

1.8.1 Major Issues to be Addressed in the CCP 

The core planning team evaluated the issues and concerns raised during public scoping. Issues are 

defined as matters of controversy, dispute, or general concern over resource management activities, 

the environment, land uses, or public use activities. Issues are important to the planning process 

because they identify topics to be addressed in the CCP, pinpoint the types of information to gather, 

and help define alternatives for the Draft CCP/EA. Numerous issues, concerns and opportunities 

were raised during the public scoping process; we addressed them all in some manner in the CCP. It 

is the Service’s responsibility to focus planning on the major issues. Major issues typically suggest 

different actions or alternative solutions, are within the refuge’s jurisdiction, and have a positive or 

negative effect on the resource. The following issues, concerns, and opportunities were considered 

during the development of the CCP. 

Wildlife and Habitat Management. What actions should the Service take to sustain and restore 

priority species and habitats over a period of 15 years? What percentage of the refuge should be 

maintained as intensively managed habitats that primarily benefit migrating and overwintering 

waterfowl, and what percentage should be native habitats of the historic lower Columbia River 

ecosystem? How can the refuge improve the health and productivity of its wetlands, where natural 

hydrologic fluctuations no longer exist? Are there opportunities to restore riparian and bottomland 

forest, and restore tidal connections to wetlands?

Invasive Species. How will the refuge control invasive species and prevent new invasives from 

becoming established? What are the most appropriate strategies for controlling invasive species on 

the refuge? 

Rare and Listed Species Recovery. What is the refuge’s role in assisting in the recovery of 

threatened and endangered species native to the lower Columbia River ecosystem, while at the same 

time meeting refuge purposes to provide migration and wintering habitat for dusky Canada geese and 

other waterfowl? What opportunities exist to reintroduce rare and listed native species to the refuge? 

What actions can be taken to protect and restore habitat values for other declining species?

Impacts of Development and Climate Change. How shall the refuge address the impact of 

increasing development of adjacent lands on its wildlife and habitat? How will the refuge address 

the potential impacts of climate change?

Contaminants and Water Quality. How shall the refuge monitor for contaminants and address 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 1. Introduction and Background 1-33

contaminant and water quality issues? How will the refuge improve conditions in its instream habitat 

and tidal wetlands for native fish? 

Public Use and Access. How will the refuge meet the increasing demand for safe, accessible, high 

quality wildlife-dependent recreation opportunities in the future? How will the refuge provide 

visitors with safe and accessible access to the refuge in compliance with the Americans with 

Disabilities Act (ADA)? How will the refuge improve the quality of its waterfowl hunt program, 

while minimizing impacts to dusky Canada geese? How will the refuge address the impacts of 

increasing visitation on wildlife, and minimize impacts to purposes species?

Cultural Resources. How shall the refuge protect its significant archaeological and historic sites? 

What level and type of cultural resources education should be provided to the public? How will the 

Cathlapotle Plankhouse fit into interpretation and education programs on the refuge? 

1.8.2 Issues Outside the Scope of the CCP

While CCPs are very comprehensive plans, no single plan can cover all issues. The planning team 

has compiled a list of issues which are currently considered to be outside the scope of this CCP. 

Nature Center and Pedestrian Bridge to Carty Unit. In 2009 the refuge received funding to plan 

a nature center and administrative offices, and a pedestrian bridge to replace the existing office and 

bridge at the Carty Unit (the existing bridge does not meet ADA standards). The refuge prepared a 

draft Environmental Assessment (EA) for the construction and operation of these facilities. The EA 

was prepared because of potential funding timelines. The new facility would provide office space for 

refuge staff and areas for visitor services and educational programs, display areas, and storage. Both 

the new building and the bridge would meet current standards of accessibility. In the Preferred 

Alternative, the proposed facility would be located on the Carty Unit southwest of the existing office 

trailer, and the bridge would be located south of the existing footbridge. A second alternative 

proposes a location on Port of Ridgefield property (two other locations, the River ‘S’ Unit and 

property owned by Taverner LLC, adjacent to Hillhurst Road, were considered but not selected for 

detailed analyses). The public comment period for the Draft EA began on March 23, 2010, and

closed on April 26, 2010. A Finding of No Significant Impact was signed by the FWS Regional 

Director on April 29, 2010. 

Expansion of Refuge’s Acquisition Boundary. A proposal to expand the refuge’s acquisition 

boundary is not included in this CCP. The Service will analyze additional habitat protection needs 

and possible additions to the approved refuge boundary in future conceptual studies for habitat 

protection in the lower Columbia River area. In addition, an expansion will be considered as a part 

of a feasibility study for restoring a tidal connection to Post Office Lake (see Chapter 2, Goal 6). 

Priorities for acquisition of lands within the current acquisition boundary are described in Appendix 

M, Land Protection Plan. 

City of Ridgefield Sewer Line. In 2005 the City of Ridgefield began preliminary planning to 

relocate its existing wastewater treatment plant outfall from its current location in Lake River to a 

future location in the Columbia River, in anticipation of future needs for increased capacity. As of 

2006, the preliminary preferred route for a pipeline to deliver treated effluent to the Columbia River 

was through the refuge. Concerns about this issue were raised during public scoping. Since that 
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1-34 Chapter 1. Introduction and Background

time, other options for a pipeline route have been developed. Development of a new pipeline and 

outfall would be subject to a separate NEPA process led by the City of Ridgefield. Therefore, this 

issue is outside the scope of the CCP. 

Eroding County Road (SR501) and Dike. Concerns regarding the erosion of the dike road at the 

south boundary of the refuge (Lower River Road/SR 501) were raised during public scoping. The 

State closed Lower River Road at the refuge’s boundary due to road failure in July of 2005. In 

January 2006, the State abandoned its right of way from milepost (MP) 11.40 to MP 12.72. The 

WDOT concluded, “This road serves no useful function at this time, and this portion is unlikely ever 

to be extended through the RNWR.” Ownership of the abandoned section reverted to Clark County, 

which also owns the dike. The road is barricaded, and portions of this segment have washed away, 

with significant bank undercutting by the Columbia River. Since the dike and road are owned by 

Clark County, the Service does not have the authority or the obligation to repair the road or dike. 

Since the dike is likely to fail in a major flood event, the CCP includes a contingency plan in the case 

of a dike breach (see Chapter 2). 

Waterfront Development on Port of Ridgefield Property. The Port of Ridgefield is planning a 

mixed use waterfront development on the old Lake River Industrial Park site adjacent to the refuge, 

just south of Carty Lake. Redevelopment will be conducted in 7 stages over several years (Port of 

Ridgefield 2009). While this facility is not on refuge lands, there are safety, aesthetic, and resource 

concerns associated with having a high density public use area and boat launch adjacent to the 

refuge. On the other hand, this development would provide opportunities to improve refuge access 

by eliminating dangerous in-grade railroad crossings, and to create links between the refuge and local 

trail systems, and potentially, with mass transit systems. This issue is outside the scope of the CCP 

and can be better addressed as part of the planning process for that facility. However trail/access 

linkages with the Port of Ridgefield property were considered in the CCP (see Chapter 2, 

Management Direction, and Appendix L, Transportation Analysis). 

Management Issues on Adjacent WDNR Land. The Washington Department of Natural 

Resources (WDNR) owns Turtle Lake and a portion of the shoreline of Bachelor Island. This area 

has become increasingly popular with hunters and other recreational users, but to date public use has 

been unregulated. Hunting and beach use have become a source of disturbance to wildlife on 

adjacent refuge lands. Developing a cooperative agreement to manage WDNR land on Bachelor 

Island was considered during alternatives development, however, due to limited refuge law 

enforcement staff, it is not feasible at this time. The Service will continue ongoing consultation with 

WDNR on law enforcement issues. 

Floathouses. A floathouse community is located on Lake River adjacent to refuge lands, outside the 

refuge boundary. This topic will not be addressed in the CCP because it is outside the Service’s 

jurisdiction. However, the impacts of refuge access alternatives to the floathouse community were 

considered in the development of transportation alternatives for the refuge (see Chapter 2, 

Management Direction, and Appendix L, Transportation Analysis). 
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Chapter 1. Introduction and Background 1-35

1.9 Refuge Vision

Our vision of the future refuge follows. 

Ridgefield National Wildlife Refuge is a place where people of all abilities can experience 

nature and share their outdoor traditions with others. This island of habitat with its rich 

diversity of floodplain forests, freshwater marshes, and meadows, will continue to sustain 

thriving populations of wintering dusky Canada geese, migrating waterfowl, and other 

wildlife. With collaboration from our conservation partners, the refuge will apply sound, 

scientific principles to sustain the long-term ecological health and integrity of lower 

Columbia River floodplain habitats; expand environmental education; encourage 

participation in wildlife-dependent recreational opportunities; protect and interpret unique 

cultural resources; and foster natural and cultural resources stewardship. As the rural 

character of the landscape changes, the refuge will become even more important to wildlife 

and those seeking to understand our natural and cultural heritage.

1.10 Refuge Goals

1.10.1 Wildlife and Habitat Goals

1. Provide and manage a mixture of secure, diverse, productive grassland habitats for foraging 

migratory waterfowl and grassland-dependent wildlife. 

2. Annually provide agricultural crops as forage for migratory waterfowl and sandhill cranes. 

3. Provide, manage, and enhance a diverse assemblage of wetland habitats characteristic of the 

historic lower Columbia River. 

4. Protect, manage, and restore a natural diversity of native floodplain forests representative of 

the historic lower Columbia River ecosystem. 

5. Protect, manage, and restore a natural diversity of native upland forests representative of the 

historic lower Columbia River ecosystem. 

6. Protect, enhance, and where feasible, restore riverine habitat and tidal wetlands representative 

of the historic lower Columbia River ecosystem, to benefit salmonids and other native 

aquatic species.

7. Collect scientific information (inventories, monitoring, and research) necessary to support 

adaptive management decisions on the refuge, associated with Goals 1-6. 

1.10.2 Cultural Resources Goal

The refuge will protect and manage its cultural resources for their educational, scientific, and cultural 

values for the benefit of present and future generations of refuge users and communities. 

 

1.10.3 Public Use Goals

1. Waterfowl hunters of all abilities will enjoy a quality, safe hunting program that provides a 

variety of waterfowl hunting experiences, promotes youth hunting, balances hunt program 

needs with other public use program needs, and reduces impacts to nontarget species. As a 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

1-36 Chapter 1. Introduction and Background

result of participating in the waterfowl hunting program, hunters will gain a better 

appreciation of the refuge’s mission and its resource management. 

2. Visitors of all abilities will have the opportunity to participate in safe, quality wildlifedependent recreation programs, including wildlife observation, photography, interpretation, 

and fishing, consistent with the needs of other public use programs, in a manner that limits 

wildlife disturbances, even with increasing refuge visitation. These programs will focus on 

enhancing public understanding and appreciation of wildlife, and building support for the 

Ridgefield Refuge. 

3. The refuge’s cultural resources and the Cathlapotle Plankhouse will be interpreted to 

enlighten visitors about the refuge’s unique natural and cultural history. Through accurate 

interpretive and educational opportunities, visitors will gain an understanding and 

appreciation of the refuge’s natural and cultural heritage. 

4. Through refuge outreach efforts local residents will have the opportunity to gain an 

appreciation and understanding of the refuge and Refuge System mission. 

5. Environmental Education: Students from southwest Washington will participate in quality 

environmental education programs on the refuge that meet State educational requirements, 

and provide safe and memorable experiences that foster a connection with nature and the 

refuge. As a result of their participation in these programs, students will understand the 

refuge’s role in wildlife conservation and incorporate a conservation ethic into their everyday 

lives. The refuge’s environmental education (EE) program shall: 

• Focus on community groups, schools, and students in southwest Washington; 

• Tier to Washington state educational objectives;

• Balance class facilitation between refuge staff, teachers, volunteers, and partners; 

• Be fully accessible for all students; and 

• Be coordinated by a permanent full time Environmental Education Specialist. 

1.11 Planning Process

A core planning team, consisting of a Project Leader, Refuge Manager, Complex Biologist, Outdoor 

Recreation Planner, and a Regional Planner, began developing the CCP in the fall of 2005. An 

extended team assisted in CCP development, particularly in reviewing preliminary goals, objectives 

and strategies, and in developing alternatives for the Draft CCP/EA. The extended team consisted of 

various professionals from other agencies and divisions within the Service. A list of core and 

extended team members is located in Appendix I. 

Early in the planning process, the core team identified 15 priority wildlife species (resources of 

concern) for the refuge, their associated habitats, and other species that would benefit from managing 

the resources of concern. These resources of concern are listed in Chapter 4 and Appendix F. 

Wildlife and habitat goals and objectives were designed directly around the habitat requirements of 

species designated as priority resources of concern. The analytical framework for analyzing the 

resources of concern and for devising appropriate conservation objectives and strategies was based 

on the Service’s Identifying Resources of Concern and Management Priorities for a Refuge: A 

Handbook (USFWS 2008). The handbook was still in draft form while this CCP was being 

developed, however, it had been adopted by the Service’s Pacific Region as the process to develop 

wildlife and habitat goals and objectives for CCPs. 

Public use planning centered on developing goals, objectives and strategies around the “Big Six” 

wildlife dependent public uses—hunting, fishing, wildlife observation and photography, and 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 1. Introduction and Background 1-37

environmental education and interpretation—and the transportation and infrastructure needs 

associated with those uses. 

Public scoping began in the fall of 2006. In September, scoping meetings were held in Ridgefield 

and Vancouver, Washington. Public comments were also solicited through distribution of a planning 

update to the refuge mailing list. In the spring of 2009 a public open house meeting was held to 

gather public comments on preliminary draft alternatives. An internal draft was distributed to 

Service Region 1 reviewers in January 2010. All changes requested by reviewers and extended team 

members and actual changes made were documented. The Ridgefield NWR Draft Comprehensive 

Conservation Plan and Environmental Assessment (DCCP/EA) was issued for public review and 

comment on June 16, 2010. The plan was provided on CD to a mailing list of 432 recipients, and was

made available on the FWS Region 1 Planning website. Printed copies of the DCCP/EA were 

available upon request. The 30-day review occurred from June 16 through July 16, 2010. All changes 

made as a result of public and agency comments were documented. A summary of public 

involvement is included in Appendix J; public comments on the DCCP/EA and the Service’s 

responses to comments are included in Appendix N. 

1.12 References 

Altman, B. 1999. Conservation strategy for landbirds in coniferous forests of western Oregon and 

Washington. U.S. Fish and Wildlife Service, Migratory Birds and Habitat Programs, Portland, OR. 

Altman, B. and A. Holmes. 2000. Conservation strategy for landbirds in lowlands and valleys of 

western Oregon and Washington. U.S. Fish and Wildlife Service, Migratory Birds and Habitat 

Programs, Portland, OR. 

Ames, K.M., C.M. Smith, W.L. Cornett, S.C. Hamilton, E.A. Sobel, S.C. Hamilton, J. Wolf and D. 

Raetz. 1999. Archaeological Investigations at 45CL1 Cathlapotle (1991–1998), Ridgefield Wildlife 

Refuge, Clark County, Washington; A Preliminary Report. Cultural Resource Series Number 13. 

U.S. Fish and Wildlife Service, Portland, OR. (Wapato Valley Archaeological Project Report #7, 

Portland State University, Portland, OR). 

Bielke, S. 2001. Burlington Bottoms Wildlife Mitigation Site, Project No. 1991-078-00, 24 

electronic pages, (BPA Report DOE/BP-00004888-1)

Brown, S., C. Hickey, B. Harrington, and R. Gill, eds. 2001. The U.S. Shorebird Conservation Plan, 

2nd ed. Manomet Center for Conservation Sciences, Manomet, MA. 

Drut, M.S. and J.B. Buchanan. 2000. U.S. Shorebird Conservation Plan. Northern Pacific Coast 

Regional Shorebird Management Plan. U.S. Fish and Wildlife Service, Office of Migratory Bird 

Management, Portland, OR. 

Evarts, R.C., J.E. O’Connor, R.E. Wells, I.P. Madin. 2009. The Portland Basin: A (big) river runs 

through it. GSA Today 19(9): 4-10. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

1-38 Chapter 1. Introduction and Background

Floberg, J., M. Goering, G. Wilhere, C. MacDonald, C. Chappell, C. Rumsey, Z. Ferdana, A. Holt, P. 

Skidmore, T. Horsman, E. Alverson, C. Tanner, M. Bryer, P. Iachetti, A. Harcombe, B. McDonald, 

T. Cook, M. Summers, D. Rolph. 2004. Willamette Valley-Puget Trough-Georgia Basin 

Ecoregional Assessment, Volume One: Report. Prepared by The Nature Conservancy. 

Hays, D.W., K.R. McAllister, S.A. Richardson, and D.W. Stinson. 1999. Washington state recovery 

plan for the western pond turtle. Washington Dept. of Fish and Wildlife, Olympia, WA. 

Ivey, G.L., C.P. Herziger, and T.J. Hoffman. 2005. Annual Movements of Pacific Coast sandhill 

cranes. Proceedings of the North American Crane Workshop 9:25-35. 

Littlefield, C.D. and G.L. Ivey. 2002. Washington State Recovery Plan for the Sandhill Crane. 

Washington Department of Fish and Wildlife, Olympia, WA. 

Lower Columbia River Estuary Program (LCREP). 1999. Comprehensive Conservation and 

Management Plan. Lower Columbia River Estuary Program, Portland, OR. 

Lower Columbia Fish Recovery Board. 2004. Lower Columbia Salmon Recovery and Fish and 

Wildlife Subbasin Plan, Vol. II.A. Lower Columbia Mainstem and Estuary. URL: 

www.subbasins.org/fw/subba-sinplanning/lowerColumbia/plan/Vol%20II%20A--

Col%20Estuary%20mainstem.pdf

Lower Columbia Fish Recovery Board. 2004. Lower Columbia Salmon Recovery and Fish Wildlife 

Subbasin Plan, Vol. II.G. North Fork and East Fork Lewis, and Salmon-Washougal Rivers (WRIAS 

27-28). 354 pp. 

http://www.subbasins.org/fw/subbasinplanning/lowerColumbia/plan/Vol%20II%20G--Lewis.pdf

Moulton, Gary E., ed. 1990. The Journals of the Lewis and Clark Expedition, Vol. 6, November 2, 

1805-March 22, 1806. Meriwether Lewis and William Clark. University of Nebraska Press, 

Lincoln, NE. 

Moulton, Gary E., ed. 1991. The Journals of the Lewis and Clark Expedition, Vol. 7, March 23 to 

June 9, 1806. Meriwether Lewis and William Clark. University of Nebraska Press, Lincoln, NE. 

ODFW. 2006. Oregon Conservation Strategy. Oregon Department of Fish and Wildlife, Salem, 

OR. 

Oregon Habitat Joint Venture. 1994. Joint Venture Implementation Plans, Lower Columbia River. 

Oregon Habitat Joint Venture, West Linn, OR. 

Oregon Natural Heritage Program. 2003. Oregon Natural Heritage Plan. Department of State 

Lands, Salem, OR. 

Pacific Flyway Council. 1998. Pacific Flyway Management Plan for Northwest Oregon - Southwest 

Washington Canada Goose Agricultural Depredation Control. Canada Goose Agricultural 

Depredation Working Group. U.S. Fish and Wildlife Service, Migratory Birds and Habitat 

Programs, Portland, OR. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 1. Introduction and Background 1-39

Pacific Flyway Council. 1999. Pacific Flyway Management Plan for the Cackling Canada Goose. 

U.S. Fish and Wildlife Service, Migratory Birds and Habitat Programs, Portland, OR. 

Pacific Flyway Council. 2001. Pacific Flyway Management Plan for the Western Population of 

Tundra Swans (unpublished report). Pacific Flyway Subcomm. on Tundra Swans. U.S. Fish and 

Wildlife Service, Portland, OR. 

Pacific Flyway Council. 2008. Pacific Flyway management plan for the dusky Canada goose 

(unpublished report). Dusky Canada Goose Subcomm., U.S. Fish and Wildlife Service, Portland, 

OR. 

Port of Portland. 2002. Government Island Management Plan. URL: www.portofportland.com/PDFPOP/Miti_Gvrnmnt_Is.pdf, acessed December 3, 2009.

Port of Portland. 2004. Vanport Wetlands Comprehensive Management Plan. URL: www.portofportland.com/PDFPOP/Miti_Vanport_Wetlands.pdf, accessed December 3, 2009. 

Port of Portland. 2009. Port of Portland West Hayden Island Development Scenario: Potential 

Natural and Cultural Resources Impact and Mitigation Evaluation. Technical Memorandum. URL: 

www.port-ofportland.com/PDFPOP/Prj_Wst_Hydn_IS_Stdy_NRA_Memo.pdf, accessed December

3, 2009. 

Port of Ridgefield. 2009. Miller’s Landing Mixed Use Development. URL: www.portridgefield.org/what/current-projects/millers-landing-development.aspx, accessed December 9, 2009. 

Subcommittee on Dusky Canada Geese. 1992. Pacific Flyway Management Plan for Dusky Canada 

Geese (unpublished report). Pacific Flyway Study Comm. U.S. Fish and Wildlife Service, Portland, 

OR. 

 

Subcommittee on Pacific Population of Western Canada Geese. 2000. Pacific Flyway Management 

Plan for the Pacific Population of Western Canada Geese (unpublished report). U.S. Fish and 

Wildlife Service, Portland, OR. 

USFWS. 1983. Columbian White-tailed Deer Recovery Plan, First Revision. U.S. Fish and 

Wildlife Service, Portland, OR. 

USFWS. 1994. The Plant, Water Howellia (Howellia Aquatilis), Determined To Be a Threatened 

Species. Federal Register 59:35860-36864. URL: ecos.fws.gov/docs/frdocs/1994/94-17134.pdf

USFWS. 1996. Water howellia (Howellia aquatilis) recovery plan: public and agency review draft. 

U.S. Fish and Wildlife Service. Helena, MT

USFWS. 2009. Waterfowl Population Status 2009. Accessed online July 2009 

http://www.fws.gov/migratorybirds/NewReportsPublications/PopulationStatus.html 

USFWS. 2010. Ridgefield National Wildlife Refuge, Draft Comprehensive Conservation Plan and 

Environmental Assessment.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

1-40 Chapter 1. Introduction and Background

WDFW. 2005. Washington’s Comprehensive Wildlife Conservation Strategy. Washington 

Department of Fish and Wildlife, Olympia, WA. 

Washington Department of Natural Resources (WDNR). 2007. State of Washington Natural 

Heritage Plan 2007. Olympia, WA. 

WDNR. 2009. State of Washington Natural Heritage Plan 2009 Update. Olympia, WA. 

Wiberg, C. and S. Greene. 1981. Blackwater Island Research Natural Area. Supplement No. 11 to 

Franklin, J.F., Hall, F.C., Dyrness, C.T. and Maser, C., 1972. Federal Research Natural Areas in 

Oregon and Washington: A Guidebook for Scientists and Educators. USDA Forest Service, Pacific 

Northwest Forest and Range Experiment Station, 498 pp. 
Chapter 2. Management Direction

 Refuge staff manages

 habitat to benefit both

 wildlife and people/

 USFWS

Mallard pair/Jim Cruce

A dramatic encounter between a rough-legged hawk and a red-tailed hawk shows why

Ridgefield is a destination for wildlife watchers and photographers. /Jim Cruce
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-1 

Chapter 2. Management Direction 

2.1 Overview 

During development of this CCP, the Service reviewed and considered a variety of resource, social, 

economic, and organizational aspects important for managing the refuge. These background 

conditions are described more fully in Chapters 3, 4, 5, and 6. As is appropriate for a national 

wildlife refuge, resource considerations were fundamental in designing alternatives. House Report 

105-106 accompanying the Improvement Act states “...the fundamental mission of our System is 

wildlife conservation: wildlife and wildlife conservation must come first.” 

The refuge planning team reviewed available scientific reports and studies to better understand 

ecosystem trends and the latest scientific recommendations for species and habitats. The team met 

with staff from local, state, and Federal agencies, and elected officials to ascertain priorities and 

problems as perceived by others. Refuge staff met with refuge users, nonprofit groups, and 

community organizations to ensure that their comments and ideas were considered during CCP 

development. Refuge access emerged as an important issue, therefore, the Service commissioned a 

transportation access analysis that was completed by the Federal Highway Administration’s Western 

Federal Lands Highway Division (see Appendix L). The study identified transportation alternatives 

that were either carried forward in the CCP or dismissed from further consideration. 

2.2 Management Directions Considered but Not Developed

The details of public participation can be found in Appendix J. During development of the 

alternatives, the planning team considered the actions detailed below. All of these actions were 

ultimately eliminated for the reasons provided. 

Major expansion or reduction of waterfowl hunt program. A significant expansion of the 

waterfowl hunt area was suggested during scoping and public review of preliminary draft 

alternatives. This was not included in the alternatives, because of conflicts with resource protection, 

and the ability of the refuge to provide adequate sanctuary area for dusky Canada geese, cackling 

geese, and other species. Establishing a hunt area outside the dike on Bachelor Island, in conjunction 

with closing core dusky Canada goose habitat on the south end of the River ‘S’ Unit to hunting, was 

been proposed in Alternative 4 of the Draft CCP/EA; however, the number of hunted acres is only a 

modest increase (40 acres) over current acreage. The primary rationale for this action was to create a 

larger contiguous block of sanctuary area for duskys and cranes. Ultimately, Alternative 4 was not 

selected as the Preferred Alternative. 

Increasing the number of blinds within the current hunt area was also proposed in public comments 

on preliminary draft alternatives. This was not included in the range of alternatives, due to concerns 

with safety and hunt quality. Closing the refuge to hunting was suggested in public scoping. This 

was not included in the range of alternatives in the Draft CCP/EA because providing waterfowl 

hunting is one of the purposes for which the refuge was established (see Chapter 1). 

Major expansion or reduction of wildlife observation and photography programs. Closing the 

auto tour route on hunt days, or for the entire hunting season, was proposed in public comments on 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

2-2 Chapter 2. Management Direction

the preliminary draft alternatives. This was not included as an alternative in the Draft CCP/EA due 

to the impacts it would have on the refuge visitors who use the auto tour route to view and 

photograph wildlife during the waterfowl season. 

During scoping, many comments were received requesting the Service to build several additional 

observation/photography blinds on the River ‘S’ Unit, and/or allow the use of hunt blinds for wildlife 

observation/photography. These proposals were not included in the range of alternatives in the Draft 

CCP/EA due to conflicts with resource protection. Many comments were also received requesting 

that the Service allow self-guided hiking, wildlife observation, and wildlife photography (along with 

infrastructure to support these uses) in currently closed areas. These were not included in the range 

of alternatives because of impacts to sensitive species. However, guided tours to these areas (which 

do not require additional infrastructure) were included in the range of alternatives and appear as 

strategies in the CCP. 

Allowing certain nonwildlife-dependent uses. The planning team considered the appropriateness 

of providing opportunities for various nonwildlife dependent recreational activities suggested during 

scoping including bicycling, dog walking, and horseback riding. These activities have been shown to 

have unacceptable levels of disturbance to wildlife; unacceptable public safety issues; or would 

interfere with users engaged in compatible wildlife-dependent uses. Therefore, bicycling, dog 

walking, and horseback riding were not included in the range of alternatives in the Draft CCP/EA. 

Based on policy guidance in the Service’s Appropriate Refuge Uses Policy 603 FW 1 (2006), these 

uses were determined not appropriate, and are documented on Service Form 3-2319 in Appendix A. 

Developing a southern access point to the refuge. The planning team considered developing a 

southern access point to the refuge, through the Ridgeport Dairy and Roth units, to replace the 

current entrance road and bridge to the River ‘S’ Unit. This was not included in the range of 

alternatives in the Draft CCP/EA because a transportation access analysis (see Appendix L) 

concluded that such an access point would result in unacceptable impacts to dusky Canada geese and 

sandhill cranes, and conflict with management needs.

Reconnecting Carty Lake to the Columbia River. Although many wetlands on the River ‘S’ and 

Bachelor Island units are cut off from tidal influence by the refuge’s levee system, most of the water 

bodies and large wetlands on the Carty, Roth, and Ridgeport Dairy units are connected to the 

Columbia River and their water levels fluctuate with river elevations. These fluctuations are 

associated with hydroelectric plant operations, seasonal fluctuations related to precipitation and 

snowpack levels, and daily fluctuations associated with tides. The tidal range on the Columbia River 

near the refuge is approximately 3.3 feet, but varies with weather patterns and lunar phases. 

Although these wetlands are tidal, they are situated well above the salt front with salinity levels less 

than 1 parts-per-trillion (ppt). 

Restoring tidal influence to refuge waterbodies that are currently cut off from the Columbia River 

would benefit several fish species such as juvenile coho and Chinook salmon, which use tidal 

wetlands and waterbodies for cover and foraging during out-migration. Tidal fluctuations would also 

allow periodic drying, nutrient release, and organic matter transport which benefits wetland plant 

species such as water plaintain and smartweeds. The refuge is examining the feasibility of 

reconnecting several wetlands and waterbodies to the Columbia River (see Chapter 2, Goal 6). 

Restoring a tidal connection between Carty Lake and the Columbia River was considered but 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-3 

dismissed as a CCP action for several reasons: The reconnection would require dredging and spoil 

disposal; dredging sediments could release contaminants that originated from the Pacific Wood 

Treatment site; although carp currently occur in Carty Lake, their numbers are limited, in part by 

reducing the water’s depth during summer and early fall; and a direct connection to the Columbia 

River would allow carp to emigrate into the lake from the river and speed recolonization. As the 

clean-up of the Pacific Wood Treatment site progresses and innovative methods of excluding 

undesirable fish species are developed, we may revisit this decision in the future. 

2.3 Description of Management Direction

2.3.1 Summary of Management Direction

Implementation subject to funding availability. After the CCP is completed, actions will be 

implemented over a period of 15 years as funding becomes available. Project priorities and projected 

staffing/funding needs are included in Appendix D, Implementation. 

State coordination. Under the CCP, the Service will continue to maintain regular discussions with 

the Washington and Oregon Departments of Fish and Wildlife (WDFW and ODFW). Key topics of 

discussion will include management of dusky Canada geese, cackling geese, and other waterfowl; 

depredation; updates of waterfowl management and depredation plans; wildlife monitoring; hunting 

and fishing seasons and regulations; and management of Federal and State-listed species. 

Tribal coordination. The Service will coordinate and consult with the Cowlitz Tribe and the 

Chinook Tribe on a regular basis regarding issues of shared interest. Other Tribes with interests 

relating to the traditionally shared resource corridors along the lower Columbia River will also be 

included in consultations affecting those resources. Local Tribes include the Confederated Tribes of 

the Grande Ronde, the Shoalwater Bay Tribe, the Confederated Tribes of Warm Springs, and the 

Yakama Tribe. Currently, the Service seeks assistance from Tribes on issues related to cultural 

resources education and interpretation, special programs, and the National Historic Preservation Act 

(NHPA).

Follow recommendations in the Pacific Flyway Management Plan for the Dusky Canada Goose 

(2008). The Pacific Flyway Council (PFC) prepares management plans for most populations of 

swans, geese, and sandhill cranes in the Pacific Flyway (www.pacificflyway.gov). These plans help 

state and Federal agencies cooperatively manage migratory game birds under common goals. The 

Pacific Flyway Management Plan for the Dusky Canada Goose identifies a set of goals and 

objectives to assist in maintaining the dusky Canada goose population within a range of 10,000 to 

20,000 (see Chapter 1). 

The Dusky Canada Goose Plan also identifies three action levels for increasingly intensive 

management efforts to benefit the population status of dusky Canada geese. These levels are 

designed to ensure that adequate time is taken for management actions to take effect, based on 

biological constraints, and the expected response times of dusky Canada geese to the proposed 

management actions. The action levels listed below are population based, and management 

procedures that relate to these levels are described in the Dusky Canada Goose Plan:
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

2-4 Chapter 2. Management Direction

• Action Level 1: 20,000-10,000 

• Action Level 2: 9,999-5,000 

• Action Level 3: below 5,000 

In 2009 the population fell below 10,000; Action Level 2 and appropriate management actions were 

initiated. In the event that Action Level 3 is reached, the agencies will initiate a thorough population 

risk assessment, review the conservation status of dusky geese, and reevaluate all feasible and 

practical intensive management options. 

As a cooperating wildlife agency (the Service) for the welfare and management of the dusky Canada 

goose population, refuge management actions for the benefit of duskys will adhere to the 

recommendations prescribed in the Pacific Flyway Management Plan for the Dusky Canada Goose. 

Management recommendations that will be implemented include:

• Maintaining existing pastures for goose browse: The present acreage of improved pasture 

will be maintained to provide forage for migrating and wintering geese. 

• Continuing to provide sanctuary areas for dusky Canada geese (sanctuary areas are defined 

as–areas closed to hunting and significant disturbance from other public uses, to provide 

resting and/or feeding areas for waterfowl during the hunting season); 

• Protecting dusky Canada geese, by prohibiting on-refuge goose hunting once the refuge’s 

annual dusky harvest quota (assigned by the State) has been reached (see Appendix B, 

Compatibility Determination-Waterfowl Hunting). 

Follow recommendations in the Pacific Flyway Management Plan for the Cackling Canada 

Goose (1999). Major objectives of the cackling goose plan are to achieve a population of 250,000 

cackling geese on breeding grounds. The plan targets a 5 to 10 percent average annual population 

increase toward the population objective (see Chapter 1). By the time the cackling goose plan was 

written, the population was approaching the restoration goal of 250,000. However, populations of 

cackling geese have declined over the past decade and at the present time are well below the 

restoration goal. As a result, providing both forage and sanctuary areas for cackling geese in Oregon 

and Washington is a priority for waterfowl managers. Management recommendations that will be 

implemented include:

• Maintaining existing pastures for goose browse: The present acreage of improved pasture 

will be maintained to provide forage for migrating and wintering cackling geese. 

• Continue to provide sanctuary areas for migrating and wintering cackling geese. 

• Protecting cackling geese by adhering to State bag limits (currently 2 birds with a 4 bird 

possession limit) and following the recommendations of the Pacific Flyway Management 

Plan for the Cackling Canada Goose (See Appendix B, Compatibility DeterminationWaterfowl Hunting). 

Follow recommendations in the Northwest Oregon/Southwest Washington Canada Goose 

Agricultural Depredation Plan (1998). The depredation plan addresses agricultural depredation 

caused by the large number of wintering Canada and cackling geese in the Willamette Valley-Lower 

Columbia River (WV-LCR) area. Public lands in the WV-LCR are to be managed to provide 

abundant, high quality goose forage, while reducing public use disturbances, to increase the number 

of geese on public lands, while subsequently decreasing the number of geese on private lands. 

Specifically, the Federal lands within the WV-LCR are to support the plan’s objectives to: 

• Increase the amount of Canada goose use on public lands, while subsequently decreasing the 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-5 

amount of Canada goose occurrence on private lands; 

• Review habitat management programs on refuges and wildlife areas to develop programs to 

increase and improve goose forage; and 

• Decrease disturbance to wintering Canada geese and increase goose use of public lands by 

implementing public use restrictions. 

Management recommendations that will be implemented include:

• Maintaining existing pastures for goose browse: The present acreage of improved pasture 

will be maintained to provide green forage for migrating and wintering geese and reduce 

depredation. 

• Maintain sanctuary areas for migrating and wintering geese.

Invasive Species Control. Because invasive plants and animals currently represent the greatest 

threat to the refuge’s wildlife and habitat, control of invasive species will be a high priority 

management activity. Invasive species such as ricefield bulrush, and State and County-listed noxious 

weeds, will continue to be a primary management concern. Nonnoxious weeds such as blackberry, 

reed canarygrass, and teasel, and introduced animals such as carp and nutria, also limit the refuge’s 

ability to provide high quality habitat for purposes and trust species, and will be controlled to the 

degree that funding permits. Invasive species control will be initiated prior to or concurrently with 

habitat restoration efforts. An Integrated Pest Management plan was developed concurrently with 

the CCP to address invasive species control on the refuge, and is included as Appendix K. 

Integrated Pest Management. In accordance with Department of the Interior and Service policy 

(517 DM 1 and 7 RM 14), an integrated pest management (IPM) approach will be utilized where 

practicable, to eradicate, control, or contain pest and invasive species (herein collectively referred to 

as pests) on the refuge. An IPM approach will involve using methods based upon effectiveness, cost, 

and minimal ecological disruption, which considers minimum potential effects to nontarget species 

and the refuge environment. Pesticides may be used where physical, cultural, and biological methods 

or combinations thereof, are impractical or incapable of providing adequate control, eradication, or 

containment. Furthermore, pesticides will be used primarily to supplement, rather than as a 

substitute for practical and effective control measures of other types. 

If a pesticide is needed on the refuge, the most specific (selective) chemical available for the target 

species will be used, unless considerations of persistence or other environmental and/or biotic 

hazards preclude it. In accordance with 517 DM 1, pesticide usage will be further restricted, because 

only pesticides registered with the Environmental Protection Agency (EPA), in full compliance with 

the Federal Insecticide, Fungicide, and Rodenticide Act, and as provided in regulations, orders, or 

permits issued by EPA, may be applied on lands and waters under refuge jurisdiction. 

Environmental harm by pest species will refer to a biologically substantial decrease in environmental 

quality as indicated by a variety of potential factors, including declines in native species populations 

or communities, degraded habitat quality or long-term habitat loss, and/or altered ecological 

processes. Environmental harm may result from direct effects to native species from pests, including 

preying and feeding on native species; causing or vectoring diseases; preventing natives from 

reproducing or killing their young; out-competing native species for food, nutrients, light, nest sites 

or other vital resources; or hybridizing with natives so frequently that within a few generations few if 

any truly native individuals remain. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

2-6 Chapter 2. Management Direction

In contrast, environmental harm can be the result of an indirect effect of pest species. For example, 

decreased waterfowl use may result from invasive plant infestations reducing the availability and/or 

abundance of native wetland plants that provide forage for native species during the winter. 

Environmental harm may also include detrimental changes in ecological processes. For example, 

reed canarygrass in bottomland ash forest can prevent recruitment of ash, and displace native sedges, 

grasses, forbs, and shrubs. 

See Appendix K for the refuge’s IPM program documentation to manage pests. Along with a more 

detailed discussion of IPM techniques, this documentation describes the selective use of pesticides 

for pest management on the refuge, where necessary. Throughout the life of the CCP, most proposed 

pesticide uses on the refuge will be evaluated for potential effects to refuge biological resources and 

environmental quality. These potential effects will be documented in Chemical Profiles (see 

Appendix K). Pesticide uses with appropriate and practical best management practices (BMPs) for 

habitat management as well as cropland/facilities maintenance will be approved for use on the refuge

where there likely will be only minor, temporary, and localized effects to species and environmental 

quality based upon non-exceedance of threshold values in Chemical Profiles. However, pesticides 

may be used on a refuge where substantial effects to species and the environment are possible 

(exceed threshold values) in order to protect human health and safety (e.g., mosquito-borne disease). 

Contingency plan for dike breach. Post Office Lake, on the Ridgeport Dairy Unit, is a 75-acre 

former tidal wetland that is now separated from the Columbia River by a dike. The dike is not 

owned by the Service, and is currently in poor condition. The dike is likely to fail during the next 

major flood event. A dike breach would re-establish the former tidal connection between the river 

and the lake. Post Office Lake would be allowed to re-establish a tidal connection to Columbia River 

through natural processes. The CCP includes the development of a contingency plan that will take 

effect in the event of a dike breach. Because the southern tip of the lake is outside the current refuge

boundary, a boundary expansion will need to be considered. This will be done as part of a larger 

land protection planning study for the Lower Columbia River area (see below). As part of this study, 

we will analyze alternatives for possibly expanding the refuge’s boundary to include the southern 

portion of Post Office Lake and adjoining areas. 

Participation in Lower Columbia River Land Protection Planning. Within 2 years of CCP 

completion we will initiate and complete a Land Protection Planning effort within the Lower 

Columbia River area (Bonneville Dam to the mouth of the Columbia) in cooperation with other 

refuges, agencies, and interested parties to assess and identify land conservation priorities. Potential 

additions or expansion of the refuges within this focus area, including Ridgefield NWR, and 

examination of various land protection tools will be explored. Land Protection as part of the NWRS 

may include fee title acquisition, conservation easements and cooperative agreements. 

Nature center and pedestrian bridge to the Carty Unit. The refuge has prepared a separate 

Environmental Assessment (EA) for the construction and operation of an administrative site, 

including staff offices, a nature center, and a pedestrian bridge to replace the existing office and 

bridge at the Carty Unit (see Chapter 1, Issues Outside the Scope of the CCP). The EA was prepared

in a separate planning effort to meet potential funding timelines. The Draft EA was released for 

public review on March 23, 2010, and the public comment period closed on April 26, 2010. A 

Finding of No Significant Impact was issued on April 29, 2010. Because the refuge has had an 

ongoing need for staff offices and visitor facilities, seeking funding for the construction of these 

facilities is part of the CCP. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-7 

Cultural resource protection and Section 106 compliance. Actions with the potential to affect 

cultural resources will undergo a thorough review before being implemented, as is consistent with the 

requirements of cultural resource laws. All ground-disturbing projects will undergo a review under 

Section 106 of the National Historic Preservation Act. 

Emphasis on wildlife-dependent public uses. With its close proximity to the cities of Portland and 

Vancouver, and as the surrounding area is developed, Ridgefield Refuge has become an increasingly 

“urban” refuge. Refuge visitation has increased 8-fold since the 1980s when approximately 22,000 

people visited the refuge annually. The average annual visitation from 2000 to 2007 has been over 

162,000 visitors. Most of this increase has been in visitation for nonconsumptive uses (wildlife 

observation and photography). There is also considerable demand for environmental education 

programs from local schools. Because of its proximity to a large urban area, the potential for the 

refuge to connect urban dwellers to nature—and thereby build support for the Refuge System 

mission—is high. Therefore, providing wildlife dependent public uses is a high priority. 

Maintain waterfowl hunting opportunities. Because providing waterfowl hunting opportunities is 

one of the refuge’s establishing purposes and when compatible, is considered a priority public use on 

National Wildlife Refuges, and because demand for waterfowl hunting on the refuge has remained 

constant over the past 40 years despite declining trends elsewhere in the region, the refuge will 

continue to provide, at a minimum, the same hunting opportunities as it currently does. Location of 

hunt areas and blinds may be adjusted based on habitat conditions or safety concerns. 

Monitor effects of public use programs on wildlife. Monitoring to assess the effects of public use 

on wildlife will be conducted. Area, timing, and/or conduct of public use will be modified if 

disturbance to wildlife or habitat degradation reaches unacceptable levels. 

Maintenance and updating of existing facilities. Periodic maintenance and updating of refuge

buildings and facilities will be necessary. Periodic updating of facilities is necessary for safety and 

accessibility, reducing the refuge’s carbon footprint, and to support staff and management needs; and 

is incorporated in the Service Asset Management System.

Reduce the refuge’s carbon footprint. The Service has developed a Strategic Plan for Responding 

to Accelerating Climate Change in the 21st Century (2009), and a 5 year Action Plan outlining 

specific actions needed to implement the Strategic Plan. The Action Plan calls for the Service to 

make its operations carbon-neutral by 2020. The refuge will work toward this goal by replacing its 

current vehicles with more fuel efficient vehicles, and by building appropriately sized, energy 

efficient facilities, as funding becomes available. The refuge will also reduce the carbon footprint of 

land management activities by using energy-efficient techniques, where feasible and in line with

management goals. The refuge will also explore ways of offsetting any remaining carbon balance, 

such as carbon sequestration. 

Management of minor recreational uses. Minor recreational activities are occasionally pursued on 

the refuge. Such recreational activities not specifically addressed in this document may be allowed 

on refuge lands if the Refuge Manager first finds that they are appropriate and compatible. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

2-8 Chapter 2. Management Direction

Participation in planning and review of regional development activities. The Service will 

actively participate in planning and studies pertaining to future industrial and urban development, 

transportation, recreation, contamination, and other potential concerns that may affect refuge

resources. The Service will continue to cultivate working relationships with county, State, and 

Federal agencies to stay abreast of current and potential developments; and will utilize outreach and 

education as needed to raise awareness of refuge resources and dependence on the local environment. 

Volunteer opportunities and partnerships. Volunteer opportunities and partnerships are key 

components of the successful management of public lands, and are vital to refuge programs, plans, 

and projects, especially in times of static or declining budgets. Currently the refuge makes extensive 

use of volunteers in invasive species control, habitat restoration, and public use programs. In the 

future, successful implementation of native habitat restoration, survey and monitoring activities, and 

environmental education and interpretation programs will require the use of partnerships and 

volunteers. 

Wilderness review. The Service’s CCP policy requires that a wilderness review be completed for 

all CCPs. If it is determined that the potential for wilderness designation is found, the process moves 

on to the wilderness study phase. As part of the process for this CCP, the planning team completed a 

wilderness review which can be found in Appendix E. This review concluded that the refuge is not 

suitable for wilderness designation. 

2.3.2 Summary of Management Direction

A brief description of the management direction follows. Maps displaying the management direction

for the refuge follow this description. Maps 4 through 7 display the targets for habitat management 

over the next 15 years, while map 8 displays public use facilities that will be maintained or 

developed over the next 15 years. 

Wildlife and Habitat. The refuge will continue to protect, maintain, and where feasible, restore 

habitat for priority species, including dusky Canada geese, other waterfowl, and Federal and State 

listed species. Sanctuary area (area closed to public use) will remain the same as current 

management practices (see Public Use and Access). 

Winter browse (managed pasture) for Canada and cackling geese will be maintained. The refuge will

provide overwintering and migrating waterfowl with high quality, easily accessible food, by 

maintaining high quality green forage in improved pastures and wet meadows, promoting the growth 

of food plants in shallow wetlands, and planting crops to supplement natural food production. 

Management actions to increase forage quality for dusky Canada geese in their primary-use foraging 

habitats receive the highest priority. Approximately 150 acres of old fields are converted to managed 

pasture and wet meadow to benefit geese. There is an increase in acres managed as cropland (from 

the current range of 155-185 acres, to a range of 290-330 acres, including interseeded small grains 

and corn). These management actions are also expected to benefit sandhill cranes. 

Wetlands will be maintained, but management will be enhanced to increase productivity. Managed 

wetlands will undergo rotation to manage vegetation and control invasive species. Where water 

control capabilities exist, seasonal wetlands will be managed as moist soil units to promote growth of 

native food plants for waterfowl. Incremental floodup of seasonal wetlands through the fall and 

winter will reduce pumping costs, and improve the availability of food for waterfowl. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-9 

Invasive species and State and county-listed noxious weeds continue to be a primary management 

concern. Treatment will focus on existing populations; however, annual priorities for control may 

change, depending on the extent of current species coverage and the occurrence of new species. 

The refuge will increase management to enhance or where feasible, restore native habitats of the 

lower Columbia River where this does not conflict with management for purposes and trust species. 

Enhancing and restoring riparian/bottomland forest and oak woodland receive greater emphasis than 

under current management practice. Invasive species monitoring and control in forest and oak 

woodland habitats increases. Approximately 160 acres of bottomland forest, 20 acres of oak 

woodland, and 5 acres of ash forest will be restored over the lifetime of the CCP, mostly on areas 

currently in old fields. Restoration projects emphasize habitat connectivity (creating larger blocks of 

contiguous habitat). A tidal wetlands restoration plan, and habitat assessments of Gee Creek, 

Campbell Slough, and Campbell Lake, will be completed to guide future restoration of instream and 

tidally influenced habitats. 

The refuge will contribute to the recovery of threatened, endangered, or rare species of the lower 

Columbia River and the Willamette Valley-Puget Trough ecoregion. Feasibility studies for the 

reintroduction of native species such as Columbian white-tailed deer and western pond turtle will be

conducted. Working with partners, the refuge will increase inventory and monitoring efforts and 

address pressing research needs, for example: inventory and monitoring of waterfowl populations 

and habitat conditions; habitat assessments of woodland, grassland, and aquatic habitats; and baseline 

inventories of small mammals, reptiles, and amphibians, and other species groups that have been 

studied very little to date. 

Public Use and Access. The River ‘S’ and Carty units will be open to public use year-round. 

Current wildlife sanctuary areas (areas closed to public use) will be maintained. The Roth, Ridgeport 

Dairy, and Bachelor Island units will remain closed to public use. A new access point to the River 

‘S’ Unit will be developed (a 2-lane bridge originating from the Port of Ridgefield property). The 

existing bridge to the River ‘S’ Unit will be removed and the easement abandoned. The waterfowl 

hunt area/location will remain the same as in current management practice (790 acres, River ‘S’

Unit). The hunter check station will be moved to the current entrance; Teal Marsh will be

rehabilitated, and 1 or 2 new blinds will be established on the west side of the River ‘S’ Unit to 

compensate for losing blind 4 (lost to new bridge construction). Changes in flooding regime will be 

expected to benefit food plants used by waterfowl; therefore, the hunt program will improve over 

time. The location of hunting blinds will be adjusted where necessary due to the change in flooding 

regime. 

The existing auto tour route will remain in its current location, and be open year-round; however, the 

length will be reduced from 4.3 to 4.0 miles by cutting off a small loop at the southeast corner to 

provide contiguous habitat area for dusky Canada geese and cranes. Walking dates on the River ‘S’ 

Unit will remain the same as current (May 1-Sept 30). A new 1.5- mile (one way) dike-top walking 

trail and overlook will be constructed on the north end of the River ‘S’ Unit. Environmental 

education programs will increase from 2,000-3,000 students served annually to 4,500. Cultural 

resources education and interpretation programs will increase.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

2-10 Chapter 2. Management Direction

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Ba

c

helor

Island Slough

L

a

ke Ri

ver

River S Unit

Roth Unit

Bachelor Island

Unit

Carty

Unit

122°45'0"W

122°45'0"W

PRODUCED IN THE DIVISION OF REALTY & REFUGE INFORMATION

PORTLAND, OREGON

DATA CURRENT TO: 03/09/09

MAP DATE: 08/19/10

BASEMAP: 2009 NAIP

MERIDIAN: WILLAMETTE

FILE: 10-178-1.MXD UTM ZONE 10

NAD 83 0 0.25 0.5 1

Kilom eters

0 0.25 0.5 1

Miles

T 4 N T 4 N

R 1 W R 1 E

R 1 W R 1 E

C

o

l

u

m

b

i

a

R

i

v

e

r

Legend

Future wetlands and habitat conditions

FWS Approved Acquisition Boundary

Early successional floodplain forest

Improved pasture - Duskys

Improved pasture - other geese

Old field

Managed seasonal wetlands

Managed semipermanent wetlands

Permanent non-tidal wetlands

Wet meadow

Mid-late successional floodplain forest

Ash floodplain forest

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Map 4 Future Management, Wetlands and Habitat for the River 'S' Unit

__________________________________________________________________________________________________ Ridgefield National Wildlife Refuge Comprehensive Conservation Plan ___________________________________________________________________________________________________ 

Chapter 2. Management Direction 2-11
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

2-12 Chapter 2. Management Direction

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Ba

chelor Island Slough

River S Unit

Bachelor Island

Unit

Carty Unit

122°45'0"W

122°45'0"W

45°50'0"N 45°50'0"N

PRODUCED IN THE DIVISION OF REALTY & REFUGE INFORMATION

PORTLAND, OREGON

DATA CURRENT TO: 03/09/09

MAP DATE: 08/19/10

BASEMAP: 2009 NAIP

MERIDIAN: WILLAMETTE

FILE: 10-178-2.MXD

Map 5 Future Management, Wetlands and Habitat for the Bachelor Island Unit

UTM ZONE 10

NAD 83 0 0.25 0.5 1

Kilom eters

0 0.25 0.5 1

Miles

T 4 N T 4 N

R 1 W

R 1 W

C

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Legend

Future wetlands and habitat conditions

FWS Approved Acquisition Boundary

Early successional floodplain forest

Improved pasture - other geese

Old field

Native grasses

Managed semipermanent wetlands

Nonmanaged seasonal wetlands

Permanent non-tidal wetlands

Permanent tidal wetlands

Wet meadow

Mid-late successional floodplain forest

Lands Not Managed by FWS

! ! ! !

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___________________________________________________________________________________________________ Ridgefield National Wildlife Refuge Comprehensive Conservation Plan __________________________________________________________________________________________________ 

Chapter 2. Management Direction 2-13
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

2-14 Chapter 2. Management Direction

To preserve the quality of our map, this side was left blank intentionally.
Bach

elor Isla

n

d

S

ol ugh

River S

Unit

Bachelor Island

Unit

Carty Unit

122°45'0"W

122°45'0"W

45°50'0"N 45°50'0"N

PRODUCED IN THE DIVISION OF REALTY & REFUGE INFORMATION

PORTLAND, OREGON

DATA CURRENT TO: 03/09/09

MAP DATE: 08/19/10

BASEMAP: 2009 NAIP

MERIDIAN: WILLAMETTE

FILE: 10-178-3.MXD

Map 6 Future Management, Wetlands and Habitat for the Carty Unit

UTM ZONE 10

NAD 83 0 0.25 0.5 1

Kilom eters

0 0.25 0.5 1

Miles

T 4 N T 4 N

R 1 W

R 1 W

C

o l u

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b i a

R i v e r

Legend

Future wetlands and habitat conditions

FWS Approved Acquisition Boundary

Early successional floodplain forest

Improved pasture - other geese

Native grasses

Nonmanaged seasonal wetlands

Permanent non-tidal wetlands

Permanent tidal wetlands

Oak woodland

Mid-late successional floodplain forest

Ash floodplain forest

Mixed conifer forest

Lands Not Managed by FWS

__________________________________________________________________________________________________ Ridgefield National Wildlife Refuge Comprehensive Conservation Plan ___________________________________________________________________________________________________ 

Chapter 2. Management Direction 2-15
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

2-16 Chapter 2. Management Direction

To preserve the quality of our map, this side was left blank intentionally.
Lake River

River S Unit

Roth Unit

Ridgeport

Dairy

Unit

122°45'0"W

122°45'0"W

45°45'0"N 45°45'0"N

PRODUCED IN THE DIVISION OF REALTY & REFUGE INFORMATION

PORTLAND, OREGON

DATA CURRENT TO: 03/09/09

MAP DATE: 08/19/10

BASEMAP: 2009 NAIP

MERIDIAN: WILLAMETTE

FILE: 10-178-4.MXD

UTM ZONE 10

NAD 83 0 0.25 0.5 1

Kilom eters

0 0.25 0.5 1

Miles

T 4 N

T 3 N

T 4 N

T 3 N

R 1 W R 1 E

R 1 W R 1 E

C

o

l

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R

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v

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Legend

Future wetlands and habitat conditions

FWS Approved Acquisition Boundary

Early successional floodplain forest

Improved pasture - Duskys

Improved pasture - other geese

Old field

Permanent tidal wetlands

Wet meadow

Mid-late successional floodplain forest

Ash floodplain forest

Lands Not Managed by FWS

Map 7 Future Management, Wetlands and Habitat for the Roth and Ridgeport Dairy Units

___________________________________________________________________________________________________ Ridgefield National Wildlife Refuge Comprehensive Conservation Plan ___________________________________________________________________________________________________ 

Chapter 2. Management Direction 2-17
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

2-18 Chapter 2. Management Direction

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Ba

chelor

Island Slough

L

a

ke

River

New access

point/bridge

Remove

existing

bridge

Ridgefield

(WA)

SR501 - Pioneer Street N. Main Street

S. Hillhurst Road

River 'S' Unit

Roth Unit

Bachelor Island

Unit

Carty

Unit

122°45'0"W

122°45'0"W

PRODUCED IN THE DIVISION OF REALTY & REFUGE INFORMATION

PORTLAND, OREGON

DATA CURRENT TO: 04/29/09

MAP DATE: 08/19/10

BASEMAP: 2009 NAIP

MERIDIAN: WILLAMETTE

FILE: 10-178-5.MXD

UTM ZONE 10

NAD 83

0 0.25 0.5 1

Kilom eters

0 0.25 0.5 1

Miles

T 4 N T 4 N

R 1 W R 1 E

R 1 W R 1 E

Map 8 Future Public Use for the River 'S' Unit

Legend

FWS Approved Acquisition Boundary

Auto Tour Route (Open Year Round)

Kiwa Trail (May 1 - Sept.30)

Walking Trail (May 1 - Sept.30)

Waterfowl Hunting Area

Lands Not Managed by FWS

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__________________________________________________________________________________________________ Ridgefield National Wildlife Refuge Comprehensive Conservation Plan __________________________________________________________________________________________________ 

Chapter 2. Management Direction 2-19
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

2-20 Chapter 2. Management Direction

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Table 2.1 Summary of Management Direction 

Issue

Management Direction

How will the refuge maintain 

and manage wildlife habitat? 

What is the appropriate 

balance of managed habitat 

(e.g. pastures, managed 

wetlands) to native habitat? 

• Maintain existing acreage of wetlands (1,700 acres); slight increase in managed pastures (1,525 acres) to 

benefit dusky Canada geese and other migrating/over-wintering waterfowl.

• Maintain existing floodplain/riparian forest, oak woodland, and mixed conifer habitat (1,150 acres), and 

restore an additional 160-185 acres, over 15 years.

• Over the lifetime of the CCP, convert 265-280 acres of old fields to other habitat types: 90 acres to wet 

meadow, 65 acres to improved pasture, 85-100 acres to floodplain/riparian forest (willow/cottonwood), 20 

acres to oak woodland, and 5 acres to ash forest. 

• Increase cropland to 290-330 acres to benefit waterfowl, and sandhill cranes. 

• Manage wetlands using drawdowns, disking, mowing, and water level manipulation to improve 

productivity, manage vegetation, and control undesirable plants. 

• Increase monitoring to determine efficacy of habitat management, need for additional treatments, and 

document wildlife response. 

• Hire additional staff to expand volunteer program and partnerships (needed to meet research, monitoring 

and invasive species control goals).

How will the refuge maintain 

and restore native habitats of 

the lower Columbia River?

• Maintain/enhance existing floodplain/riparian forest and oak woodland. Allow natural succession of 

floodplain forest to continue in select wetland basins. 

• Restore 165-190 acres of floodplain/riparian forest habitat over lifetime of CCP. 

• Restore 20 acres of oak woodland over lifetime of CCP.

• Increase efforts to maintain and enhance floodplain/riparian forest habitat.

• Investigate techniques to enhance recruitment of ash and cottonwood in older, even-aged stands. 

• Conduct habitat assessments and baseline inventories of native fish, wildlife and vegetation to guide future 

management actions.

• Pursue burning permit to manage/restore oak woodland habitat. 

• Study feasibility of restoring native wet meadow and grassland. 

• Allow Post Office Lake to re-establish tidal connection to Columbia River through natural processes.

• Restore tidal connection to Duck Lake.

• Tidal wetland restoration plan and feasibility studies (see Instream Habitat).

How will the refuge control 

invasive species and prevent 

new invasives from becoming 

established?

• Increase monitoring of all habitat types for invasive species, efficacy of treatment, and need for additional 

treatment

• Conduct studies to investigate control techniques for ricefield bulrush, reed canarygrass, carp, and nutria.

• Increase application of wetland management techniques (flooding, drying, disking) to reduce reed 

canarygrass; resume these control methods in areas where ricefield bulrush has been controlled.
Issue

Management Direction

• Annual invasives monitoring and control on up to 115 acres (approx 10%) of floodplain/riparian forest, oak 

woodlands, and upland mixed forest.

How will the refuge assist in 

recovery of endangered and 

threatened native species of 

the lower Columbia River 

ecosystem?

• Continue monitoring ponds containing water howellia. 

• Continue partnerships to conduct test plantings of Bradshaw’s lomatium, and Nelson’s checkermallow.

• Conduct feasibility studies for reintroducing Columbian white-tailed deer (within 5 years); and western 

pond turtle. 

• Conduct baseline surveys to establish presence/absence of rare plants and animals.

How will the refuge address 

climate change impacts, and 

increasing development on 

surrounding lands? 

• Acquire land within existing acquisition boundary from willing sellers if funding is available.

• Use green building technology in new construction. 

• Increase habitat connectivity by: 

- Restoring riparian habitat to link existing blocks of habitat. 

- Initiating a land protection plan study, to analyze alternatives for potentially expanding the refuge boundary to 

include a portion of Post Office Lake and adjoining areas south of the current boundary. 

• Monitor changes in migration patterns; monitor climate-sensitive species (e.g. salmonids) and their key 

habitat parameters (e.g. stream temperature).

• Assist in local/regional planning efforts for facilities that link the refuge to regional walking/bicycling 

trails, and mass transit.

• Develop partnerships/incentives to decrease emissions from auto tour route.

• Incorporate climate change messages into communications, interpretation, and environmental education. 

How will the refuge improve 

instream habitat and tidal 

wetland conditions for native 

fish?

• Continue Gee Creek watershed partnerships.

• Conduct riparian plantings along 0.8 miles of Gee Creek. 

• Prepare a dike breach contingency plan for Post Office Lake. 

• Conduct riparian plantings along 0.8-1.25 miles of Gee Creek.

• Conduct habitat assessments on Gee Creek, Campbell Slough, and Campbell Lake to guide future 

restoration. 

• Develop a tidal wetlands restoration plan. 

• Initiate a land protection plan study to analyze alternatives for possible refuge boundary expansion to 

include a portion of Post Office Lake.

How will the refuge address 

the impacts of increasing 

visitation on wildlife, and 

minimize impacts to purposes 

species?

• Public use footprint and sanctuary area remains same as present.

• Hunt area remains at 790 acres in current location. 

• Auto tour route remains in current location; open year-round; with length reduced from 4.3-4 miles by 

removing the south end loop to provide contiguous habitat for duskys and sandhill cranes.

• Retain closure of Roth, Bachelor Island, and Ridgeport Dairy units to public use, except for guided tours.
Issue

Management Direction

• River ‘S’ Unit closed to walking Oct 1-April 30.

• Refuge closed to bicycling, dog walking, and horseback riding. Monitor wildlife response to public use; 

change timing/location of use if unacceptable levels of disturbance occur..

H ow will the r efuge pr ovide 

safe, accessible, high quality 

wildlife-dependent r ecr eation 

in the futur e?

Visitor access (River ‘S’ Unit)

• Develop a new access point to the River ‘S’ Unit from Port of Ridgefield property with new 2-lane bridge 

to eliminate in-grade railroad crossing; and new 1-mile entrance road

• Abandon existing entrance road and easement to River ‘S’ Unit; and demolish existing bridge. 

Visitor facilities, access (Carty 

Unit)

• Construct new nature center, including environment education classrooms (covered under separate EA)

• Replace footbridge to Carty Unit with ADA accessible structure (covered under separate EA).

• Create walking and limited (emergency) vehicle access to Carty Unit from Port site, with small bridge over 

Gee Creek.

Trails • Maintain existing walking trails (Oaks to Wetlands, Kiwa); River ‘S’ Unit open to walking May 1- Sept 30; 

and Carty Unit open year-round. 

• Develop new 1.5-mile dike-top walking trail, running north to an overlook and south to existing River ‘S’ 

bridge, open May 1-Sep 30 (see maps).

• Implement measures to reduce congestion on auto tour route at peak times and encourage use of walking 

trails (e.g., provide pedestrian access to refuge walking trails from Ridgefield)

Environmental education (EE) • Expand EE program to serve 4,500 students annually.

• Hire full time EE coordinator; and develop curricula and refuge-specific instructor training.

• Offer 1-2 annual training sessions to prepare teachers to instruct all/portions of their educational visits

• Recruit and train volunteer instructors (with an emphasis on retired educators) to lead EE activities; 

maintain 30 trained volunteer instructors. 

• Explore options to partner with the Ridgefield School District to integrate the refuge’s EE programming 

into the District’s curriculum.

• Provide EE shelter and study sites on Carty Unit; and EE classrooms as part of new nature center (pending 

separate EA and funding).

How will the refuge improve 

the quality of its waterfowl 

hunt, while minimizing 

impacts to dusky Canada 

geese?

• 790-acre hunt area/ location remain the same as present.

• Move hunter check station to current entrance; rehabilitate Teal Marsh; and establish 1-2 new blinds on 

west side of River ‘S’ Unit to compensate for loss of blind 4 (lost to new bridge construction)

• Staged floodup of hunt areas to provide more shallow-water habitat (not all wetlands will have water early 

in season; reduces pumping needs late in season).

• Provide alternate early/late season hunt blinds, and/or movable blinds.
Issue

Management Direction

• Wetland rotation to improve productivity and habitat conditions for waterfowl.

How will the refuge protect its 

cultural resources and 

educate the public about 

them?

• Explore grant to hire full time plankhouse coordinator; within 7 years have plankhouse staffed at least 4 

hours/day on weekends and as needed for EE groups. 

• Provide at least 2 cultural events (open to general public) at Cathlapotle Plankhouse annually. 

• Develop interior interpretive plan and quality standards for artifact replicas used in plankhouse. 

• Develop EE program tailored to the Plankhouse. 

• Hold semiannual meetings with affected Tribes; and establish protocol for consultation.

• Pursue funding to provide secure artifact storage and curation on the refuge.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-25

2.4 Goals, Objectives, and Strategies

Goals and objectives are the unifying elements of successful refuge management. They identify and 

focus management priorities, resolve issues, and link to refuge purposes, Service policy, and the 

Refuge System mission.

A CCP describes management actions that help bring a refuge closer to its vision. A vision broadly 

reflects the refuge purposes, the Refuge System mission and goals, other statutory requirements, and 

larger-scale plans as appropriate. Goals then define general targets in support of the vision, followed 

by objectives that direct effort into incremental and measurable steps toward achieving those goals. 

Strategies identify specific tools and actions to accomplish objectives (USDI 2002). 

The goals for Ridgefield Refuge for the 15 years following completion of the CCP are presented on 

the following pages, in tables. Each goal is followed by the objectives that pertain to that goal. 

Some objectives pertain to multiple goals and have simply been placed in the most reasonable spot. 

Similarly, some strategies pertain to multiple objectives.

The goal order does not imply any priority in this CCP. Priority actions are identified in the staffing 

and funding analysis (Appendix D). 

Readers, please note the following:

Below each objective statement are the strategies that could be employed in order to accomplish the 

objectives. Symbols used in the following tables include: 

 % percent sign 

> greater than

< less than

 > greater than or equal to 

 < less than or equal to 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

2-26 Chapter 2. Management Direction

2.4.1 Goal 1: Provide and manage a mixture of secure, diverse, productive 

grassland habitats for foraging migratory waterfowl and grassland-dependent 

wildlife. 

Objective 1.1 Enhance/Maintain Improved Pasture for Dusky Canada Geese

Enhance and annually maintain 340 acres of improved pasture in core dusky Canada goose use 

areas, with the following attributes:

• Field size range from 2 to 45 acres with a minimum predator-detection width of 250 feet. 

• Field (or portion of field) should be adjacent to accessible wetland* (within 400 ft) or consist of 

hydric soils.

• Short vegetation along the field/wetland interface. 

• Mix of desirable, palatable grasses* (e.g., perennial ryegrass, orchardgrass, fescues) and forbs 

(e.g., clover) with a height of < 4 inches by October 15. 

• < 20% cover of invasive species (e.g., Canada thistle, buckhorn plantain, tansy ragwort, teasel).

• No encroaching woody vegetation (e.g., blackberry). 

• No false indigo and poison hemlock. 

• Minimal thatch.*

• Minimal human disturbance when duskys are present (October 1 to April 1) limited to necessary 

management activities. 

*Definitions

Accessible wetland: Wetland without fences or vegetative barriers (tall, dense vegetation) at its margins. 

: 

Palatable grasses: Short, actively growing grass preferred as forage by geese. 

Thatch: The dense covering of cut grass that remains after mowing.

Strategies Applied to Achieve Objective

Mow and/or hay pastures after July 15, unless surveys indicate a specific pasture is not being used by 

nesting grassland birds.

Mow after July 15, as needed, to maintain grass palatability and minimal thatch and provide < 4 inch 

height by October 15.

Graze (domestic animals) between May 1and October 1 (after geese have migrated and as field 

conditions allow) to maintain grass palatability, minimal thatch, and provide < 4 inch height by October 

15. Grazing will only occur in areas where refuge staff has determined that significant impacts to 

grassland nesting birds will not occur. 

Hay from July 15-September 30 (as conditions allow) to maintain grass palatability, minimal thatch, and 

provide < 4 inch height by October 15.

Use agricultural practices (e.g., seeding, disking, planting cover crops, fertilizing, soil amendments, and 

herbicides) to rehabilitate pastures that do not meet the objective.

Use prescribed fire during late summer to eliminate thatch, invasive plants, and rank grasses (contingent 

upon receiving Southwest Washington Clean Air permit).

Use IPM strategies including mechanical, biological, and chemical means to eradicate, control, or contain 

invasive plants (see Appendix K, IPM Program).

Continue to cooperate with the County Weed Board to control county-listed invasive weeds.

Control weeds in accordance with the refuge’s IPM program using methods such as crop rotation, 

mechanical treatment, biological controls, and low toxicity approved pesticides (see Appendix K).

Pesticide use must be in compliance with the Service’s policy requirements for completing an approved 

Pesticide Use Proposal, and must meet other State and Federal requirements.

Cooperators that conduct haying, mowing, or grazing on the refuge will only apply herbicides with prior 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-27

refuge approval and will provide a record of herbicides used including chemical name, amount used, 

date, location, and how applied.

Pursuant to the refuge’s CLMA, cooperators will provide annual records of animals grazed on and plant 

products removed from the refuge.

Rationale: The refuge was established to protect and provide wintering habitat for the dusky Canada 

goose, a subspecies that winters primarily in the Willamette Valley of Washington and Oregon. The 

dusky Canada goose has experienced substantial declines over the past several decades. While once the 

predominant goose in the Willamette Valley, dusky Canada geese now comprise > 5% of the overall 

goose population in its Washington winter range. Population declines coupled with loss of breeding and 

wintering habitat, has elevated this subspecies to one of management emphasis by the Federal and state 

governments (Bromley and Rothe 2003, PFC 2008), therefore, they continue to be the primary 

management focus for the refuge.

While many Canada and cackling geese are readily adaptable to foraging in large open agricultural fields 

and croplands, dusky Canada geese in the northern Willamette Valley continue to utilize more natural 

habitats reminiscent of the historic Columbia River floodplain. These habitats include small wet 

meadows and upland grasslands, shorelines and seasonal wetlands, frequently interspersed among 

riparian bottomland forest. Despite the substantial alterations to the Willamette Valley landscape, dusky 

Canada geese continue to prove relatively traditional in their habits, their habitat use, and their preference 

for maintaining relatively small flock associations. These behaviors and preferences negate the ability to 

manage goose habitats similarly for the eight species and subspecies of geese utilizing the refuge. Due to 

the dusky Canada goose’s penchant for using traditional sites, many portions of the refuge with 

seemingly suitable habitats are under-utilized. This traditionalism has, however, allowed staff to identify 

preferred sites through surveys, and focus management on these core use areas. Under the CCP, the 

Service will increase management of improved pasture in core dusky areas to improve quality of green 

browse. Wet meadows are also an important foraging habitat for duskys (see Objective 3.6).

Minimizing disturbance in core dusky foraging areas is also a high priority. The most recent update of the 

Pacific Flyway Management Plan for the Dusky Canada Goose (2008) proposes that the Service, WDFW, 

and ODFW “Develop new public land management guidelines that result in increased goose food 

production and reduced disturbance of geese during winter, especially for dusky geese.” The CCP

proposes removing a portion of the auto tour route along the south side of Rest Lake on the River ‘S’ Unit, 

reducing disturbance from vehicles, and creating a larger contiguous sanctuary area for duskys. 

Young grass and forb shoots are preferred forage of Canada and cackling geese. We use management 

tools (grazing, mowing and haying) in combination to achieve the maximum cover of short, actively 

growing grass, where appropriate and feasible based on soil condition and other factors. Pastures in need 

of rehabilitation may be planted with cover crops to break weed cycles (winter wheat, clover, or alfalfa). 

This treatment will count toward total crop acreage planted (see Objective 2.1). 

Meeting the habitat quality objectives for pastures (< 20% weed cover, height < 4 inches, and minimal 

thatch) will ensure that the refuge provides high quality goose habitat. The refuge staff assesses fields at 

the beginning of the growing season and several times during the summer to determine whether these 

objectives are being met and treating those fields where the objectives are not being met. For example, 

thatch inhibits growth of new grass and also inhibits goose foraging. Mowing treatments must either be 

frequent to minimize thatch, or if less frequent (e.g. once a year) include a means of thatch removal (e.g., 

raking, mulching, burning.) Haying and grazing preferred to mowing, where feasible, as these treatments 

eliminate thatch. A field with >20% thatch cover and visible windrows of thatch would be treated by 

grazing, haying, or prescribed fire depending on the field. The specific treatment would depend on site 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

2-28 Chapter 2. Management Direction

conditions; a field that is not fenced or not near a water supply would likely be hayed instead of grazed. 

Prescribed fire would only be used where it can be accomplished safely, and will require approval from 

the Southwest Washington Clean Air Agency.

Objective 1.2 Enhance/Maintain Improved Pasture for Other Canada Geese and Waterfowl

Enhance and annually maintain 1,100 acres of improved pasture for other subspecies of Canada 

geese, cackling geese, American wigeon, and other migratory birds with the following attributes:

• Field size of >35 acres with a minimum predator-detection width of 450 feet 

• Short vegetation along the field/wetland interface 

• Mix of desirable, palatable grasses (e.g., perennial ryegrass, orchard grass, fescues) and forbs (e.g., 

clover) with a height of <4 inches by October 15 

• <20% cover of invasive species (e.g., Canada thistle, buckhorn plantain, tansy ragwort, teasel) 

• No encroaching woody vegetation (e.g., blackberry) 

• No false indigo and poison hemlock 

• Minimal thatch

• Minimal human disturbance in areas closed to public use (limit to necessary management 

activities from Oct 1 to May 1)

• Limit human disturbance areas open to public use

Strategies Applied to Achieve Objective

Mowing and haying will only occur after July 15, unless surveys indicate that the specific pasture is not 

being used by nesting grassland birds.

Mow after July 15, as needed, to maintain grass palatability and minimal thatch and provide <4 inch 

height by Oct 15.

Graze (e.g., domestic animals) between May 1and October 1 (after geese have migrated and as field 

conditions allow) to maintain grass palatability and minimal thatch and provide <4 inch height by Oct 15. 

Grazing will only occur only in areas where refuge staff has determined that significant impacts to 

grassland nesting birds will not occur. 

Hay from July 15 to Sept 30 (as conditions allow) to maintain grass palatability and minimal thatch and 

provide < 4 inch height by Oct. 15.

Use agricultural practices (e.g., seeding, disking, planting cover crops, fertilizing, soil amendments, 

herbicides) to rehabilitate pastures that do not meet the habitat objective. 

Use prescribed fire during late summer to eliminate thatch, invasive plants, and rank grasses (Contingent 

upon receiving permit with Southwest Washington Clean Air).

Maintain the between-field contiguity of grasslands and croplands by minimizing new visual barriers 

such as tall shrubs and trees, where appropriate.

Use IPM strategies including mechanical, biological, and chemical means to eradicate, control, or contain 

invasive plants (see Appendix K, IPM Program)

Continue to cooperate with the County Weed Board to control county-listed invasive weeds.

Control weeds in accordance with the refuge’s IPM program using methods such as crop rotation, 

mechanical treatment, biological controls, and low toxicity approved pesticides (see Appendix K-IPM 

Program).

Pesticide use must be in compliance with the Service policy requirements for completing an approved 

Pesticide Use Proposal, and must meet other State and Federal requirements.

Cooperators that conduct haying, mowing, or grazing on the Refuge will only apply herbicides with prior 

refuge approval and will provide a record of herbicides used including chemical name, amount used, 

date, location, and how applied.

Pursuant to the refuge’s CLMA, Cooperators will provide an annual record of animals grazed on, and 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-29

plant products removed from, the Refuge.

In portions of fields where Nelson’s checkermallow was planted, grazing will not be permitted, mowing 

will only occur after checkermallow plants have entered senescence.

Rationale: Although Ridgefield NWR was initially established with a focus on management of habitat for 

dusky Canada geese, management for all waterfowl and their habitats is also a priority. At establishment 

in 1965, dusky Canada geese were the primary subspecies of goose wintering in the area. Since then, 

other species and subspecies of geese, namely cackling geese, and Taverner’s and lesser Canada geese, 

have re-distributed their population region-wide and now comprise over 90% of the overall wintering 

goose population on Ridgefield NWR. Cackling geese are now a subspecies of management concern since 

the wintering population has shifted north from California to the Willamette Valley and SW Washington. 

Although the population has increased dramatically since 1984, when less than 26,000 birds were counted 

in California and Oregon, numbers are still below the flyway population objective of 250,000 (USFWS 

2008; Pacific Flyway Council 1999). Therefore, providing secure winter habitat for cackling geese has 

assumed an increased management priority. 

Cackling geese forage in large flocks and tend to prefer large, open pastures for foraging. Therefore, this 

objective recognizes that larger field sizes with minimal visual barriers are necessary to provide habitat 

for cackling geese. Issues of grass palatability and thatch reduction are the same as for dusky Canada 

geese; see discussion in Objective 1.1 above.

This increase in the total goose population has led to increased issues with crop and pasture depredations 

on private lands along the lower Columbia River. In an effort to alleviate economic losses from 

depredation on private lands, the refuge has placed an increased emphasis on management for these geese. 

Unlike dusky Canada geese, cackling, Taverner’s and lesser Canada geese (the primary geese associated 

with depredation issues) prefer large open agricultural fields and croplands. A variety of crops have been 

grown on the refuge since 1965 including corn, potatoes, winter wheat, barley, alfalfa, and clover. Refuge 

studies have shown that these crops, though preferred by geese, were quickly depleted while fall planted 

grass crops were pulled out by the roots. This left little forage for geese refuge-wide during the late winter 

and spring, when off-refuge crop depredations were more prevalent. This prompted a switch in 

management during the mid-late 1990s to provide primarily sustainable grass crops (pastures) to target 

open pasture feeders such as cackling geese, and to ameliorate spring depredation concerns. The impetus 

for this switch can be found in the Northwest Oregon/Southwest Washington Canada Goose Agricultural 

Depredation Plan (Pacific Flyway Council 1998).

Objective 1.3 Old Fields and Old Field/Wetland Borders

Annually maintain up to 140 acres of old fields and old field borders to provide thermal cover and 

nesting habitat for migratory birds (e.g., nesting waterfowl, raptors, short-eared owls, western 

meadowlarks, savannah sparrows) and dispersal habitat for small mammals and native 

amphibians with the following attributes:

• Mosaic of vegetation heights between 6-24 inches, > 80% cover of desirable grasses (e.g., 

perennial ryegrass, orchardgrass, fescues) and forbs (e.g. clover), < 10% cover of shrubs 

• > 60% of acres un-manipulated residual cover*

• Old field size >5 acres

 remaining annually for nesting species 

• No poison hemlock and false indigo 

• < 30% cover of invasive species (e.g., Canada thistle, buckhorn plantain, tansy ragwort, teasel)

*Definition: 

Un-manipulated residual cover: Tall decadent grass and/or forbs left standing through the fall and winter 

seasons.
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2-30 Chapter 2. Management Direction

Strategies Applied to Achieve Objective

Mowing and haying will only occur after July 15, unless surveys indicate that the specific pasture is not 

being used by nesting grassland birds. 

Use agricultural practice (e.g., seeding, disking, fertilizing, soil amendments, herbicides) to rehabilitate 

old fields that do not meet the habitat objective. 

To keep fields in appropriate successional stage and control/eradicate invasive plants, mow (after July 

15) and/or spray herbicides in a 2-3 year rotation (see Appendix K, IPM Program). 

Restore old fields and old field/wetland borders that are adjacent to improved pasture undergoing 

restoration by removing invasive plants such as blackberry, teasel, and reed canarygrass through 

agricultural practices (see above) and supplement native plant regeneration with pasture grasses listed 

above, and small numbers of shrubs that are appropriate to the site. 

Utilize burning regimes where feasible (recommended frequency is every 2 years). (Contingent upon 

receiving permit with Southwest Washington Clean Air). 

Continue to cooperate with the County Weed Board to control county-listed invasive weeds.

Control weeds in accordance with the refuge’s IPM program using methods such as crop rotation, 

mechanical treatment, biological controls, and low toxicity approved pesticides (see Appendix K, IPM 

Program).

Pesticide use must be in compliance with the Service policy requirements for completing an approved 

Pesticide Use Proposal, and must meet other State and Federal requirements.

In portions of fields where Nelson’s checkermallow was planted, grazing will not be permitted, and 

mowing will only occur after checkermallow plants have entered senescence.

Rationale: Old fields are areas formerly used for pasture or crops that are now a mixture of tall decadent 

grasses, forbs, and shrub. Old field/wetland borders on the Refuge are typically strips of tall decadent 

grass and/or forbs between fences and roads, or on dikes. Most of the vegetation is nonnative. However, 

these areas provide nesting and foraging habitat for ground-nesting birds, and winter thermal cover for 

short-eared owls, small mammals, and other wildlife. These areas also provide migration or dispersal 

corridors for amphibians and small mammals. For example, red-legged frogs require dispersal habitat 

between wetland breeding areas and riparian areas. Old fields require regular treatment for weeds (see 

strategies above), otherwise they become infested with invasive plants and can become a seed source for 

invasive species. Currently the Refuge has approximately 400 acres in this habitat type. Those fields and 

field/wetland borders identified as necessary habitat for ground-nesting birds or as migration/dispersal 

corridors (140 acres) will be maintained in this habitat type. The remainder (260 acres) will be converted 

into other habitat types that will benefit purposes species (e.g. improved pasture) and/or contribute to the 

Refuge’s biological diversity, integrity and environmental health (riparian habitat, oak woodland).

Objective 1.4 Maintain and Enhance Native Grassland Habitat

Enhance and annually maintain up to 15 acres of native grassland habitat on the Carty Unit for 

grassland-dependent birds and native plant species. Native grassland habitat is characterized by the 

following attributes: 

• Optimal patch size or

• Mosaic of vegetation heights between 6-36 inches 

 contiguity with oak woodland habitat is >50 acres 

• >50% cover of native grasses (e.g., Roemer’s fescue, California oatgrass, tufted hairgrass, red 

fescue) and native forbs (e.g., northwest cinquefoil, common camas, blue eyed Mary, yarrow, 

largeleaf lupine) 

• <20% cover of invasive/undesirable nonnative grasses (e.g., poverty brome), forbs (e.g., ox-eye 

daisy, thistle and trefoil), and shrubs (e.g., blackberry)

Strategies Applied to Achieve Objective
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-31

Conduct survey of native plants in grassland areas of the Carty Unit to determine which native and 

nonnative species are present, densities, and need for treatment (also see Objective 7.4). 

Use IPM strategies including mechanical, biological, and chemical means to eradicate, control, or contain 

invasive plants (see Appendix K -IPM Program). 

Utilize prescribed fire, where feasible and necessary, to maintain native plant communities. (Contingent 

upon receiving permit with Southwest Washington Clean Air). 

Pending survey results, drill native grass seed and plant native forbs (seed or head-started seedlings) to 

increase proportion of native to nonnative species. 

Conduct site monitoring to determine efficacy of restoration and need for follow-up treatments.

Rationale: Small patches of grassland occur on the Blackwater Island RNA (approx.15 acres total) as 

small openings within oak woodland habitat. These grasslands are dominated by an introduced species 

(poverty brome), and the native grass component appears to be small. However grassland habitat on the 

RNA appears to be an important area for native wildflowers. Soils on RNA grassland are thin, overlying 

basalt bedrock, and well drained. Because of thin soils, some restoration and management techniques that 

could be utilized on bottomland grasslands with deeper soils (e.g. grazing, mowing, disking) are not 

appropriate here. 

Inventories of the Blackwater Island RNA include vegetation surveys and community descriptions 

developed from the 1970s through the early 1990s, annual surveys for the federally listed water howellia, 

and pit trap and live trap mammal and amphibian surveys conducted in the 1990s. Updated inventories of 

native habitats and vegetation, and habitat conditions (including presence of invasive species) are needed 

in order to manage grasslands and oak woodland habitat on the RNA (also see Objective 7.4: Conduct 

Baseline Inventories of Native Habitats/Vegetation and Major Fish and Wildlife Groups.) 

2.4.2 Goal 2: Provide agricultural crops as forage for migratory waterfowl 

and sandhill cranes annually. 

Objective 2.1 Provide Crops for Waterfowl and Sandhill Cranes 

Annually provide 290-330 acres of agricultural crops (e.g., corn, small grains, legumes), including 

60-145 acres of corn, as forage for sandhill cranes, dusky Canada geese, and other waterfowl.

Strategies Applied to Achieve Objective

Plant corn in areas outside the hunt area for use by cranes and dusky Canada geese. The cropping 

program will consist of normal planting, normal harvest, and normal post-harvest manipulation. Corn 

may be manipulated (knocked down) after the close of the hunt season to make it more available to 

geese.

Use agricultural practices such as seeding, disking, soil amendments, fertilizing, herbicides, and plant 

cover crop.

Weeds will be controlled in accordance with the refuge’s IPM program using methods such as crop 

rotation, mechanical treatment, biological controls, and approved low toxicity pesticides (see Appendix 

K).

The refuge will work to prevent the spread of weeds by cleaning equipment between fields and will 

continue to cooperate with the County Weed Board to control county-listed invasive weeds.

Pesticide use must be in compliance with Service policy requirements for completing an approved 

Pesticide Use Proposal, and must meet other State and Federal requirements.

Rotate cropping patterns with planned rehabilitations of improved pastures to break weed cycles, fix 

nitrogen, and increase soil tilth where appropriate (see Objectives 1.1-1.2).

If additional crops are planted using disking, use existing fields, or old fields currently in fallow, weedy 
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2-32 Chapter 2. Management Direction

condition.

In portions of fields where Nelson’s checkermallow was planted, no crops will be established.

Continue to pursue cooperative farming agreements (CFA). When the refuge develops a CFA for crop 

production, the cooperator will provide an annual record of planting efforts, fertilizer and herbicide 

applications, and plant products removed from the refuge. Cooperators will only apply herbicides and 

fertilizers with prior refuge approval. 

Monitoring of the cropland farming program will be performed by qualified refuge staff.

Rationale: Croplands are managed primarily for the benefit of waterfowl and sandhill cranes, but many 

other species benefit such as bald eagles, which rely on refuge waterfowl concentrations. Approximately 

158 acres of refuge lands are currently farmed using refuge staff and equipment, including 55-85 acres of 

corn. Formerly, large areas of the refuge were planted in crops via a cooperative farming program, but 

these massive farming efforts were discouraged by the Oregon/Southwest Washington Canada Goose 

Agricultural Depredation Plan (PFC 1998). As a result of recommendations in the plan, the refuge began

maintaining large areas of pasture, with scattered crops. By providing a variety of foods within close 

proximity to each other, the refuge is able to hold geese throughout the winter months and reduce 

depredation on adjacent lands. The small overall acreage, small fields, spread out set-up of crop lands, and 

the fact that farmers would have to leave a portion of the crops for wildlife, makes the refuge undesirable 

for cooperative farmers. For these reasons the refuge has not prioritized locating cooperative farmers in 

the past. 

The refuge’s 2004 Wildlife and Habitat Management Review (USFWS 2004) recommended providing 

additional grain for wintering waterfowl and cranes. The number of acres planted in corn is limited by 

high cost (due to soil prep, fertilizer and weed control), the need to rotate crops, and the need for increased 

weed control activities in fallow cornfields. As a result, the refuge proposes to provide the majority of 

supplemental food for waterfowl and cranes through increased use of interseeding legumes and small 

grains such as clover and winter wheat, or planting less resource intensive crops. However, corn is 

preferred by sandhill cranes and dusky Canada geese; therefore, we propose limited corn planting in key 

areas utilized by duskys and cranes. Both duskys and sandhill cranes can access standing corn (especially 

shorter varieties or stunted corn), while the smaller-bodied cackling geese cannot. We propose to increase 

the quantity of corn produced on the refuge using irrigation as well as evaluating the use of other grains 

such as milo and buckwheat to increase forage for duskys and cranes. Planting corn outside the hunt area 

will also help keep duskys out of the hunt area and reduce the harvest of duskys. Given the difficulty in 

consistently propagating a productive corn crop, the refuge will examine the feasibility of using a 

cooperative farmer to produce a crop, under refuge supervision. The cooperative farmer will be allowed to 

remove a predetermined share of the crop as compensation. The refuge’s share of the crop will remain in 

field and be available to wildlife. If the refuge finds cooperative farming to be feasible, it will be 

conducted in accordance with guidelines, best practices, and acreages outlined in the existing Cropland 

Management Plan. Per Service law enforcement, hunting can occur on the refuge only if the cropping 

program consists of: a normal planting; normal harvest; and normal post harvest manipulation. To avoid 

any issues associated with baiting, crops cannot be manipulated beyond this during the hunt season, 

regardless of location or distance from hunt program. 

2.4.3 Goal 3: Provide, manage, and enhance a diverse assemblage of wetland 

habitats characteristic of the historic lower Columbia River.

Objective 3.1 Managed Seasonal Wetlands 

Enhance and annually maintain a minimum of 445 acres of managed seasonal wetlands for 

migratory waterfowl, wading birds, shorebirds, and other wetland-dependent wildlife species in the 

River ‘S’ Unit. Seasonal wetlands are characterized by the following attributes: 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-33

• > 60% cover of desirable and/or native wetland plants including moist-soil annuals (e.g., 

smartweeds, wild millet, and water plantain), wapato, and nutsedges. 

• < 20% cover of native emergent species (e.g., cattail, hardstem bulrush) that are > 5 feet tall. 

• < 40% cover of undesirable/invasive plants including reed canarygrass and ricefield bulrush. 

• No purple loosestrife and false indigo present. 

• During initial flood-up (October to November), water depths of 4-12 inches. 

• Water depths 24-30 inches from late January to May; achieve drawdown by June 15. 

• Minimal damage to wetland infrastructure by nutria. 

*Definition

Managed seasonal wetlands: Wetlands which have existing infrastructure (pumps, culverts, water 

control structures) to manipulate water levels on a seasonal basis, relatively independent of water 

conditions in the surrounding watershed. 

: 

Strategies Applied to Achieve Objective

Wetland rotation: As needed, rotate 225 acres of seasonal wetland to semipermanent wetland to control 

undesirable plants (e.g. reed canarygrass). Flood wetlands to > 24 inches from late January to May. Once 

control is achieved resume management as seasonal wetland.

Except where needed to control reed canarygrass and ricefield bulrush, incrementally floodup and 

drawdown (e.g., using water control structures, pumps) to promote waterfowl foraging within the entire 

basin, and create mudflats for use by shorebirds. 

Use mechanical techniques (e.g. disking, mowing) to set back succession of emergent vegetation and 

promote moist-soil and native plant production as well as control invasive/undesirable plants such as reed 

canarygrass.

Use IPM strategies including mechanical, cultural, biological, and chemical means to eradicate, control, 

or contain invasive and undesirable plants, particularly ricefield bulrush (see Appendix K, IPM Program). 

As needed, reconfigure water delivery system to allow to enhance water level management 

Use IPM techniques to control beaver and nutria from damaging water control structures and dike 

systems (see Appendix K). Protect desirable trees from beaver using fencing and propagating a dense 

shrub layer to exclude them from shorelines. Protect levees from nutria by periodically lowering water 

levels where practicable, and by removing animals in accordance with the refuge’s IPM plan and 50 CFR 

31.14, Official Animal Control Operations, which allows the take of animals that are detrimental to a 

refuge’s wildlife management program.

Partner with counties for education/weed control along refuge borders and reduce sources.

Rationale: The refuge was established to provide migration and wintering habitat, including wetlands for 

dusky Canada geese and other waterfowl. Providing a diversity of wetlands is vital to the refuge’s 

purposes. Yet because of the numerous dams along the length of the Columbia River, and the construction 

of levees to protect private landowners along the lower river, the natural hydrological processes of a freeflowing riverine system have been eliminated. Managed seasonal wetlands Refuge waters inside diked 

areas of the River ‘S’ Unit (23 wetlands totaling 445 acres) are now intensively managed to mimic natural 

disturbance mechanisms, providing and maintaining the cyclical aging and renewal processes of wetlands 

over time. By maintaining the number of acres of open shallow marsh through active management such as 

mechanical soil disturbance and wetland infrastructure, the refuge can provide a diversity of early 

successional vegetation stages that increase overall biodiversity and prevent wetland loss over time. 

Species benefiting from these seasonal wetland habitats include waterfowl, wading birds, rails, cranes, 

shorebirds, amphibians, and muskrats. 

Currently, the refuge spends approximately $10,000 annually to operate electrical pumps to fill and 

maintain wetland water levels within the waterfowl hunt area on the River ‘S’ Unit during the hunting 
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2-34 Chapter 2. Management Direction

season. Water is pumped onto the managed wetlands in early fall (September). As winter rains add more 

water to these wetlands, it is necessary to then pump the water off to avoid flooding refuge roads, and 

other infrastructure. Because out-pumping generally cannot keep pace with inflow from rains, this 

pumping regime creates relatively deep-water conditions for most of the fall through spring season. Over 

time, this has caused changes in wetland vegetation. In addition, these depths are not conducive for most 

foraging waterfowl (for example, mallard, wigeon, and pintail), but instead favor ducks deft of gathering 

food from near the water’s surface (shovellers) and diving ducks (ring-necked ducks and scaup). In 

contrast to current management, a more natural, gradual floodup regime is proposed. With gradual 

floodup these wetlands will support foraging by a wider range of waterfowl species. This management 

change will also result in cost savings (less pumping costs) that can be used for other habitat management 

activities.

Invasive plants (primarily reed canarygrass) are widespread in many refuge wetlands. Altered plant and 

animal community composition was identified as a very high stress to refuge wetland systems. Invasive 

plants limit native plant production and cause impacts to food, nesting, and cover for wildlife. Invasive 

plants in wetlands reduce waterfowl food availability during the migration and wintering periods. 

Limiting invasive species will help the refuge to comply with county and state noxious weed ordinances. 

In wetland basins, reed canarygrass is best controlled by disking followed by prolonged deep flooding 

(Kilbride and Paveglio 1999, Paveglio and Kilbride 2000, Tu 2004). This has been done in past years;

however, recent infestations of ricefield bulrush have reduced the use of this treatment protocol in many 

areas. As a result, reed canarygrass has spread in refuge wetlands. We propose re-initiating reed 

canarygrass control in areas with minimal ricefield bulrush and monitoring these areas for ricefield 

bulrush. A primary method of controlling reed canarygrass and other undesirable species will be 

periodically managing these wetlands as semipermanent wetlands, with deeper and a longer duration of 

flooding until control is achieved. Nine wetlands on the River ‘S’ Unit, totaling 225 acres (about half of 

the acreage in this habitat type) have sufficient basin depth to allow for this management regime. The 

interval of rotation will vary according to the wetland, but could typically be expected to be 4-5 years. 

However, 14 seasonal wetlands on the River ‘S’ Unit do not have sufficient basin depth or water control 

capability to allow management as semipermanent wetlands. These will be drawn down and disked 

approximately every 2 years, or as needed. 

Lack of staffing and funding to contain the expansion of invasive species and reduce infested acreage has 

been an ongoing issue with all wetland habitats on the refuge. An increase in staffing and funding will be 

needed to meet this and other wetland habitat objectives (see Appendix D, Implementation Analysis). 

Objective 3.2 Managed Semi-permanent Wetlands 

Enhance and annually maintain 228 acres of managed semi-permanent wetlands* for migratory 

waterfowl, wading birds, shorebirds, and other wetland-dependent wildlife species. Semipermanent wetlands are characterized by the following attributes: 

• 20-30% cover of desirable and native wetland plants including moist-soil annuals (e.g., 

smartweeds, wild millet, and water plantain).

• 40-50% cover of submergent plants (e.g., pondweeds). 

• 20-40% cover of native emergent species (e.g., cattail, hardstem bulrush, wapato, and bur-reed) 

that are > 5 feet tall. 

• < 20% cover of undesirable/invasive plants including reed canarygrass and ricefield bulrush. 

• No purple loosestrife and false indigo present. 

• Water depths 24-30 inches by late January to control undesirable plants with no more than 60-

80% of wetland bottoms exposed (dry) by October 1. 

• Minimal damage to wetland infrastructure by nutria. 
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Chapter 2. Management Direction 2-35

*Definition

Managed semi-permanent wetlands: Wetlands which have existing infrastructure (pumps, culverts, water 

control structures) to manipulate water levels on a seasonal basis, relatively independent of water 

conditions in the surrounding watershed. 

: 

Strategies Applied to Achieve Objective

Wetland rotation (definition): Use mechanical techniques (e.g., disking and mowing) to control 

undesirable plants, set back succession to maintain a desirable ratio of robust emergent vegetation to open 

water, and increase wetland productivity. Use heavy equipment to remove mineral and organic deposits to 

deepen wetlands as necessary. 

Except where needed to control reed canarygrass, use water control to incrementally flood-up, to promote 

waterfowl foraging within the entire basin.

Use water control structures and pumping, where possible, to maintain 24-30 inches water depth by late 

January.

Use IPM strategies including mechanical, cultural, biological, and chemical means to eradicate, control, or 

contain invasive and undesirable plants (see Appendix K).

As needed, reconfigure water delivery system to enhance water level management.

Inventory wetland plant communities and annually monitor effectiveness of invasive plant control 

measures. Control any reinvasion by nonnative plants. 

Partner with counties for education/weed control along refuge borders and reduce sources.

Rationale: The refuge was established to provide migration and wintering habitat, including wetlands, for 

dusky Canada geese and other waterfowl. Providing a diversity of wetlands is vital to the refuge’s 

purposes. Yet because of the numerous dams along the length of the Columbia River, and the construction 

of levees to protect private landowners along the lower Columbia River, the natural hydrological and 

floodplain processes of a free-flowing riverine system have been eliminated. Refuge waters inside diked 

areas of the River ‘S’ Unit are now intensively managed to mimic natural disturbance mechanisms, 

providing and maintaining the cyclical aging and renewal processes of wetlands over time. 

The Refuge’s managed semi-permanent wetlands include four wetlands, totaling 133 acres, on the River 

‘S’ Unit; and five wetlands, totaling 58 acres, on the Bachelor Island Unit. The total acreage reflects 

maintenance of existing managed semi-permanent wetlands, and conversion of 37 acres of other wetlands 

(Wigeon Lake and Wetland 013E on Bachelor Island) to this type. 

By maintaining the number of acres of open shallow marsh through active management (e.g. mechanical 

disturbance and wetland infrastructure), the refuge can provide a mosaic of early to late successional 

vegetation stages that increase overall biodiversity and prevent wetland loss over time. Species benefiting 

from these seasonal wetland habitats include waterfowl, wading birds, rails, shorebirds, amphibians, and 

muskrats.

Currently, water is pumped onto the managed wetlands of the River ‘S’ Unit in early fall (September). As 

winter rains add more water to these wetlands, it is necessary to pump the water off to avoid flooding 

refuge roads and other infrastructure. Because out-pumping generally cannot keep pace with inflow from 

rains, this pumping regime creates relatively deep-water conditions for most of the fall through spring 

season. These depths are not conducive for most foraging waterfowl. In contrast, a more natural, gradual 

floodup regime is proposed. This will also result in cost savings (less pumping costs) that can be used for 

other habitat management activities. The depth and timing of inundating individual wetland units will be 

determined in annual habitat work plans. 

 

In addition, where topography and soils are appropriate and water management capability exists, we 

propose rotating the four semi-permanent wetlands on the River ‘S’ Unit, totaling 133 acres, between 
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2-36 Chapter 2. Management Direction

semi-permanent and seasonal wetlands. These wetlands will primarily be managed as semi-permanent, 

however, wetlands with extensive and persistent cover of emergent vegetation, or with more than 50% 

open water, will be periodically drawn down, disked, and/or mowed to maintain a desirable ratio of robust 

emergent vegetation to open water and increase wetland productivity. Mineral and organic deposits that 

lead to filling and wetland loss will be removed as necessary. These actions will help mimic natural cycles 

of flood and drought and help maintain productivity as organic matter decomposes and nutrients that 

accumulated during flooded periods are made available to plants during dry periods. 

As in Objective 3.1, we propose reinitiating reed canarygrass control in areas where good control of 

ricefield bulrush has been achieved, and monitoring these areas for presence of ricefield bulrush. 

Objective 3.3 Seasonal wetlands 

Enhance and annually maintain a maximum of 125 acres of seasonal wetlands* for the benefit of 

migratory waterfowl, wading birds, shorebirds, and other wetland-dependent wildlife species in the Carty 

and Bachelor Island units. Seasonal wetlands are characterized by the following attributes:

Water depths range from saturated soils to 12 inches in winter (December-March) from rainfall.

• Naturally dry in summer (June-September). 

• 40-60% cover of desirable and native wetland plants including moist-soil annuals (e.g., 

smartweeds, wild millet, and water plantain). 

• < 20% cover of native emergent species (e.g., cattail, hardstem bulrush) that are > 5 feet tall. 

• < 40% cover of invasive plants (e.g., reed canarygrass, and ricefield bulrush). 

• No woody species (e.g., willows). 

• No purple loosestrife and false indigo present. 

*Definition

Seasonal wetlands: Wetlands that are typically dry in summer (June-September) and fill with rainwater 

in fall.

:

Strategies Applied to Achieve Objective

Allow natural flood-up and drawdown (minimal water pumping on Bachelor Island, and none on Carty 

Unit).

When appropriate, manage water levels of seasonal wetlands on Bachelor Island (using water control 

structures, and pumps).

Use mechanical techniques such as disking and mowing, to set back succession of emergent vegetation, 

promote moist-soil and native plant production, control invasive/undesirable plants, and remove woody 

species. 

As needed, reconfigure water delivery system to enhance water level management.

Use IPM strategies including mechanical, biological, and chemical means to eradicate, control, or 

contain invasive and undesirable plants (see Appendix K).

Rationale: Currently, most of the Refuge’s seasonal wetlands (approximately 120 acres) occur on the 

Bachelor Island Unit. Some smaller seasonal wetlands (approx 20 acres total) occur on the Carty Unit, 

and one 16-acre seasonal wetland is on the Carty Unit (River ‘S’ point). Seasonal wetlands on Bachelor 

Island are generally not supplemented with pumped water, while there are no capabilities to supplement 

wetlands on the Carty Unit. Wetland basins in the Carty Unit may be inundated during unusually high 

water events (Columbia River floods), but otherwise are disjunct from the daily fluctuations of the 

Columbia River and Gee Creek wetland systems. The refuge does not have any capabilities to manage 

water on these sites. 

Wetland restoration projects on Bachelor Island in the late 1990s have been only partially successful. Soil 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-37

porosity coupled with reduced water levels in the Columbia River since the restoration project was 

completed, has resulted in some wetland basins having poor water holding capability. Many wetlands are 

incapable of retaining water until river levels approach 13 feet mean sea level (MSL). Water retention 

increases in late winter (despite low river levels) in some wetlands, probably due to complete soil 

saturation and regular inputs of precipitation, but retention is generally short term. As a result of this 

long-term drying trend, some of these seasonal wetlands are being infested by reed canarygrass and/or 

upland-adapted invasive plants such as Himalayan blackberry, teasel, tansy ragwort, and Canada thistle. 

Once established, these invasive plants can only be controlled mechanically or chemically. The River ‘S’ 

point wetland is undergoing natural succession to riparian forest; this will be allowed to continue (see 

Objective 4.1a). Basins with good water holding capabilities will continue to be managed as open, 

shallow-water areas. It is possible that over time the water-holding capabilities of some of the wetland 

basins on Bachelor Island will improve as a layer of organic material and silt builds up.

Objective 3.4 Howellia wetlands 

Enhance and maintain the four small seasonal wetlands totaling 1.2 acres that support 

populations of the federally threatened water howellia (Howellia aquatilis). Howellia wetlands have

the following attributes: 

• Water depths range from saturated soils to 20 inches in winter (November-June), drying to 

mudflats in late summer and fall.

• < 20% cover of emergent wetland plants and shrubs. 

• 80% open water with Howellia and other native submergent plants. 

• < 10% cover of invasive/undesirable plants, primarily reed canarygrass. 

• Minimal encroachment by woody species (e.g., spirea).

Strategies Applied to Achieve Objective

Allow natural flood-up (no pumping capabilities).

Use IPM strategies including mechanical, physical, biological, and chemical means to eradicate, control, 

or contain invasive and undesirable plants (see Appendix K). Timing of treatment (after drying, but 

before fall rains) and minimizing soil disturbance is critical to protect Howellia seedlings.

As needed, hand-remove or chemically treat spirea and tree seedlings invading the wetlands. This 

should be accomplished with a minimum of soil disturbance and conducted after basin drying has 

occurred, but before fall rains begin.

Rationale: Water howellia is a federally threatened, annual submergent plant species that occurs in 

ephemeral and seasonal wetlands. Federally-listed species are trust resources and are essential to 

maintaining refuge and regional biological integrity. This species is known from only 3 sites in 

Washington and has been extirpated from much of its historic range. On the refuge, these plants are part 

of the submergent plant community, and occur along the shorelines of several small, ephemeral ponds on 

the Carty Unit. These wetlands fill naturally with rainwater in fall, but dry during the summer months. 

These wetlands cannot be supplemented with pumped water or artificially dewatered. 

Howellia requires wetlands or wetland edges that dry down in late summer and fall, as seed must be 

exposed to air for fall germination (USFWS 1996). As an aquatic annual plant, howellia plants are 

fragile, vulnerable to destruction by premature wetland drying and trampling. Moreover, howellia seed is 

not considered to have a long period of viability, so several years of poor seed production can have 

negative effects on the population. 

Howellia does not persist in wetlands overgrown with emergent vegetation, reed canarygrass, or woody 

plants. Currently, one of the refuge’s four howellia ponds has been largely taken over by reed 

canarygrass, and growth of woody vegetation (Spirea) is a problem at another pond. Therefore, removal 
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2-38 Chapter 2. Management Direction

of these plants to achieve optimal habitat conditions for howellia is proposed. Because of its life history, 

invasive plant control must occur post-drawdown but prior to fall germination; soil disturbance within the 

basin should be kept to a minimum during these activities. (Canopy cover from associated upland 

deciduous trees does not appear to be a limiting factor; in fact one howellia pond on the refuge occurs in a 

wooded wetland.) 

Objective 3.5 Permanent, nontidal wetlands 

Enhance and annually maintain 70 acres of permanent wetlands* for the benefit of migratory 

waterfowl, wading birds, and other wetland-dependent wildlife species. Permanent nontidal 

wetlands are characterized by the following attributes:

• Maximum water depths of 24-36 inches with potentially increased depths in winter due to 

precipitation. 

• Natural drying may occur in summer. 

• Open water with native submergent vegetation (e.g., sago pondweed) covering > 75% of 

wetland basin. 

• < 25% cover of desirable and native emergent (e.g., hardstem bulrush, cattails) and other 

wetland plants (e.g., annual moist-soil plants, wapato). 

• < 10% cover of invasive plants (e.g., reed canarygrass, purple loosestrife, and milfoil). 

*Definition: 

Permanent wetlands: Wetlands that rarely dry completely via evaporation during the summer, though 

significant reduction in surface area and depth may occur. 

Strategies Applied to Achieve Objective

Maintain/create open water areas: Mechanically reopen areas that have become vegetated with persistent 

emergent vegetation, to set back succession, and maintain open, shallow water areas. 

Use heavy equipment to remove silt and choking vegetation as needed, but retain woody debris (e.g. in 

Bower Slough). 

Use IPM strategies including mechanical, biological, and chemical means to eradicate, control, or 

contain invasive and undesirable plants. 

If needed, utilize appropriate IPM strategies (e.g., drawdown and, if necessary, exclusion followed by 

rotenone application) to kill carp populations. For effective use of rotenone, and facilitation of 

equipment needs, exclude any ingress of carp from the source (river) and remove residual vegetation 

when appropriate. Coordinate with WDFW on rotenone projects, funding initiatives, and partnerships.

Rationale: The refuge has substantial wetland resources that provide habitat for wildlife. Refuge 

management has traditionally focused on those seasonal and semi-permanent wetlands with water 

management capabilities. The refuge also contains a system of permanent and tidal wetlands that 

function somewhat naturally as part of the larger lower Columbia River system. 

The wetlands in this category include Carty Lake (52 acres) on the Carty Unit, Post Office Lake (74 

acres) on the Ridgeport Dairy Unit, and Bower-Mallard Slough on the River ‘S’ Unit (part of the refuge’s 

water delivery system). Historically these wetlands were connected to the Columbia River, but are now 

cut off from the river by dikes and/or cessation of major flooding events. The refuge may or may not 

have some minimal water management capabilities on these wetlands. The wetlands retain water 

throughout the summer, though significant reduction in surface area and depth may occur. It appears that 

water retention is in part a function of the current water levels within the Columbia River system, 

probably due to seepage/groundwater levels. These wetlands are generally capable of supporting 

persistent warmwater fish populations; plant communities are primarily comprised of submergent species. 

Outside of their extensive use by waterfowl and other migratory birds, little is known about the 

submerged vegetation and other aquatic species inhabiting Carty and Post Office Lakes. Bower Slough 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-39

contains abundant woody debris and gets heavy use by hooded mergansers, wood ducks, and waterfowl 

broods, and is a summer refugium for painted turtles and amphibians. 

Due to the loss of the connections these wetlands had with the Columbia River system, their functionality 

has been reduced, particularly as anadromous fish rearing habitat and native mussel beds. Post Office 

Lake is currently managed as a nontidal wetland. The dike separating Post Office Lake from the 

Columbia River is eroding and likely to fail in the next major flood event (the dike is not owned by the 

refuge). Dike failure would restore a connection between Post Office Lake and the Columbia River (see 

Objective 6.2). The refuge proposes to develop a contingency plan for Post Office Lake in the event of a 

dike breach, as part of a larger study to evaluate the feasibility of restoring the lake to a more natural tidal 

system (see Objective 7.7). As part of the feasibility study, the refuge will examine the potential impacts 

and benefits of various management actions to fish, waterfowl, amphibians, and wetland vegetation. 

Carp, which are widespread in permanent wetlands on the refuge, are thought to represent a high threat to 

the wetland system’s ecological functions due to their impacts on submergent vegetation and water 

quality. Carp uproot and eliminate submerged vegetation, increase turbidity, and decrease the overall 

abundance and diversity of the invertebrate community (Miller 2006). Treatments using the natural plant 

chemical rotenone are expensive, but can be more effective if the amount of water to be treated is 

minimal, if carp are concentrated in a small area, and if re-establishment can be prohibited through the 

installation of carp excluders or similar structures. 

Objective 3.6 Wet Meadow Habitat

Enhance and annually maintain up to 400 acres of wet meadow habitat to provide feeding and 

resting habitat for dusky Canada geese and dabbling ducks and migration corridors for native 

amphibians and reptiles. Restore 90 acres of selected old fields (Wigeon Lake South on Bachelor 

Island and Dusky Meadow on the Ridgeport Dairy Unit) to wet meadow habitat. Wet meadow is 

characterized by the following attributes:

• Patch size ranges from 2 to 45 acres with a minimum predator-detection width of 250 feet. 

• Hydric soils.

• Flat or very gently sloping topography. 

• Mix of palatable forage with a height of < 6 inches by October 1 

• > 10% cover of native grasses and forbs such as Columbia sedge, tufted hairgrass, camas, spike 

bentgrass, dense sedge, California oatgrass, annual hairgrass, meadow barley, American 

sloughgrass, one-sided sedge, Western mannagrass, spreading rush, wild barley, and buttercup. 

• < 5% cover of native shrubs.

• < 20% cover of invasive plants (other than mowed/grazed reed canarygrass).

• Water depths range from moist soil to 4 inches from December through at least March. 

• No willows. 

Strategies Applied to Achieve Objective

Mow between July 15 and Oct. 1 to maintain grass palatability, minimal thatch, and provide < 4-inch 

height prior to flood up October 1. 

Graze (e.g., domestic animals) from April 15 to September 30 (as conditions allow) to maintain grass 

palatability, reduce thatch, and provide < 4 inch vegetation height by October 1.

Hay from mid-May to Sep. 30 (as conditions allow) to maintain grass palatability, reduce thatch, and 

provide < 4-inch height by October 1.

Use IPM strategies including mechanical, physical, biological, and chemical means to eradicate, control, 

or contain invasive and undesirable plants (see Appendix K. IPM Program).

Pending feasibility study (see Objective 7. 7b) use appropriate restoration techniques to reduce reed 

canarygrass cover and increase cover of native wet meadow vegetation.
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2-40 Chapter 2. Management Direction

Rationale: Wet meadows are a primary foraging habitat for dusky Canada geese, and can also provide 

foraging areas for species such as American wigeon, sandhill cranes, and shorebirds; and nesting areas for 

northern harrier and ducks. The refuge’s current wet meadow sites are overflow sites from lakes or 

wetlands. Native wet meadow vegetation may have included Columbia sedge and tufted hairgrass, but 

these sites have been largely taken over by reed canarygrass on the lower Columbia River (Christy 2004; 

and Christy and Putera 1993). If mowed, canarygrass does provide some value to foraging wildlife, 

especially Canada and cackling geese. Currently, wet meadows on the refuge do get good dusky Canada 

goose use. Wigeon use these areas when they are grazed, possibly because grazing provides shorter grass 

than mowing. Target meadows based on dusky Canada goose surveys include: all or portions of Sora 

Marsh, East-West Meadow, Twining Field, Midlands Meadow, Ruddy Lake, Outer Swartz Meadow, 

Roth Lowlands, South River Pasture, Roth Field, and Dusky Marsh. 

In the immediate future, management of these areas will focus on annual mowing and periodic disking (2 

consecutive years repeated every 5 years) of wet meadows to provide short grass for goose browse and 

prevent encroachment of willows. Because mowing may leave significant quantities of thatch, twice 

annual mowing in high use dusky Canada goose areas is recommended to enhance decomposition. 

However, mowing alone stimulates additional stem production so under this management regime, wet 

meadows will continue to be dominated by reed canarygrass. Over the lifetime of the CCP, 

approximately 90 acres of selected old fields will be converted to wet meadow habitat as well. Future 

management strategies should target reducing reed canarygrass cover and increasing cover of the native 

grass and forb species noted in the objective. However, restoring native wet meadow habitat in areas 

dominated by reed canarygrass is time and resource-intensive, requiring 2-3 years of initial treatments, 

and continued monitoring and follow-up for 5-10 years to prevent reinfestation (Kilbride and Paveglio 

1999, Paveglio and Kilbride 2000, Tu 2004). Therefore, a feasibility study with test treatments and 

plantings is recommended (see Objective 7.7b).

2.4.4 Goal 4: Protect, manage, and restore a natural diversity of native 

floodplain forests representative of the historic lower Columbia River 

ecosystem.

Objective 4.1 Early Successional Floodplain Forest

Protect and maintain at least 330 acres of early successional floodplain forest benefiting migratory 

and resident landbirds, native reptiles, and native amphibians. Early successional floodplain forest 

is characterized by the following attributes: 

• Understory with 30-80% cover of native shrubs (3-12 feet tall) such as red-osier dogwood, 

willow, snowberry, Douglas’ spirea, serviceberry, red elderberry, Indian-plum, cascara, rose 

with scattered openings containing native herbaceous species (e.g., Columbia sedge, greensheathed sedge, wooly sedge, retrorse sedge, and stinging nettle). 

• < 30% cover of invasive plants (e.g., reed canarygrass, false indigo, and blackberry) in 

understory/herbaceous layer. 

• < 20% canopy cover of native trees (> 12 feet tall) such as Pacific willow, cottonwood, and redosier dogwood.

Strategies Applied to Achieve Objective 

Monitor and treat up to 10% of early successional forest annually for invasive plants. Use IPM strategies 

including mechanical, physical, biological, and chemical means to eradicate, control, or contain invasive 

and undesirable plants.

Allow natural succession via natural willow/cottonwood seedfall. 
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Chapter 2. Management Direction 2-41

Pump water to mimic floodplain processes in units with water management capabilities to control 

invasive plants and promote native seed germination. 

Rationale: In presettlement times, Pacific willow (Salix lucida ssp. lasiandra) swamps were a 

widespread plant community along the lower Willamette and Columbia rivers. Presettlement components 

of this plant community probably included Columbia sedge (Carex aperta), green-sheathed sedge (Carex 

feta), wooly sedge (Carex pellita), retrorse sedge (Carex retrorsa), and stinging nettle (Urtica dioica) 

(Guard 1995). Since the arrival of settlers in the early 1800s, between 50% and 90% of riparian habitat in 

Washington has been lost or extensively modified (Knutson and Naef 1997). This was once a common 

habitat type on the refuge and contributes to the species diversity. Much of the native understory has 

been lost or highly degraded by livestock grazing and alterations to natural hydrology (levees, dams). 

Today Pacific willow and reed canarygrass form a common community type.

Intact riparian areas are important to the conservation of Washington’s vertebrate species. Of the 118 

species of landbird migrants occurring in Washington, 67 (57%) use riparian habitat (Andelman and 

Stock 1994). Avian densities in riparian forests along the Columbia River can be as high as 1,500 birds 

per 100 acres (Tabor 1976). Approximately 85% of Washington’s terrestrial vertebrate species use 

riparian habitat for essential life activities (Knutson and Naef 1997). Riparian habitat is additionally 

important to supporting healthy native fish populations by benefiting instream characteristics including 

temperature, water quality, water chemistry, cover, and nutrients.

The refuge contains approximately 1,100 acres of riparian and/or floodplain forest habitat in various seral 

stages or conditions. Most of this habitat on the refuge is vulnerable and/or remains in a degraded 

condition due to invasive plants, past grazing practices, alteration of hydrologic regimes, altered river 

levels, and poor native plant recruitment/ recovery. The refuge can contribute toward providing habitat or 

habitat connectivity for species that are dependent on riparian and floodplain forests by enhancing or 

restoring a mix of early, mid, and late successional floodplain forests on the refuge.

Objective 4.1a Restore Early Successional Floodplain Forest

Within the lifetime of the CCP, restore up to 160 acres of selected old fields, pasture, and 

nonmanaged wetlands to early successional floodplain forest. Restored early successional floodplain 

forest is characterized by the following attributes: 

• Understory with 30-80% cover of native shrubs (3-12 feet tall) such as red-osier dogwood, 

willow, snowberry, Douglas’ spirea, serviceberry, red elderberry, Indian-plum, cascara, and rose 

with scattered openings containing native herbaceous species (e.g., Columbia sedge, greensheathed sedge, wooly sedge, retrorse sedge, and stinging nettle). 

• < 30% cover of invasive plants (e.g., reed canarygrass, false indigo, and blackberry) in 

understory/herbaceous layer. 

• < 20% canopy cover of native trees (> 12 feet tall) such as Pacific willow, cottonwood, and redosier dogwood.

Strategies Applied to Achieve Objective

Seed or plant willow and red-osier dogwood in wetlands, wetland edges, or other appropriate hydric 

areas. Incorporate techniques to remove competing vegetation such as reed canarygrass by mechanical 

or chemical methods and use fencing or mats to reduce rodent damage to new plantings. New plantings 

will focus on connecting or expanding existing riparian stands in areas that are unlikely to be used by 

focus species such as dusky Canada goose or cranes.

Use IPM strategies including mechanical, cultural, biological, and chemical means to eradicate, control, 

or contain invasive and undesirable plants (see Appendix K).

Allow natural succession via natural willow/cottonwood seedfall.
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2-42 Chapter 2. Management Direction

Pump water to mimic floodplain processes in units with water management capabilities to control 

invasive plants and promote native seed germination and survival. 

Rationale: The refuge has an opportunity to restore early successional floodplain (bottomland) forest in 

selected old fields, pastures with low productivity, and wetland basins with poor water holding 

capabilities. Restored early successional floodplain forest benefits migratory and resident landbirds, 

native reptiles, and native amphibians. Planting willow and red osier dogwood will accelerate 

regeneration, enhance habitat quality, and provide habitat connectivity with existing floodplain forest. 

Highest priority areas for restoration will be based on their size and connectivity on and off the refuge. 

Though these acreages are relatively small, restoration efforts may provide valuable habitat or habitat 

connectivity for some species that are dependent on riparian and bottomland forests. New plantings will 

focus on connecting or expanding existing riparian stands in areas that are unlikely to be used by focus 

species such as dusky Canada geese or cranes. One seasonal wetland on River ‘S’ Point (16 acres) is 

undergoing succession to native trees. Under the CCP, this succession will continue; therefore, this 

wetland is now included under the early successional floodplain forest habitat type.

Objective 4.2 Mid to Late Successional Floodplain Forest

Protect and maintain 400 acres of mid to late successional floodplain forest benefiting migratory 

and resident landbirds, native reptiles, and native amphibians. Mid to late successional floodplain 

forest is characterized by the following attributes: 

• Understory with > 50% cover in shrub layer that is primarily (> 75%) native species (e.g., redosier dogwood, snowberry, Douglas’ spirea, serviceberry, red elderberry, Indian-plum, cascara, 

and rose). 

• > 50% canopy cover of native trees such as black cottonwood, Pacific willow, and Oregon ash. 

• < 30% cover of invasive plants (e.g., reed canarygrass, blackberry) in understory/herbaceous 

layer.

Strategies Applied to Achieve 

Monitor and treat up to 10% of mid to late successional forest annually for invasive plants. Use IPM 

strategies including mechanical, cultural, biological, and chemical means to eradicate, control, or 

contain invasive and undesirable plants (see Appendix K).

Allow succession of early successional floodplain forest to mid-late successional forest. 

Promote regeneration of black cottonwood woody and herbaceous understory, using appropriate forestry 

techniques. If shade is restricting shrub growth and the regeneration of shade intolerant tree species, 

thin the overstory to 50% to 75% cover and remove competing invasive plants such as reed canarygrass. 

Consider fencing or tree seedling protection if vole or beaver gnawing or deer browsing is preventing 

regeneration. 

Endorse and partner (where feasible) with public and private agencies and adjacent landowners to 

maintain and enhance connectivity and forest habitat quality on adjoining lands.

Rationale: As stated above, at least 50% and as much as 90% of riparian habitat in Washington has been 

lost or extensively modified since the 1800s (Knutson and Naef 1997). Today much of the native 

understory has been destroyed by livestock grazing and alterations to natural hydrology (levees, dams) 

and the understory is dominated by reed canarygrass. Pre-settlement components of this plant community 

probably included Columbia sedge (Carex aperta), green-sheathed sedge (Carex feta), wooly sedge 

(Carex pellita), retrorse sedge (Carex retrorsa), and stinging nettle (Urtica dioica) (Guard 1995). 

Recruitment of cottonwood in particular, is also low due to alterations in hydrology and many stands are 

composed of old, even aged trees. 

The refuge currently contains approximately 330 acres of mid to late successional floodplain forest 

habitat in various conditions. In addition, approximately 70 acres of early successional floodplain forest 

are expected to attain mid-successional status over the lifetime of the CCP. Most of this habitat on the 
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Chapter 2. Management Direction 2-43

refuge is threatened and/or remains in a degraded condition due to invasive plants, past grazing practices, 

alteration of hydrologic regimes, lower river levels, and poor native plant recruitment/recovery. 

Management will focus on improving habitat conditions in this existing habitat. 

Objective 4.3 Oregon Ash Floodplain Forest 

Protect and maintain approximately 330 acres of Oregon ash-dominated floodplain forest for 

migratory and resident land birds, native reptiles, and native amphibians. Oregon Ash Floodplain 

forest is characterized by the following attributes:

• Canopy cover > 50% dominated by Oregon ash. 

• Shrub layer < 20% cover consisting of native floodplain species such as Douglas’ spirea and 

red-osier dogwood. 

• Herbaceous layer > 50% native species (e.g. Columbia sedge, green-sheathed sedge, wooly 

sedge, retrorse sedge, and stinging nettle).

• < 30% cover of invasive plants (e.g., reed canarygrass, and blackberry) in 

understory/herbaceous layer..

Strategies Applied to Achieve Objective 

Monitor and treat up to 10% of Oregon ash forest annually for invasive plants. Use IPM strategies 

including mechanical, physical, biological, and chemical means to eradicate, control, or contain invasive 

and undesirable plants (see Appendix K).

Promote regeneration of Oregon ash, and woody and herbaceous understory using appropriate forestry 

techniques such as fencing to protect existing mature trees and natural regeneration, removing reed 

canarygrass and competing vegetation, and supplementing natural re-generation by planting (protect 

with tubes or fencing as necessary). 

Endorse and partner (where feasible) with public and private agencies and adjacent landowners to 

maintain and enhance connectivity and forest habitat quality on adjacent lands

Rationale: Protecting and maintaining Oregon ash floodplain forest is consistent with the Service’s 

2001policy on Biological Integrity, Diversity, and Environmental Health (601 FW 3). In presettlement 

times, seasonally flooded Oregon ash forest was a widespread plant community along the Willamette and 

lower Columbia rivers. Early survey records indicate that ash forests were a common plant community 

on the bottomlands of Clark County. Since the arrival of settlers in the early 1800s, at least 50% and as 

much as 90% of riparian habitat in Washington has been lost or extensively modified (Knutson and Naef 

1997). 

The refuge contains 330 acres of Oregon ash forest habitat in various conditions. The native understory 

component has been severely degraded by past livestock grazing and alterations to natural hydrology 

(levees and dams) and the understory is now dominated by reed canarygrass. Presettlement components 

of this plant community probably included Columbia sedge (Carex aperta), green-sheathed sedge (Carex 

feta), wooly sedge (Carex pellita), retrorse sedge (Carex retrorsa), and stinging nettle (Urtica dioica) 

(Guard 1995). Recruitment of ash is also low due to alterations in hydrology and many stands on the 

refuge are composed of old, even aged trees. Strategies to enhance this habitat could involve thinning 

and planting of young ash to create multi-aged stands, eradicating invasive species, and establishing 

native understory in existing ash forests. However, establishing native understory is difficult, and study 

plots will be needed to determine the most appropriate strategies before they are implemented on a large 

scale (see Objective 7.7).
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2-44 Chapter 2. Management Direction

Objective 4.3a Restore Oregon Ash Floodplain Forest 

Restore up to 5 acres of Oregon ash-dominated floodplain forest for migratory and resident land 

birds, native reptiles, and native amphibians. Oregon Ash Floodplain forest is characterized by the 

following attributes:

• Canopy cover > 50%, dominated by Oregon ash. 

• Shrub layer < 20% cover, consisting of native species such as Douglas’ spirea, and red-osier 

dogwood. 

• Herbaceous layer > 50% native species (e.g. Columbia sedge, green-sheathed sedge, wooly 

sedge, retrorse sedge, and stinging nettle). 

• < 30% cover of invasive plants (e.g., reed canarygrass and blackberry) in understory/herbaceous 

layer. 

Strategies Applied to Achieve Objective

Use IPM strategies including mechanical, cultural, biological, and chemical means to eradicate, control, 

or contain invasive and undesirable plants (see Appendix K) in restoration area. 

Plant Oregon ash and other native trees and shrubs, using exclosures or other devices to protect plantings.

Endorse and partner (where feasible) with public and private agencies and adjacent landowners to 

maintain and enhance connectivity and forest habitat quality on adjacent lands. 

Rationale: Restoring Oregon Ash floodplain forest habitat is consistent with the Service’s 2001 policy on 

Biological Integrity, Diversity, and Environmental Health (601 FW 3). A small but important area is 

targeted for ash restoration. Though the acreage is relatively small, restoration efforts may provide 

valuable habitat or habitat connectivity for high priority landbird species that are dependent on riparian 

and floodplain forests, and allow refuge staff to evaluate efficacy of restoration techniques before 

implementing them on a larger scale.

2.4.5 Goal 5: Protect, manage, and restore a natural diversity of native 

upland forests representative of the historic lower Columbia River ecosystem. 

Objective 5.1 Oregon White Oak Woodlands

Protect and maintain 70 acres of oak woodlands benefiting migratory and resident land birds (e.g., 

slender-billed white-breasted nuthatch), as well as other native wildlife. Oak woodland has the 

following attributes:

• Canopy cover of 30%-80%, with no less than 70% oak canopy cover. 

• No conifers. 

• Native shrub layer > 40% cover (appropriate native species may include poison oak, snowberry, 

rose, spirea, and oval-leaf viburnum). 

• Mean dbh of oaks > 21 inches, with 20% of oaks > 28 inches. 

• < 20% cover of invasive plants (e.g., reed canarygrass and blackberry) in understory/herbaceous 

layer.

Strategies Applied to Achieve Objective 

Monitor and treat up to 10% of Oregon white oak woodlands annually, for invasive plants. Use IPM 

strategies including mechanical, cultural, biological, and chemical means to eradicate, control, or contain 

invasive and undesirable plants. 

Use forestry techniques (e.g. hand-pull, girdle, cut, and spray) to remove encroaching conifers, another 

woody vegetation necessary to maintain canopy dominance of oaks. 

In over dense stands, thin overstory trees to achieve 30%-80% canopy cover.

Evaluate need to gather acorns and head-start seedlings for planting as part of subsequent stand 

maintenance and future habitat expansion.

Use prescribed fire to maintain this fire-dependent habitat. Coordinate with Clean Air District to obtain 
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Chapter 2. Management Direction 2-45

permit for controlled burning of oak woodland and native grassland habitat.

Prohibit livestock grazing.

Endorse and partner (where feasible) with public and private agencies and adjacent landowners to 

maintain and enhance connectivity and forest habitat quality on adjacent lands.

Rationale: Protecting and maintaining Oregon white oak woodland habitat is consistent with the 

Service’s 2001 policy on Biological Integrity, Diversity, and Environmental Health (601 FW 3). Oregon 

white oak woodlands in the Willamette Valley/Puget Trough ecoregion are threatened and/or remain in 

degraded conditions due to an extensive history of conversion to agriculture and other land uses, grazing, 

and fire suppression. In the Willamette Valley, 80% of oak woodlands present in 1850 have disappeared 

(Floberg et al. 2004; figures are not available for the lower Columbia region). The refuge contains 

approximately 70 acres of Oregon white oak woodland, all located in the Carty Unit. 

The basalt knobs in the Carty Unit contain a rare plant community, Oregon white oak/oval-leaf 

viburnum/poison-oak woodland, which is classified as a Priority 2 ecosystem in the Washington Natural 

Heritage Plan (WDNR 2009). Most of this habitat lies within the Blackwater Island RNA and the 

Washougal Oaks Natural Area Preserve/Natural Resource Conservation Area. The slender-billed whitebreasted nuthatch has been confirmed in this habitat. This subspecies has declined significantly in the past 

century and is now limited to oak woodlands in Clark County. It is currently listed by the Service as a 

subspecies-of-concern, and is a candidate for listing by the WDFW. In addition, a number of rare or 

uncommon native wildflowers have been found in this habitat. 

Periodic low intensity fire is one of the key ecological processes affecting the viability of the oak 

woodland ecosystems. An anthropogenic fire regime by American Indians was probably present 

historically. Fire maintained open understory conditions in oak woodland, and favored dominance of oak 

over Douglas fir. The recent history of fire suppression on the refuge has allowed encroachment of 

Douglas fir and invasive plants in oak woodlands, and may have contributed to a decline in oak 

recruitment and in native wildflowers. To maintain this rare plant community, control of invasive plants, 

and planting oak seedlings or saplings, and maintaining sufficient forest floor light conditions by thinning 

dense, even-aged oak stands may be necessary.

Objective 5.1a Restore Oak Woodlands 

Restore 10-20 acres of oak woodlands benefiting migratory and resident land birds, as well as other 

native wildlife. Restored oak woodland has the following attributes: 

• Total canopy closure of 30%-80%, with no less than 70% oak canopy. 

• No conifers. 

• Native shrub layer > 40% (appropriate native species may include poison oak, snowberry, rose, 

spirea, and oval-leafed viburnum). 

• Mean diameter breast height (dbh) of oaks > 21 inches, with 20% of oaks > 28 inches. 

• < 20% cover of invasive plants (e.g., reed canarygrass and blackberry) in understory/herbaceous 

layer.

Strategies Applied to Achieve Objective

Use IPM strategies including mechanical, cultural, biological, and chemical means to eradicate, control, 

or contain invasive and undesirable plants (see Appendix K).

Use forestry techniques (e.g. hand-pull, girdle, cut, and spray) to remove encroaching conifers and other 

woody vegetation as necessary to maintain canopy dominance of oaks. 

Evaluate need to gather acorns and head-start seedlings for planting as part of subsequent stand 

maintenance and future habitat expansion. 

Use prescribed fire to maintain this fire-dependent habitat. Coordinate with Clean Air District to obtain 
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2-46 Chapter 2. Management Direction

permit for controlled burning of oak woodland and native grassland habitat.

Prohibit livestock grazing.

Endorse and partner (where feasible) with public and private agencies and adjacent landowners to 

maintain and enhance connectivity and forest habitat quality on adjacent lands.

Rationale: Restoring oak woodland habitat is consistent with the Service’s 2001policy on Biological 

Integrity, Diversity, and Environmental Health (601 FW 3). Oak woodland provides habitat for the 

slender-billed white-breasted nuthatch, which has declined significantly in the past century and is now 

limited to oak woodlands in Clark County. It is currently listed by the Service as a subspecies-of-concern, 

and is a candidate for listing by the WDFW. In addition, a number of rare or uncommon native 

wildflowers have been found in this habitat. Oregon white oak woodlands in the Willamette Valley/Puget 

Trough ecoregion are threatened and/or remain in a degraded condition due to an extensive history of 

conversion to agriculture and other land uses, grazing, and fire suppression. In the Willamette Valley 80% 

of oak woodlands present in 1850 have disappeared (Floberg et al. 2004; figures are not available for the 

lower Columbia region). 

Objective 5.2 Upland Mixed Forests

Enhance and annually maintain 15 acres of upland mixed forest benefiting migratory landbirds and 

other native wildlife. Upland mixed forests are characterized by the following attributes: 

• > 50% canopy cover of mixed deciduous and coniferous forest species (Douglas-fir, western red 

cedar, grand fir, Oregon white oak, Oregon ash and bigleaf maple). 

• > 30% cover of native deciduous shrubs (poison oak, common snowberry, rose, spirea, oval-leafed 

viburnum, native Rubus species, ninebark, Indian-plum, tall Oregon grape, and elderberry) and 

small sub-canopy trees < 15 feet tall (black hawthorn, vine maple, and beaked hazelnut) 

collectively cover > 30%. 

• > 30% herbaceous cover consisting of native forbs and ferns with a major native component of 

flowering perennial species (e.g., Solomon’s-seal, trillium, lilies, columbine, and sanicle).

• < 20% cover of invasive plants (e.g., reed canarygrass and blackberry) in understory/herbaceous 

layer 

Strategies Applied to Achieve Objective 

Inventory, prevent further spread of, and control encroaching blackberry and other invasive species into 

existing upland mixed forests. Assess canopy density to provide a mosaic of shade tolerant and 

moderately tolerant understory species. Annually monitor and treat approximately 20% of existing 

upland mixed forests for blackberry and other invasives (see Appendix K). Blackberry requires methods 

of control that are both cost and labor intensive. Habitat restoration of areas invaded by blackberry will

require cutting and spraying for several years in a row, and then planting with native vegetation.

Endorse and partner (where feasible) with public and private agencies and adjacent landowners to 

maintain and enhance connectivity and forest habitat quality on adjacent lands. 

Rationale: Maintaining existing upland mixed forest is consistent with the Service’s 2001policy on 

Biological Integrity, Diversity, and Environmental Health (601 FW 3). This habitat provides thermal 

cover, migration and dispersal corridors for a diverse assemblage of wildlife species, including 

amphibians, reptiles, and migratory landbirds. A number of rare or uncommon native wildflowers have 

been found in this habitat. Blackberry has overtaken native understory vegetation in the native mixed 

forest on the Carty Unit, including habitat for the small-flowered trillium, listed as Sensitive in 

Washington. 
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Chapter 2. Management Direction 2-47

2.4.6 Goal 6: Protect, enhance and where feasible restore riverine habitat and 

tidal wetlands representative of the historic lower Columbia River ecosystem, 

to benefit salmonids and other native aquatic species.

Objective 6.1 Instream and Riverine Habitats

Enhance and improve in-stream and riverine conditions of Gee Creek (3.76 miles) and Campbell 

Slough (2.6 miles) as well as other appropriate areas for the benefit of salmonids and other native 

aquatic species. Instream and Riverine habitat is characterized by the following attributes: 

• 7-day mean maximum water temperature < 63.5° F1. 

• Low turbidity (<70 nephelometric turbidity units [NTU]2

). 

• Lack of barriers to upstream spawning and rearing habitats. 

• Presence of instream woody debris. 

• Minimal presence of warm water fishes. 

1 WA water quality standards for salmonid spawning, rearing, and migration (WDOE 2006) 2 Threshold for avoidance by juvenile coho salmon (Bisson and Bilby 1982)

Strategies Applied to Achieve Objective 

Improve instream habitat conditions by planting riparian trees and shrubs (primarily willow, black 

cottonwood and Oregon ash) along the 0.8 miles of shoreline of Gee Creek, at a minimum, from the east 

refuge boundary to Middle Lake (Also see Objectives 4.1a and 4.3a). 

In Gee Creek, endorse watershed-wide approaches and partner (where feasible) with private and public 

agencies, and adjacent landowners to maintain temperature and water quality and reduce in-flow of 

siltation from upstream sources.

Pending results of study (see Objective 7.3), implement techniques to reduce populations and 

reproduction of carp without negatively affecting salmonids in Campbell Slough. Coordinate with 

WDFW on funding initiatives and partnerships. 

Based on results of sedimentation and fish passage assessments in lower Gee Creek (see Objective 7.7), 

implement restoration actions if necessary (e.g., deepen channel near the mouth, excavate historic (1929) 

channel, and other actions), to improve fish passage. 

Based on results of the Campbell Slough assessment for salmonid rearing habitat (see Objective 7.7), 

implement appropriate restoration actions if necessary (e.g., deepen channel, increase canopy cover, and 

eliminate passage barriers) to improve salmonid rearing habitat.

Rationale: Under this objective, aquatic habitat management activities will be developed and 

implemented to protect and restore instream/riverine habitats, for the benefit of salmonids, and other 

native aquatic species. Over the past 150 years, watershed conditions on the lower Columbia River and its 

tributaries have been severely degraded as the result of land use practices (e.g. forest clearing, agricultural 

uses, and urban and industrial development). Hydrologic regimes have also been altered by diking, 

channelization of streams and rivers, and dam operations. 

 

Gee Creek and Campbell Slough represent the major riverine habitats within the refuge that are 

connected to the Columbia River, and the connectivity is not directly affected by dikes. Approximately 

3.76 miles of Gee Creek, and all of Campbell Slough (2.6 miles) lie within refuge boundaries. The 

refuge also includes riparian areas adjacent to Lake River, Bachelor Slough, and the Columbia River. 

The refuge boundary extends only to mean high tide of Lake River, Bachelor Slough, and the Columbia 

River. Therefore, these water bodies are outside the refuge’s management control. Watershed-wide 

approaches and partnerships with private and public agencies and adjacent landowners will be necessary 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

2-48 Chapter 2. Management Direction

to maintain or improve habitat conditions in Lake River and Bachelor Slough. Management of the 

refuge’s riparian areas adjacent to Lake River, Bachelor Slough, and the Columbia River will have a 

slight influence on habitat quality, and nutrient dynamics of these waters. 

By being outside the dikes, Gee Creek and Campbell Slough likely possess habitat conditions similar to 

those historically present in the lower Columbia River, more so than other areas directly affected by 

dikes, and offer the best opportunities to restore some historic conditions. A comprehensive assessment 

of habitat conditions is needed to prioritize and guide restoration efforts (see Objectives 7.4 and 7.7). 

The present physical, chemical, and biological attributes of these habitats, including use by salmonids 

and other native aquatic species, need to be described and quantified to assess their current status. 

Implementation of habitat management/restoration strategies under this objective will be contingent upon 

the results of these studies. 

Several species/stocks of anadromous fish including coastal cutthroat trout, Chinook and coho salmon and 

steelhead spend portions of their life history either on or adjacent to refuge waters and shorelines on the 

Columbia River. Historically, Gee Creek, Campbell Slough, Lake River, Bachelor Slough, and shallow 

overflow lakes such as Campbell Lake served as nurseries for young developing salmonids. Spawning 

chum salmon were noted in a tributary of Gee Creek in the late 1940s, and there was an anecdotal account 

of coho salmon trying to get past a barrier near Royle Road on Gee Creek “prior to the 1950s.” Trout 

(mostly identified as cutthroat) have been reported anecdotally in the creek for many decades (Cornelius 

2006). 

Surveys in 1995-1997 found cutthroat trout, juvenile steelhead, and juvenile salmon (coho and Chinook) 

in lower Gee Creek. More recent surveys (2002-2005) conducted upstream of the earlier ones have 

found only cutthroat trout and juvenile coho in Gee Creek (Cornelius 2006). A May 2007 survey found 

juvenile Chinook salmon in Campbell Slough. Numbers of cutthroat trout in Gee Creek are low 

compared to similar creeks nearby. The creek has stretches of suitable habitat (Hogle 2006), but others 

appear to be of marginal quality. In addition to degraded habitat, low cutthroat numbers may be due in 

part to the presence of large numbers of warmwater fish, which compete with or prey upon native fish. 

The presence and size of cutthroat suggests that spawning occurs in the drainage, and therefore, habitat 

improvements could enhance populations of this species. The source of the juvenile coho in Gee Creek 

has not been determined and it is possible though unlikely, that coho spawning habitat may exist in the 

upper areas of Gee Creek off the refuge. 

Although Gee Creek and Campbell Slough offer the best opportunities to restore historical habitat 

conditions, these areas have been degraded by multiple stressors (both on and off the refuge) influencing 

water temperature, water quality, sediment transport, habitat complexity, and fish passage. Existing and 

new information generated by habitat and biological assessments (Objective 7.7) will be used to identify 

location-specific (e.g., on a stream or slough basis) habitat objectives for which management strategies 

will be developed. Using these strategies, specific management actions (e.g., protecting habitats, 

removing fish passage barriers, planting native vegetation, and modifying channel form) will be 

implemented. This approach will also be applied to areas where it is feasible to establish connectivity 

with the Columbia River. Because watersheds represent a natural unit for focusing habitat restoration 

efforts, the Service intends to engage in partnerships at the watershed scale to coordinate activities so that 

refuge actions are not negated by other activities within the watershed. 

The refuge is currently partnering in a project to improve instream habitat throughout the Gee Creek 

watershed. Although Gee Creek and Campbell Slough are the top priorities for habitat enhancement and 

restoration, where funding and partnership opportunities become available restoration/enhancement could 

be undertaken in other tidal and riverine habitat on the refuge.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-49

Conserving and restoring trout, salmon, and steelhead populations is an important regional priority, not 

only for protecting the species, but also because of their cultural, historical, and ecological value. These 

fish are important food sources for numerous wildlife species. Protection and/or restoration of instream 

habitats and tidal wetlands may also benefit turtles, amphibians, and waterbirds. Planting shoreline 

vegetation will improve water quality by creating shade and reducing shoreline erosion; and will provide 

habitat for migratory and resident landbirds.

Objective 6.2 Tidal wetlands 

Enhance and annually maintain 490 acres of tidally influenced freshwater wetlands for the benefit 

of anadromous fish, waterfowl, and wading birds. Attributes of this habitat include: 

• Hydroperiod and water depth naturally varies with the Columbia River. 

• ≥ 70% open water containing submergent plants (e.g., sago pondweed). 

• < 30% cover of tall, native emergent plants creating a mosaic. 

• Barrier-free passage for juvenile salmonids between the river/main sloughs and the wetlands. 

• 7-day mean maximum water temperature < 63.5o F1 and turbidity < 70 Nephelometric Turbidity 

Units2

 (NTU) during summer months. 

• Carp < 200 pounds per acre.

• < 10% cover of invasive plants (e.g., reed canarygrass).

1 WA water quality standards for salmonid spawning, rearing, and migration (WDOE 2006) 2 Threshold for avoidance by juvenile coho salmon (Bisson and Bilby 1982)

Strategies Applied to Achieve Objective

Allow natural processes to re-establish connection between Post Office Lake (approx 75 acres) and the 

Columbia River. (Also see tidal wetlands restoration and dike breach contingency plans, Objective 7.7.)

Within 2 years of CCP completion, initiate a Land Protection Plan study to analyze alternatives for 

possible refuge boundary expansion to include the portion of Post Office Lake and adjoining areas south 

of the current approved refuge boundary. (Also see Summary of Management Direction; tidal wetlands 

restoration and dike breach contingency plans, Objective 7.7.) 

Pending results of habitat assessment (see Objective 7.7), mechanically reopen areas of Campbell Lake 

that have become vegetated with persistent emergent vegetation, in order to set back succession and 

maintain open, shallow water areas. 

Use IPM strategies including mechanical, cultural, biological, and chemical means to eradicate, control, 

or contain invasive and undesirable plants including knotweeds, reed canarygrass, yellow flag iris, and 

false indigo-bush (see Appendix K).

Strategically locate water gaps and improve fencing along Campbell Lake to protect bank vegetation 

from livestock grazing in improved pastures. 

Use rotenone to remove carp from Duck Lake (4.6 acres.). After carp removal, remove blockages 

between Duck Lake and Gee Creek to re-establish historic connection. Install adult carp exclusion device 

(while permitting passage of juvenile salmonids) and reintroduce native submergent vegetation. 

Rationale: An estimated 90% of tidally influenced freshwater wetlands in the lower Columbia River 

region have been lost (Floberg et al. 2004). Diking and filling have been a primary cause of decreases in 

tidal wetland area in the Columbia River estuary. These actions eliminated most of the natural, tidal 

exchange of water, materials, and organisms between the Columbia River and the adjacent bottomland 

forests and shallow overflow lakes; however, limited exchange occurs through tide gates.
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2-50 Chapter 2. Management Direction

Tidally influenced freshwater wetlands along the lower Columbia River historically provided important 

rearing habitat for Chinook and coho salmon, cutthroat trout, and steelhead. Tidal exchange is important 

not only for the access and use of these habitats by fish, but also for maintenance of habitat-forming 

processes such as sedimentation and erosion. By restoring tidal exchange, these processes are restored, 

and the habitats can develop naturally as well as provide their functions to the ecosystem (Johnson et al. 

2003). 

Outside the dikes, some refuge wetlands retain tidal connections to the Columbia River. Tidal wetlands 

are currently present on the Roth, Ridgeport Dairy, Carty, and Bachelor Island units. About 40% of this 

habitat type is one large lake (Campbell Lake is 189.4 acres) on the Roth Unit. Other large tidal wetlands 

include Canvasback Lake on Bachelor Island (52.1 acres), Campbell Slough on the Roth Unit (29.6 

acres), and South Campbell Lake on the Ridgeport Dairy Unit. Tidal wetlands (a network of sloughs, 

channels and open lakes) are also located on the Carty Unit, totaling 101.9 acres. However, due to lower 

river levels and altered flooding regimes, water levels are lower than they were historically and some 

open water areas are being lost to tall emergents. Campbell Lake, in particular, is a tidal wetland that 

supports large numbers of migratory and overwintering waterfowl as well as an important roost for 

migrating sandhill cranes. A current concern is that open water is being lost to tall emergents, impacting 

waterfowl and crane habitat. Average year-round water levels within Campbell Lake appear to be 

consistently lower since the 1996-1997 flood seasons, when Campbell Lake was predominantly 

nonvegetated, exposed mudflat. Since then, emergent plant species have colonized much of the shallow 

wetlands and mudflats once utilized by roosting cranes. The middle and northern portions of the lake are 

still relatively vegetation-free; however, water levels may be too deep for roosting during the highest 

tides. This habitat change in Campbell Lake may account for the some cranes shifting their roosting sites 

to Canvasback Lake beginning in 2003, although additional comprehensive surveys are needed to 

delineate the roosting pattern with respect to waterfowl hunt days and variable water conditions. It is 

expected that if the vegetation trend continues on Campbell Lake, the site may lose its value as roosting 

habitat. Protection of current roost sites is essential as they provide unique features such as proper water 

depths and isolation that are not located elsewhere along the river (Engler et al. 2003). However, to date 

little effort has been placed on studying nonmanaged aquatic habitats on the refuge, including Campbell 

Lake. Effective restoration techniques rely on valid data and knowledge of habitat conditions. 

Restoration is likely to be difficult and costly. A habitat assessment of Campbell Lake (see Objective 

7.7) will be needed to provide refuge staff with necessary scientific information to restore and manage 

the lake comprehensively. 

Post Office Lake is a 73.7-acre permanent wetland on the Ridgeport Dairy Unit. The lake had at least 

some tidal connection to the Columbia River as late as the mid-1990s. Formerly, this lake had substantial 

use by diving ducks, but use by divers has declined over the past 10 years. Most of the lake lies within 

the refuge boundary but a small portion of the lake is on private land. It is separated from the Columbia 

River by a dike, which is not owned by the Service. The dike is in poor condition and is likely to fail 

during a major flood event. Dike failure would re-establish the tidal connection between Post Office 

Lake and the Columbia River, but would also flood private land south of the refuge. Rain-on-snow flood 

events are relatively common in western Washington. The last major flood of this type was in 1996 and 

overtopped and breached the Bachelor Island dike (USFWS 1996). Projected warmer, wetter winters 

associated with climate change suggest further increases in the risk of winter flooding (Mote et al. 2003). 

Because it is possible that a dike breach will occur within the lifetime of the CCP, this lake has been 

designated as a tidal wetland. Tidal wetlands restoration planning for the refuge (Objective 7.7) will

include a contingency plan for Post Office Lake in the event of a dike breach, as well as evaluating and 

developing strategies to maintain and/or enhance connectivity between the Columbia River and Post 

Office Lake. The refuge will also participate in a Land Protection Plan study for the Lower Columbia 

River area, including options to bring lands currently outside of the refuge boundary, under Service 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-51

management, either through cooperative agreement, conservation easement, or fee acquisition. A 

separate planning process, including public input and agency compliance requirements, will accompany 

this study (see Summary of Management Direction, page 2-6). 

The historic connection between Duck Lake (4.6 acres) and Gee Creek will be restored, thereby 

converting it from a permanent wetland to a tidal wetland. Before the introduction of carp, Duck Lake 

had abundant wapato beds. Wapato could be reestablished here if carp were controlled before 

reestablishing the connection to Gee Creek, and fish exclusion devices installed thereafter.

Outside of their extensive use by waterfowl and other migratory birds, little is known about submerged 

vegetation and other aquatic species inhabiting refuge wetlands. Carp enter Campbell Lake via Campbell 

Slough by the thousands during the breeding season. They probably occur in Post Office Lake as well. 

Carp are thought to represent a high threat to the functioning of the wetland system due to their impacts 

on submergent vegetation and water quality. Carp uproot and eliminate submerged vegetation, increase 

turbidity, and decrease the overall abundance and diversity of the invertebrate community (Miller 2006). 

However, despite the presence of carp in Campbell Lake, this lake still supports a reasonably high-quality 

native plant community and receives high waterfowl use. Reducing carp populations and reproduction 

will be beneficial to these wetlands; however, complete eradication of carp in an open (tidal) system is 

probably impractical.

2.4.7 Goal 7: Collect scientific information (inventories, monitoring, and 

research) necessary to support adaptive management decisions on the refuge 

associated with Goals 1-6.

Objective 7.1 Inventory and Monitoring Activities

Throughout the life of the CCP, conduct high-priority inventory and monitoring (survey) activities 

that evaluate resource management and public-use activities to facilitate adaptive management. 

These surveys contribute to the enhancement, protection, use, preservation, and management of wildlife 

populations and their habitats on- and off-refuge lands. Specifically, they can be used to evaluate 

achievement of resource management objectives identified under Goals 1-6. 

Strategies Applied to Achieve Objective 

Conduct surveys on goose foraging and habitat use in relation to habitat management objectives and 

techniques. Conduct vegetation monitoring on goose pastures utilizing established techniques including 

but not limited to measuring species composition, percent of vegetation cover, cover height, and 

palatability. 

Monitor composition and distribution of aquatic vegetation in managed wetlands every 2 to 5 years to 

determine need for and/or efficacy of treatments, and assess benefits to waterfowl. 

Inventory wetland plant communities and monitor effectiveness of invasive plant control measures

annually in seasonal and semi-permanent wetlands. Control any reinvasion by nonnative plants. 

Monitor water quality and temperature in Gee Creek and Campbell Slough. Continue work with the 

Estuary Partnership to collect and analyze water quality data at Campbell Slough.

Annually monitor vegetation (species composition and condition of plantings) in restored riparian and 

oak woodland habitat. 

Conduct breeding bird surveys, banding, and habitat assessments for grassland, riparian, and woodland 

species to determine the effects of restoration activities and habitat condition on nesting success and 
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2-52 Chapter 2. Management Direction

recruitment.

Monitor and treat up to 10% of floodplain/riparian forest, oak woodland, and mixed conifer forest, 

annually for invasive plants. Use IPM strategies including mechanical, physical, biological, and 

chemical means to eradicate, control, or contain invasive and undesirable plants (see Appendix K). 

Rationale: Monitoring the wildlife and vegetation response to habitat management practices is 

necessary to implement adaptive management techniques on the refuge. The Refuge Improvement Act 

requires the Service to monitor the status and trends of fish, wildlife, and plants on each refuge. An 

inventory and monitoring plan needs to be developed, and should include as priorities: The monitoring of 

vegetation and wildlife responses to habitat management activities; and the response of vegetation and 

wildlife to habitat restoration projects. 

Existing staff and funds are prioritized to perform the most pressing habitat management projects on the 

refuge, leaving few resources available to conduct studies of the effectiveness of habitat management or 

restoration treatments. This lack of data, for managed sites as well as appropriate reference sites that are 

necessary to account for variability, hinders the refuge’s ability to use adaptive management to evaluate 

the effectiveness of its management practices and make necessary course corrections. Additional staff 

positions needed to conduct inventory and monitoring activities are identified in Appendix D. 

Vegetation monitoring in goose pastures was conducted using various techniques between 1995 and 

2003. Loss of staff positions and funding has prevented data collection on goose use and vegetation since 

2003. This data is necessary to make decisions regarding management of goose habitat on the refuge. 

An opportunity exists to partner with universities and other refuges to study the relationship between 

forage quality and goose use. This information will be extremely useful in making decisions regarding 

the management of goose habitat on the refuge, determining carrying capacity, and conducting landscape 

level management of Canada geese on their wintering grounds in southwest Washington and Oregon. 

Objective 7.2 Conduct surveys

Conduct surveys for purposes species and other species of management concern, including dusky 

Canada geese: other subspecies of Canada geese and cackling geese; breeding waterfowl; sandhill 

cranes; bald eagles; and great blue herons.

Strategies Applied to Achieve Objective 

Participate in regionally based waterfowl surveys and banding studies, such as the mid-winter waterfowl 

survey, dusky Canada goose surveys, and other specific waterfowl surveys, following established 

protocols. 

Resume refuge-based goose surveys (all subspecies). Conduct goose surveys from October through May.

Conduct comprehensive regional roost, habitat use and distribution surveys for sandhill cranes to 

determine if vegetation and elevation changes in Campbell Lake are decreasing the value of the roost.

Conduct annual monitoring for the presence of sandhill cranes during the breeding season (April to 

August). Any cranes detected will be further monitored to determine nesting status. If nesting and/or 

brood-rearing activities are confirmed, the Refuge will determine whether any management actions 

would be appropriate. Non-essential Refuge activities that may increase disturbance and reduce nest 

success will be avoided to the extent practicable in these areas.

Continue to partner with the Oregon Zoo and other volunteers to conduct semi-annual great blue heron 

nesting surveys. Monitor size of nesting colony, and identify potential threats to production including 

loss of nesting habitat, contaminants, and disturbance. 

Conduct breeding waterfowl surveys (pair counts and reproduction surveys).

Assist with regional bald eagle nesting surveys. Identify potential short- and long-term threats to 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-53

production, including contaminants and disturbance.

Coordinate with other refuges and state wildlife areas in Oregon and southwest Washington to develop 

uniform survey protocols and collect data on seasonal use patterns and distribution of Canada and 

cackling geese.

Rationale: Surveys for purposes species and species associated with biological diversity, integrity, and 

biological health (BIDEH) are necessary to conduct adaptive management for these species on the refuge.

Dusky Canada Geese: The refuge has participated annually in regional dusky Canada goose surveys. 

While these surveys provide a population index for the entire population, they are inadequate to discern 

population shifts on a local level. Dusky use of the refuge appears to be declining. Updated information 

is needed on seasonal use patterns and distribution of dusky Canada geese in Oregon and southwest 

Washington to understand how geese are redistributing themselves in wintering areas. Combined with 

studies of the relationships between goose use and habitat type or forage quality, this will help managers 

develop regional strategies for managing dusky Canada goose wintering habitat.

Other subspecies of Canada geese and cackling geese: Although the refuge participates in the Midwinter Waterfowl Surveys, this survey does not provide a picture of local trends. Data from annual 

surveys go to the Migratory Bird Office which only provides the refuge with a flyway population total. 

Wintering Canada geese were surveyed between pre-1993 and 2004. Monitoring was modified in 1999 

to collect additional data on all refuge geese and their habitat use. However, these goose surveys were 

suspended after 2004 due to funding declines resulting in the loss of the biological technician position 

which conducted the daily surveys. As with duskys, updated information is needed on seasonal use 

patterns and distribution of Canada geese and cackling geese in Oregon and southwest Washington to 

understand how these geese are redistributing themselves in wintering areas. Combined with studies of 

the relationships between goose use and habitat type or forage quality, this will help managers develop 

regional strategies for managing wintering habitat for geese. Although various local surveys have been 

done, survey intensity, survey area, and protocols have changed considerably over time, rendering a longterm, direct comparison of survey results on a local basis difficult. A consistent approach and data 

sharing between refuges and wildlife areas in Oregon and southwest Washington is needed. Data on 

regional and state-wide habitat alterations/losses are not collected, so resource managers are unable to 

assess how local changes to goose habitat may affect populations and distribution. 

Sandhill Cranes: The refuge has partnered with The Nature Conservancy of Oregon to conduct sandhill 

crane roost surveys since 1991. A number of other surveys, studies, and banding projects were 

terminated between 1998 and 2002 due to lack of staff. Local concern regarding the viability of the 

migrant and wintering population of sandhill cranes dictates that habitat for this species should be 

effectively managed on the refuge. Recently, refuge staff has made periodic summer observations of 

sandhill cranes on the Bachelor Island Unit. In recognition of the breeding potential of sandhill cranes in 

the region, cranes will be monitored during the breeding season and nesting attempts will be documented. 

Great Blue Herons: Until 2009, Bachelor Island provided nesting habitat for over 400 pairs of great blue 

herons and great egrets. Only 96 nests were counted on Bachelor Island in 2009, but no adults were 

present during the survey and it is unclear if any young were fledged that year. Additional active 

colonies were located on the Ridgeport Dairy Unit during the summer of 2009, and these will be 

monitored in 2010 to confirm use. Potential causes of the colony decline may include lower availability 

of prey species, changes to nesting habitat (through natural succession or management changes), 

proximity to nesting bald eagles and corvids, and human recreation/ disturbance. In addition to these 

factors, management of water/hydropower, animal and human population changes, and presence of 

contaminants in river waters and sediments affect waterbird populations. Therefore, these populations 
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2-54 Chapter 2. Management Direction

will continue to change and provide a good barometer of habitat integrity. Monitoring these populations 

is essential for early identification of issues that may impact these populations. 

Bald eagle: The refuge provides nesting and/or summer foraging habitat for at least 7 pairs of bald 

eagles. The reproductive success of these eagles has been monitored since 1990 by the Oregon 

Cooperative Fish and Wildlife Research Unit at Oregon State University, as a part of larger cooperative 

state-wide surveys. With the delisting of the bald eagle in 2007, these surveys are expected to be 

curtailed. If so, the refuge should initiate efforts to continue monitoring current nest sites and expansions 

on the refuge to ensure compliance with the Bald Eagle Protection Act, and identify potential issues that 

may jeopardize nesting eagles.

The refuge also supports migrant and wintering bald eagles that utilize the Columbia River floodplain for 

foraging on salmonids, Pacific smelt, and other fish. The refuge provides a substantial foraging 

opportunity for eagles via the high populations of waterfowl that utilize the refuge. This food base is 

important, particularly for subadult eagles, and in between fish runs, when fish resources are scarcer. 

Objective 7.3 Partner to conduct invasive species monitoring and control, and studies of invasive 

species control techniques.

Strategies Applied to Achieve Objective

Pursue funding for a full time volunteer coordinator position to locate, train, effectively utilize, and retain 

volunteers to assist with invasive species monitoring and control efforts.

Conduct a refuge management study to identify appropriate integrated pest management strategies to 

control and/or eradicate ricefield bulrush on the refuge.

Monitor and map wetlands for invasive plants such as reed canarygrass, false indigo-bush, purple 

loosestrife, knotweeds, and yellow flag iris, and annually monitor effectiveness of invasive plant control 

measures.

Annually monitor the presence and extent of reed canarygrass, other invasive species, and native shrubs 

within wetlands containing water howellia. 

Partner to conduct invasive mammal (beaver and nutria) monitoring and investigate IPM techniques to 

control damage to water control structures and dike systems.

Monitor effectiveness of treatment for invasive plants in riparian and woodland areas (see Goals 4, 5).

Partner with other agencies to monitor refuge waters for exotic mollusks carried in ship ballast (zebra and 

quagga mussel).

Partner to conduct carp monitoring to determine current abundance/biomass, seasonal distribution, and 

spawning habitat. 

Develop and/or evaluate suitability of techniques to reduce populations and reproduction of carp and 

other warmwater fish in wetlands and instream habitat, without negatively affecting salmonids. 

Coordinate with WDFW on funding initiatives and partnerships. 

Rationale: Invasive weeds are the biggest habitat management issue on the refuge (see Chapter 4). A 

large percentage of the refuge’s annual operating budget goes towards control of invasive species, which 

includes mowing, spraying, disking, water management, and hand grubbing. Nevertheless, existing 

budgets and staffing levels do not allow as many acres to be treated for weeds as would be desirable. As 

a result, weeds are kept in check on areas of the refuge that receive treatment, but are spreading 

elsewhere on the refuge. Volunteers and partners will continue to be essential for controlling weeds on 

the refuge. However, some significant roadblocks to utilizing volunteers exist. Often the most effective 

treatment options involve physically taxing work (such as grubbing or hand pulling); application of 

herbicides; or using heavy equipment (mowing or disking). The number of volunteers willing or able to 

do this physically taxing work, or who have the necessary permits and certifications for pesticide 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-55

application or heavy equipment operation is limited. Many invasives grants are tied to using volunteers 

for invasive treatment, but these grants are often not feasible because volunteers cannot be used for the 

most effective treatment options. Finding qualified volunteers, and managing those volunteers requires a 

significant investment of staff time. A full time volunteer coordinator position is needed to locate, train, 

effectively utilize, and retain volunteers.

Weeds that have a particularly large impact on refuge habitats include reed canarygrass, Himalayan 

blackberry, and ricefield bulrush. Teasel, tansy ragwort, Canada thistle, poison hemlock, and Italian 

thistle are a problem in old fields, especially on the south end of the refuge. These invasives are a major 

concern for the Clark County Weed Management Program and the adjacent landowner. False indigobush was introduced to the upper Columbia River for bank stabilization and has migrated downstream 

with floods. Indigo bush lines the majority of suitable shoreline around the refuge. Some aquatic plants, 

for example water milfoil and curly-leaf potamogeton, are also a problem. Although native, horsetail 

(Equisetum) has begun to infest pastures and can be found as dominant vegetation in some fields. 

 

Invasive ricefield bulrush (Schoenoplectus mucronatus) was accidentally introduced to refuge wetlands 

in 1999, and was identified in 2002 (see Chapter 4). Significant refuge resources have been diverted to 

fighting this weed. Control methods to date have included hand pulling, spraying with herbicide, and 

altering water management in wetlands. Hand pulling has been successful in eradicating small satellite 

populations, and therefore, containing spread of ricefield bulrush into new areas. However control of 

bulrush in wetlands where it was originally seeded has not been attained. New and innovative 

eradication techniques (such as fire) may need to be used before eradication can occur. Before 

infestation of ricefield bulrush, management and restoration of wetlands to control canarygrass had 

included water drawdowns by May 1, followed by disking and rototilling. After the infestation of 

ricefield bulrush was discovered, this disking rotation regime for wetlands was discontinued. 

Consequently, canarygrass infestations in refuge wetlands have increased, especially in those units with 

bulrush. 

Invasive animal species are also a concern (see Chapter 4). Nutria damage wetland management 

infrastructure and eat native vegetation needed by native species, and cause problems with wetland 

management. Bullfrogs eat or compete with native species such as turtles, ducklings, and frogs. Carp 

reduce water quality and food availability in wetlands for waterfowl, waterbirds, and native salmonids. 

The refuge is also concerned about the introduction of exotic mollusks carried in ship ballast (zebra and 

quagga mussel). Asian clam is abundant in some areas of the refuge and New Zealand mudsnails are 

likely to be present. Zebra and quagga mussels have not been found in the Columbia Basin to date but 

are a serious potential threat; a monitoring program should be implemented.

Objective 7.4 Conduct Baseline Inventories of, and Sustain Applied Scientific Research On, Native 

Habitats, Vegetation, and Major Fish and Wildlife Groups

Conduct baseline inventories of habitat, plant, and wildlife resources on the refuge, with particular 

emphasis on wetland bathymetry; riparian and bottomland forest; the Blackwater Island RNA; and 

other areas likely to contain remnant native plant communities. Inventories should focus on 

determining the presence and abundance of birds, mammals, reptiles, amphibians, fish, rare plants and any 

key functional areas such as nest and roost sites. Inventories should also map the occurrence of invasive 

species.

Strategies Applied to Achieve Objective

Pursue cooperative funding and partner contributions for baseline inventories.

Develop and support research projects that explore factors affecting focus wildlife species and their 

habitats, with the intent to increase our understanding and ability to manage these resources.
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2-56 Chapter 2. Management Direction

Develop program to attract qualified researchers to conduct monitoring, surveys, and other studies on the 

refuge.

Conduct a wetland basin assessment and topographic survey of aquatic habitats (in conjunction with data 

collection needed for a tidal wetlands restoration plan; see Objective 7.7).

Update and refine wetland bathymetry data and maps for use in annual habitat work plans and restoration 

plans. Obtain bathymetric (fine contour) data, perform mass point conversions of existing LIDAR data to 

obtain 6 inch wetland contours. Prepare spatial template of slough and ditch network, including passage 

barriers and water control structures, and digital elevation model (DEM) for fine-scale topography 

mapping. 

Annually, monitor populations of water howellia during the blooming season (May-June) to verify 

population persistence and basin conditions. 

Reinstate landbird monitoring station (MAPS) on Bachelor Point.

Conduct breeding bird surveys for grassland birds to determine which pastures are primary nesting sites, 

and therefore, should be mowed late, remain in an unmanaged condition, or receive other management 

treatments.

Conduct surveys of fish species, distribution and abundance in Gee Creek, Campbell Lake, and Campbell 

Slough, with emphasis on salmonids, lamprey, and carp, to assist in identifying habitat restoration 

priorities (see Objective 7.7, Habitat Restoration Studies). 

Conduct aquatic habitat assessments in order to prioritize instream and riverine areas for enhancement or 

restoration (also see Objective 7.7, Habitat Restoration Studies). 

Conduct plant surveys in the Blackwater Island RNA.

Rationale: The Refuge Improvement Act requires the Service to monitor the status and trends of fish, 

wildlife, and plants on each refuge. Existing staff and funds are prioritized to perform the most pressing 

habitat management projects on the refuge, leaving few resources available to do baseline surveys. Few 

biological surveys have been conducted on the refuge in recent years, and older surveys are in need of 

updating, for example vegetation surveys of the Blackwater Island RNA and riparian areas outside the 

dikes are needed. Because there are currently no biologists or biological science technicians solely 

dedicated to the refuge, we will need volunteers and partnerships to conduct most survey activities. 

Although the avifauna of the refuge has been well described, comparatively little information exists on 

other fish and wildlife groups. Inventories of plant species occurring in native habitats on the refuge 

needs to be updated. Habitats, areas, or species groups where work is particularly needed follow. 

Nonmanaged wetlands and instream habitat. Effective restoration techniques rely on valid data and 

knowledge of habitat conditions. To date, little effort has been placed on nonmanaged aquatic habitats on 

the refuge, therefore, relatively little is known about their health and potential benefits. Habitat 

assessments of these systems and surveys of aquatic species will provide refuge staff with necessary data 

to restore and manage these habitats comprehensively.

Water howellia. Howellia aquatilis was surveyed in 1995 and again in 1998. The 1995 surveys located 

two new populations. This species is re-surveyed every year to assess habitat problems, i.e. reed 

canarygrass encroachment. 

Wetland plants. Wetland plant composition was conducted annually until the Scirpus issue arose in 

2002; the data has never been summarized adequately. 

Landbirds. Winter banding of songbirds occurred for many years between 1995 and 2003, providing 

information on species composition and some habitat use information. A landbird monitoring station 

(MAPS) was maintained on Bachelor Point for 10 years (1993-2003). A study by DeSante et al. (2004) 
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Chapter 2. Management Direction 2-57

showed that this station was one of the most productive and diverse within the Pacific Northwest.

Grassland Birds: Breeding bird surveys for grassland birds are needed to evaluate impacts on these 

species by weed control alternatives and pasture management techniques. These surveys will also help 

determine which pastures are primary sites for breeding birds, and therefore, should be mowed late, 

remain in an unmanaged condition, or receive other management treatments.

Fish and Mollusks. Surveys for fish have occurred over the past 15 years in part through specific 

fisheries studies conducted by the Service. These studies have occurred primarily on the Carty Unit within 

the Gee Creek system. The refuge hosts primarily warmwater, nonnative species but also supports rearing 

habitat for salmonids such as coho and Chinook salmon, and cutthroat trout. Lampreys have also been 

identified in Gee Creek. Remaining tidal wetlands on the refuge such as Campbell Lake have not been 

fully surveyed for anadromous fish. Managed wetland units have not been surveyed systematically but are 

known to host warmwater fishes, as well as native stickleback. Aquatic habitats on the refuge are 

potentially suitable for native mussels but a systematic inventory has never been conducted. 

Blackwater Island RNA. The RNA is known to contain rare habitat types (Oregon white oak/ovalleaf 

viburnum/poison oak woodland) and support rare and sensitive species such as water howellia and the 

slender-billed white breasted nuthatch, which is a Federal species of concern, and a candidate for listing in 

Washington. There is the potential for several rare species of mammal, reptile, and amphibian species to 

be present as well. Inventories of the Blackwater Island RNA include vegetation surveys and community 

descriptions developed from the 1970s through the early 1990s (Morrison 1973; Tabor 1976a, b; and 

Christy and Putera 1993), annual surveys for the federally-listed water howellia, and pit trap and live trap 

mammal and amphibian surveys conducted in the 1990s. Updated inventories of native habitats and 

vegetation, and habitat conditions (including presence of invasive species) are needed in order to manage 

grasslands and oak woodland habitat on the RNA. 

Small mammals. The refuge lies within the historic range of the western gray squirrel (State threatened, 

Federal candidate), the Mazama (Western) pocket gopher (State threatened, Federal candidate), and graytailed vole (State species of concern). Clark County is considered core habitat for the gray-tailed vole. 

Suitable habitat for these species may exist on the refuge, but their presence has not been confirmed. 

Virtually no information exists on bats occurring on the refuge. Further information will help us to 

understand refuge species richness and diversity.

Native amphibians. The refuge conducted pitfall trapping for amphibians (frogs and salamanders) and 

small mammals during 1995-1997 in selected habitats, which provided a good idea of what species occur 

and what habitats they use. However, not all species are sampled adequately by pitfalls, so gaps remain. 

The refuge also conducted frog breeding surveys on the River ‘S’ Unit in 2000; this provided additional 

information on habitats utilized for breeding as well as some data on other amphibian species. Painted 

turtle trapping occurred from 1996-2000; painted turtle telemetry was conducted in 2001. These studies 

provided data on population and habitat use on the River ‘S’ and Bachelor Island units. Information on 

nesting sites and production is lacking. Only the amphibian breeding information has been analyzed with 

a report written (Beale and Akins 2001).
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2-58 Chapter 2. Management Direction

Objective 7.5 Partner to evaluate feasibility of techniques for reintroduction of rare and listed 

species native to the lower Columbia River and Willamette Valley/Puget Trough ecoregion. 

Partner with Recovery Teams and State agencies to identify potential habitat areas for the 

reintroduction of rare and listed species; the feasibility of reintroduction; and habitat or population 

management strategies. If reintroduction is determined to be feasible, prepare specific habitat and 

wildlife objectives. The following species are currently under consideration for reintroduction:

• Columbian white-tailed deer (lower Columbia River population) (Federal endangered, State 

endangered). 

• Western pond turtle (Federal species of concern; State endangered). 

• Bradshaw’s lomatium (Federal, State endangered). 

• Golden paintbrush (Federal threatened, State endangered). 

• Nelson’s checkermallow (Federal threatened, State endangered).

Strategies Applied to Achieve Objective

Continue partnership with the Washington Natural Heritage Program to evaluate feasibility and 

techniques for introducing Bradshaw’s lomatium and Nelson’s checkermallow on the refuge. Conduct 

test plantings of rare plant species to determine suitable reintroduction sites. 

Within 5 years, partner with the Columbian White-tailed Deer Recovery Team to conduct a feasibility 

study for the establishment of a population of CWT deer on the refuge. 

Continue partnership with WDFW to survey for western pond turtles to determine if this species is 

successfully breeding on the refuge, and the age structure of the population. 

In partnership with WDFW, conduct a feasibility study to determine whether sufficient habitat exists to 

establish a breeding population of western pond turtles on the refuge, including evaluation of 

reintroduction sites for head-started turtles. 

Rationale: Restoring populations of species which historically occurred (or may have occurred) on the 

refuge is consistent with the Service’s 2001 policy on Biological Integrity, Diversity, and Environmental 

Health (601 FW 3). Species were selected for reintroduction feasibility studies primarily due to their 

sensitive status (threatened, endangered, etc); because they may have historically occurred on the refuge; 

and/or because suitable habitat exists on the refuge, and therefore, the refuge has an opportunity to 

contribute to recovery efforts. Specific information is summarized below. 

Listed Willamette Valley Plants: The Draft Recovery Plan for Bradshaw’s lomatium specifies that 

recovery will require at least two stable populations in permanently protected status in southwest 

Washington (USFWS 2007). The Washington Natural Heritage Program is currently partnering with the 

refuge to evaluate the feasibility or and techniques for introduction of Bradshaw’s lomatium on the refuge.

Test plantings were conducted in February 2007, with an additional planting of seedlings in the winter of 

2007-2008 (Arnett 2007). A similar approach should be used to determine suitable reintroduction sites for 

other rare plants. 

In 2007, the refuge worked with the Service’s Ecological Services offices and the Washington Natural 

Heritage Program to outplant 1,000 seedlings of Nelson’s checkermallow on the refuge. The initial 

planting occurred in fall 2007, with subsequent plantings conducted in following years. Experimental 

plantings were done in Smith Lake Field (11.5 acres) and Hundred Acre Field (43.6 acres) on Bachelor 

Island; and Texas Island and the Kiwa Trail on the River ‘S’ Unit. A Section 7 consultation allows for 

supplemental plantings only in those plots designated in the original Section 7. Additional plantings 

would require a new Section 7 consultation. 

Columbian White-tailed Deer (CWT deer): The Columbian White-tailed Deer Recovery Plan 

(USFWS 1983) recommends that a minimum of 400 deer be maintained in three viable subpopulations 
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Chapter 2. Management Direction 2-59

occupying secure habitat. Currently, most of the secure habitat for the lower Columbia River population 

of CWT deer is on the Julia Butler Hansen Refuge. At present, only 1,600 acres of secure habitat exists 

outside this refuge. Increasing the deer’s range and numbers above the minimum recovery goals will

reduce the risk of catastrophic losses to disease and floods, and will be consistent with Service policy on 

biological integrity and diversity. Ridgefield Refuge has been proposed as a reintroduction site for CWT 

deer. 

A strategy in the CCP is a study to determine the feasibility of establishing a population of CWT deer on 

the refuge. The study will evaluate: Whether the refuge has enough appropriate habitat to support a selfsustaining CWT deer population; if establishing a population of CWT deer would conflict with managing 

for refuge purposes; and if habitat management for refuge purposes species and priority resources of 

concern will also meet the needs of CWT deer. Current habitat management for purposes species, and 

habitat management proposed in the CCP, will support a mix of habitats suitable for CWT deer. The 

major issues of concern associated with a reintroduction are: 

• Dispersal of deer onto adjacent private lands; 

• Presence of predators that could cause undesirable levels of fawn mortality; and 

• The lack of connectivity between the refuge and other suitable habitat, leading to an isolated 

subpopulation. 

Refuge staff supports the reintroduction as long as existing management for purposes species can 

continue, and staff and funding resources are not diverted from purposes species. A nonessential 

experimental population (NEP) designation would allow more management flexibility should deer move 

onto private lands adjacent to the refuge; however NEPs must be managed as threatened species on 

Federal lands. In addition, it may not be possible to determine if Ridgefield deer belong to the 

reintroduced population or dispersed upriver from the Julia Butler Hansen and Lewis and Clark refuges. 

Therefore, the designation of reintroduced deer will also be addressed in the feasibility study. 

Western Pond Turtle: The refuge may provide suitable habitat for the western pond turtle, a species 

listed as endangered by the State. A single adult western pond turtle was found on the refuge in 2005, but 

no others have been found during subsequent trapping. The WDFW has expressed interest in 

reintroducing western pond turtles to the refuge. The feasibility of an introduction must be assessed, 

including an evaluation of whether sufficient habitat exists to maintain a breeding population; whether 

the refuge’s management activities are compatible with establishing a breeding population of pond 

turtles, and whether establishing a breeding population will materially detract from the purposes for 

which the refuge was established. 

Objective 7.6 Partner to conduct mosquito population surveillance to provide for public 

health and safety concerns.

Strategies Applied to Achieve Objective

Continue to renew Special Use Permits for the Clark County Mosquito Control District to monitor larvae 

on the refuge and treat ponds for mosquitoes. Follow established and current mosquito surveillance 

protocols. 

Continue to allow Clark County Mosquito Control District to treat ponds on the refuge for mosquitoes, 

with applications of the larvicide Bacillus thuringensis var. israelensis (B.t.i) via backpack or buggy 

pack, if dip surveys show an average of 5 mosquito larvae in 10 dips. 

Rationale: The public is concerned about mosquitoes as a vector for West Nile virus. Mosquitoes can 

also be a quality of life issue (a nuisance) when people want to go outside in habitats occupied by 

mosquitoes. The Clark County Mosquito Control District has responsibility for mosquito control in the 

local area. The District has an annually renewed Special Use Permit that allows mosquito crew members 
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2-60 Chapter 2. Management Direction

to visit the refuge to monitor larvae at specific sites and during specific time periods during the year. 

Monitoring consists of collecting dip samples from target wetlands; when there is an average of 5 

mosquito larvae in 10 dips, treatment can occur. The District currently treats wetlands on the refuge that 

have been identified through monitoring as significant mosquito breeding sites. Mosquito larvae are 

treated with applications of the larvicide Bacillus thuringensis var. israelensis (B.t.i) via backpack or 

buggy pack. 

The Service recognizes that mosquitoes are an integral part of the food chain, both adult and larvae, 

providing a food resource for a multitude of bird, fish, amphibian, and other aquatic species. Mosquito 

larvae are an important detritivore in many aquatic systems, and therefore, crucial for decomposition of 

organic matter and ultimately water quality. While difficult to validate in complex aquatic habitats, it can 

be surmised from basic ecological principles and simplified predator/prey relationships that an abundance 

of food (mosquito larvae) translates into increased reproduction and survival in predator species. This in 

turn, can have a significant beneficial effect up the food chain for many species of wildlife. 

Unfortunately, these periods of increased food resources (mosquito outbreaks) also cause the most 

consternation with some of the public. The Service is, therefore, working to find a balance between the 

ecological values of mosquitoes and mosquito control. 

Objective 7.7 Conduct studies to determine the feasibility, need, and priorities for habitat 

restoration projects; and to develop or refine restoration techniques.

Strategies Applied to Achieve Objective

Within 5 years, establish study plots to evaluate techniques for enhancing ash recruitment and restoring 

native understory in Oregon ash floodplain forests (also see Objective 4.3).

Following wetland basin assessment and mapping and aquatic habitat assessments (Objective 7.4) 

develop a tidal wetlands restoration plan for the refuge. In the plan, evaluate the feasibility of, and 

develop strategies to, restore, maintain, and/or enhance connectivity between Columbia River and 

backwater sloughs, lakes, and ponds, including Post Office Lake. This should include a prioritization of 

sites for restoration, and a contingency plan in the case of dike breaching caused by a major flood event 

(see Objective 6.2).

Assess sedimentation and fish passage in lower Gee Creek to determine potential impediments to fish 

movement, and evaluate appropriate restoration actions (e.g., deepen channel near the mouth, excavate 

historic (1929) channel, and other actions). 

Assess Campbell Slough relative to salmonid rearing habitat (i.e., water temperature, depth, cover, and 

passage) and evaluate appropriate restoration actions (e.g., deepening channel, and increasing canopy).

Conduct habitat assessment of Campbell Lake, including emergent cover and sedimentation rates, to 

determine need for vegetation removal, dredging, or other habitat enhancement and restoration actions. 

Rationale: Native habitats along the lower Columbia River have been lost or highly degraded by the 

introduction of nonnative plants and animals, past land management practices (e.g. livestock grazing, and 

fire suppression) and alterations to natural hydrology (levees, and dams). Alterations to natural 

hydrology have been particularly problematic for riparian habitat; because without seasonal flooding and 

periodic scouring events, recruitment of native trees such as black cottonwood and Oregon ash is poor. It 

is desirable to reduce cover of nonnative vegetation and increase cover of native species in the refuge’s 

extant native plant communities. It is also desirable to restore historic connections between former tidal 

wetlands and the Columbia River. However, habitat restoration is both costly and labor intensive. 

Efforts to return highly altered areas to their precontact condition, or to a self-sustaining system, are 

fraught with difficulties due to the altered nature of the surrounding environment. In some cases, altered 

or heavily managed habitats (e.g. pasture, and managed wetlands) can meet habitat requirements for 

native species. Therefore, studies to determine the need and priorities for restoration, and to investigate 

the feasibility and effectiveness of restoration techniques, are needed before any large scale actions are 
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Chapter 2. Management Direction 2-61

undertaken.

Objective 7.7a Grassland restoration feasibility study.

Within 15 years, conduct habitat assessment to determine the feasibility of restoring up to 40 acres 

of native grassland habitat for grassland-dependent birds and native plant species. Native grassland 

habitat is characterized by the following attributes: 

• Optimal patch size or

• A mosaic of vegetation heights between 6 and 36 inches. 

 contiguity with old field/old field border habitat is > 15 acres. 

• > 50% cover of native grass (e.g. Roemer’s fescue (Festuca idahoensis var. roemeri), red fescue 

(Festuca rubra), prairie junegrass (Koeleria macrantha), slender hairgrass (Deschampsia

elongata), or California oatgrass (Danthonia californica); and native forbs (e.g. clover, western 

bittercress (Cardamine occidentalis), and American vetch (Vicia americana), western wood 

strawberry (Fragaria vesca), spring beauty (Claytonia), chickweed (Cerastium), California brome, 

and blue wild rye. 

• < 20% cover of invasive/undesirable nonnative grasses (e.g. reed-canarygrass), forbs (e.g., ox-eye 

daisy, thistle and trefoil), and shrubs (e.g. blackberry).

Strategies Applied to Achieve Objective

Within 15 years, conduct habitat assessment to assess the feasibility of restoring up to 40 acres of native 

grassland habitat for grassland-dependent birds and native plant species.

To prioritize areas for grassland restoration, conduct surveys and/or test plantings to identify areas with:

• Little goose use; 

• High use by ground nesting birds; 

• High potential for use by other native species;

• Existing native plant community components; 

• Good potential and appropriate site conditions for establishment of native grasses and forbs;

• Patch size large enough to benefit native ground nesting birds, with adequate adjacent dispersal 

areas for young; and 

• Inactive, formerly grazed or cultivated lands or areas no longer needed for crop production.

Rationale: Currently, approximately 400 acres of old fields (abandoned former pasture and agricultural 

lands) on the refuge provide nesting habitat for grassland-dependent birds, and migration corridors and 

thermal cover for amphibians and small mammals. However these fields are dominated by nonnative 

grasses and forbs, and many are currently in rank, weedy condition with limited value to wildlife. 

Approximately, 260 acres are suitable for restoration to riparian and other habitat types and are identified 

as such. The remaining 140 acres of old fields could be restored to a native grassland community. Native 

grasses and forbs will provide improved habitat for native wildlife. Restoration will involve mechanical 

and chemical weed control, fall native grass drilling, and selective plantings of native forbs. However, 

relatively little is known about native upland grassland communities on the refuge, and appropriate species 

for restoration will need to be determined using existing reference sites in the region with similar soils, 

hydrology, and climate, followed by test plantings of selected species and site monitoring to determine 

efficacy of restoration and need for follow up treatments. The long-term feasibility of restoring “islands” 

of native grassland within large tracts of nonnative pasture grasses should also be assessed. The needs of 

high priority grassland wildlife species including nesting and/or wintering waterfowl, raptors, short-eared 

owls, western meadowlarks, and savannah sparrows must also be carefully considered prior to initiating 

restoration projects. 
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2-62 Chapter 2. Management Direction

Objective 7.7b Wet Meadow/Prairie Restoration Feasibility Study

Within 15 years, conduct a study to assess the feasibility of restoring a native wet meadow plant 

community in areas dominated by reed canarygrass. Wet meadow is characterized by the following 

attributes:

• Hydric soils. 

• Flat or very gently sloping topography. 

• > 50% cover of native grasses and forbs such as Columbia sedge, tufted hairgrass, camas, spike 

bentgrass, dense sedge, California oatgrass, annual hairgrass, meadow barley, American 

sloughgrass, one-sided sedge, Western mannagrass, spreading rush, wild barley, and buttercup. 

• < 5% cover of native shrubs (e.g., willow, and Douglas’ spirea). 

• < 20% cover of undesirable nonnative grasses (e.g. reed-canarygrass). 

• Water depths ranging from moist soil to 4 inches from December through at least March. 

• No willows.

Strategies Applied to Achieve Objective

Compare the efficacy of techniques to control reed canarygrass (tillage and prolonged flooding, and 

mowing combined with herbicide treatment). 

Identify sites with good potential and appropriate site conditions for native plants by conducting test 

plantings where reed canarygrass control has been achieved.

Use site monitoring and multiyear follow-up treatments in study areas.

To prioritize areas for wet meadow restoration, conduct surveys and/or test plantings to identify areas 

with:

• High use by dusky Canada geese, or appropriate patch size and proximity to wetlands; 

• High potential for use by other native species; 

• Existing native plant community components; 

• Good potential and appropriate site conditions to contribute to native plant recovery. 

Rationale: Wet meadow, or prairie, is a primary foraging habitat for dusky Canada geese. It also can 

provide foraging areas for species such as American wigeon, sandhill cranes, and shorebirds; and nesting 

areas for northern harrier and ducks. Wet meadows were once a common habitat type along the lower 

Columbia River. Columbia sedge was probably the dominant species; however, today Columbia sedge 

meadows are extremely rare, with only one high quality occurrence along the lower Columbia River 

(Christy and Putera 1993). Other possible wet meadow species include tufted hairgrass, camas, spike 

bentgrass, dense sedge, California oatgrass, annual hairgrass, meadow barley, American sloughgrass, onesided sedge, Western mannagrass, spreading rush, spikerush, sedges, wild barley, and buttercup (Campbell 

2004; and Wilson et al. 1998). 

Current wet meadows on the refuge, for example the Carty Unit’s Long Meadow, are overflow sites from 

lakes or wetlands. These sites are dominated by reed canarygrass. It is desirable to reduce reed 

canarygrass cover and increase cover of native grass and forb species. Converting reed canarygrass stands 

into native plant communities is time and resource-intensive, requiring 2-3 years of initial treatments, and 

continued monitoring and follow-up for up to 5-10 years to prevent reinfestation (Kilbride and Paveglio 

1999; Paveglio and Kilbride 2000; and Tu 2004); also see recommendations in Campbell (2004) for 

restoring native wet prairie. The most effective treatment strategy for controlling reed canarygrass in large 

areas involves tillage and prolonged deep flooding, which is not practical in the refuge’s wet meadow 

areas. Mowing combined with herbicide treatment is another option; however, multiple applications over 

several years are likely required to achieve desired habitat conditions. A question remains whether native 

plant species are in the seed bank, if not native species would need to be planted. 

Native grassland plantings were attempted in Smith Lake Field (11.5 acres), 8 Spit Field (6.7 acres), and 
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Chapter 2. Management Direction 2-63

the far south end of Hundred Acre Field on Bachelor Island. Smith Lake Field was disked and planted to 

natives in 2002. The native grasses did not persist, and the area was replanted in 2007 before the 

experimental Nelson’s checkermallow planting. The native grass plantings on 8 Spit Field and the far 

south end of Hundred Acre Field (approx 20 acres total) did not persist and have not been replanted. Long 

Meadow on the Carty Unit (27.7 acres) is an area where restoration of native wet meadow or prairie could 

be attempted. Because of the potentially high cost and labor intensive nature of wet meadow restoration, a 

study to investigate the effectiveness of restoration techniques is recommended before any large scale 

action is undertaken.

Objective 7.8 Monitor effects of public use programs on the refuge’s wildlife and habitat. 

Periodically monitor and evaluate public use sites and programs to determine if objectives 

are being met and the resource is being degraded.

Strategies Applied to Achieve Objective

Monitor public use levels by activity on the refuge using established visitor counting techniques; prepare 

seasonal activity estimates for visitors by type and location.

Monitor effects of visitor activities on wildlife and re-evaluate program every 5 years.

Monitor effects of hunting activities on distribution and habitat of cackling geese and dusky Canada 

geese, and re-evaluate goose hunting program every 5 years.

Monitor effects of auto tour usage on distribution of sandhill cranes, dusky Canada geese, and other 

waterfowl, and re-evaluate auto touring program every 5 years. 

Conduct systematic monitoring of trail use to determine the amount of usage, trail condition, and the 

effects of this use on wildlife and habitat.

Conduct systematic monitoring of free-roam hiking on the Carty Unit to determine amount of use and 

effects on wildlife and habitat. 

Further investigate wildlife disturbance effects with on-site studies. Develop protocol for monitoring 

impacts to habitats at public use sites.

Rationale: A substantial body of scientific literature has documented the disturbance effects of human 

activities, including recreational activities, on wildlife (Owens 1977; Boyle and Sampson 1985; Bartelt 

1987; Cole and Knight 1990; Havera et al. 1992; Klein 1993; Klein et al. 1995; Knight and Cole 1995; 

Gabrielsen and Smith 1995; Madsen 1995; Madsen and Fox 1995; Hamann et al. 1999; Pease et al. 2005; 

and USGS 2006). The refuge is mandated by law to provide wildlife-dependent recreational 

opportunities; however, these should not materially interfere with the refuge’s ability to manage for 

purposes and trust species. Waterfowl, sandhill cranes, nesting bald eagles, and nesting great blue herons 

are species of particular concern because they are especially sensitive to disturbance. Therefore, the 

refuge must design public use programs and facilities based on the best available science on disturbance 

effects, monitor changes in wildlife use patterns following changes to public use programs and facilities, 

and make adjustments as necessary should disturbance reach unacceptable levels.
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2-64 Chapter 2. Management Direction

2.5 Ridgefield Refuge Cultural Resources Goal and Objectives

2.5.1 Goal 1: The Refuge will protect and manage its cultural resources for 

their educational, scientific, and cultural values for the benefit of present and

future generations of Refuge users and communities.

Objective 1.1 Inventory, evaluate, monitor, and protect the Refuge’s cultural resources.

Strategies Applied to Achieve Objective

Identify cultural resources that coincide with existing and planned roads, facilities, public uses areas, 

habitat projects, and other undertakings in compliance with Section 106 of the National Historic 

Preservation Act (NHPA). Evaluate threatened and impacted sites for eligibility to the National Register 

of Historic Places (NRHP). Plan and implement activities to avoid or mitigate impacts to significant 

cultural resources as necessary.

Evaluate and prioritize areas for shoreline protection. Stabilize cultural resources (as needed) along the 

banks of Lake River or the Columbia River that are threatened by bank erosion.

Coordinate with the State Historic Preservation Offices (SHPO) and WDNR to protect cultural resources 

below mean high tide along refuge shorelines. 

Complete a comprehensive cultural survey of the refuge as called for in Section 110 of the NHPA, and 

pull together all previous site surveys, work requests, and reports for easy access by managers.

Submit nomination to place the Cathlapotle village site on the National Register of Historic Places.

Cooperate with others to conduct archaeological investigations for the refuge, as appropriate. 

Within one year of hiring, train refuge law enforcement officers in the enforcement of the Archaeological 

Resources Protection Act (ARPA), Native American Graves Protection and Repatriation Act 

(NAGPRA), and other State and Federal cultural resource regulations. 

Conduct periodic visits to known archaeological and historic sites, and maintain written records and 

photo documentation. 

Bi-annually, provide all refuge staff with 2-4 hours of training on managing historic, archaeological, and 

cultural resources. 

Pursue funding and space to provide secure storage/curation on the refuge that meets Department of the 

Interior (DOI) museum standards.

Review, and edit if necessary, brochures, flyers, the refuge website, and other outreach materials to 

strengthen statements on cultural resources protection. 

Rationale: The refuge contains several archeological sites including the Cathlapotle Village site which is 

one of the few sites in the lower Columbia River that has not been lost to erosion, development, or looting 

(Ames et al. 1999). This site is both regionally and nationally important and should be nominated for 

inclusion in the NRHP. The refuge also contains a historic basalt quarry district which is on the NRHP. 

Although further excavations for the purposes of archaeological study are not envisioned, excavations may 

occur as needed, at new building sites or to protect cultural resources. All such activities will be 

conducted in compliance with NHPA, NAGPRA, and other applicable federal laws and regulations.

Protection of cultural resources on the refuge from looting or shoreline erosion is also an issue of concern. 

Bank stabilization was completed at the Wapato Portage site; however, anglers are causing damage to 

riprap placed over the site. Erosion from boat wakes may threaten cultural resources at the refuge. The 

refuge should explore the potential for shoreline bank stabilization and bioengineering at eroding shoreline 

areas to protect cultural resources listed on or eligible for listing on the NRHP.
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Chapter 2. Management Direction 2-65

In 1996, the refuge entered into a Memorandum of Understanding (MOA) with the ACHP and the SHPO 

which stipulated that the artifacts from Cathlapotle could be housed in a facility on or close to the refuge 

should such a facility become available. The refuge is currently in negotiations with FVNHP to accept the 

Cathlapotle collection for curation. A stipulation of acceptance is that ownership of the collection will 

transfer to FVNHP after five years if an acceptable facility has not been created at the refuge. The Tribes 

want to be informed about the location of artifacts recovered from the refuge (for example if they are 

loaned out for museum display or study.) 

Objective 1.2 Coordinate and Consult with Tribes on Cultural Resources Protection.

Strategies Applied to Achieve Objective

In partnership with Tribes and the Regional Cultural Resources Team, establish "protocols for 

consultation" to help managers meet NHPA and NAGPRA requirements including consultation, 

identification, inventory, and evaluation of projects and sites. 

Establish NAGPRA protocols and procedures for handling inadvertent discoveries of human remains, 

burial objects, sacred objects, and objects of cultural patrimony. 

Meet at least semiannually to discuss programs and projects with cultural resources staff from the 

Cowlitz Indian Tribe; Chinook Indian Tribe; and Confederated Tribes of the Grand Ronde. 

Coordinate with the Tribal cultural resources programs to identify and plan for protection of significant 

sites.

Ensure that information generated from archaeological investigations is shared with Tribes.

Rationale: The Chinook Indian Tribe, Cowlitz Indian Tribe, Confederated Tribes of the Grand Ronde, 

Shoalwater Bay Tribe, Confederated Tribes of the Warm Springs, and the Yakama Indian Nation have a 

cultural interest in the refuge, either because the refuge lies on lands historically occupied by these Tribes, 

or because these Tribes have descendants of families that once occupied the refuge. Issues of concern to 

the Tribes include: Conduct of archaeological investigations, storage of artifacts recovered from the 

refuge, cultural resource protection, repatriation of human remains and other objects of cultural patrimony, 

and education and interpretation programs related to Tribal cultures. Although the refuge has had 

consultations and meetings with Tribes in the past, it is important that communication and consultation 

become more regular and systematic. 

At this time, further excavations are not envisioned, except as needed at new building sites or to protect 

cultural resources. However, the artifacts recovered from the Cathlapotle site continue to be the subject of 

scientific investigations and are still yielding important information about the lifeways of the people who 

lived at this site for the past 3,000 years. 
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2.6 Ridgefield Refuge Public Use Goals and Objectives

2.6.1 Goal 1: Waterfowl hunters of all abilities will enjoy a quality, safe

hunting program that provides a variety of waterfowl hunting experiences, 

promotes youth hunting, balances hunt program needs with other public use 

program needs, and reduces impacts to nontarget species. As a result of 

participating in the waterfowl hunting program, hunters will gain a better 

appreciation of the refuge’s mission and its resource management.

Objective 1.1a Provide a quality, safe, waterfowl hunt program on 790 acres of the refuge, 

capable of supporting approximately 2,000 hunter visits per season, including youth hunts

and disabled hunters, and reducing conflicts between hunters, adjacent landowners, and 

other user groups.

Objective 1.1b Increase opportunities for duck hunters to hunt desirable waterfowl 

species, for example, mallard, wigeon, and pintail.

Objective 1.1c Provide goose hunting opportunities on 790 acres of the refuge while 

reducing the disturbance to, and rate of take of, dusky Canada geese.

Strategies Applied to Achieve Objective

Limit disturbance to dusky Canada geese in primary foraging habitat by maintaining existing total closure 

to hunting in the Roth, Ridgeport Dairy, and Bachelor Island units (River ‘S’ Unit only open to waterfowl 

hunting). 

Allow both goose and duck hunting in south end of River ‘S’ Unit (207 acres, blinds 17-19).

Only ducks, geese, and coots may be taken in accordance with Washington State bag and possession 

limits. Hunters will check all harvested waterfowl prior to leaving the refuge. 

Hunters will use existing open roads and parking areas to access hunting sites. Camping, overnight use, 

and fires are prohibited.

Rehabilitate Teal Marsh and establish 1-2 new blinds on west side of River ‘S’ Unit to compensate for 

loss of blind 4 to new bridge construction (see Objective 2.6).

Move hunter check station to visitor contact station; rehabilitate the old check station site and habitat to 

offer greater flexibility in blind spacing and replacement. 

Where feasible, use gradual floodup to create shallow-water areas on the River ‘S’ Unit to increase 

habitat for desirable waterfowl species; as needed, move blinds or use mobile or alternate high and low 

water blinds. 

Every 2 years, reevaluate ADA access at existing hunt blinds; and upgrade where feasible. Additionally, 

reevaluate the rate of occupancy and demand for accessible hunting blinds relative to number of blinds 

reserved for hunters with disabilities. 

Rationale 1.1a: The waterfowl hunting opportunities that are currently offered at the refuge are quite 

popular and allow people of all abilities to enjoy hunting. Since 1965 the refuge’s waterfowl hunting 

program has served an average of 44.7 hunters per hunt day. Over the last decade, the program serves 

45.6 hunters per hunt day. By this measure, demand for waterfowl hunting on the refuge has remained 

relatively constant since the refuge was established. The consistency of this data set counters Statewide 

projections of declining numbers of waterfowl hunters. This suggests that hunters have moved to 
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Chapter 2. Management Direction 2-67

Ridgefield as hunting opportunities elsewhere have declined.

The hunting reservation system is an attractive feature of the refuge’s hunt program. This system 

guarantees reservation holders with up to two guests, access to a hunt blind on the day of the reservation. 

In addition, the reservation system provides hunters a better selection of blinds and avoids delays. The 

reservation system is popular with hunters that want assurances they will have access to the blinds on a 

specific day. The reservation system is currently attracting approximately 175 reservation requests per 

hunting day. With 19 reservations generated per hunting day, an applicant to the reservation system has 

about a 1 in 9 chance of being selected on a particular hunting day. It is currently difficult to quantify if 

demand for the reservation system is increasing. The reservation application system changed three years 

ago from one to three application periods per season, and from 10 to 30 maximum picks in the reservation 

lottery. Therefore, long term direct trends in the reservation system are problematic. Since the new 

reservation system was implemented, there has been an increase in applicants to the reservation system of 

approximately 10% over three years. By this measure, the new application system is showing increased 

interest by refuge waterfowl hunters. 

When the refuge was established, it was assigned a purpose, to provide wintering habitat for dusky Canada 

geese and other waterfowl. The importance of the refuge to dusky Canada geese was explicitly 

recognized: “The dusky Canada goose has an extremely limited winter range, concentrated along the 

Willamette and lower Columbia rivers. This subspecies is limited in numbers and requires protection and 

habitat to insure its continued existence.” Today, the management of wintering dusky Canada geese and 

their habitat continues to be the refuge’s priority. “Substantial public shooting” was also specifically 

mentioned as a refuge purpose. Over the years the refuge has also maintained a quality public waterfowl 

hunting season with approximately 1,760 hunt visits during a typical season. The refuge’s waterfowl hunt 

program represents one of two public waterfowl hunt programs in Clark County. The refuge uses the only 

public hunting advance reservation system in Washington, west of the Cascades. Comparing the refuge’s 

average duck harvest from 2003 to 2007 (2,917 ducks) to the projected duck harvest for Clark County 

(9,651 ducks) suggests that the refuge’s 790-acre hunt program harvests 30% of all ducks in the 656 

square mile county. The refuge has established and continues to maintain a substantial public hunt 

program within southwest Washington. 

A major habitat concern is the loss of suitable habitat for ducks, geese, swans, cranes, and other purposes 

species. As of the early 1990s over half of the historic riverine wetlands in the lower Columbia River had 

been lost or substantially degraded as a result of flow regulation, diking, draining, filling, and dredging 

(Christy and Putera 1993). An estimated 90% of tidally influenced freshwater wetlands in the lower 

Columbia River region have been lost (Floberg et al. 2004). Losses within the lower Columbia River 

below Portland, Oregon include 52,000 acres of wetland/marsh and 27,000 acres of forested wetland 

habitat; these losses have significantly reduced the ecosystem’s ability to produce and sustain wildlife 

resources (USACE 2008). Projected population growth over the next 20 years will add 500,000 people to 

the Portland-Vancouver metropolitan area. During the life of the CCP, there will be a continuing trend of 

loss, degradation, and fragmentation of wildlife habitat in the region. This loss will put greater pressure on 

wetland obligate species, including swans, ducks, geese, herons, and sandhill cranes. Wildlife will place 

higher demands on the remaining wetlands, as they congregate in greater densities in suitable habitat. 

While the Refuge Improvement Act recognizes that wildlife-dependent recreation is an appropriate use of 

Refuge System lands, the Act also mandates that the needs of wildlife come first on refuges. Opening 

additional refuge wetland areas to any public use through this planning process would effectively reduce 

the refuge’s value to wintering waterfowl, dusky Canada geese, and other purpose species. Due to current 

and projected losses of waterfowl habitat in the area related to development and increasing demand for all 

public uses, it is not feasible to significantly increase the number of acres hunted on the refuge. Safety and 
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2-68 Chapter 2. Management Direction

hunt quality concerns also limit the number of blinds in the existing area. For these reasons, significant 

expansion of the size of the hunt area, or increasing the number of blinds within the existing hunt area, was 

considered but dismissed. 

It is our intent to maintain the current number of hunting blinds, thereby, not reducing overall hunter 

opportunity. Under the CCP, the hunt area and number of blinds will remain the same as present. The 

number of ADA accessible blinds (2) is reasonable and meets the current need. Additional ADA 

accessible blinds or programmatic changes concerning access to blinds may be needed over the next 15 

years to meet the needs of a growing and aging population. 

Reducing User Group Conflicts: Since the refuge was established over 40 years ago, the local 

population surrounding the refuge, and nonconsumptive uses of the refuge (wildlife observation and 

photography) have increased significantly. This has led to conflicts between hunters, other user groups, 

and neighboring landowners. During public scoping, many hunters complained that traffic on the auto tour 

route decreases the quality of the hunting experience (desire for solitude free from outside distractions) 

and causes birds to flare away from blinds. However, it has also been argued that auto tour traffic may 

benefit hunters by keeping birds moving. Hunters have also complained about shot from other blinds 

raining down on them. In the past, houseboat residents have complained about noise and pellet spray. 

These conflicts have been resolved to some degree as the public use and hunt programs have evolved. 

Blinds have been spaced to reduce pellet spray and where necessary, directional blinds have eliminated 

house boat conflicts. Strategies under this objective will further address resolving those conflicts. 

Two strategies to reduce hunter conflicts with nonconsumptive users were considered in the Draft 

CCP/EA: reducing the length of the auto tour route during the hunt season; and closing the auto tour route 

on hunt days, or during the entire hunt season. Alternative 4 of the Draft CCP/EA proposed closing the 

south end of the auto tour route October 1-March 15. However, the primary rationale for this seasonal 

closure, combined with moving the hunt area north, was to reduce disturbance to duskys and cranes in a 

core use area. This strategy did not address user group conflicts because auto touring and hunting would 

still be happening concurrently on most of the River ‘S’ Unit. Closing the tour route during all or part of 

the hunt season was considered in the Draft CCP/EA but dismissed from further consideration. This 

strategy would have addressed hunter concerns, but would have had a very large impact on the majority of 

visitors to the refuge, by severely limiting wildlife observation and photography opportunities during the 

peak observation season. 

Rationale 1.1b: Currently the refuge spends approximately $10,000 annually to operate electrical pumps 

to fill and maintain wetland water levels within the waterfowl hunt area during the hunting season. Water 

is pumped onto the managed wetlands in early fall (September). As winter rains add more water to these 

wetlands, it is necessary to pump water off to avoid flooding refuge roads, and other infrastructure. 

Because out-pumping generally cannot keep pace with inflow from rains, this pumping regime creates 

relatively deep-water conditions for most of the fall through spring season. Water depth coupled with the 

availability of vegetative food resources have created conditions within the hunt area that favor ducks deft 

of gathering food from near the water’s surface (shovellers) and diving ducks (ring-necked ducks and 

scaup). Currently, shovellers are the primary bird species harvested on the refuge (30%), whereas 

statewide, shovellers comprise only 2-3% of hunter bags (USFWS 2005). When the refuge was 

established, wigeon were the primary bird taken (40% of bags) with mallard and pintail coming in second. 

Hunters have reported that water is too deep near the blinds, and have expressed a desire for habitat 

management to create shallower water that enhances availability of food plants and attracts more desirable 

species of dabblers. Hunting quality will likely improve because changes in wetland management (e.g. 

rotation, gradual floodup, see Habitat Objective 3.1) could be expected to increase the proportion of 

desirable species. Savings in pumping costs could be used to address other habitat management needs. 
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Chapter 2. Management Direction 2-69

Rationale 1.1c: Sanctuary Area for Dusky Canada Geese and Other Waterfowl: The necessity for 

sanctuary areas free from human disturbance has been noted in the Pacific Flyway Management Plan for 

the Dusky Canada Goose (PFC 2008) and the Pacific Flyway Management Plan for the Cackling Canada 

Goose (PFC 1999). Providing secure feeding and roosting habitat for duskys is the refuge’s top priority 

since it was the primary establishing purpose for the refuge. “Substantial public shooting” is also 

specifically mentioned in the refuge’s purpose, including “A portion of the area in line with management 

findings, but not to exceed 40%, will be considered for waterfowl hunting in the future” (see Chapter 1).

When the refuge was established both wildlife and public use were addressed in the purpose statement. 

Since the refuge’s establishment, hunting and other wildlife-dependent recreation have been identified as 

priority public uses of Refuge System lands to receive enhanced consideration by the Refuge 

Improvement Act. Should a conflict arise between a public use and biological purposes of the refuge, the 

Refuge Improvement Act mandates that the needs of wildlife come first. Additional planning guidance 

comes from the Dusky Canada Goose management plan, which proposes that the Service, WDFW, and 

ODFW “Develop new public land management guidelines that result in increased goose food production 

and reduced disturbance of geese during winter, especially for dusky geese.” With the increasing 

population of southwest Washington and loss of waterfowl habitat, providing sanctuary areas for 

waterfowl is more critical than ever.

Hunting can alter behavior (e.g., foraging time), population structure, and distribution patterns of wildlife 

(Owens 1977; Raveling 1979; White-Robinson 1982; Thomas 1983; Bartelt 1987; Madsen 1985; and 

Cole and Knight 1990). These impacts can be reduced by the presence of adjacent sanctuary areas closed 

to public use. Sanctuaries or nonhunt areas have been identified as the most common solution to 

disturbance problems caused from hunting (Havera et al. 1992). Currently, 4,458 acres on the refuge are 

closed to waterfowl hunting. Monitoring has shown that geese relocate onto these sanctuary areas of the 

refuge during the hunting season and most geese stay on the refuge during the hunt season rather than 

relocate to other areas (Anderson 2001). They may also relocate to sanctuary areas on nearby refuges 

and wildlife management areas. The Roth and Ridgeport Dairy units, in particular, are heavily utilized 

by dusky Canada geese. Some pastures on Bachelor Island receive use by duskys. Some dusky use has 

also been noted north of Rest Lake, on the River ‘S’ Unit outside the hunt area. 

The Bachelor Island Unit is heavily utilized by cackling geese, disturbance to and take of cackling geese 

is a management concern. Recent concerns over declining numbers of cackling geese have made 

providing sanctuary for this subspecies (in order to meet treaty obligations to Native Alaskans) a high 

priority for flyway managers. For these reasons, the Service will maintain current sanctuary areas and 

public use closures, and maintaining the hunt area and auto tour route in their current locations. 

Reducing take of dusky Canada geese: In 8 of the past 15 seasons, goose hunting has been closed 

early on the refuge because the dusky Canada goose quota was met. Duskys have been taken 

disproportionately from blinds located on the south end of the River ‘S’ Unit (blinds 15 and 17-19). 

From 1995 to 1999, four blinds in this area were closed to see if this was effective in reducing take of 

duskys. While 2 out of 4 seasons had to be closed prematurely during this period, it took significantly 

longer to meet the quota of 10 duskys (an average of 20 days, versus 13 days in the years when these 

blinds were not closed.) On the other hand, blinds 17-19 are extremely productive and popular duck 

blinds. For this reason, the Service will keep blinds 17-19 open for both goose and duck hunting, with 

the expectation that goose hunting may be closed early in most years. 

The State of Washington implemented additional techniques to reduce the take of dusky Canada geese. 

Nearly a decade ago, all goose hunters in Goose Management Area 2 had their goose hunt authorization 

revoked. All hunters interested in hunting geese in Management Area 2 in subsequent seasons had to 
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2-70 Chapter 2. Management Direction

retest into the program by showing aptitude in goose subspecies identification. This honed hunter 

identification skills and purged intermittent hunters from the program with presumably less experience or 

proficiency in subspecies recognition. 

2.6.2 Goal 2. Visitors of all abilities have the opportunity to participate in 

safe, quality wildlife-dependent recreation programs, including wildlife 

observation, photography, interpretation, and fishing, consistent with the 

needs of other public use programs, with limited wildlife disturbance in the 

face of increasing Refuge visitation. These programs will focus on enhancing 

public understanding and appreciation of wildlife and building support for 

the refuge. 

Objective 2.1 Provide facilities for self-guided wildlife observation and photography 

opportunities on the River ‘S’ and Carty Units, while limiting the impacts of noise and 

human activity to sensitive species.

Limit disturbance to sensitive species (dusky Canada geese in primary foraging habitat, roosting 

sandhill cranes, nesting bald eagles, and nesting great blue herons) as follows: 

• Roth, Ridgeport Dairy, and Bachelor Island Units: Maintain existing total closure to public use, 

except for special guided tours. 

• River ‘S’ Unit: Closed to walking October 1-April 30.

Strategies Applied to Achieve Objective

Evaluate the impacts, compliance and demand and determine the need to expand the photo blind 

program. 

Improve wetland conditions in the vicinity of the observation blind to improve photographic and wildlife 

observation opportunities. 

Where feasible, plant native trees and shrubs to create screening along trails and at observation points to 

reduce disturbance to wildlife. 

Require advance reservations for groups over 20 on the River ‘S’ Unit to avoid conflicts with other 

groups and management activities.

Require advance reservations for groups requiring staff or volunteer assistance on the Carty Unit to avoid 

conflicts with other groups and management activities.

Prohibit camping, overnight use, fires, and littering.

Prohibit collection of plants and animals unless a Special Use Permit is obtained from the refuge (except 

for recreational fishing). 

Provide signs, pamphlets, and verbal instructions from refuge staff and volunteers that promote 

appropriate use of trails, blinds, and platforms to minimize wildlife and habitat disturbance. These 

materials will clearly state pertinent refuge-specific regulations.

Rationale: Along with Sauvie Island, Jackson Bottoms, and the Sandy River Delta, the refuge is one of 

the top birding spots in the Portland-Vancouver area. In public scoping there was a high demand for 

increased opportunities to view and photograph wildlife on the refuge. Refuge records indicate that 

currently 15% of refuge use is on the Carty Unit and 85% on the River ‘S’ Unit, mostly on the auto tour 

route. Carefully planned, improved, and expanded wildlife viewing facilities will allow the refuge to 

manage visitation to limit impacts to wildlife and habitats. Improvements to the Carty Unit (Objective 

2.3) will help attract visitors, while reducing public use demands on and impacts to the River ‘S’ Unit.

The refuge supports large flocks of migrating or overwintering waterfowl and cranes, and breeding habitat 
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Chapter 2. Management Direction 2-71

for several groups of species, including colonial waterbirds, raptors, and waterfowl. The Roth and 

Bachelor Island units contain important sandhill crane roosts, great blue heron nesting colonies, and bald 

eagle nesting areas.

Sanctuary area and/or buffers from human activity were identified as a key ecological attribute supporting 

the refuge’s wildlife communities. The necessity for sanctuary areas free from human disturbance have 

been noted in the Pacific Flyway Management Plan for the Dusky Canada Goose (PFC 2008) and the 

Pacific Flyway Management Plan for the Cackling Canada Goose (PFC 1999). Management 

recommendations published by WDFW recommend a 1,640-foot buffer from construction activities for 

sandhill crane roosts, a 2,620-foot buffer from new construction and increased traffic for crane feeding 

areas, and an 820- to 985-foot buffer between the outer edge of great blue heron colonies and human 

activity from nest initiation (February 15) through fledging (July 31) (WDFW 2004).

Recent literature on wildlife disturbance indicates that of public uses currently or formerly allowed on the 

refuge, hunting, foot traffic, and bicycling have the greatest disturbance effects on waterfowl and 

waterbirds. People walking or bicycling cause more ducks to fly than vehicular traffic does (Klein 1995; 

and Pease et al. 2005). Distance from the activity is also a factor. (Flight response is of greatest interest 

because it requires the highest energetic output for birds.) To date, public use on the Roth, Ridgeport 

Dairy, and Bachelor Island units has been limited to a few guided birding tours annually. Reasons for 

limiting public use include providing secure feeding and roosting habitat for dusky Canada geese, cackling 

geese, and for subspecies of Canada geese named in the Canada Goose Depredation Plan (PFC 1998); and 

limiting disturbance of roosting sandhill cranes, nesting great blue herons, and nesting bald eagles. Effects 

of public use programs on wildlife and habitat should be monitored and programs adjusted, if needed (see 

Inventory and Monitoring Objective 7.8).

Objective 2.2. Maintain a 4.0-mile year-round auto tour route that provides visitors 

opportunities to view and photograph wildlife, and supports a maximum of 200 vehicles on 

peak use days. 

Strategies Applied to Achieve Objective

Auto tour route remains open year-round in current configuration, except a 0.3 mile section on the 

southeast corner is cut off to reduce disturbance to geese and cranes using Swartz Pasture.

Should regular visitation to the auto tour route regularly exceed 200 vehicles per day, consider 

alternatives to reduce congestion on the tour route (excluding special events, like BirdFest, that impose 

anticipated and temporary visitation peaks). Strategies to reduce congestion may include buses, trams,

private vehicle reservations, or permits. 

Construct pullouts or passing lanes a minimum of one every 0.5 mile so that vehicles can pass more 

easily.

Pave or apply surface treatment to auto tour route using Refuge Roads funds to minimize summer dust 

and annual maintenance, if daily average during peak season exceeds 150 cars per day. 

Construct a maintenance lane between contact station and Roth Gate to allow refuge staff, cooperators, 

and equipment to safely access the southern portions of the refuge. 

Rationale: The looped configuration of the auto tour route, which opened in 1998, has proven to be 

extremely popular with wildlife watchers and photographers. Refuge records indicate that currently, 85% 

of refuge use is on the River ‘S’ Unit, mostly on the auto tour route. After the auto tour route was 

established and foot traffic on the River ‘S’ Unit was limited to the nonwaterfowl season (May 1-

September 30) and on designated trails only (Kiwa Trail and auto tour route), visitors reported that they 

saw more birds, and seemed more satisfied with the quality of wildlife viewing and photography 

opportunities on the refuge. These observations are consistent with studies of wildlife disturbance that 
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2-72 Chapter 2. Management Direction

concluded that many species of waterfowl habituate to vehicle traffic compared with walking and 

bicycling which cause more disturbance (Klein 1995; and Pease et al. 2005). Use by some wildlife 

species has decreased in the auto tour route area, (e.g. sandhill cranes and dusky Canada geese), but it is 

difficult to establish the cause of these declines. Data that show a direct link between the auto tour route 

expansion and declines in wildlife use are lacking. Goose surveys before and after the tour route was 

expanded to its current configuration do not show a clear trend. It is likely that a combination of factors 

including cessation of grain planting in the area, changes in habitat, and establishment of the auto tour 

route, contributed to declines in use by some wildlife species. Under the CCP, the Service will eliminate 

a short portion of the tour route adjacent to Schwartz Field, which is frequently used by cranes and dusky 

Canada geese. This will reduce the length of the tour route from 4.3 to 4.0 miles. 

The advantages of the auto tour route are that it allows visitors of all abilities to observe wildlife and it is 

also a convenient way for visitors with limited time or mobility impairments to observe wildlife. As noted 

above, slow-moving vehicles cause fewer disturbances to wildlife than pedestrians or bicyclists, and 

therefore, the auto tour offers visitors a high probability of seeing wildlife. The disadvantages are that 

auto touring does not provide visitors with a direct, personal experience of nature and the solitude that 

some prefer. Dust and exhaust emissions are environmental impacts of the auto tour route. 

Hunters have complained that traffic on the auto tour route decreases the quality of the hunting experience. 

Conversely, it has also been argued that auto tour traffic may benefit hunters by keeping birds moving. 

Two strategies to reduce conflicts between hunters and users of the auto tour route were considered in the 

Draft CCP/EA: reducing the length of the auto tour route during the hunt season (Alternative 4); and 

closing the auto tour route on hunt days, or during the entire hunt season. Alternative 4 did not address 

user group conflicts because auto touring and hunting would still be happening concurrently on most of 

the River ‘S’ Unit. Closing the tour route during all or part of the hunt season would have addressed

hunter concerns, but would have had a very large impact on the majority of visitors to the refuge, by 

severely limiting wildlife observation and photography opportunities during the peak observation season. 

This strategy was considered but dismissed in the Draft CCP/EA. Due to the fact that the auto tour route 

allows large numbers of visitors of all ages and abilities to observe and photograph wildlife, and the lack 

of clear evidence that the auto tour route has reduced wildlife use of the area, the auto tour route will 

remain in its current location and be open year-round, except for a eliminating the portion adjacent to 

Schwartz Field.

Traffic on the auto tour route has been increasing and is expected to continue to increase over the next 15 

years (see Chapter 5). Heavy traffic on the auto tour route is already a problem on holidays and on 

weekends during peak waterfowl use times, and is likely to increase to the point where a quality wildlife 

viewing experience can no longer be provided. In the future there are likely to be increasing conflicts 

between wildlife watchers and photographers vying for the best viewing sites on the auto tour route. The 

strategies above propose ways to limit auto tour traffic once it reaches unacceptable levels. Unacceptable 

levels are based on current peak use days associated with special events or attractions. In addition, 

wildlife use of the area will be monitored and the program re-evaluated as needed (see Inventory and 

Monitoring Objective 7.8).
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Chapter 2. Management Direction 2-73

Objective 2.3. Provide 6.9 miles of seasonal pedestrian access on refuge trails and roads 

and 2 miles of year-round pedestrian access on refuge trails. 

Enhance and improve wildlife viewing, interpretation, trails, and facilities at the Carty and River 

‘S’ units. 

Strategies Applied to Achieve Objective

Add a 1.5-mile (out and back) dike-top walking trail on north end of River ‘S’ Unit, open between May 1 

and September 30. 

Construct elevated wildlife viewing platform/observation deck near the end of the new1.5-mile dike-top 

trail offering views of Bachelor Island Slough and remote views of Bachelor Island, River ‘S’ Point, and 

River ‘S’ Unit.

Partner with City/County to connect the Carty Unit to the City of Ridgefield via a trail being developed. 

Improve existing spur trail from Gee Creek to the Carty Unit for school groups walking to the refuge. 

Continue to allow free-roam walking on the Carty Unit. If the number of annual visitors to the Carty Unit 

exceeds 40,000, or if resource degradation warrants, limit use through seasonal closures or a quota/permit 

system (also see Objective 7.8, Monitoring)

Work with the City of Ridgefield, Clark County, and other partners to examine linkages between regional 

trails and refuge trails, when and where they are compatible with refuge purposes. 

Seek joint funding for trail and facility construction.

Improve the service road around the Plankhouse over Gee Creek to facilitate all season passage to Carty 

Field. Pending development of the Port of Ridgefield property, a trailhead could be developed at the Port 

of Ridgefield’s waterfront, and connected back to town via a 1.5-mile developed refuge trail. Given the 

elevation of this trail, strategies may include board walks and elevated wetland crossings. 

Rationale: Currently, most public use at the refuge is focused on the Carty and River ‘S’ units. (A 

limited number of guided tours are conducted on the Roth and Bachelor Island Units but no public use 

facilities have been developed on these units.) During public scoping there were many requests to allow 

self-guided access into areas that are currently seasonally or permanently closed to public use. After 

careful consideration, the planning team has recommended that new facilities−new or improved hiking 

trails and overlooks−should be confined to the existing public use footprint, in order to preserve existing 

sanctuary areas. However, guided tours of these areas are proposed (see Objective 2.4). A proposal to 

build trails and viewing platforms in the Roth and Ridgeport Dairy units was considered but not proposed 

due to impacts to sensitive species. Linkages to trails south of the refuge will be best accomplished 

through a cooperative effort to build a trail and overlook on nonrefuge land to the east of Lake River. A 

variety of tools to prevent trespass into closed areas and disturbance to wildlife will be used, including 

seasonal closures, design and placement of trails and access points, and public education efforts.

The current Oaks to Wetlands Trail on the Carty Unit provides a relatively flat two-mile nature walk 

through native oak and mixed woodland habitats, and along the shores of several wetlands. However, the 

trail could be improved with certain modifications. Most pressing is the replacement of an outdated 

pedestrian bridge with a bridge that is accessible to all users. This was considered in a separate EA due to 

funding timelines (see Chapter 1). More of the Oaks to Wetlands Trail could be made accessible, and a 

section of all-weather trail created between Middle and Carty Lake. The CCP proposes improving 

accessibility of trails within 1/8 mile of the Plankhouse.

 

Users also requested enhancement of viewing areas along the south side of the slough, which can be 

provided by opening the dense vegetation along the shoreline area. There is an intriguing potential

opportunity to connect the Oaks to Wetlands Trail directly to the City of Ridgefield via the Gee Creek 

spur trail. The trail will facilitate safe pedestrian visits and local school educational visits to the Carty 
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Unit from town. The refuge, along with the City of Ridgefield and partners, will need to develop bridge 

and trail accommodations across Gee Creek. Access will also allow bicycle access to the proposed 

nature center and Carty footbridge. Bicycle access will be limited to the Carty administrative site.

The Carty Unit also provides free-roam walking opportunities year-round. Although much public use on 

the refuge is structured through facility or program design, some visitors desire a more unstructured 

experience where they can explore the refuge alone or in small groups. They desire an immersion 

experience in undeveloped or very lightly developed areas where they can experience solitude, and 

explore the wildlife and habitats of the refuge with a minimum of distractions from modern life and other 

user groups. At the present time, the Carty Unit provides this experience since there are some portions of 

this unit where very few people go. However, given increasing visitation and development surrounding 

the refuge, there is a question as to whether the refuge can realistically continue to provide these 

opportunities in the future, while preserving the sanctuary areas necessary to meet wildlife and habitat 

goals and objectives. Monitoring of visitation, wildlife and habitat will be necessary to ensure that this 

use continues to be compatible with the needs of wildlife (see Inventory and Monitoring Goal 7.8).

The River ‘S’ Unit provides excellent viewing of large concentrations of waterfowl in the fall and winter 

from the auto tour route, as well as waterfowl hunting opportunities. A 1.1-mile seasonal walking trail 

(Kiwa Trail, open May 1-September 30) is also provided on the River ‘S’ Unit. Walking is allowed on the 

4.3-mile auto tour route between May 1 and September 30, however, relatively few people use this 

opportunity due to the presence of cars on the route. A proposed 1.5-mile dike-top walking trail on the 

north end of the River ‘S’ Unit (Alts 2, 3, and 4) will provide scenic views of the refuge and adjoining 

waterways while safely removing hikers from the auto tour route. 

The refuge will work with Clark County and other partners to plan linkages between local trail systems 

and refuge trails, when and where they are compatible with refuge purposes. Currently, proposed trails 

with potential linkages include the Lewis and Clark Greenway Trail, a Vancouver to Ridgefield walking 

trail (Vancouver-Clark Parks and Recreation 2006), and a Waterfront Trail at the proposed Miller’s 

Landing development at the site of the old Pacific Wood Treatment plant adjacent to the refuge’s Carty 

Unit (Port of Ridgefield 2008). The City of Ridgefield has long-term plans to create a passive trail 

system along Gee Creek. With several new subdivisions being planned adjacent to Gee Creek, this trail 

system could greatly increase visitation to the Carty Unit.

There is also an increasingly popular canoeing and kayaking route along the refuge’s shoreline and 

around Bachelor Island via Bachelor Island Slough. Although the refuge has no jurisdiction over these 

waters, undertaking cooperative efforts to define and advertise a canoe/kayak trail along the refuge 

shoreline will expand visitor awareness of safe boating opportunities, enhance users’ ability to view and 

enjoy riparian and aquatic birds and other wildlife, and promote good wildlife viewing ethics.

Objective 2.4. Conduct up to 25 volunteer-guided wildlife tours annually, to provide 

visitors with access to areas of the refuge that are otherwise closed to protect sensitive 

species. Tours will focus on expanding visitors’ awareness of the flora and fauna of 

riparian, grassland, wetland, and oak woodland habitats. 

Tours will focus on expanding visitors’ awareness of the flora and fauna of riparian, grassland, wetland, 

and oak woodland habitats.

Strategies Applied to Achieve Objective

Develop standards and requirements for volunteer guides or the Friends group’s Naturalist Corps to 

conduct guided walks. 

Authorize non-Service organizations (Vancouver and Portland Audubon, and Friends Groups) to lead 
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guided wildlife observation and photography on designated refuge areas.

Develop periodic programs of scheduled tours focusing on areas and times not currently open to the 

public, or tours to unique resource areas. Tours will be led by refuge staff, qualified volunteers, and/or 

designated content specialists. Tours may include full moon hikes, night tours for bats/owls, and bird call 

tours for visually impaired refuge visitors.

Expand current programming for guided natural history hikes, refuge history hikes, and spring/fall guided 

birding hikes. These hikes will be conducted by qualified personnel/volunteers and will be open to all 

public at no cost beyond the entrance fee. 

Rationale: There is considerable demand from birdwatchers to be able to view wildlife on the Roth, 

Ridgeport Dairy, and Bachelor Island units. Due to the presence of sensitive species and biological 

resources, guided/structured wildlife observation and photography opportunities will be emphasized on 

the Bachelor Island, Roth, and Ridgeport Dairy units. Disturbance to sensitive wildlife species will be 

limited by providing reasonable buffers between the visiting public and heron and egret colonies, bald 

eagle nests, crane roosting areas, and areas used by dusky Canada geese and other waterfowl. Refuge 

management will approve special guided tours considering season, resource impacts, disturbance 

potential, timing, group size, and frequency of tours. Tours will be guided by refuge staff or authorized 

representatives that are cognizant of resource concerns and will work to minimize the impacts of each 

specific tour.

As visitation continues to increase, the refuge needs to consider moving toward the concept of controlled 

or structured visitation. Structured opportunities will allow the refuge to manage visitation more 

effectively to limit impacts to wildlife and habitats, and to limit conflicts between user groups. The 

refuge may need to limit the amount of self-guided, unstructured use, and focus resources on developing 

guided/structured activities. In fact, changing the focus to guided activities will allow the refuge to offer 

new opportunities in the future, for example allowing public access to trails or viewing areas currently 

closed. 

Objective 2.5 Improve visitor contact and orientation facilities, signage, and interpretation 

welcoming and orienting visitors to the refuge.

Strategies Applied to Achieve Objective

Construct a new administrative site, including staff offices and a nature center with environmental 

education classrooms on the Carty Unit (covered under separate EA, see Rationale). (Also see 

Environmental Education Objective 5.3.) 

Co-locate the existing visitor contact station on the River ‘S’ Unit with the hunter check station (see 

Objective 1).

With assistance from the Friends group, staff visitor contact stations with volunteers, ensuring that the 

stations are open consistently, on weekends and during peak public visitation times. Develop a training 

program and Standard Operating Procedures for volunteers staffing contact stations.

Maintain up to date signage and information brochures with current public use regulations.

Develop an interpretive plan to guide exhibit themes, including interpretive exhibits and associated media 

at visitor contact points, observation viewpoints, and/or along trails, that increase awareness of the lower 

Columbia River ecosystem, the wildlife and habitats of the refuge, and instill a sense of stewardship and 

environmental ethics. 

Develop interpretive and orientation exhibits for visitor contact station and kiosks at the River ‘S’ 

entrance located at the Oaks to Wetlands Trail head, to orient visitors to the Refuge System, the refuge’s 

recreational opportunities, and wildlife viewing tips/ethics.
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Rationale: Staffed visitor contact stations will provide improved service to refuge visitors by providing 

easily accessible locations where they can purchase annual passes and obtain information. These facilities 

also increase program visibility, and promote visitor compliance with refuge regulations. By creating a 

focal point for visitors, these facilities assist refuge staff in gaining a better understanding of visitors, and 

their use needs and patterns. Because of visitor use patterns and access issues, it is envisioned that staffed 

visitor contact stations will be needed at both the River ‘S’ Unit (where there is a small contact station 

currently) and the Carty Unit. Most refuge visitors access the refuge via the River ‘S’ Unit. Collocating 

the visitor contact station and the hunter check station on the River ‘S’ Unit will reduce the public use 

footprint by reducing duplication of parking, restrooms, utilities, and structures. Classes participating in 

EE programs, visitors to the Cathlapotle Plankhouse, and most hikers access the refuge via the Carty Unit. 

Visitor and EE facilities are also needed on this unit.

In 2009 the refuge received funding for planning a new administrative site, which includes staff offices, a 

nature center with environmental education classrooms, and a new ADA accessible footbridge to the Carty 

Unit, to replace the existing bridge which does not meet ADA standards. Due to funding timelines, a 

separate EA was prepared that included an analysis of site alternatives. The Preferred Alternative under 

the EA was to construct these facilities on the Carty Unit near the existing office. A Finding of No 

Significant Impact was issued on April 29, 2010.

Objective 2.6 Improve public facilities

Improve visitor infrastructure to enhance safety, sanitation, comfort, and access for the visiting 

public, including visitors with disabilities.

Strategies Applied to Achieve Objective

Within the lifetime of the CCP, develop new vehicular access to the River ‘S’ Unit from the Port of 

Ridgefield property, including a 2-lane bridge to eliminate the in-grade railroad crossing, and a new 1-

mile entrance road. (See Transportation Access Study, Appendix L.) 

Within 5 years, replace current footbridge to the Carty Unit with a fully accessible bridge for pedestrians 

(covered under separate EA, see Rationale). (Bridge should be accessible to small emergency vehicle or 

ATVs.)

Within 10 years, create walking and limited (emergency) vehicle access to the Carty Unit from the Port 

site, with a small bridge over Gee Creek.

Construct 700-foot accessible trail from the Carty Unit bridge to the Plankhouse. 

Upgrade the trail surfaces of the first loop of the Oak to Wetlands Trail beyond the Plankhouse 

(approximately 2,500 feet) to allow a portion of this trail to be ADA accessible (may be compacted 

gravel, hardened surface, boardwalk, or a combination thereof). Establish appropriate resting areas, 

bump-outs, and/or trail widths as dictated by ADA standards. Seek funding through National Recreation 

Trails program. 

Construct secure bicycle parking areas at refuge entrances. (Bicycle access will be limited to 

administrative sites.)

Work with Clark County and other partners to address access issues along Lower River Road. 

Improve and pave parking lots as needed using Refuge Roads funding. 

Address the need for a restroom near Kiwa Trail by constructing a trail between the observation blind 

restroom and Kiwa Trail parking lot.

Add benches on the Kiwa and Oaks to Wetlands trails, at a minimum one bench for every 1,000 feet of 

trail.

Review and modify public use and recreation related facilities, interpretive materials, and programs, to be 

accessible to and usable by persons with disabilities.
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Chapter 2. Management Direction 2-77

Rationale: Universal safe access is important to the refuge and its programs. The refuge faces several 

access issues related to its aging infrastructure and the lack of funding for major upgrades to existing 

facilities. Visitors to the River ‘S’ Unit currently drive along an access road that is not owned by the 

refuge. Rather, the refuge holds an easement for using the road. The road is flanked by steep slopes 

subject to slides and slumps. During the winter of 1996, a slide blocked the road and trees fell on refuge 

equipment working to clear the debris. This event underscores the potential of this access point (in its 

current condition) to fail, trap visitors, preclude access to the refuge, and potentially risk the safety of 

visitors and staff. Currently, this road also requires an at-grade railroad crossing. Demand is increasing 

for high-speed rail traffic from Portland to Seattle along this railroad track. While the crossing is regulated 

by warning lights and crossing arms, train speeds and train volume along this track is anticipated to 

increase, creating delays and safety concerns for visitors to the refuge. Lastly, the current access road 

connects to the River ‘S’ Unit by a 40-year-old wooden bridge. In November 2008, the bridge required 

major repairs to sufficiently ensure public safety and to increase its capacity to support refuge equipment, 

delivery trucks, equipment associated with refuge haying/grazing practices, and school bus crossings. In 

April 2009, the bridge was again closed to make safety improvements to guardrails. 

A transportation access study was completed by Federal Highways in 2009 evaluating access alternatives 

to the refuge (see Appendix L). This study examined the feasibility of different access alternatives and 

identified alternatives that conflicted with safety, resource protection, and management needs. Using this 

study, the planning team brought three access alternatives forward. The access alternatives presented here 

include a new bridge to the north of the current location from the Port of Ridgefield. 

Another major access concern for the refuge is foot access to the Carty Unit. Visitors currently access the 

Carty Unit via a foot bridge that was constructed in 1981. The bridge is aging, and was not built to meet 

today’s accessibility standards. The grade of the bridge makes footing difficult during wet or inclement 

weather. Currently, ADA access to the Carty Unit is achieved by allowing visitors to drive to the unit via 

a service road, which has an in-grade railroad crossing. As noted above, the refuge has concerns with 

continuing to use in-grade crossings. Due to funding timelines, the planning and site design of a new 

footbridge was considered in a separate EA, and a FONSI was issued on April 29, 2010 (see Chapter 1).

Objective 2.7 Maintain access to fishing opportunities at the refuge.

Strategies Applied to Achieve Objective

Allow fishing during the State season, daylight hours only, within the Carty Unit, a portion of the River 

‘S’ Unit adjacent to the north side of the Lake River bridge, and on the bridge once it is closed to vehicle 

traffic and modified into a fishing pier. 

Convert existing bridge to River ‘S’ Unit into a pier after the new 2-lane bridge is constructed and the 

existing bridge is closed to vehicle traffic.

Provide walk-in access to fishing opportunities. Anglers must park in designated parking areas and walk 

to fishing areas.

Convert the existing bridge to River ‘S’ Unit into a pier after the new 2-lane bridge is constructed, and 

the existing bridge is closed to vehicle traffic.

Explore ADA accessible fishing opportunities.

Create a Web page mapping fishing opportunities at refuge locations.

Pursue cooperative efforts to develop a fishing area in conjunction with the Port of Ridgefield site 

development. 

Continue to define and map fishing locations. Develop tear sheets for the public, including information 

such as parking, roads, local boat launches, and ADA accessibility. Seek partnerships with State and 
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2-78 Chapter 2. Management Direction

private groups for funding and publication. 

All persons fishing shall be required to have a valid State license and follow applicable refuge and 

Washington State regulations.

Law enforcement patrols will be conducted on a regular basis to assure compliance with State and refuge 

regulations.

Rationale: Currently the refuge provides limited fishing opportunities on Lake River. Because the refuge 

has relatively limited potential to provide unique fishing opportunities, and because good fishing 

opportunities exist on nearby public lands and waters, fishing will receive less emphasis than other 

wildlife-dependent public uses on the refuge. Anglers on the banks of the Carty Unit have left trash and 

damaged rip-rap protecting the Wapato Portage site. Enhancing communications with the fishing 

population will provide an opportunity to inform these users about the refuge and Refuge System, and to 

create greater awareness of good fishing practices. 

Objective 2.8 Reduce illegal activities (trespass into closed areas, vandalism, trash 

dumping).

Strategies Applied to Achieve Objective

Close unauthorized routes and access points. Sign authorized entrance point(s) as is appropriate for a 

national wildlife refuge. 

Increase law enforcement, signing, and education, to cut down on illegal activity, especially dumping.

Increase both law enforcement patrols and regular (scheduled) staff presence on the site by all refuge 

staff and/or volunteers. 

Use increased patrols, brochures, leaflets, signing, and news releases to educate refuge users and deter 

illegal public uses. 

Rationale: Problems with illegal trespass and shooting, trash dumping, and vandalism to refuge and 

visitor property appear to be increasing. Zone Officers assigned to multiple refuges and large geographic 

regions work to enforce special refuge regulations, protect resources, and maintain public safety. 

However, with the loss of law enforcement officers stationed on the refuge, there has been a reduction of 

field patrols and officer presence.

State Route 501 (SR 501) on the south end of the refuge has been a popular site for bird watching. The 

road is currently eroding and has been closed and fenced off since 2005 to protect visitors and prevent 

entry into closed areas of the refuge. However, pedestrians and bicyclists routinely trespass into refuge 

fields to get around fences and eroded areas, and continue down the closed portion of SR-501. At the last 

turn-around at the refuge’s boundary gate, some pedestrians and bicyclists are ignoring boundary signage 

and gates, and trespass along service roads into the Ridgeport Dairy and Roth units. This isolated “dead 

end” road has also attracted a variety of illegal uses, including shooting and trash dumping. 

Trespass by boaters does not appear to be a major problem at this time, although anglers on the banks of 

the Carty Unit have left trash and caused damage to rip-rap protecting Wapato Portage. Bachelor Slough 

is not passable in most water levels and is signed as a closed area to hunting. However, it is possible that 

motorboats may be able to pass at high tide and during high run-off. 

The sand bar on the southwest perimeter of Bachelor Island is owned by Washington DNR. There is 

considerable beach use by campers and picnickers on summer weekends and by hunters in the fall and 

winter. Much trash is left by visitors. This beach is probably a source of trespass problems on the 

refuge. The bald eagles that nest on Turtle Lake appear to be reacting to people using this beach by 

repeatedly moving their nests over the past 5 years.
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Eliminating illegal uses, defining access routes, and permanently closing informal access routes into 

closed areas of the refuge, will be necessary to protect sensitive wildlife resources.

2.6.3 Goal 3: The refuge’s cultural resources and the Cathlapotle Plankhouse 

will be interpreted to enlighten visitors about the refuge’s unique natural and 

cultural history. Through accurate interpretive and educational 

opportunities, visitors will gain an understanding and appreciation of the 

refuge’s natural and cultural heritage.

Objective 3.1 Increase public awareness and appreciation of the refuge’s historic, 

archaeological, and cultural resources.

Strategies Applied to Achieve Objective

Conduct regular communications with the public through lectures and publications about the refuges 

archaeological discoveries and research.

Where feasible and appropriate, produce exhibits (permanent, temporary or traveling) incorporating 

artifacts found on the refuge, or replica artifacts.

Continue the partnership with the Friend’s Plankhouse Committee to share information about the refuge’s 

archaeological discoveries with area students and community members, through annual outreach events, 

educational resource kits, and other public outreach products such as CDs, DVDs, and pamphlets. 

Partner with Tribes, historical societies, and interested groups to impart the history and interpret the 

cultural resources of the refuge. Prepare media (pamphlets, exhibits, and multimedia productions) 

describing the history of American Indians and early settlers in this area, with emphasis on the fish and 

wildlife resources and their historic uses. 

Pursue partnerships with Tribes, local and regional historical museums and organizations, and other 

Federal agencies to achieve this objective and associated strategies.

Rationale: The refuge preserves a 3,000-year history of human occupation, trade, and commerce, and 

the interaction between people and their environment (Ames et al. 1999). As a result of sharing 

information about the refuge’s unique and irreplaceable cultural resources, the public will develop an 

understanding of the importance of these cultural resources and play a role in protecting those resources 

for future generations.

Objective 3.2 Partner with Tribes, friends groups, and volunteers to provide cultural 

resources interpretation and education programs and exhibits for both Tribal members 

and the general public.

Strategies Applied to Achieve Objective 

Hire a full time coordinator to conduct programs and oversee maintenance and operations of the 

Cathlapotle Plankhouse. Explore grants and/or partnerships to create an endowment, to fund the 

Plankhouse Coordinator and other positions. 

With assistance from the Friend’s Plankhouse Committee, develop an interior interpretive plan for the 

Plankhouse, including a list of interpretive themes, a prioritized list of replica artifacts needed to furnish 

the Plankhouse, and detailed plans to protect exhibitory from the climate and secure items from theft. 

Work with partners to hold at least 2 cultural events for the public annually at the Plankhouse that 

provide authentic experiences delivered by American Indians exercising and demonstrating their culture. 

Pursue funding for honoraria to support speakers, performers, artisans, and workshop leaders. 

Partner with Tribes to develop quality/authenticity standards (i.e. approved samples) for artifact 

replications used in the Plankhouse. 
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Work with appropriate artisans to fabricate topical artifact replicas of high quality and accuracy for use in 

the Plankhouse. 

Partner with Tribes to conduct artifact replication workshops. Workshop products that meet 

quality/authenticity standards may become part of the Plankhouse education collection, used to furnish 

and interpret the Plankhouse. 

Work with all Tribes with cultural interests in the region to develop interpretive exhibits on the Carty 

Unit that increase awareness of the history and cultural resources of the refuge, and interactions between 

wildlife and people over time. 

Rationale: The Portland/Vancouver metro area does not have a historical venue that focuses on local 

native lifeways of the Columbia River. The Cathlapotle Plankhouse could help fill that gap. 

The Chinook Tribe has been a partner in the design, construction, and interpretation of the Plankhouse 

and has a deep interest in and connection with the Cathlapotle Village site. Therefore, it is appropriate 

that the Chinook Tribe and the refuge maintain a cooperative partnership to maintain the cultural 

integrity, vision, and interpretation of the Plankhouse. Other tribes also have a cultural interest in the 

region (such as the Cowlitz Tribe and the Confederated Tribes of the Grand Ronde) and should also be 

included in developing and implementing interpretive programs and exhibits as they pertain to their 

heritage. All existing MOUs will be honored in developing cultural presentations. 

The Plankhouse is already nationally recognized for its quality, its artistic merit, and its potential for 

heritage tourism and education. The refuge shall continue to ensure that interpretive products and 

programs delivered at the Plankhouse continue to meet established high standards of quality and 

accuracy. Currently, the scarcity of trained artisans who can produce high quality artifact replicas has 

been an obstacle to furnishing the Plankhouse. Strategies that will allow the refuge to acquire these 

furnishings are suggested here. 

Objective 3.3 Integrate the Plankhouse into the refuge’s interpretation and environmental 

education programs. 

Integrate the Plankhouse into the refuge’s interpretation and environmental education programs 

by developing programs that deliver wildlife and habitat messages through the lens of cultural 

resources. Through participation in this program, visitors can learn about the links between cultures and 

the natural resources they depend upon, and develop a lasting bond with the refuge. 

Strategies Applied to Achieve Objective

Establish a fulltime position to develop and implement an environmental and cultural education program, 

including teacher training, classroom materials, and site visits. Explore grants and/or partnerships to fund 

this position.

Utilize volunteers to deliver environmental interpretation and education programs at the Cathlapotle 

Plankhouse. Within 7 years, have the Plankhouse staffed by volunteers and grant-funded staff, at a 

minimum of 4 hours per day on weekends from spring through fall, and as needed for environmental 

education groups. 

Work with partners to incorporate environmental education into educational programs and special events 

held at the Plankhouse.

Develop approved interpretive and educational scripts to ensure the consistency and accuracy of 

messages conveyed to the public.

Develop volunteer training; conduct at least two volunteer training workshops annually.

Conduct at least 2 summer gathering workshops for plants traditionally used for food, shelter, and tools. 

Integrate messages about wildlife, habitat protection, and conservation into these workshops. 

Rationale: From its inception, the Plankhouse was envisioned to serve as a venue where visitors could 
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Chapter 2. Management Direction 2-81

discover the refuge’s natural and cultural heritage. Therefore, one appropriate use of the Plankhouse is as 

a venue to educate visitors about the natural history of the refuge (wildlife and habitat, habitat 

management and change over time) and to explore natural themes through the lens of native 

cultures−how people used and interacted with the local environment. The Plankhouse provides a unique 

and evocative place to convey these messages. As with cultural programs, all existing MOUs with Tribes 

will be honored in developing these presentations. 

Given staff and budget limitations, implementing the strategies listed above will be contingent upon 

having a full-time Plankhouse coordinator. In addition to the Plankhouse Coordinator, a committed corps 

of volunteers and an active Friends Group will be needed to effectively implement this objective. 

Education programs at the Plankhouse should be run by trained educators funded through an endowment. 

Other potential sources for staffing and volunteers to conduct cultural resources education programs 

include AmeriCorps students; university or MA thesis candidates; or the Center for Columbia River 

History.

2.6.4 Goal 4: Through Refuge outreach efforts local residents will have the 

opportunity to gain an understanding of and appreciation for the refuge and 

Refuge System mission.

Objective 4.1 Conduct Public Outreach.

Provide at least 20 outreach programs annually to inform the public about the refuge and help 

them understand the differences between national wildlife refuges and other public lands, and their 

respective missions. Engage all staff in face-to-face outreach events/opportunities; talks or briefings 

with focus audiences annually.

Strategies Applied to Achieve Objective

Designate focus audiences, including adjacent landowners, watershed interests, community political, 

economic and social leaders, members of local conservation organizations, and interest groups.

Develop outreach themes focusing on the wildlife, habitat, and conservation needs of the lower Columbia 

River ecosystem; the mission of the Refuge System and how it differs from that of other public lands; 

practical conservation advice and tips; and how to become involved in conservation efforts both on and 

off the refuge.

Develop portable outreach presentation kit.

Develop outreach materials (website) showing local canoeing and kayaking opportunities.

Hire part-time outreach specialist or contractor to perform the above tasks. Pursue a grant to fund this 

position. 

Work with the Friends Group to create a volunteer speakers bureau that would give presentations to 

groups on behalf of the refuge. 

Maintain a refuge presence at community events that have high potential to deliver refuge messages to 

key audiences. Staff a booth at a minimum of 3 events annually. Where possible, coordinate with friends 

groups, other natural resource agencies, and Service offices to ensure coverage at key events. The refuge 

has participated in BirdFest, Ridgefield’s 4th of July celebration, the Clark County Fair, Ideas Fair, 

Wapato Days, Sturgeon Festival, Earth Day, Heritage Days, and Ridgefield Night Out.

Develop a welcome package for new residents inviting them to the refuge, explaining the refuge’s role 

and mission, and articulating public use opportunities on the refuge. 

Update and maintain the refuge’s web page.

Update and maintain refuge brochures.
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Rationale: The area surrounding the refuge is becoming increasingly developed; as a result the refuge 

has many new neighbors who may have little knowledge of the Refuge System or the differences 

between refuges and local parks. Outreach is needed to this new and growing audience. Outreach 

programs are an effective tool in educating the public about how refuges enhance natural resources, 

improve water quality, and provide educational and economic benefits to communities. When the public 

knows and understands these qualities, they are more likely to support the refuge. Outreach will also 

improve visitors’ awareness of regulations and policies, and the reasons for them (i.e. closed/sanctuary 

areas; why certain activities are not allowed on refuges) and hopefully, reduce law enforcement 

violations on the refuge.

Objective 4.2 Continue recruiting, training, retaining, and utilizing volunteers for support of 

refuge programs and activities. 

Build volunteer participation so that within 7 years, the number of active and engaged volunteers 

that regularly participate in refuge programs and projects on a recurring basis exceeds 150 

annually.

Strategies Applied to Achieve Objective

Work with the Friends Groups to pursue funding for a full time position to coordinate volunteers, create 

work plans for volunteers, and develop training and certification. Consider hiring through the Americorps 

program. (Note: If this is achieved the refuge can support a larger volunteer program.)

Continue to work with the Friends group to provide volunteer coordination.

Hold at least 12 annual community work days for habitat improvement/restoration projects per year.

Effectively utilize volunteers to maintain and improve trails. Continue volunteer programs with partners 

to work on at least 2 trails per year.

Create and promote opportunities for advanced/master hunters to donate conservation hours.

In conjunction with the Friends Groups, develop 5 long-term volunteer restoration/habitat projects that 

support refuge needs. Projects will be led by Friends organizations and entirely dependent upon 

volunteers in all phases (planning, funding, implementation, maintenance, monitoring, and evaluation). 

Train a project leader volunteer via the Friends Groups to coordinate and manage the refuge’s purple 

martin and duck box nesting programs. 

Rationale: Currently, more than 500 volunteers participate in refuge programs, or assist with habitat 

projects such as tree plantings or invasive species control activities annually. However, most of these 

volunteers participate on a one time basis. The number of volunteers that participate on a recurring basis 

is estimated at 100. These repeat volunteers have an excellent knowledge of the refuge and its resources, 

and often add value to the programs by working on more than one project and better knowing the resource. 

For example, in recent years volunteers working on Christmas Bird Counts, also identified invasive 

species. Increasing this core of dedicated repeat volunteers will provide major benefits to both habitat 

management and public use programs. 

Objective 4.3 Establish and Maintain Partnerships 

Establish and maintain a diversity of partnerships within the private sector, with nongovernmental 

organizations, educational institutions, and government agencies that have common goals for the 

lower Columbia River ecosystem. Partners could assist the refuge in fundraising and providing 

matching funds where appropriate.

Strategies Applied to Achieve Objective

Through outreach efforts enlist partners to undertake at least 2 refuge conservation or public use projects 

annually. Focus on projects that restore, maintain, or improve habitat or public use facilities. 

Facilitate partnerships between hunting and birding groups that emphasize joint interests and support 

refuge programs and activities.
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Chapter 2. Management Direction 2-83

Cooperate with the City of Ridgefield to produce interpretive materials for an off-refuge visitor contact 

site to interpret the wildlife, history, and cultural resources of the lower Columbia River. Develop an 

interpretive prospectus to guide exhibit themes. (Site may consist of an off-refuge kiosk, booth, or 

center.)

Continue programs with waterfowl organizations to work on at least 4 projects per year to maintain or 

improve hunting facilities or habitat in the hunt area. 

Create, foster, and/or maintain strategic community and conservation partnerships to address resource 

issues impacting refuge resources beyond the refuge’s jurisdictional boundaries (e.g. watershed 

protection, fisheries restoration, habitat protection). 

Work with the City of Ridgefield and adjacent landowners to develop a viewing platform on the bluffs 

overlooking the refuge’s east side and Campbell Lake.

2.6.5 Goal 5: Students from southwest Washington will participate in quality 

environmental education programs on the refuge that meet State educational 

requirements and provide safe and memorable experiences that foster a 

connection with nature and the refuge. As a result of participating in EE

programs, students will understand the refuge’s role in wildlife conservation 

and incorporate a conservation ethic into their everyday lives. 

The refuge’s EE program shall: 

• Focus on community groups and schools in southwest Washington; 

• Tier to the State’s educational objectives; 

• Feature class facilitation balanced between refuge staff, teachers, volunteers, and partners; 

• Be fully accessible for all students; and

• Be coordinated by a permanent fulltime environmental education specialist.

Objective 5.1 Provide quality environmental education opportunities.

Provide quality environmental education opportunities for up to 4,500 annual student visits from 

southwest Washington, tiered to the State’s Essential Academic Learning Requirements (EALRs) 

for grades 2 through 12.

Strategies Applied to Achieve Objective

Seek grant opportunities to staff a full time EE coordinator/specialist.

By the end of 15 years, the refuge will implement measures (e.g. curricula development, trainings, and 

workshops) needed to empower teachers to lead 75% of educational visits. Teachers will lead field 

activities/lessons for their students; thereby, reducing the refuge’s EE staffing needs by 25%. (Depending 

upon group size, visiting teacher(s) would have to lead 1-3 activities/lessons.)

Within 3 years, refine the refuge’s scope of educational programming to those Grade Level Expectations 

(GLEs) and EALRs that are best suited for refuge field trips. Eliminate educational programming that is 

better suited to other educational venues or is delivered in other local educational sites. (Currently the 

program is too broad.) 

Within 7 years, develop up-to-date EE curricula to be used with teacher-led classes. Design instructional 

materials to encourage the development of an environmental ethic and commitment to land stewardship 

in addition to conveying scientific knowledge. Enlist local teachers to help develop curricula to ensure 

that educational requirements are met. (Note: Existing Clark County education materials could be 

integrated.)
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2-84 Chapter 2. Management Direction

Within 7 years, ensure that all refuge EE curricula is age appropriate, has clear linkages to age level 

content, is supplemented by teacher workshops/trainings, is user-friendly to the instructor, and is 

supported by backpacks that can be checked out from the refuge to implement lessons onsite. 

During the life of the plan, partner with Ridgefield School District to develop educational programming 

for multiple disciplines and grade levels to maximize the refuge as an educational resource. 

Within 5 years, develop refuge specific instructor training for teachers (“teach the teacher” programs).

Annually offer 2 teacher training workshops and establish a program to encourage and select trained 

teachers to use the refuge’s facilities, curricula, and programs for teacher led EE.

Foster long-term support for environmental education by ensuring the refuge has a minimum of 10 

committed teachers and 30 qualified trained volunteers available for the program.

Develop and implement evaluation techniques with volunteers, students, and teachers to maintain 

program quality. 

Every two years, review EE curricula with focus groups of educators at appropriate levels. Update 

curricula and materials as necessary to ensure specific, age-appropriate learning objectives are articulated 

and that proper emphasis is placed on the Refuge System, current science of lower Columbia River 

ecosystems, current management issues, and adherence to current State environmental education 

standards. 

Develop EE program for children with disabilities (for example a program for identifying birds by 

sound). 

Rationale: Currently the refuge provides EE for 2,000-3,000 students annually, primarily in grades 3-6. 

The number of students served is limited by the availability of staff and volunteers needed to manage the 

program. Existing EE materials need to be reviewed and updated. With a rapidly increasing population 

in the local area, demand for EE programs on the refuge is increasing. 

With limited staff time available to run EE programs, teacher-led programming is needed. An EE 

program that focuses on teaching the teacher has the potential to both expand the number of potential 

students participating in EE and to broaden the base of knowledgeable EE instructors in the community. 

Indirectly, this will have the effect of broadening support for the Ridgefield Refuge Complex within the 

community. Because it takes time for teachers to receive training and become familiar with the 

educational materials and environment, we anticipate slowly but gradually moving toward a 75% mark 

over the life of the CCP. Currently, the Refuge Complex’s Instructional Systems Specialist and 

Volunteer Coordinator spend approximately 750 hours per year total coordinating and implementing the 

current EE program. The support needs of the program would be better served by a full time EE 

Specialist, who could potentially evaluate, refine, and improve the program. 

There is an increasing awareness in the Service and the conservation community, of the need to get 

children outdoors to experience nature directly. Today, many children are distanced from nature, which 

over time will result in lack of awareness of, and support for wildlife conservation. The refuge has a 

unique opportunity to reach school children because of its proximity to the town of Ridgefield and the 

Portland-Vancouver metro area. Therefore, EE will receive high emphasis. The refuge will focus on 

providing activities that are educational and experiential. A scattered approach to environmental 

education should be avoided. Instead, a progressive EE program that builds a relationship between the 

refuge and local communities and schools should be designed. EE programs on the refuge should get 

students outdoors and foster a connection with nature. In the future, if resources permit, the EE program 

could be expanded to serve students outside the local area.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 2. Management Direction 2-85

Objective 5.2 Effectively utilize volunteers, Friends Groups, and partnerships to create a 

high quality and self-sustaining refuge environmental education program. 

Strategies Applied to Achieve Objective

Foster long-term support for environmental education by ensuring that the refuge always has a minimum 

of 30 committed, qualified, and trained volunteers available to implement high-quality educational 

experiences for local school visits and youth group outings (e.g. scouts, and summer camps).

With the assistance of the Friends group, hold at least two teacher workshops per year to train educators 

and facilitators.

Maintain annual Naturalist Corps training to ensure volunteer base has skills and knowledge necessary to 

effectively work with children.

Maintain Committee for Ridgefield Refuge Environmental Education Development (CRREED) to 

improve Ridgefield’s EE program. 

Through the Friends Group, seek continued grants to provide transportation funding for school groups to 

visit the refuge.

Maintain involvement in Clark County’s Environmental Education Coordination Council (EECC) to 

assess and coordinate local EE programs, venues, and needs.

Continue to support the Friends partnership with supplies and facility space.

Rationale: The Friends group plays a critical role in supporting the refuge’s EE program, annually 

funding thousands of dollars of bus transportation to the refuge, acquiring educational materials, funding 

educational programs, and funding interpretive/educational contract personnel. The Friends group 

recently voted to make assisting the refuge with environmental education efforts their main focus for the 

near future. With increasing demand for EE, the support of the Friends Group will be more important 

than ever. Supporting the Friends with needed office space, supplies, and an available staff partnership is 

vital to allow the Friends to continue to provide this critical service. In addition, because the Friends 

group is comprised mainly of retired citizens, for the long-term health of the EE program it is essential to 

recruit and maintain additional volunteers. 

Objective 5.3 Expand environmental education facilities.

Expand EE facilities on the Carty Unit to support on-refuge EE programs. Within 15 years build a 

designated, covered gathering area or classrooms, and several study sites in a variety of habitats on 

the Carty Unit. These facilities allow use by 2 groups of up to 40 students and teachers at a time. 

Strategies Applied to Achieve Objective

Build a covered, open-air shelter with seating for EE classes; shelter should accommodate groups of up to 

40. 

Within the lifetime of the CCP, build 1-2 EE classrooms as part of an administrative site (see Objective 

2.5), in addition to an open-air shelter.

Maintain a vault toilet at the main gathering area, and maintain parking areas to accommodate buses.

Maintain four EE study sites, with one in rest/rotation at any given time.

Utilize alternative funds to construct EE sites at the Carty Unit. Explore opportunities to apply for 

wildlife-dependent use grants through the Fish and Wildlife Foundation. 

Develop backpacks with lesson plans and materials for each study site.

Ensure that all EE facilities are accessible to individuals with disabilities.

Rationale: The refuge currently lacks facilities dedicated to EE. The EE program is currently concentrated 

at the Plankhouse. In 2009 the refuge has received funding to plan a new administrative site with EE

classrooms (see Objective 2.5). Due to funding timelines, a separate EA was prepared for the site.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

2-86 Chapter 2. Management Direction

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WA.

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with emphasis on salmonids in the Columbia River estuary. Pacific Northwest National Laboratory, 

Richland, WA. 

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Kilbride, K.M. and F.L. Paveglio. 1999. Integrated pest management to control reed canarygrass in 

seasonal wetlands of southwestern Washington. Wildlife Society Bulletin, 27(2): 292-297. 

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Klein, M.L., S.R. Humphrey and H.F. Percival. 1995. Effects of ecotourism on distribution of 

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Gutzwiller, editors. Wildlife and recreationists: coexistence through management and research. 

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Chapter 2. Management Direction 2-91

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Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

2-92 Chapter 2. Management Direction
Chapter 3. Physical Environment

Gee Creek winds through the Carty Unit/USFWS

Above: A rare tornado damaged

Refuge facilities in 2004.

Right: The Refuge receives snow

about once every six years./USFWS
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 3. Physical Environment 3-1 

Chapter 3. Physical Environment

3.1 Climate

The maritime climate in Ridgefield, Washington produces mild temperatures, wet winters, and 

relatively dry summers. The region’s climate is greatly influenced by the Pacific Ocean which 

moderates temperatures throughout the Pacific Northwest. From fall through early spring, prevailing 

winds bring warm, moist, marine air into western Washington. The Coast Range buffers the interior 

valleys of western Washington from severe winter storms moving inland from the Pacific. This 

results in a predominantly mild and rainy winter climate at the refuge. 

Periodic cold weather, with temperatures at or below freezing for days or very rarely weeks at a time, 

occurs in the winter when cold, dry air from eastern Washington funnels through the Columbia River 

Gorge into the valleys of western Washington and Oregon. Days with temperatures below 32°F are 

infrequent and are usually associated with the strong east winds from the Columbia Gorge. When 

warm, moist air masses moving onshore from the ocean overtop cold air from the Gorge, snow or ice 

storms may occur. 

From late spring through September, prevailing winds flow from the northwest. This cold and 

relatively dry air becomes warmer and drier as it moves inland, resulting in a dry season from late 

spring to September. Summer high temperatures during July and August are generally around 80°F. 

The drier conditions result in only 20 percent of the annual precipitation occurring between June 1 

and September 30. Relative humidity is typically high in the winter and spring, but can reach single 

digits in the summer and fall months. 

Meteorological measurements have been taken at the St. Helens Meteorological Station in Oregon 

since 1971, which lies 5.1 miles from the refuge. This station can be considered representative of the 

general climate of the refuge because it is on the Columbia River. Data collected at this station 

between 1971 and 2006 are used below to discuss weather patterns on the refuge (Oregon Climate 

Service 2007). 

3.1.1 Temperature

Based on data collected from 1971 through 2000, the average monthly temperatures range from a 

low of 40°F in January to a high of 69°F in August. The highest average winter temperature 

recorded for one month was 44°F in December 1979, and the lowest average winter temperature 

recorded for one month was 31.6°F in January 1979. The highest summer average temperature 

recorded for one month was 73.6°F in July 1996, and the lowest average summer temperature was 

64°F in July 1993. 

Daily maximum temperatures vary from an average of 46°F in late December and early January to 

83°F in August. There are on average, 2 days between November and February with a maximum of 

32°F or below. There is an average of 18 days during the summer months with maximum 

temperatures of 90°F or above. The greatest number of consecutive days on record with maximum 

daily temperatures of 90°F or above was 16 days in 1994. The record maximum temperature was 

107°F, recorded on August 10, 1981. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

3-2 Chapter 3. Physical Environment

The average daily minimum in January is 33°F. On average, the daily minimum temperature drops 

to 32°F or below 47 days per year, with more than half of these days in December and January. The 

greatest number of consecutive days on record with minimum daily temperatures of 32°F or below is 

28 days in 1979. The record minimum temperature recorded at the St. Helens station was 1°F, 

recorded on March 20, 2002. 

3.1.2 Precipitation

Annual precipitation at Ridgefield Refuge is approximately 46 inches, the majority (about 80 

percent) falling as rain from October through April. More than half of annual rainfall occurs from 

November through February, and less than 7 percent of annual precipitation falls during June, July, 

and August. On average, precipitation greater than 0.50 inches occurs 30 days per year. The wettest 

season on record was the winter of 1996-1997, with 60.13 inches of precipitation between October 

1996 and May of 1997. The wettest year on record, 1996, precipitation measured 64.39 inches. 

There was widespread flooding in 1996, with the highest floods on record for many southwest 

Washington rivers (see below). In 2004, the driest year, only 25 inches of precipitation was 

measured. The driest season was the summer of 1987, with only 1.84 inches of precipitation. 

Snow events are infrequent. Over the past 30 years, measurable precipitation as snow has occurred 

once every 6 years on average, which contributed to a 30 year average of 2.9 inches per year. A 

record monthly snowfall of 24.3 inches occurred in January 1980. 

3.1.3 Climate Cycles in the Pacific Northwest

Two climate cycles have major influences on the climate and hydrologic cycles in the Pacific 

Northwest: the El Niño/La Nina Southern Oscillation (ENSO) and the Pacific Decadal Oscillation 

(PDO). El Niño/La Nina events are linked to ocean temperatures in the tropical Pacific and last 6-18 

months. In El Niño years, ocean temperatures are warmer than average; in La Nina years, cooler. A 

single warm or cool PDO phase lasts 20-30 years, and the strongest signal for the PDO is in the north 

Pacific. The triggering cause of the PDO phase shift is not understood. The potential for 

temperature and precipitation extremes increases when ENSO and PDO are in the same phases and 

thereby reinforce each other. This additive effect is also seen in the region’s stream flow and 

snowpack. When ENSO and PDO are in opposite phases, their opposite effects on temperature and 

precipitation can cancel each other out, but not in all cases and not always in the same direction 

(Climate Impacts Group 2009b). 

The ENSO and PDO cycles have significant effects on both Columbia River flows at The Dalles, and 

on sediment transport. For example, Columbia River flows at The Dalles are approximately 25 

percent higher during La Niña/cold PDO years than during El Niño/warm PDO years. This effect is 

even strong in the Willamette River. La Niña/cold PDO years have more than a 150 percent higher 

sediment transport rate than El Niño/warm PDO years. Winter freshets in La Niña/cold PDO years 

are especially effective in delivering fine sediment (Jay 2001).

Between 1900 and 1998, PDO phase shifts occurred on a 20-30 year cycle. Since 1999, the PDO has 

shifted every few years between cool and warm phases, making it difficult to determine at this time if 

the 1998 shift was a true shift to a cold phase. The 1999-2002 time period was relatively cool, while 

2003-2005 was a warm period (Climate Impacts Group 2009a). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 3. Physical Environment 3-3 

3.1.4 Floods

Northwestern Oregon and southwest Washington are one of the most active areas for flooding in the 

United States. Flooding is most common during the rainy season (October through April), when 

storms from the Pacific Ocean, 60 miles away, bring intense rainfall to the area. The consistent, 

drenching rains saturate the soil and often fill rivers and streams. When rivers and streams rise and 

exceed their channel capacity, water spills out onto surrounding floodplains. Larger floods result 

from heavy rains that continue over the course of several days, increased by snowmelt at a time when 

the soil is near saturation from previous rains. Frozen topsoil also contributes to flooding (Clark 

County 2009). 

Most of the region’s major flood events since 1860 have been rain-on-snow events that occur during 

the winter months, when heavy rainfall over a short period of time accelerates snowmelt runoff. 

Periods of intense cold, followed by a rapid transition to a warm and wet weather pattern, have 

produced the most severe flooding. The floods of February 1996 followed this pattern. 

The winter of 1995-1996 was wet, with precipitation in northwest Oregon and southwest Washington 

at about 125 percent of the average. Soils became saturated and streams and reservoirs were running 

high. Between January 15 and 31, average snowpack went from 29 percent of average to 112 percent 

of average. An intense cold spell froze soil during the last week of January. From February 6-9, a 

warm, moisture-laden air mass from the tropics—the “Pineapple Express”—hit the region, producing 

record rainfall. Freezing levels rose to 7,000-8,000 feet and nighttime temperatures hit the 50s. This 

major rain-on-snow event resulted in significant snowmelt and runoff, and record flooding (Wilde 

2006). Many rivers and creeks throughout the region rose to 100-year flood levels. The average 

river level for the Columbia River is usually 7-8 feet in winter; it crested at just over 26 feet in 

February 1996. Overall damage to Clark County businesses, residences and infrastructure was 

estimated to be roughly $25 million (Clark County 2009). In the February 1996 flood, the Bachelor 

Island dike was overtopped and breached, inundating the entire island and all of its croplands 

(USFWS 1996). Water was 15-20 feet deep in some fields. In December 1996, mild subtropical 

moisture once again led to extensive flooding. 

While the 1996 floods were devastating, the floods of December1861 (the “Great Flood”), February 

1890, and December 1964-January 1965 exceeded the 1996 events in terms of velocity and volume 

of water (Clark County 2009). During the Christmas Flood of 1964, the Columbia River reached 

27.6 feet at Vancouver, caused $157 million in damage, and the loss of 47 lives in Clark County and 

the Portland metro area. 

Major spring floods have also occurred on the Columbia River during years of unusually heavy 

snowpack, followed by heavy spring rains. In June 1894 the Columbia River reached 33.6 feet at 

Vancouver, the highest flood stage ever recorded there. If the Columbia River dams had been in 

place during that event, the river would have reached only a maximum elevation of 26 feet (Port of 

Vancouver 1965). During the Memorial Day (Vanport) Flood of May 1948, the river reached 30.2 

feet at Vancouver (Taylor and Hatton 1999). Columbia River dams and flow regulation now make 

major spring floods unlikely. 

Flood control projects on the refuge: Shortly after construction of the Bonneville Dam on the 

mainstem Columbia River, diking projects were initiated on lower Columbia River bottomlands. 

Diking of the River ‘S’ Unit was completed by local interests in 1941, protecting 1,565 acres of 
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3-4 Chapter 3. Physical Environment

bottomlands from flooding. In 1947, the River ‘S’ dike was strengthened, drainage ditches were 

improved, a tide box was installed, and an expulsion pump was constructed. The levees were 

overtopped in 1948 and 1956, with emergency repairs to the dikes and pump stations completed by 

the Corps after each of these floods. In 1959, interior drainage was improved and a new pump was 

added to an existing pumping station. During 1963 and 1964 the dike was improved to 25.4 feet 

National Geodetic Vertical Datum (NGVD) and the expulsion pump station was relocated. The last 

breach of the River ‘S’ dike occurred in June of 1972. Due to funding constraints, the dike remained 

open until late 1974, when repairs were completed by the Army Construction Battalion from Fort 

Lewis, Washington. The River ‘S’ dike is considered safe for river levels to 16 feet NGVD (Army 

Corps of Engineers 1978). However, in February of 1996 the River ‘S’ dike withstood flooding of 

23.0 feet NGVD (USFWS 1996). 

On Bachelor Island, the initial diking started in 1942 with the construction of five miles of levee 

protecting 1,120 acres. In 1947 flood prevention activities included strengthening and enlarging the 

dike, excavating a one-half mile drainage canal, and installing an expulsion pump station. During the 

Vanport Flood of 1948, the Columbia River reached 32.8 feet NGVD at the Vancouver gage, and 

overtopped the Bachelor Island dike, damaging it in several locations. From 1950 to 1956 the 

owners of Bachelor Island reinforced and raised the levee to approximately 25 feet NGVD. Floods 

during 1956, 1964, and 1996 breached the Bachelor Island dike, causing significant damage to 

infrastructure and facilities. The February 1996 flood overtopped and breached the Bachelor Island 

dike, inundating the entire island and causing significant damage to infrastructure and facilities 

(USFWS 1996). The current dike around Bachelor Island has structural deficiencies relating to free 

board, crest width, slope, and erosion. While the top elevation of the dike is approximately 25.0 

NGVD, it is only operationally safe at river levels of 20.0 feet NGVD (USACE 1978, USFWS 

1983). 

3.1.5 Wind and Severe Weather Events

Prevailing winds over most of Clark County are northwesterly during the summer and southeasterly 

during the winter. In general, winds are lower from late spring through September and higher during 

the fall and winter. From late spring through September, high pressure over the Pacific Ocean brings 

a prevailing flow of cold and relatively dry air from the northwest, with the winds being more 

moderate than during the winter. From fall through early spring, prevailing winds from the west 

bring warm, moist, marine air into western Washington. However, under certain conditions, strong 

east winds may occur when an intense pressure gradient develops between a high pressure center 

over the Upper Columbia River Basin and a strong low pressure area over the eastern Pacific Ocean. 

The Columbia Gorge funnels the winds, resulting in strong winds at the exit point of the gorge. 

Although high winds can come from the east, the most destructive winds blow from the southwest, 

and are associated with storms moving into the coast from the Pacific Ocean. On average, south 

wind storms that cause significant property damage occur about once every decade. The worst storm 

of the 20th century, the Columbus Day storm of October 12, 1962, was a classic example of a south 

wind storm. It originated as a tropical storm that formed in the central Pacific Ocean, and then 

became an extratropical cyclone as it moved into colder waters and interacted with the jet stream. 

Gusts of 92 mph were recorded in Vancouver and 116 mph in Portland (National Weather Service 

2007). A windstorm on Dec 12, 1995, was compared with the Columbus Day storm. Many trees on 

the refuge were felled by this storm, including cottonwoods in the heron rookery on Bachelor Island 

(USFWS 1996). 
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Chapter 3. Physical Environment 3-5 

Thunderstorms are infrequent. Tornadoes are infrequent and generally small in the northwestern part 

of the United States. The worst tornado on record in southwest Washington, with a magnitude of F3, 

touched down in Vancouver on April 5, 1972. Six deaths and $50 million in property damage were 

recorded. On May 31, 1977, a record 6 tornados touched down in Washington in a single day, 

including an F0 tornado in Vancouver. On September 13, 2004, a small tornado touched down on 

the River ‘S’ Unit. The tornado caused approximately $300,000 in damage to refuge facilities. A 

trailer was lifted off its foundation by the tornado and moved 30 feet (USFWS 2004, NOAA 2004). 

3.2 Climate Change

A growing body of scientific evidence has emerged supporting the theory of human-caused global 

climate change. During the 20th century, the global environment experienced increases in average 

worldwide temperatures, sea levels, and chemical concentrations. Average annual air temperatures 

on the earth’s surface have increased by 1.3°F since the mid 19th century (Solomon et al. 2007). 

Furthermore, the increasing trend in global temperatures over the last 50 years is approximately twice 

the trend of the previous 50 years (IPCC 2007). Globally, during 11 of 12 years from 1995 to 2006, 

surface temperatures are the warmest on record since 1850 (IPCC 2007). 

During the next 20-40 years, the climate of the Pacific Northwest (Washington and Oregon) is 

projected to change significantly. Global climate models project mid- 21st century temperatures in 

the northwest that are well outside the range of temperature observed in the 20th century. Important 

changes in future precipitation are also predicted: nearly all the climate models project wetter winters 

and drier summers in the 2020s and the 2040s (Mote et al. 2003). 

3.2.1 Predicted Future Ecological Trends

Projected temperature increases for the coming century are expected to increase the proportion of 

winter precipitation falling as rain, increase the frequency of winter flooding, reduce snowpack, 

increase winter stream flow, result in earlier peak stream flow, and decrease late spring and summer 

stream flows (Hamlet and Lettenmaier 1999, Mote et al. 2003, Payne et al. 2004, Mote et al. 2005, 

Hamlet et al. 2007, Tague et al. 2008). 

Summer stream flow reduction is expected to continue and become more widely spread (Mote et al. 

1999, Miles et al. 2000, Snover et al. 2003, Mote 2003, Stewart et al. 2004, Climate Impacts Group 

2008, 2009c). For example, July-October decreases in the Tualatin Basin stream flows are expected 

to reach 10-20 percent by 2040 (Climate Impacts Group 2008). 

While the region is forecasted to become wetter overall, the projected increase in precipitation is less 

than the precipitation range associated with natural decadal variability (Hamlet et al. 2005). 

Furthermore, most increases in precipitation are projected for the winter months. Likewise, increases 

in winter stream flows have the potential to increase the risk of winter floods, and streambed 

scouring events (Climate Impacts Group 2008, 2009c). Secondary to warmer temperatures, some of 

the changes/effects in the Pacific Northwest that we are likely to see over the next 20-40 years follow 

(Climate Impacts Group 2008, 2009c): 
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3-6 Chapter 3. Physical Environment

Changes in water resources

• Decreased mountain snowpack 

• Earlier snowmelt

• Higher winter stream flow in rivers that depend on snowmelt 

• Higher winter stream flow in rain-fed river basins if winter precipitation increases in the 

future as projected 

• Lower summer stream flow in rivers fed by snowmelt (most rivers in the Pacific Northwest) 

• Earlier peak (spring) stream flow in rivers fed by snowmelt (most rivers in the Pacific 

Northwest) 

• Decreased water for irrigation, fish, and summertime hydropower production 

Changes in salmon

• Increased difficulties due to increased winter floods, decreased summer stream-flow, and 

increased water temperature

Changes in forests

• Tree growth. 

• Seed regeneration.

• Potential increases in forest fires.

• Overall increased forest growth region-wide over the next few decades followed by 

decreased forest growth as temperature increases overwhelm the ability of trees to make use 

of higher winter precipitation and higher carbon dioxide. 

• Potential for extinction of local tree populations and loss of biological diversity if 

environmental shifts outpace tree species migration rates and interact negatively with 

population dynamics. 

Changes along the coasts 

• Increased coastal erosion and beach loss due to rising sea levels. 

• Increased landslides due to increased winter rainfall.

• Permanent inundation, especially in south Puget Sound around Olympia. 

• Increased coastal flooding due to sea level rise and increased winter stream-flow from 

interior and coastal watershed. 

Temperature Changes

• Temperature has increased. Average annual temperature increased 1.5°F in the Pacific 

Northwest between 1920 and 2003. The warming has been fairly uniform and widespread, 

with little difference between warming rates at urban and rural weather monitoring stations. 

Only a handful of locations recorded cooling. Although the warmest year was 1934, the 

warmest decade was the 1990s (Mote et.al. 2003). 

• Warming trends have been most evident between 1930 and 1995 during the months of 

January-March. Minimum daily temperature rose faster than maximum daily temperature 

through the mid-20th century. In the second half of the 20th century, minimum and 

maximum temperatures rose at about the same rate (Mote et.al. 2003, Hamlet and 

Lettenmaier 2007). 
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Chapter 3. Physical Environment 3-7 

Precipitation Changes 

• Decadal variability has dominated annual precipitation trends. Annual precipitation 

increased 14 percent for the period 1930-1995 for the Pacific Northwest region. Sub-regional 

trends ranged from 13 percent-38 percent (Mote et.al. 2003). However, these trends are not 

statistically significant and depend on the time frame analyzed. Decadal variability is 

therefore the most important feature of precipitation during the 20th century. 

• Cool season precipitation variability has increased. Cool season precipitation in the Pacific 

Northwest is more variable from year to year, displays greater persistence, and is more 

strongly correlated with other regions in the West since about 1973 (Hamlet and Lettenmaier 

2007). 

• Between 1950 and 2000, April 1 snow water equivalent (SWE) declined at nearly all sites in 

the Pacific Northwest. The declines are strongest at low and middle elevations, and can be 

explained by observed increases in temperature and declines in precipitation over the same 

period of record (Mote et al. 2003, Hamlet et al. 2005, Mote 2006). Many low elevation 

stations showed SWE declines of 40 percent or more (Mote et al. 2003, Mote et al. 2005). 

Timing of peak runoff has shifted. Timing of the center of mass in annual river runoff in 

snowmelt basins shifted 0-20 days earlier in much of the Pacific Northwest between 1948 

and 2002 (Stewart et al. 2005). The largest change in these trends occurred in the Pacific 

Northwest, including the mountain plateaus of Washington, Oregon, and western Idaho. 

These findings are corroborated by modeling studies which show similar changes in runoff 

timing (Hamlet et al. 2007).

3.2.2 Detailed Future Climate Change in the Pacific Northwest

Temperature/Precipitation Changes. Global climate models scaled to the Pacific Northwest 

project an increase in average temperature on the order of 0.2°-1.0°F (0.1°-0.6°C) per decade 

throughout the mid-21st century with a best estimate average of 0.3°C (0.5°F) per decade (Table 

3.2). Temperature increases occur across all seasons with the largest increases in summer. 

The best estimate rate of warming in the Pacific Northwest through the mid-21st century—0.5°F 

(0.3°C) per decade—is three times the rate of change per decade observed in the Pacific Northwest 

during the 20th century (0.15°F [0.8°C] per decade). The rate of change per decade for the second 

half of the 21st century is dependent on the choice of emissions scenarios. 

Precipitation changes are projected to be small compared to the inter-annual and decadal variability 

observed during the 20th century. Most of the models analyzed by Climate Impacts Group (CIG) 

project showed decreases in summer precipitation and increases in winter precipitation with little 

change in the annual mean. Analysis of future storm tracks indicates a basis for more confidence in 

wet season increases, particularly in the second half of the 21st century (Salathé 2006). 

Coastal sea surface temperature (SST) helps determine the biological and physical conditions of the 

marine environment and estuaries of the Pacific Northwest. Climate models project warming in 

summer SSTs for the 2040s on the order of 2.7°F (1.5°C). This change is somewhat less than the 

warming projected in the 2040s for Pacific Northwest land areas (3.5°F [2.0°C]), but is significant 

relative to the small inter-annual variability of the ocean. 
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3-8 Chapter 3. Physical Environment

Table 3.1 Projected Changes in the Pacific Northwest Climate (Data from CIG 2008)

Changes in Annual Mean

Temperature Precipitation

2020s

Low + 1.1oF (0.6oC) - 9%

Average + 2.2oF (1.2oC) + 1%

High + 3.4oF (1.9oC) + 12%

2040s

Low + 1.6oF (0.9oC) - 11%

Average + 3.5oF (2.0oC) + 2%

High + 5.2oF (2.9oC) + 12%

2080s

Low + 2.8oF (1.6oC) - 10%

Average + 5.9oF (3.3oC) + 4%

High + 9.7oF (5.4oC) + 20%

Average changes in Pacific Northwest climate from 20 climate models and two greenhouse gas emissions scenarios (B1 and 

A1B) for the 2020s, 2040s, and 2080s (Climate Impacts Group 2008). All changes are benchmarked to average temperature and 

precipitation for 1970-1999. Model values are weighted to produce the “average.” 

3.2.3 Potential Changes to the Refuge

There have been no specific studies documenting potential effects to the refuge from future climate 

change. There have already been major and irreversible changes to refuge habitats and wildlife due 

to Columbia River flow regulation, diking, introduced species, land conversion to agriculture, and 

surrounding land uses. The impacts of climate change will be difficult to distinguish from these 

other impacts, at least in the near term. However based on the various climate modeling scenarios 

for the Pacific Northwest, several potential problems are envisioned. 

One of the main concerns is the River ‘S’ Unit and the Bachelor Island Unit, which are protected by 

flood control dikes. The dikes prevent the Columbia River from flooding the units during periods of 

high water. In addition to refuge administrative facilities, critical waterfowl habitat and the 

infrastructure to maintain that habitat is protected by the dikes. Rain-on-snow events are a normal 

feature of Pacific Northwest climate. However, projected warmer, wetter winters associated with 

climate change suggest further increases in the risk of winter flooding (Mote et al. 2003). The 1996 

flood completely overtopped refuge dikes, and breached the Bachelor Island dike. This dike may be 

vulnerable to breaching in future flood events. The dike underlying Lower River Road, which is not 

owned by the Service, is eroding and a breach of this dike is considered likely in the next major flood 

event (see Chapter 2). 

A recent National Wildlife Federation study of potential habitat changes associated with sea-level 

rise in coastal Oregon and Washington projected that the average sea level at the study locations in 

the Willapa Bay, lower Columbia River, and Tillamook Estuary could increase by 0.69 meters (27.3 

inches) by 2050 (Glick et al. 2007). At Julia Butler Hansen Refuge, approximately 30 river miles 

downstream from Ridgefield, managers believe this would cause severe recurring flooding problems 

during periods of high tide, and likely in time undermine the integrity of the dikes. Projected sea 

level rise would probably have little effect on Columbia River levels at Ridgefield in the near future. 

Flow regulation (through operation of Columbia River dams) would continue to dominate river 

levels.
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Chapter 3. Physical Environment 3-9 

A second concern is the increasing temperatures projected by many of the climate models. The CIG 

at the University of Washington has averaged a large number of climate models. When averaged, the 

predicted average annual temperature increase is 3.5° F by 2040. Numerous changes to the refuge’s 

habitat and wildlife would likely result from increases in the ambient temperature and precipitation 

over the next 50 to 100 years. However, until a more detailed analysis of the effects of global 

climate change can be completed on specific refuge units, more generalized modeling will continue 

to be used to assess how and what the refuge should do to prepare for upcoming changes to the 

natural environment. While this CCP covers a 15-year time span, it is clear that for us to adequately 

plan for climate change, we will have to look further into the future. It is also clear that to address an 

issue of this magnitude, land managers must plan collaboratively on a regional level. During the 15-

year time span of this CCP, Ridgefield and other refuges will develop strategies to address climate 

change effects on the lower Columbia River. 

3.3 Hydrology

3.3.1 Columbia River and Changes due to Hydropower Operations 

The Columbia River Basin is the most hydroelectrically developed river system in the world (Center 

for Columbia River History 2009). Eleven dams on the mainstem of the Columbia River, and 

hundreds of major and modest structures on the Columbia, Snake, and their tributaries, now impose 

water level fluctuations to meet demand for hydroelectricity, agriculture, navigation, pool recharge, 

recreation, fisheries, and water quality priorities (Scherer 1991). Rock Island Dam, completed in 

1932, was the first major hydropower producer on the Columbia, followed by the much larger 

Bonneville and Grand Coulee dams, completed in 1938 and 1941, respectively. The last dams built 

on the Columbia came on line during the 1960s and 1970s. In 1973, Canada completed the last of 

the mainstem dams, Mica Dam on the upper river. These dams, along with four dams on the lower 

Snake River, created large reservoirs that provide water for vast irrigation systems on the Columbia 

Plateau, and power that fueled the growth of cities and industries in the Pacific Northwest. 

Historically, flooding within the Columbia River was the product of regional precipitation, the rate 

and volume of snowmelt, and synchronization of runoff between the Columbia and Snake River 

drainages. Prior to dam construction, average spring floods (freshets) regularly inundated 170,000 

acres of bottomland along the lower Columbia River for periods of up to 60 days. Major spring flood 

events would have inundated up to 300,000 acres of the lower Columbia River floodplain (Christy 

and Putera 1993). The linear, shallow troughs and low ridges of Bachelor Island, which run roughly 

parallel to the Columbia River, are relics of high energy floods that occurred prior to flood control. 

Due to short and long term climate cycles in the Pacific Northwest (ENSO and PDO), and snowpack, 

the volume of the spring freshet varied greatly from year to year, or decade to decade (see section 

3.1.C above). 

Construction of over 200 dams on the Columbia River and its tributaries radically altered the flow 

regime of the river during the 20th century. Reservoir storage projects have created an active storage 

capacity equivalent to 1/3 of the mean annual flow of the river, as measured at The Dalles, Oregon 

(WDOE and WDFW 2004). Dams now impose additional water level fluctuations to meet demands 

for hydro-electricity, agriculture, navigation, pool recharge, recreation, fisheries, and water quality 

priorities. Spring flood elevations on the lower Columbia River average 37 percent lower today than 

prior to dam construction (Habegger et al. 1998). Regulated winter flows are typically less than 
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3-10 Chapter 3. Physical Environment

200,000 cubic feet per second (cfs). Peak flows in May and June have declined from about 600,000 

cfs to 350,000 cfs (Christy and Putera 1993). In the 30-year period between 1975 and 2005, the 

historic average annual spring flood level of 21.5 feet was only achieved twice (NOAA 2005). 

In the pre-dam era, the river typically had relatively low flows during the fall and winter (October 

through March) and much higher flows during the snowmelt runoff period (the spring freshet) in the 

spring and summer (April through September). In the post-dam era, normal high water flows have 

been reduced with the peaks flattened out. Rather than peaking strongly during late spring and 

summer, spring runoff is contained within numerous storage reservoirs and gradually released over 

the year. There are now relatively higher flows in the winter, as the stored water is tapped for power 

generation, and lower summer flows than occurred historically. Figure 3-1 illustrates the change in 

the hydrograph from historic to current times. 

Today, the lowest river flows occur during September and October, when rainfall and snowmelt are 

lowest (NPCC 2004). The highest flows occur from April to June and result from snowmelt runoff. 

High flows also occur between November and March and are caused by heavy winter precipitation. 

Discharge at the mouth of the river currently ranges from 100,000 to 500,000 cfs. Historically, 

unregulated flows were both lower and higher—with lows of 79,000 and highs of 1 million cfs, 

respectively (Neal 1972 and LCREP 2002 as cited in NPCC 2004). 

3.3.2 Wetlands Hydrology

The refuge is located within the floodplain of the lower Columbia River near the confluence of the 

Willamette River. Historically, the area’s hydrology was dynamic and subject to natural influences 

including river levels, precipitation, evaporation, tides, runoff, soil saturation, and soil permeability. 

Before dam construction within the Columbia River system, spring floods would have been the 

primary hydrological influence within the lower Columbia River. The average annual spring flood 

reached a stage of 21.5 feet at the gage at Vancouver, Washington. The History of Clarke County 

(Alley and Munro-Fraser 1885) notes that the bottomlands along the Columbia were “subject to the 

annual overflow, which reaches its highest in June.” Historically, spring flooding would have 

annually inundated most of the refuge, recharging broad, shallow overflow lakes and ponds. Deeper 

ponds and sloughs would have retained water year-round, while shallow overflow lakes would have 

dried up by late summer. 

Overbank flows, formerly an annual event on the Columbia River bottomlands, occur much less 

frequently now than they did historically, in part because flow regulation, water diversions, and 

diking have reduced the number of high flows in the river. The construction of dikes or levees along 

the Columbia River and its tributaries has also reduced the frequency of overbank flows, because 

more river water is needed to cause overbank flow. Historically the bankfull level was 18,000 cubic 

meters per second (m3 s-1), while today it is 24,000 m3 s-1—fully one-third more. Only five 

overbank events have occurred since 1948 (Kukulka and Jay 2003a, b). In the absence of spring 

floods, most of the refuge’s wetlands are recharged by precipitation or by pumping from the river. 

Today, only the Carty, Roth, and portions of the Ridgeport Dairy Units remain in the floodplain of 

the Columbia River. Most wetlands in these units are directly or indirectly connected to the 

Columbia River. Water level patterns in these wetlands, therefore, generally follow the water level 

pattern of the Columbia River. For those wetlands that lack a direct connection to the river, for 
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Chapter 3. Physical Environment 3-11

Figure 3.1 Historic and current hydrograph of the Columbia River 

Exceedence curve: A flow exceedence curve shows the percent of time a flow has occurred historically. In this case, 

during 50 percent of the years, the flow equaled or exceeded the value shown. Source: Managing the Columbia River: 

Instream Flows, Water Withdrawals and Salmon Survival (2004) by Committee on Water Resources Management, 

Instream Flows, and Salmon Survival in the Columbia River Basin, National Research Council, 268 pages.

example Post Office Lake and Carty Lake, water fluctuations are generally muted relative to the 

river, with increases and decreases occurring more gradually. 

The River ‘S’ Unit and Bachelor Island were diked while in private ownership to increase the 

agricultural values of the lowlands. Diking began in 1941 when 1,565 acres of the River ‘S’ Unit 

were diked; in 1942, 1,120 acres of Bachelor Island were diked. Within the dikes of the River ‘S’ 

and Bachelor Island units, and portions of Ridgeport Dairy Unit, the hydrology is highly manipulated 

to provide wetland habitat for migratory waterfowl. The Service installed impulsion pumps to 

increase wetland habitat on the River ‘S’ unit in 1976. The River ‘S’ system was expanded in 1999 

with the construction of a second pump station. In 1999, water delivery systems and pump stations 

were also constructed on Bachelor Island and Ridgeport Dairy. Expansion of the irrigation system 

allows water manipulation within individual wetland basins to support habitat, wildlife, and public 

use priorities (for more detail on refuge water control infrastructure, see Chapter 5). However, the 

pumping costs and efficacy of the delivery system are major limiting factors in the movement of 

water within these units. Natural factors including soils, temperature, precipitation, elevation, tides, 

and river levels impose additional limitations to water delivery and retention within the diked units of 

the refuge. 

Due to their soil composition, some wetland basins within the diked portion of the Bachelor Island 

Unit do not retain water unless river levels are high. This is because they have layers of poorly 
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3-12 Chapter 3. Physical Environment

drained, clay soils interspersed with permeable layers of sand. When river levels are high, this sandy 

substratum allows water to move underground to interior portions of diked land. The water table 

rises and the wetlands hold water. Conversely, when river levels are low, water pumped into these 

wetlands dissipates rapidly. In most years, these wetlands only hold water in late winter and early 

spring. 

3.3.3 Gee Creek and Campbell Slough

Gee Creek, a 4th order tributary of the Columbia River, lies in western Clark County between the 

East Fork Lewis River and other smaller streams draining to Lake River. Gee Creek occupies a 

watershed basin of approximately 12,000-acres in size. The drainage consists of a main stem of 

approximately 11.5 miles in length, which branches into headwater tributaries, and a small mid-reach 

tributary locally named Tee Creek. The headwaters are located in the southernmost portion of the 

basin just west of the Interstate 5 freeway (I-5). After following I-5 north for about one mile and 

recrossing the freeway several times, the creek turns northwest through canyons and the City of 

Ridgefield, crosses Main Street and the Burlington Northern Santa Fe (BNSF) Railroad tracks via a 

culvert, and enters the Columbia River floodplain on the refuge’s Carty Unit. The lower 3.76 miles 

of Gee Creek meanders through the refuge in a series of lakes and ponds before emptying into the 

Columbia River at approximately river mile 87, a 1⁄4 mile upstream from the mouth of the Lewis 

River. The lower reach of Gee Creek is tidally influenced. Gee Creek is part of the Terrace 

hydrogeologic unit, characterized by rain-dominated precipitation, west to southwesterly trending 

groundwater flow, and a large delta (now a terrace) formed by glacial floods consisting of gravels, 

sand, silts and clay (WDOE 2007). 

The Gee Creek watershed is composed of three subwatersheds: Cathlapotle (the portion of Gee Creek 

on the refuge, from its confluence with the Columbia River to Main St. in Ridgefield); Lower Gee 

(Main St. to Royle Road); and Upper Gee (upstream of Royle Road to the headwaters east of I-5). 

The Cathlapotle subwatershed occupies the Columbia flood plain, and includes both the Carty Unit 

and privately held forestland north of refuge lands. Upper and Lower Gee are rural and urban areas 

above the Columbia River flood plain. Lower Gee includes the rapidly growing City of Ridgefield. 

The I-5 corridor bisects Upper Gee Creek subwatershed. An assessment of the geomorphology and 

hydrology of the upper Gee Creek watershed was done in 2008 for the Clark County Clean Water 

program (Clark County 2008a), but a detailed hydrologic assessment of the other subwatersheds has 

not been done. 

Portions of Gee Creek upstream from the refuge have been straightened and/or channelized. Grading 

and filling of the original watershed contours began with road and bridge construction in the late 

1800s, and was expanded with the construction of I-5 in the late 1950s and early 1960s. Currently, 

Gee Creek is restricted and confined by I-5, passing through two culverts, running in the divider 

between the north- and south-bound lanes for a 1⁄2 mile, and finally passing through a third culvert 

beneath the entire road grade before exiting the freeway corridor. By the 1960s, Gee Creek had been 

straightened to accommodate Pioneer Street and Abrams Park in Ridgefield. The Main Street 

Bridge, which crossed Gee Creek, was replaced with a culvert in the 1950s when the road was 

straightened. The Northern Pacific Railroad crosses the Gee Creek floodplain on a fill roadbed-dike 

more than 15 feet tall, confining and constricting the creek through an 8-foot diameter concrete 

culvert as it enters the Columbia River floodplain and the refuge (Cornelius 2006). 
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Chapter 3. Physical Environment 3-13

The hydrology of Gee Creek is impacted by the reduction in forest cover and an increase in the 

impervious surface in the watershed compared to historic conditions. Total forest cover in the upper 

and lower subwatersheds is 18 and 29 percent respectively, and forest cover in the Cathlapotle 

subwatershed is 38 percent (Clark County 2008b). This percent cover is well below the level at 

which watershed processes become degraded (less than 65 percent cover, Booth and Jackson 1997). 

Total impervious area (TIA) in upper and lower subwatersheds is 16 and 19 percent respectively. 

(The NOAA Fisheries standard is less than five percent TIA for fully functional watersheds; 

watersheds with greater than 15 percent TIA are considered nonfunctional habitat for anadromous 

fish.) 

Data from the stream gauge on Gee Creek at Abrams Park, about one stream-mile upstream of the 

refuge, suggests that Gee Creek is a relatively flashy stream. Examination of a simple hydrology 

metric, the TQmean (percent of a year when mean discharge was exceeded), showed that only 25 

percent of the daily flows were greater than the mean daily flow. This is indicative of a flashy urban 

or unforested rural watershed (Clark County 2008b). Most reaches of Gee Creek are incised but 

relatively stable at present; however, many are susceptible to future erosion. Projected increases in 

effective impervious area in the watershed will cause increased rates of channel incision, bank 

failures, and accelerated channel migration unless adequate runoff controls are in place.

Campbell Slough, which connects Campbell Lake to the Columbia River, was originally a backwater 

slough of the Columbia River. The slough is approximately 2.6 miles long and lies entirely within 

the refuge. Campbell Slough retains its connection to the Columbia River and is considered a 

permanent tidal riverine system.

3.4 Topography and Bathymetry

The topography of Ridgefield Refuge is largely flat to gently rolling, with most areas below 20 feet 

in elevation. The topography of the River ‘S’ and Bachelor Island units is generally sloping from 

south to north; wetlands fill on the south and drain to the north. Bachelor Island is notable for a 

series of roughly north-south trending ridges and swales (scroll bars) created by past high-energy 

flood events. The Carty Unit is a mosaic of shallow lakes and small knolls, with elevations varying 

from 0 to 60 feet above mean sea level. This hummocky topography, combined with fluctuating 

river levels and variable soil permeability, create an exceptionally patchy, fine-grained habitat where 

relatively small variations in elevation are associated with major shifts in vegetation type (see 

Chapter 4). 

A land cover mapping project was completed for the Ridgefield Refuge Complex by Ducks 

Unlimited in 2000. This included developing land cover maps from Airborne Data Acquisition and 

Registration (ADAR) imagery (2 meter resolution) acquired in 1997. As part of a project plan for 

proposed wetland restoration on Bachelor Island, elevation contours for Bachelor Island were created 

(intermediate contours between 5-foot index contours) and 350 acres of wetlands on Bachelor Island 

were restored in 1998, including recontouring of several wetland basins. Therefore, mapping does 

not reflect current conditions and needs to be updated.

Fine scale topographic and bathymetric mapping for use in habitat management and habitat 

restoration plans is identified as a priority in this CCP (see Chapter 2, objective 7.4). This will

include collecting fine-contour bathymetric data and performing mass point conversions of existing 
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3-14 Chapter 3. Physical Environment

Light Detection And Ranging (LIDAR) data to obtain 6-inch wetland contours, and preparing a 

spatial template of the slough and ditch network, including passage barriers and water control 

structures, and digital elevation model (DEM) for fine-scale topography mapping. 

3.5 Geology and Geomorphology

3.5.1 Physical Setting

The Ridgefield Refuge lies within the lower Columbia River ecosystem, which extends 146 river 

miles from Bonneville Dam to the Pacific Ocean. After it emerges from the Columbia River Gorge 

at river mile 126, the Columbia River widens to include a broad floodplain, and flows west and north 

through the Portland Basin, the broad, nearly level to undulating valley occupied by Portland and 

Vancouver and the confluence of the Columbia and Willamette Rivers. The Portland Basin is the 

northernmost of several sediment-filled basins that collectively constitute the Willamette Valley 

segment of the Puget-Willamette Lowland. The Basin is approximately 37 miles (60 km) long and 

18.6 miles (30 km) wide, with its long dimension oriented northwest. The Basin is flanked on the 

west by the uplifted marine rocks of the Coast Range and the Willapa Hills, and on the east by the 

volcanic Cascade Range (Ames 1999). 

Elongated islands divide the Columbia River and form sloughs and side channels in the formerly 

marshy lowlands. Where the Willamette River meets the Columbia, the floodplain expands. Here, 

the sloughs and lakes of North Portland, the Vancouver lowlands, Sauvies Island, and Ridgefield 

Refuge contain the Portland metropolitan area's last major remnants of the wetland and riparian 

system formerly nourished by annual flooding of the non-dammed rivers. 

About 10 miles (16 km) north of Saint Helens, the Columbia River exits the Portland Basin through a 

confined bedrock valley less than 1.5 miles (2.5 km) wide. Here it cuts through the Coast Range, a 

passage marked by steep-shouldered bluffs and broad alluvial floodplains. The river channel, dotted 

with low islands of deposited sediments throughout its lower reaches, opens out below Skamokawa, 

Washington, into several broad bays that extend more than 30 miles to the Pacific Ocean. At its 

mouth below Astoria, Oregon, the river passes between two jetties approximately two miles apart as 

it enters the Pacific Ocean.

3.5.2 Geomorphology

The landscape of the lower Columbia River Basin, and the refuge, is defined by cataclysmic basalt 

flows, Ice Age floods, and tectonic uplift of the Coast Range. During Pleistocene time, cataclysmic 

floods that originated in western Montana when ice dams on Glacial Lake Missoula broke, 

periodically flowed down the Columbia River drainage and inundated the Willamette Lowland. 

These floods deposited up to 250 feet of silt, sand, and gravel in the Portland Basin (Gannett and 

Caldwell 1999). 

The refuge is part of the Willamette Lowland, a 5,680-square-mile trough that lies between uplifted 

marine rocks of the Coast Range to the west and volcanic rocks of the Cascade Range to the east. In 

the northern two-thirds of the lowland, marine sedimentary rocks and Cascade Range volcanic rocks 

are overlain by up to 1,000 feet of lava of the Columbia River Basalt Group, deposited during midMiocene times. Folding and faulting during and after incursion of the basalt formed four major 
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Chapter 3. Physical Environment 3-15

basins, including the Portland Basin where the refuge lies. Portions of these basins have accumulated 

more than 1,600 feet of fluvial sediment derived from the Cascade and Coast Ranges, or transported 

into the region by the Columbia River. 

3.5.3 Geologic History

Basins and Ranges Form. The collision of the Juan de Fuca tectonic plate, off the coast of Oregon, 

with the North American plate is the dominant geologic force in the region. The Cascadia 

subduction zone, where the dense oceanic Juan de Fuca plate subducts, or dives below, the lighter 

North American plate, is responsible for producing the broad features of the landscape in western 

Oregon and Washington: the Willamette-Puget Trough, the Coast Range, and the volcanoes of the 

Cascade Range. The subduction zone lies 50 miles (80 km) off the West Coast and stretches 680 

miles (1,094 km) from mid-Vancouver Island to Northern California. The two plates move at a 

relative rate of approximately 0.4 inches (10 mm) per year at a somewhat oblique angle to the 

subduction zone (USGS 2004). 

The subduction zone began moving north to its current position about 35 million years ago. 

Evidence of this northward movement may be seen in the roughly 50 mile (80 km) northward offset 

of the Columbia River at Portland (Pacific Northwest Ecosystem Research Consortium 2002). The 

volcanoes of the Cascade Range, which formed above the subduction zone, made their first 

appearance 36 million years ago. At that time, the ancestral Columbia River drained the relatively 

low Columbia River Plateau. As the Cascades rose, the river was able to keep pace, creating the 

gorge and major pass through the Cascade Range and coast ranges seen today (USGS 2004). The 

Coast Range rose as sediments carried eastward by the subducting oceanic plate were forced under 

the western edge North American plate, pushing it upward. During this process, the future 

Willamette Valley also rose. Originally a bay, the valley became dry land about 20 million years 

ago.

The Portland Basin began to form about 20 million years ago, as a broad concave fold, or syncline, 

related to uplift of the Oregon Coast Range. The Basin formed as the Earth’s crust spread and sank 

between two fault zones (Thorson et al. 2003, Evarts 2004). Over the course of 20 million years, the 

shallow (less than 0.3 mile) basin was filled by sediments deposited by the Columbia River, and 

flows of volcanic material that followed the river’s course (Evarts 2007). Between 5.3 million and 

1.6 million years ago, the Willamette-Puget Lowland, the Cascade Range, and the Coast Range were 

in their modern locations, although today the original peaks of the Cascades are long gone, replaced 

by younger volcanoes. 

Subduction Zone Earthquakes. The process of subduction is also responsible for earthquakes that 

periodically hit the region. The coastal portion of the Cascadia Subduction Zone, between the 

leading edge of the continent and the Cascade Mountains, is where the most powerful earthquakes in 

the Pacific Northwest occur. In common with most other subduction zones, the outer continental 

margin along the Cascadia subduction zone is slowly being compressed, like a giant spring. When 

the stored energy is suddenly released by slippage across the fault at irregular intervals, very large 

earthquakes can occur. According to the geologic record, subduction earthquakes occur along the 

coast of the Pacific Northwest every 200 to 600 years (Dawes and Dawes 2001). The magnitude 9 

Cascadia earthquake of 1700 is the largest quake known to have occurred along this subduction zone 

(USGS 2004). The most recent large earthquake that occurred in the subducting plate was the 
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3-16 Chapter 3. Physical Environment

Nisqually earthquake in February of 2001, which knocked down parts of buildings in Olympia and 

Seattle (Dawes and Dawes 2001). 

Columbia River Basalts Enter the Portland Basin. About 18 million years ago, the Cascades were 

in their present location and the Columbia River flowed through a pass in the range, to the sea. The 

Portland Basin had begun to form, but major uplift of the Coast Range had yet to occur. At this time, 

one of the major events to shape the landscape of the Pacific Northwest occurred. Starting in early 

Pliocene times (18 million years ago) and continuing to the late Miocene (5 million years ago), one 

of the largest flood basalts ever to appear on the earth’s surface engulfed about 63,000 square miles 

(160,000 km2) of the Pacific Northwest (USGS 2004). 

The second-oldest of these flows, 16.5 million to 15.6 million years old, make up the Grand Ronde 

Basalt. Geologists estimate that the Grand Ronde Basalt comprises about 85 percent of the total flow 

volume. The weight of this flow caused central Washington to sink, creating the broad Columbia 

Basin (Carson and Pogue 1996, Alt and Hyndman 1995). The Grande Ronde Basalt and later flows 

travelled down the ancestral Columbia River, traversed the Cascade Range through a broad lowland, 

and spread out to cover large areas of the Coast Range province. Some of the basalt even reached the 

Pacific Ocean and flowed into Willapa Bay and Grays Harbor (Lasmanis 1991). 

Within the Portland Basin, the basalt lies more than 1,000 feet below the surface, and may be as 

much as 200 meters thick (Evarts 2004). Both upstream and downstream from Vancouver, at the 

edge of the basin, there are exposures of Columbia River basalt (Lasmanis 1991). At the refuge, 

much of the basalt bedrock is overlain by sedimentary deposits. However, basalts in the Carty Unit 

were exposed by Ice Age floods (see below). The rock is typically fine-grained, dark gray, and 

dense. Vertical columnar structures with polygonal cross sections formed as the lava cooled. Basalt 

provides a good building or foundation material, and beginning about 1880, basalt from the refuge’s 

Carty Unit was quarried to provide ship ballast and cobblestones for Portland streets (see Chapter 6). 

After the Columbia River basalts were deposited, the Portland Basin continued to subside, becoming 

narrower and accumulating several hundred meters of fine-grained Columbia River deposits (Sandy 

River Mudstone), volcanic debris (Rhododendron Formation, 8-13 million years ago), and a thick 

layer of cobbly gravel (the older part of Troutdale Formation, 1.6-5 million years ago). There 

followed an episode of uplift and incision by the Columbia River, which narrowed the basin to 

approximately its present width (Evarts 2007). 

Three to four million years ago, the Simcoe volcanoes to the east erupted. Lava flowed into the 

Columbia River where it was explosively quenched, forming volcanic glass (hyaloclastic) sands. 

The volcanic sand was flushed downstream, creating an alluvial fan (the younger part of Troutdale 

Formation) in the eastern Portland Basin. This was followed by a period of volcanic activity around 

the margins of the Portland Basin 2.6 to 1.3 million years ago. Subsequent uplift of the Cascade 

Range and coincident subsidence of the Portland Basin resulted in a westward tilt of the region east 

of the basin, causing the river to entrench this fan, and creating the modern Columbia River Gorge 

(Evarts 2007). 

Ice Age Floods. The last major chapter in the story of the Portland Basin was written quite recently 

in geologic time. With the beginning of the Pleistocene time (about 1.6 million years ago), cooling 

temperatures provided conditions favorable for the creation of continental glaciers. A vast ice sheet 

covered part of the North American continent. Enormous pressure on the ice caused it to flow 
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Chapter 3. Physical Environment 3-17

outward as glaciers. One such glacier dammed the Clark Fork River in northern Idaho, forming the 

huge Glacial Lake Missoula in present-day Montana, the lake is 3,000 square miles (7,770 km2) in 

size (Bjornstad 2006). 

During multiple ice ages, the last being 18,000 to 12,000 years ago, a series of cataclysmic floods, 

popularly called the Spokane, Missoula, or Bretz Floods, inundated large portions of the Pacific 

Northwest. Periodically, perhaps every 40 to 140 years, waters from Lake Missoula breached the ice 

dams and travelled west, scouring the Channeled Scablands of Washington, and eventually emptying 

through the Wallula Gap. In a typical release occurring over less than two weeks, a quantity of water 

equal to half the present volume of Lake Michigan, more than the modern annual volume of all the 

world’s rivers, poured down the Columbia channel (Pacific Northwest Ecosystem Research 

Consortium 2002). 

On reaching the Columbia River Gorge, the flood waters reached elevations of at least 1,000 feet 

(300m). As the floodwaters rose, they were constricted by the narrow reach of the Columbia 

downstream of the Portland Basin, the Kalama Gap. This forced flood waters to back up into the 

Portland Basin and Willamette Valley. At times ponded floodwaters in the Willamette Valley 

reached 400 feet (122 m) above current sea level. The suspended load of fine sand and silt settled 

out of the ponded floodwaters, covering the older deposits of the Troutdale Formation. Collectively, 

the Ice Age floods deposited up to 250 feet (76m) of well-sorted silt, sand, and gravel in the Portland 

Basin, and up to 130 feet (40m) of silt elsewhere in the Willamette Lowland (Lasmanis 1991, 

Gannett and Caldwell 1999). Much of Vancouver, Washington, and Portland, Oregon, are built on 

sand and gravel bars left by these Ice Age floods. The basalt quarries on the refuge’s Carty Unit are 

an example of Bretz Flood scabland, created when these high energy floods scoured away soil and 

exposed the underlying bedrock. 

During the last glacial maximum, sea level was about 394 feet (120m) lower than at present and the 

Columbia River cut a narrow valley about 246 feet (75m) below the present floodplain. Following 

the last Ice Age, sea and river levels rose and the once deeply entrenched valley of the lower 

Columbia River filled with sand and silt, forming the broad floodplain seen today. Seismic reflection 

profiles and other studies indicate that as much as 1,800 feet (550m) of late Miocene and younger 

sediments have accumulated in the deepest part of the Portland Basin near Vancouver; about 230 feet 

(70 m) are late Pleistocene and Holocene alluvium deposited by the Columbia River and its 

tributaries after the last glacial period (Evarts 2004). With the exception of areas of exposed Grande 

Ronde basalt on the Carty Unit, the present-day refuge is overlain by alluvium deposited by the 

Columbia River after the last glacial period. The Columbia River continued to sculpt the landscape. 

A notable recent feature are the parallel, linear ridges and swales of Bachelor Island (scroll bars), 

created by past high-energy flood events. 

3.6 Soils

Historically, a combination of shallow depressions, poorly drained clay soils, precipitation, elevated 

water tables, and annual flooding created and maintained natural wetland complexes within the 

Columbia River bottomlands. Refuge soils are mapped and described in the Soil Survey of Clark 

County, Washington (NRCS 2007). Most of the soils on the refuge are derived from alluvial 

deposition, as fine materials transported by the Columbia River settle out upon the low elevation 

bottomlands. 
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The principal soil types on the refuge are Sauvie silty clay loam (high in both silt and clay with 7-27 

percent clay particles, 28-50 percent silt, and less than 52 percent sand) with slopes of 0-8 percent, 

and Sauvie silt loam, with slopes of 3-8 percent. These are deep, somewhat poorly to moderately 

well-drained alluvial soils. Sauvie silty clay loam has medium texture and high clay content, which 

results in low permeability and high moisture capacity. Below the surface layer of Sauvie silt loam is 

a substratum of fine sandy loam which occurs at a depth below 36 inches. A 1972 Clark County soil 

survey noted that “Diking is difficult on this soil because of the permeable fine sandy loam 

substratum. If this zone is not cut off in diking, water will move through it and break out in areas 

known locally as ‘boils’ within the diked area in periods when the water level is high.” 

Most of the River ‘S’ unit is Sauvie silt loam, however, on the south end of the unit, Sauvie silty clay 

loam is found. The Roth Unit, where most of the refuge’s ash forests occur, is also Sauvie silty clay 

loam. On the south end of the refuge, between Post Office Lake and Campbell Lake, Newberg silt 

loam occurs. This is a deep, well drained alluvial soil on 3-8 percent slopes. 

Most of the Carty Unit is composed of Sauvie silty clay loam and Sauvie silt loam. A small area of 

Gee silt loam occurs where Gee Creek enters the Carty Unit. This is a deep, moderately well drained 

alluvial soil found on terraces, with slopes of 0-8 percent. Most soil inside the Bachelor Island dike 

is Sauvie silty clay loam. Some Sauvie silt loam occurs on the east side and north tip of the island. 

Accreted dredge spoils on the southwest shoreline of Bachelor Island (owned by Washington DNR) 

are classified as Pilchuck fine sand.

 

Periodically, sand transported by the river would deposit in localized areas of the floodplain which 

would be subsequently topped with layers of finer sediments. The resulting soils are poorly drained 

with interspersed permeable layers. When river levels are high, this sandy substratum allows water 

to move underground to interior portions of diked land. In extreme examples ‘boils’ will form as the 

water surfaces from underground. Boils were noted during the flood of 1996 on the River ‘S’ Unit in 

South Big Lake. Conversely, when river levels are low, water pumped into these wetlands dissipates 

rapidly. Wetlands with these soil characteristics occur on Bachelor Island. 

The Carty Unit’s soils within the Blackwater Island Research Natural Area (RNA) are unique 

compared to most of the refuge (Wiberg and Greene 1981). These elevated terraces are generally 

outside the floodplain; therefore, they are not alluvial in origin. These shallow soils overtop basalt 

bedrock and were formed in place. The soils of the RNA are classified as Olympic very stony clay 

loam. This soil type is derived from colluvium and residuum from igneous rock and is shallow and 

well drained, with slopes of 5-15 percent. It has up to 12 percent basalt fragments by volume and an 

average depth of 30 inches. Because of its stoniness and shallow depth, this soil is very well drained, 

and supports Oregon white oak woodlands. 

3.7 Environmental Contaminants

3.7.1 Air Quality

In summer and fall, air inversions and idle air masses are common to the valleys of southwest 

Washington and the Portland metropolitan area. Stagnant air masses can accumulate pollutants and 

emissions to unhealthy levels. These pollutants are largely generated by motor vehicles and 

industries in the Portland-Vancouver Air Quality Maintenance Area. During the summer of 2002, 
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Chapter 3. Physical Environment 3-19

Portland exceeded air quality standards considered safe for some groups on three days. These 

patterns are often improved by moderate westwardly breezes which disperse pollutants from the 

metropolitan areas up the Columbia River Gorge. 

3.7.2 Water Quality and Contaminants

Columbia River Mainstem and Lake River. Like many sites in the Portland-Vancouver area, 

Ridgefield Refuge has contaminant issues related to the Columbia River mainstem and Lake River. 

Fish and wildlife in the lower Columbia River are exposed to a range of pollutants known to cause 

adverse health effects via contaminated water, sediments, and prey. In The Health of the River 

(Tetra Tech 1996), the Bi-State Water Quality Program summarized results from a six-year study to 

assess the state of the lower Columbia River. Major conclusions of the study were: 

• Fish and wildlife in the Lower Columbia River basin are exposed via water, sediments, and 

prey to a wide range of potentially harmful pollutants. The pollutants include heavy metals, 

dioxin and related compounds, PCBs, DDT and other pesticides. 

• Bald eagles nesting along the Columbia are not reproducing as successfully as eagles nesting 

in other areas of Oregon and Washington. River otter are accumulating contaminants at 

levels that are limiting their ability to reproduce. 

• The Willamette River is a major source of pollutants to the lower Columbia River and 

contributes pesticides, bacteria, and during high river flows, metals. The Columbia River 

above Bonneville Dam contributes the majority of metals, dioxins and related compounds. 

• Most pollutants entering the lower Columbia River come from diffuse sources, such as urban 

and agricultural runoff. Examples include DDT which has accumulated in soil and is 

released through erosion, and PCBs which come from abandoned landfills and hazardous 

waste sites. Some pollutants come primarily from industrial and municipal wastewater 

discharges. These include dioxins and related compounds, and some heavy metals such as 

silver and cadmium. 

• Bacteria levels in the river are generally not a health hazard for contact recreation except 

possibly along shorelines following rain storms. Bacteria comes from many sources 

including combined sewer overflows, urban storm runoff, municipal and industrial 

discharges, septic systems, marinas, boats, and other diffuse sources such as agricultural 

runoff. 

A study of food-chain effects of contaminants in the Columbia River (Buck 2004) found that DDE 

and DDD were the most commonly detected and most elevated compounds in invertebrates, fish, and 

bird eggs collected from or adjacent to the river. Polychlorinated biphenyls (PCBs) were found 

frequently in fish and bird egg samples, but were rarely detected in sediment or invertebrates. The 

PCBs and DDE found in most fish samples exceeded estimated guidance values for the protection of 

avian predators, and concentrations in eggs of some piscivorous birds exceeded estimated noobserved-adverse-effect levels (NOAELs). Nearly all fish sampled also contained dioxins and furans 

in excess of guideline values derived for the protection of avian predators, and concentrations in eggs 

of some piscivorous birds exceeded estimated NOAELs. Although bioaccumulative contaminants 

were near or below detection limits in sediment and invertebrates, the results documented 

biomagnification of some organochlorines to concentrations likely resulting in adverse impacts to 

some piscivorous bird species. 

The report recommended that refuges located along the Columbia River provide adequate riparian or 

vegetative buffers on any land supporting agriculture or pasture, or land formerly used for these 
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3-20 Chapter 3. Physical Environment

purposes, to prevent erosion of soil associated with DDT or its metabolites from entering waterways. 

The report also recommended that population monitoring or nest counts of breeding terns, 

cormorants, and bald eagles continue, and that eggs of piscivorous birds be monitored for 

contaminants every five years.

A 1999 Fish and Wildlife Service study reported on the productivity of bald eagles nesting along the 

Lower Columbia River, including pairs nesting on Ridgefield Refuge, and contaminant levels in eggs 

collected in 1994 and 1995. Eggshell thickness was determined, and egg contents were analyzed for 

organochlorine pesticides, total PCBs, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated 

dibenzofurans (PCDFs), planar PCBs, and halogenated dioxin-like compounds. Buck found that 

although total productivity increased due to the success of new nesting pairs moving into the region, 

organochlorine contaminants were continuing to impact the breeding success of lower Columbia 

River eagles (USFWS 1999). A study of contaminant effects on great blue herons nesting along the 

lower Columbia and Willamette rivers, including the Bachelor Island colony (Thomas and Anthony 

1999) found organochlorines (DDE), PCBs, dioxins, furans, and trace elements in heron eggs, 

however, reproduction at the colony level was not impaired. 

Another potential contaminant issue for the refuge is contaminants originating from houseboats. 

About 50 residents live in houseboats on Lake River, on moorage leased from WDNR. A 

Washington State Department of Ecology (WDOE) study shows a contaminated water site just north 

of the houseboats. 

Pacific Wood Treatment Site Contaminant Plume and Remediation (Carty Lake, Lake River). 

The primary contaminant issue at the Ridgefield Refuge is the former Pacific Wood Treating 

Corporation (PWT) facility. Several site and facility investigations conducted over the years have 

shown groundwater contamination on and off the PWT site (Hart Crowser 1992, Kleinfelder 1993, 

Ecology and Environment 1996, Buck 2000.) The site is located directly adjacent to Carty Lake and 

is a Washington State Model Toxics Control Act (MTCA) cleanup site contaminated with woodtreating related chemicals. The site is located at 111 West Division Street, Ridgefield, Washington. 

Burlington Northern Railroad is on the east border of the site, and Ridgefield Marina is on the south. 

Lake River, a side channel of the Columbia River, forms the west border, and Carty Lake and 

Ridgefield Refuge are on the north border. In 1963, the Port of Ridgefield leased a portion of its 39-

acre Lake River property to PWT. Wood-treating operations at the PWT site began in 1964 and 

involved a variety of chemical preservatives including penatchlorophenol (PCP), creosote, chromated 

copper arsenate, and copper napthenate. Until the 1980s, chemicals were allowed to drain directly 

onto the open ground as part of the wood treatment process. In 1985, the U.S. Environmental 

Protection Agency (EPA) required PWT to begin cleaning up the contamination. Preliminary 

investigations on this site began in 1986 when potential contaminants were identified as petroleum 

hydrocarbons; volatile and semi-volatile organics; chlorinated phenols and related compounds; trace 

elements such as arsenic, chromium, and copper; and dioxins and furans. A Resource Conservation 

and Recovery Act (RCRA) facility investigation was conducted in the early 1990s (Kleinfelder 1993; 

see Contaminants Investigations below). In 1993, PWT declared bankruptcy and ceased operations. 

In 1995, the Port and WDOE reached an agreement to begin cleaning the site. Cleanup was 

implemented by the current landowner, the Port of Ridgefield, under the WDOE Toxics Cleanup 

Program and the MTCA. In 1996, the Port of Ridgefield signed an Agreed Order with WDOE to 

conduct investigations and remediation of the site. That year, the Port began removal of onsite 

contaminated sediment in the stormwater system. In 1997, some contaminated soils were removed 
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Chapter 3. Physical Environment 3-21

and others were stockpiled on site in the former tank farm treatment cell. The initial phase of 

cleanup (removal of treating chemicals and equipment) was completed in 2000. However 

contaminants remained in soil and groundwater. 

In 2001 a Federal Housing and Urban Development grant allowed construction of a remediation 

system to remove contaminants from soil. Clean-up efforts were focused on the removal of a 

contaminant plume estimated to be approximately four acres in size and contain some 100,000 

gallons of wood treating chemicals. The plume was in a shallow underground aquifer, but threatened 

to contaminate a deeper, regional aquifer as well as Carty Lake and Gee Creek (Port of Ridgefield 

2009a). 

The remediation technology involved installation of a vapor and liquid extraction system, and a 

steam injection system for removal of contaminants (Steam Tech 2000). The Service’s 2000 report 

recommended installing additional groundwater monitoring wells in Carty Lake to evaluate the 

success of cleanup efforts, and to ensure that operation of the steam remediation system did not 

increase contamination of Carty Lake. In the fall of 2000, EPA installed three clusters of monitoring 

wells (three wells per cluster) in the south end of Carty Lake. Analytic results from groundwater 

collected from the middle well cluster revealed contamination with wood-treating chemicals and PCP 

exceeded guidance criteria for groundwater. The Service installed three new wells in the fall of 

2001, two approximately 82 feet (25m) north of the EPA well clusters and one south of the EPA 

wells and closer to the PWT site. Well monitoring showed that the plume of contaminated 

groundwater in the shallow aquifer had moved north toward Carty Lake and the refuge. Maximum 

levels of 16 micrograms per liter of water (μg/L) PCP and 9.4 μg/L trichloroethylene (TCE) were 

found in off-site groundwater wells near Carty Lake and the refuge (Buck 2000, WDOE 2001). 

Baseline data was collected from the wells in January 2002, and wells were sampled on a quarterly 

basis thereafter, until September 2003. 

The Port of Ridgefield (Port) has continued surveying for contaminants in the vicinity of the Lake 

River Industrial Site. In May 2009, the Port began an assessment along the west side of Lake River 

on the refuge to characterize indicator hazardous substances in deep groundwater. In November 

2009, the Port collected sediment samples from Carty Lake on the refuge. Results of these sampling 

efforts will be provided to the refuge by the Port. 

Installation of the steam remediation system began in 2002 and was completed in 2004. The first 

steam injections took place in May 2004. Cleanup efforts continue to the present, with 2-4 years 

estimated to completion (Port of Ridgefield 2009a). The Port of Ridgefield expects that some 

cleanup of site soils and sediments in Lake River adjacent to the site will likely continue after 2011. 

The Port expects that final clean-up of soils and sediments will occur simultaneously with site 

redevelopment (Port of Ridgefield 2009b). 

Contaminants Investigations. A facility investigation conducted by Kleinfelder (1993) documented 

onsite contaminants including PCP, volatile and semi-volatile organics, copper, chromium, and 

arsenic. It also documented wood-treating chemicals and trace elements in sediment and water in 

and around surface water outfalls in both Carty Lake and Lake River. While PWT was still in 

operation, PCP was detected in sediment samples collected from Lake River and the Ridgefield 

Refuge. Concentrations of 34 to 38 μg PCP per kg were detected on the refuge and near the 

stormwater outfall. The highest PCP concentrations were 410 and 2,200 μg/kg found in sediment 

near two outfalls draining into Lake River. Sediment conditions were evaluated using the State of 
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3-22 Chapter 3. Physical Environment

Washington’s Marine Sediment Standards for PCP, and equilibrium theory based on chronic ambient 

freshwater criteria for comparison. Both comparisons indicated a potential for adverse effects to 

benthic organisms from the 2,200 μg/kg concentration. The results from this investigations 

documented that contaminants had moved off the PWT site and could potentially harm trust 

resources. 

A study conducted for the EPA in 1996 concluded that contaminants originating from the PWT site 

had migrated off-site and into refuge lands, including Carty Lake and adjacent wetlands (Ecology 

and Environment 1996). Site contaminants had contacted soil, sediment, surface water, and 

groundwater on the refuge. A single release of a PCP-containing liquid from an overflowing tank 

was observed entering the refuge in 1995. Groundwater in wells installed on the border of the refuge 

and the site at Carty Lake contained up to 12 μg/L of PCP, which was well above the risk-based 

concentration for PCP of 0.56 μg/L.

A study was conducted by the Service in 1999 to document environmental contaminants which had 

entered the refuge from the PWT site through the groundwater or surface water, in order to request 

appropriate cleanup activities from the Port of Ridgefield (Buck 2000). In June and July 1999, 

sediment and fish (largescale sucker) were collected from Carty Lake, Lake River adjacent to the 

PWT site, and a nearby reference area. The fish and sediment samples were analyzed for 

organochlorine pesticides, total PCBs, PCP, chlorophenoxy acid herbicides, and trace elements. 

Sediment samples indicated that organochlorine contaminants and chlorophenoxy acid herbicides 

were at or below detection limits, or similar to concentrations in sediment from the reference area. 

However, the results indicated that PCP and the trace elements arsenic, chromium, copper and 

possibly lead and zinc exceeded guidance values and were elevated on the refuge as a result of 

migration from the PWT site. In fish tissue samples, most chemical constituents were below 

detection limits, or similar to values outside Carty Lake. The data suggested that trace elements are 

locked in sediment, and therefore, not available to fish in Carty Lake, although sample sizes of fish 

were limited. 

The results indicated that PCP and some trace elements in sediment at the south end of Carty Lake 

could be impacting or limiting the occurrence of some benthic fauna in the area adjacent to the PWT 

facility. Concentrations of PCP, based on sediment samples from this study and water samples from 

previous investigations, could also impact fish eggs, developing embryos, or sensitive fish species 

such as trout and other salmonids. The implication of these findings was that management activities 

that disturb sediments in Carty Lake should be avoided. Salmonids are highly sensitive to PCP in the 

water column. Contaminant concentrations in Carty Lake currently prevent restoration activities 

from occurring at the site, including activities that would benefit listed salmonids (for example, 

reestablishing the former connection between Carty Lake and the Columbia River). Even if no such 

activities take place, salmonids could be exposed to PCP from Carty Lake during periods of overflow 

into the outfall area near Gee Creek. 

Gee Creek. Under current Washington State water quality standards, Gee Creek is to be “protected 

for the designated uses of: Salmonid spawning, rearing, and migration; primary contact recreation; 

domestic, industrial, and agricultural water supply; stock watering; wildlife habitat; harvesting; 

commerce and navigation; boating; and aesthetic values” (WAC 173-201A-600, WDOE 2006). 

In the first county-wide assessment of general water quality (Clark County 2004), overall stream 

health in the West Slope Watershed, including Gee Creek, scored in the poor to very poor range. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 3. Physical Environment 3-23

Segments of Gee Creek are listed under Section 303(d) of the Clean Water Act: Category 5 (fails to 

meet clean water standards) for fecal coliform, and Category 2 listed (waters of concern) for 

dissolved oxygen and temperature (WDOE 2009). Segments of Gee Creek are also Category 1 listed 

(meets tested standards for clean waters) for dissolved oxygen, pH, and ammonia-N (Clark County 

2008b). 

As part of a subwatershed needs assessment report (Clark County 2008b), existing data on the 

geomorphology, hydrology, water quality, and macro-invertebrate diversity of Gee Creek were 

collected and analyzed. Water quality data for the portion of Gee Creek running through the refuge 

were not available, however, data collected from two monitoring stations at Abrams Park in 

Ridgefield, about one mile upstream of the refuge, were included in the assessment and provide an 

indication of the impacts of upstream activities on the water quality of Gee Creek as it enters the 

refuge. Recent data (2002-2006) from the Abrams Park stations indicate that Gee Creek has 

significant water quality issues related to temperature, dissolved oxygen, turbidity, and fecal coliform 

bacteria. Observed levels of these characteristics were high enough to have negative impacts on 

macro-invertebrate populations; salmonid spawning, rearing, and migration; primary contact 

recreation; wildlife habitat; and aesthetic values. 

Temperature. Elevated temperatures have a detrimental impact on salmonid rearing, as juveniles are 

exposed to elevated summer temperatures. Resident cutthroat trout are exposed at all age classes. 

Temperature-related impacts to salmonids begin to occur at stream temperatures greater than 64°F. 

Impacts include decreased or lack of metabolic energy for feeding, growth or reproductive behavior; 

increased exposure to pathogens; decreased food supply; and increased competition from warmwater tolerant species (ODEQ, 2004 draft). Continuous summer water temperature monitoring from 

2002 through 2006 at Abrams Park indicated that temperatures exceeded the state criterion of 63.5° F 

for protecting salmonid habitat every year, and remained elevated over substantial periods. Sevenday average maximum temperatures recorded at Abrams Park in the summers of 2002-2006 

exceeded the state criterion by 3°F to 8°F. Due to the negative effects of chronic high temperatures 

on salmonids and other cold-water animals, the amount of time spent with elevated temperatures is 

also of interest. The number of days with temperatures exceeding 64° F ranged from 39 to 81 at 

Abrams Park over the four years of monitoring (Clark County 2008b). 

Turbidity. Turbid water may limit foraging ability of fish, and indicates the presence of fine silt that 

clogs gills and spawning beds. Fine sediment deposits compromise gravel spawning areas, smother 

eggs, and impact food availability by suppressing benthic macroinvertebrate populations. Natural 

background turbidity in most Clark County streams was probably in the range of 0.5 to 2 

Nephelometric Turbidity Unit (NTU); currently the summer median for Gee Creek is 4.5 NTU and 

the fall-winter-spring median is 8.5 NTU. Turbidity readings in the 20-40 NTU range are common 

during storm events. The primary sources of excessive turbidity and silt load in Gee Creek are 

probably related to soil and bank erosion. Off-site erosion (development, agriculture, recreational 

vehicle use), and in-stream erosion (bank scour, slumping, re-suspension of sediments during high 

flows) likely contribute significantly to the elevated turbidity during rain events. Extremely high 

turbidity values have been associated with specific sediment sources during rainfall events. The 

highest recorded value in Gee Creek since 2002 was 4,660 NTU, collected at Abrams Park in August 

2004. The source of this event was insufficient erosion controls at a subdivision construction project 

a mile upstream. The event caused lasting damage to the creek, and substantial sediment from this 

source is still present (Clark County 2008b). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

3-24 Chapter 3. Physical Environment

Fecal coliform. Elevated counts of fecal coliform bacteria are a concern associated with water-based 

recreation, especially during the summer months when the majority of water contact recreation 

occurs. A manure spill in 2001 was severe enough to cause a major fish kill in the creek below 

Royle Road (Cornelius 2006). Quarterly fecal coliform values from 2003 through 2006 indicate 36 

percent of fall-winter-spring (FWS) samples and 100 percent of summer samples exceeded 200 

cfu/100mL. Ninetieth percentile values for FWS and summer seasons were 500 and 1,380 

cfu/100mL, respectively, 2.5 to 7 times the criterion. The extent of elevated fecal coliform results 

during 2007 and 2008 suggest the presence of fairly widespread and consistent sources that will 

likely require considerable effort to control (Clark County 2008b). 

Nutrients. Phosphorus and nitrogen in excess may contribute to elevated levels of algal or plant 

growth, especially in slower moving, low gradient streams or in downstream water bodies. Nutrients 

(phosphorus and nitrogen) have not been assessed for lower Gee Creek; however, 85 percent of 

samples from upper Gee Creek exceeded the EPA criterion of 0.100 mg/L. Groundwater in Gee 

Creek is naturally high in phosphorus, tending to increase in the deeper aquifers (Turney 1990). As 

shallow sources deplete during the summer, these deeper aquifers contribute a greater share of 

surface flows. Naturally elevated concentrations may be augmented by nutrients from fertilizers, 

leaking septic tanks and sewer infrastructure, wildlife, and direct livestock access. Despite high 

nutrient levels, algae growth does not appear to contribute greatly to observed turbidity in Gee Creek. 

However, the downstream impacts of high phosphorus concentrations may be more significant than 

local effects. High nutrients may contribute to blue-green algal blooms in the lower end of the Gee 

Creek watershed in the Columbia River floodplain, where high-nutrient water enters slower-moving 

areas (Clark County 2008b). 

Other Water Quality Issues. Although not a contaminant issue, an associated water quality problem 

involves carp, because they stir up the bottom, it prevents establishment of aquatic vegetation and the 

development of the invertebrate community that would provide a food source for various diving 

waterfowl, as well as numerous dabblers during the breeding season. 

3.8 Surrounding Land Uses

The refuge borders the communities of Ridgefield and Vancouver Washington and is located within 

Clark County Washington. Although the refuge falls outside of the City limits, the community of 

Ridgefield borders the south end of Carty Unit and is located directly across Lake River from most of 

the River ‘S’ Unit. The City of Ridgefield was incorporated in 1909 and began as an agricultural and 

forestry based community. In 1964, the Pacific Wood Treatment facility began operations adjacent 

to the refuge’s present-day Carty Unit. 

Bachelor Island Unit. Bachelor Island is bordered by the Columbia River to the west, Bachelor 

Slough to the East, and Lake River to the Northeast. The closest nonrefuge land use occurs across 

the Columbia River on Sauvie Island, Oregon. Sauvie Island is a mix of private and public land 

holdings. Oregon Department of Fish and Wildlife manages over 12,000 acres of the island as 

Sauvie Island Wildlife Area. Sauvie Island is an important stop during fall and spring migration of 

waterfowl, as well as an important wintering area for several species of cackling and Canada geese. 

Sauvie Island Wildlife Area works with cooperators to produce wildlife food crops. Waterfowl and 

sandhill cranes are known to fly between the refuge and Sauvie Island as disturbance or their food 

supply warrants. Public uses such as hunting, hiking, fishing, and boating are allowed on this portion 

of the island. Privately held land on Sauvie Island is still largely agricultural.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 3. Physical Environment 3-25

Carty Unit. The Carty Unit “lowlands” are bordered by Lake River to the west, Gee Creek to the 

north, the Port of Ridgefield to the south and BNSF Railroad tracks to the east. The Morgan family 

is the only major landowner between refuge lands of the Carty Unit and the Lewis River; a portion of 

their property lies within the refuge’s acquisition boundary. The Morgan family primarily utilizes 

their 1,500-acre property, purchased in 1941, for livestock grazing and tree farming. 

The Port of Ridgefield owns the Lake River industrial site, 40 acres of underdeveloped waterfront 

property along Lake River in downtown Ridgefield, adjacent to Carty Lake on the Carty Unit. The 

property is zoned for waterfront mixed use development under Ridgefield Development Code 

Chapter 18.30, and the Port has developed a comprehensive plan for the property (Port of Ridgefield 

2001, revised 2008). The Port of Ridgefield administrative and facilities management offices and 

staff are currently located at this site. Although owned by the Port of Ridgefield, the land bordering 

the southern boundary of the Carty Unit was operated by PWT from 1964 until their bankruptcy in 

1993. Further development of the Port property cannot occur until remediation of soil and 

groundwater contamination at the PWT site is completed. The City of Ridgefield also owns a small 

piece of property adjacent to the Port on the eastern shore of Carty Lake. The property currently 

houses the City’s wastewater treatment facility. 

The Port’s comprehensive plan was revised in 2008 (Port of Ridgefield 2009b) and included the goal 

of redeveloping the Lake River property as a ‘mixed-use waterfront employment center’ with a 

diversity of job types and high-wage jobs. The Miller’s Landing project would be a mixed use 

waterfront development including public green spaces, office space, light industrial, moorage, retail, 

and an Environmental Science research and development facility (a cooperative project between 

Washington State University, the Port and the Confluence Project). Before redevelopment can occur, 

individual areas must meet the clean-up criteria set forth by WDOE. The Port is currently pursuing a 

“development-based remediation” strategy on the waterfront where final clean up of the Lake River 

Industrial Site occurs with redevelopment. 

In 2006 the Port began planning a rail overpass to provide new, direct access to the Lake River 

waterfront from downtown Ridgefield. The project would extend Pioneer Street to the west via a 

curving overpass that would touch-down near Mill Street. This project would allow the at-grade 

crossings at Mill and Division Streets to be closed. Planning and construction of the overpass project 

is part of the overall waterfront redevelopment project (Port of Ridgefield 2009b). 

The clamor of trains on the BNSF railroad tracks, which separates the main body of the Carty Unit 

from the parking area, often disrupts educational programs at the plankhouse and can be a general 

annoyance for visitors searching for an undisturbed nature walk. The bridge that is necessary to span 

the railway is non-ADA compliant and acts as a barrier to many visitors with physical disabilities. 

Visitors with disabilities must be “flagged” across the at-grade crossing upon request. The refuge 

has created conceptual plans for a new ADA accessible bridge. Trains parked in front of the at-grade 

crossing have been a barrier to disabled visitors and refuge management on the Carty Unit. 

The Carty Unit parking area is currently located on the Ridgefield National Wildlife Refuge 

Complex site. This area is bordered to the north by the Carty family property, to the east by Main 

Avenue and low-density housing, and to the south by Gee Creek. 

Ridgeport Dairy Unit. Ridgeport Dairy Unit is bordered on the south by farm land owned by the 

Fazio family. Lake River borders the unit to the east with the BNSF railroad tracks running on the 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

3-26 Chapter 3. Physical Environment

opposing bank. Developed properties are perched atop steep graded hillsides. The unit is bordered 

on the west by the Columbia River, with the closest nonrefuge land use at Sauvie Island (See 

description under Bachelor Island Unit). A small portion of the northeast corner of the unit is 

bordered by cattle grazing property owned by the Roth family. 

Lower River Road, owned by Clark County, runs along the levee that separates the southwest portion 

of the unit from the Columbia River. In June 1962 the Washington State Department of Highways 

published its survey report of the state legislature’s joint fact finding committee on highways, streets, 

and bridges. The State proposed to upgrade and extend River Road, which would have passed 

through the middle of the current River ‘S’ Unit, crossed the Lewis River on a new bridge, and 

connected with U.S. 99 at Woodland (Clark County-Vancouver Regional Planning Commission 

1963). In 1963 the state legislature authorized the designation of Lower River Road and its future 

extension as far as Ridgefield as State Highway 1-T. This extension was never completed. Lower 

River Road dead-ends within the refuge and was utilized by visitors until 2004. At that time, 

portions of the levee slumped, causing the road to become impassable. At this time, the county has 

no plans for levee or road reconstruction. The road and parking area have always been a magnet for 

illegal garbage dumping, trespass, and vandalism. The State of Washington owns a right of way 

along the east side of Ridgeport Dairy unit (see Appendix M, Figure 1). This right of way is 140 feet 

wide in most places. 

River ‘S’ Unit. Lake River and Bachelor Slough form most of the west, north, and east borders of 

this unit. Across Lake River to the east lies the BNSF railway, Port of Ridgefield property (see 

description under Carty Unit), McCuddy’s Marina (which provides boat slips and houseboat 

moorages), and steep sloping hillsides. Just beyond the marina and Port property lies downtown 

Ridgefield. The entrance of the River ‘S’ Unit meanders through a steeply sloping draw with high 

density housing developments planned for the upland pastures that surround its intersection with S. 

9th Avenue. These developments are currently zoned as UH-10 properties. The population of the 

City of Ridgefield in 2004 was estimated at 2,602 residents and is projected to hit 26,200 residents by 

2024 (City of Ridgefield 2005). 

Roth Unit. The Roth Unit is bordered to the east by Lake River and the west by the Columbia River. 

The north and south boundaries of the unit border refuge lands. Forty two acres to the east of 

Campbell Lake are owned by the Roth family and used primarily for grazing. The BNSF railway 

runs along the eastern banks of Lake River. Residential development is located atop the steeply 

sloped hillside above the railroad. Sauvie Island lies on the opposing shores of the Columbia River 

(see description under Bachelor Island Unit). The State of Washington owns a right of way along the 

east side of Roth unit. This right of way is 140 feet wide in most places (see Appendix M, Figure 1). 

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Port of Vancouver. 1965. Proposed Columbia River Lowlands/Vancouver Lake “FAIR STUDY.” 

Vancouver, WA. URL: www.fishlib.org/library/Bibliographies/VLWP/documents/fairstudy.pdf, 

accessed May 12, 2009. 

Salathé, E.P. 2006. Influences of a shift in North Pacific storm tracks on western North American 

precipitation under global warming. Geophys. Res. Lett., 33. 

Salathé, E.P., L.R Leung, Y. Qian, and Y. Zhang. 2009. Regional Climate Model Projections for the 

State of Washington. Climate Impacts Group, University of Washington, Seattle, WA. 

Seattle Ecology and Environment, Inc. 1996. Pacific wood treating site assessment report, TDD:96-

02-0024. Prepared for U.S. Environmental Protection Agency. URL: 

www.lcrep.org/pdfs/59.%2002939.pdf. 

Snover, A.K., P.W. Mote, L. Whitely Binder, A.F. Hamlet, and N. J. Mantua. 2005. Uncertain 

Future: Climate Change and its Effects on Puget Sound. A report for the Puget Sound Action Team 

by the Climate Impacts Group. University of Washington, Seattle, WA. 

Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller 

(editors). 2007. Climate change 2007: The physical science basis. Contribution of working group I 

to the fourth assessment report of the intergovernmental panel on climate change. Fourth assessment 

report of the intergovernmental panel on climate change. Cambridge University Press: Cambridge, 

UK.

Stewart, I.T., D.R. Cayan, M.D. Dettinger. 2004. Changes in Snowmelt Runoff Timing in Western 

North America in a ‘Business As Usual’ Climate Scenario. Climatic Change 62: 217–232 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

3-32 Chapter 3. Physical Environment

Tague, C., G. Grant, M. Farrell, J. Choate, and A. Jefferson. 2008. Deep groundwater mediates 

streamflow response to climate warming in the Oregon Cascades. Climatic Change 86:189-210. 

Taylor, G.H., and R. Hatton. 1999. The Oregon Weather Book, pp. 96-10. 

Tetra Tech. 1996. Lower Columbia River Bi-State Program–The Health of the River, 1990-1996. 

Integrated Technical Report. Prepared for Oregon Department of Environmental Quality and 

Washington Department of Ecology. URL: www.lcrep.org/pdfs/59.%2002939.pdf. 

Thomas, C.M., and R.G. Anthony. 1999. Environmental contaminants in great blue herons (Ardea 

herodias) from the lower Columbia and Willamette Rivers, Oregon and Washington, USA. Environ. 

Toxicol. Chem. 18:2804-2816. 

Thorson, T.D., S.A. Bryce, D.A. Lammers, A.J. Woods, J.M. Omernik, J. Kagan, D.E. Pater, and 

J.A. Comstock. 2003. Ecoregions of Oregon (color poster with map, descriptive text, summary 

tables, and photographs). U.S. Geological Survey, Reston, VA. 

Turney, G.L. 1990. Quality of Groundwater in Clark County, Washington: U.S. Geological Survey 

Water Resource Investigation Report 90-4149. 

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Water Surface Levels. 

U.S. Department of Agriculture, Natural Resources Conservation Service. Web Soil Survey. URL: 

websoilsurvey.nrcs.usda.gov/, accessed June 11, 2007. 

U.S. Environmental Protection Agency. 2009. Columbia River Basin: State of the River Report for 

Toxics. Report No. EPA 910-R-08-004. URL: yosemite.epa.gov/r10/ECOCOMM.NSF/Columbia/SoRR/$FILE/SORR-columbia-09-Full.pdf, accessed January, 16, 2009. 

U.S. Fish and Wildlife Service (USFWS). 1983. Environmental Assessment for the Acquisition of 

Remaining Tracts, Ridgefield National Wildlife Refuge, Clark County, WA. 

USFWS. 1996. Ridgefield NWR, Farm Management Plan, Unpublished document. Ridgefield, 

WA.

USFWS. 1999. Changes in productivity and environmental contaminants in bald eagles nesting 

along the lower Columbia River, final report. Portland, OR. 

USFWS. 2004. Ridgefield National Wildlife Refuge Accomplishments 2004, A Year in Review. 

URL: www.fws.gov/arsnew/regmap.cfm?arskey=14614, accessed June 13, 2007. 

USFWS. 2005. Final CAP Report for Ridgefield NWR, Unpublished report. URL: 

ecos.fws.gov/cap/summaryReport.do?studyId=1106, accessed July 31,2007 

USGS. 2004. Columbia Plateau Province. URL: 

wrgis.wr.usgs.gov/docs/parks/province/columplat.html, accessed August 24, 2007. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 3. Physical Environment 3-33

USGS. 2004. Pacific Cascades Volcanic Province. URL: 

wrgis.wr.usgs.gov/docs/parks/province/cascade2.html, accessed August 24, 2007. 

Washington State Department of Ecology and Washington Department of Fish and Wildlife. 2004. 

Draft Environmental Impact Statement, Columbia River Mainstem Water Management Program. 

Publication No. 04-11-031. Olympia, WA. 

Washington State Department of Ecology. 2001. Contamination confirmed in Ridgefield 

[Washington] refuge. Department of Ecology news release - May 2001. Washington State 

Department of Ecology. Olympia, WA. 

Washington State Department of Ecology. 2006. Water Quality Standards for Surface Waters of the 

State of Washington: Chapter 173-201A WAC. Publication No. 06-10-091. URL: 

www.ecy.wa.gov/biblio/0610091.html. 

Washington State Department of Ecology. 2007. Draft Watershed Characterization of Clark 

County, version 3. URL: www.clark.wa.gov/mop/documents/watershed-characterization.pdf. 

Washington State Department of Ecology. 2004. Water quality assessments. URL: 

www.ecy.wa.gov/programs/wq/303d/2002/2004_documents/wq_assessment_cats2004.html. 

Wilde, T. 2006. Weather Events of Feb 1996 and Nov 1996. Presentation for DOGAMI Landslide 

Forum, Salem, OR. URL: www.oregongeology.org/sub/Landslide/forum2006/TyreeWildePresentation.ppt, accessed May 12, 2009. 

Wilson, K.K. 1993. Ridgefield, Washington: a glimpse of history, c. 1800 to 1992. Unpublished 

report, Clark County Historical Museum files, Vancouver, WA. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

3-34 Chapter 3. Physical Environment
Chapter 4. Refuge Biology and Habitat

Above: Scrub jays help

disperse and plant

Oregon white oaks/Jim

Cruce

Above right: A red-tailed

hawk hunts refuge

grasslands/Jim Cruce

Right: A green-backed

heron captures a non-native

bullfrog in a refuge

wetland/Jim Cruce
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-1 

The Service manages a highly altered ecosystem at the refuge, due in large part to:

• Artificial river operations; 

• Widespread nonnative invasive

species; and

• Extensive land use conversion and 

fragmentation. 

Chapter 4. Refuge Biology and Habitat

This chapter addresses the biological resources and habitats found on the refuge. However, it is not 

an exhaustive overview of all species and habitats. The chapter begins with a discussion of 

biological integrity (historic conditions and ecosystem function), as required under the Improvement 

Act. The bulk of the chapter is then focused on the presentation of pertinent background information 

for habitats used by each of the 15 Priority Resources of Concern (ROCs) and other benefitting 

species designated under the CCP. That background information includes descriptions, conditions 

and trends of habitats; key ecological attributes of habitats; and finally, threats (stresses and sources 

of stress) to the habitats and/or associated ROCs. This information was used to develop goals and 

objectives for the CCP. 

4.1 HistoricWildlife and Habitat Conditions and Changes Since 1800

The lower Columbia River ecosystem, of which Ridgefield Refuge is a part, has undergone dramatic 

alteration over the past 200 years. The three most discernible changes include: 

• Changes in the hydrology of the Columbia 

River due to dam operations; 

• Conversion of Columbia River bottomlands to 

agricultural lands (including diking and 

draining) and residential, commercial, and 

industrial development; and 

• Loss of native species, accompanied by a 

large influx of nonnative and invasive plants 

and animals into the system. 

Many habitat changes and the spread of invasive species were underway long before dams were built 

and the refuge was established. This section discusses the connection between these landscape level 

changes and the current vegetation and wildlife on the lands and waters occupied by the refuge. This 

summary is not a complete analysis of all factors related to changes in native vegetation, fish and 

wildlife. Much of the information presented here is based upon the team’s knowledge of the area. 

4.1.1 Historic Descriptions of Habitat and Wildlife

Before dam construction within the Columbia River system, spring floods, or freshets, were the 

primary hydrological influence on the lower river. Overbank flooding, scouring and sediment 

deposition created and maintained a mosaic of wetlands and bottomland forests along the river. The 

average annual spring flood reached a stage of 21.5 feet at the gage at Vancouver, Washington. 

Average spring flooding in the lower river would have inundated up to 170,000 acres for periods of 

up to 60 days, and major floods inundated up to 300,000 acres of bottomland floodplain (Christy and 

Putera 1993). Historically, spring flooding would have annually inundated most of the refuge. The 

History of Clarke County (Alley and Munro-Fraser 1885) notes that the bottomlands along the 

Columbia River were “subject to the annual overflow, which reaches its highest in June . . .” 

Vegetation. The earliest written description of refuge lands dates from November 5, 1805, when 

Lewis and Clark described Bachelor Island (which they called Green Bryor Island) as “Covered with 

tall trees & green briers” (Moulton 1990). A general description of habitat in the Portland Basin is 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-2 Chapter 4. Refuge Biology and Habitat

found in the journal of another expedition member, John Ordway. On November 3, 1805, he 

described Government or McGuire Island, opposite and upstream from present-day Portland as 

“mostly prarie and large ponds, which is full of Swan Gees brants and ducks &C” (Moulton 1996). 

Lewis’s journal entry of March 29, 1806, noted that the people of the Cathlapotle nation took “great 

quantities” of wapato (Saggitaria latifolia) “from the neighboring ponds, which are numerous and 

extensive in the river bottoms and islands” (Moulton 1991). Clark also made reference to a “large 

pond” (Carty Lake) where wapato grew in abundance, and a “butifull grassy area” between Carty 

Lake and Lake River, where the expedition encamped on March 29, 1806 (Moulton 1991). Ordway 

described the campsite as “a handsom Green where had once been a village” (Moulton 1996). Lewis 

described the vegetation of Sauvies Island (which the expedition called Wapato Island) in some 

detail on March 30: “ . . . the land is high and extremly fertile and intersected in many parts with 

ponds which produce great quantities of the sagittaria Sagittifolia, the bulb of which the natives call 

wappetoe. there is a heavy growth of Cottonwood, ash, the large leafed ash and sweet willow on 

most parts of this island” (Moulton 1991). 

Maps and survey notes from the General Land Office, made between 1851 and 1865, are the only 

reliable source for information about original vegetation of the Ridgefield bottomlands; however, 

these reports mainly contain information on tree species and little information on shrubs and 

herbaceous vegetation. Maps and survey notes from the General Land Office made in the 1850s 

indicate that the present-day refuge contained a mixture of bottomland forest, riparian forest, and 

shallow overflow lakes (Bureau of Land Management 2007a, b; and Christy and Putera 1993). The 

vegetation of much of the present day refuge was described as “W. ash, Cotton-wood, willow &c, 

undergrowth Grass, Briars, Willows &c.” An August 1853 survey of the area noted “Land level 

bottoms, subject to inundation from 1 to 4 ft. deep . . . West half prairie or meadow, [remainder] 

timbered with ash balmgelead [cottonwood] crabapple & undergrowth willow briers vines &c.” 

(BLM 2007b). An 1854 map (Figure 4.1) shows the vegetation of Bachelor Island (then called 

Columbia Island) as “Balm Gilead, Ash, Thorn with dense undergrowth” (BLM 2007a). Oral 

histories of Bachelor Island described the Island as a thick bottomland forest cut by meandering 

sloughs prior to the 1940s (Cornelius 2006). Shrub swamps were probably another habitat type once 

common on the refuge. Christy (2004) noted that “Historically, willow swamps were the second 

most abundant wetland vegetation (after wet prairies) [in the Willamette Valley], forming a wet 

landscape described by early explorers and land surveyors of the region. Many of these systems 

were maintained or enhanced by beavers and have since been lost to drainage and conversion to 

farming.” 

These early survey notes indicate that much of the present day refuge, like much of the PortlandVancouver Basin, was originally covered by bottomland 

and riparian forest dominated by black cottonwood, Oregon 

ash and willow. The forest was interspersed with tidal 

sloughs, wet meadows, and broad, shallow overflow lakes 

and ponds. Most of the area flooded in June when the 

Columbia River overflowed its banks. 

Little data exists on the original wetland vegetation, except that several early writers noted the 

presence of extensive stands of wapato (Saggitaria latifolia) growing in shallow lakes throughout the 

region. “Wapato Valley” was the name Lewis and Clark gave the region from the downstream end 

of the Columbia Gorge to the confluence of the Columbia River with the Cowlitz River at KelsoLongview. Lewis and Clark reported extensive harvest of this plant from Carty Lake by the 

Most of today’s refuge was 

originally floodplain and riparian 

forest, interspersed with tidal 

sloughs, shallow overflow lakes, 

and meadows. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-3 

inhabitants of Cathlapotle village (Moulton 1991[7]:26-30). Jewett (1927) reported Canvasback 

Lake on Bachelor Island as “being shallow and supporting a wealth of aquatic vegetation, is 

essentially a ‘mallard lake.”

Wet meadows on the shallow, drying margins of overflow lakes were probably dominated by 

Columbia sedge (Carex aperta), which was described by Piper and Beattie (1915) as “the common 

‘hay sedge’ of the Columbia River bottoms where it was first collected by Douglas.” Pacific willow 

(Salix lasiandra ssp lucida) grew on wet flats along channels and around overflow lakes. Oregon ash 

(Fraxinus latifolia) occurred on slightly higher sites protected by natural levees. Higher banks and 

the tops of natural levees were dominated by associations of Oregon ash, black cottonwood (Populus 

trichocarpa), with red-osier dogwood (Cornus stolonifera), snowberry (Symphoricapos albus) and 

stinging nettle (Urtica dioica) (Christy and Putera 1993). 

Terraces and wetland margins were covered by a mixture of prairie; oak savannah/woodland with 

understory dominated by red fescue (Festuca rubra) and California oatgrass (Danthonia californica); 

Douglas-fir; and Oregon ash. It is possible that the prairie and oak woodland communities were 

maintained by anthropogenic fire, as was the case throughout the Willamette Valley/Puget Trough 

region. GLO survey notes from the 1850s (Bureau of Land Management 2007b) describe oak 

woodlands on higher ground of the present-day Carty Unit. 

Little data exists on native prairie vegetation of the present-day refuge. Before flood control, wet 

meadows or prairies on the Columbia River bottoms were frequently flooded well into summer, and 

little is known about their original composition, because widespread invasion of reed canarygrass 

(Phalaris arundinacea) has displaced many native species. Depending on elevation and soil 

characteristics, some areas were likely dominated by tufted hairgrass (Deschampsia caespitosa) 

while others were dominated by Columbia sedge (Carex aperta) which intergraded with a complex 

of marshes and sloughs on the river bottoms (Christy 2004). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-4 Chapter 4. Refuge Biology and Habitat

Figure 4.1 General Land Office map of Bachelor Island, Gee Creek, Sauvie Island, and the 

Scappoose Flats, 1854. Source: Bureau of Land Management, Oregon State Office, Land Status 

and Cadastral Records, Willamette Meridian-Oregon and Washington.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-5 

4.1.2 Changes to Lower Columbia River Wildlife and Habitats Since 1850

Although people have lived on the present-day refuge for at least 2,300 years, the influence of human 

activity on the landscape was relatively minimal. Towns were relatively small in size; Lewis and 

Clark reported in 1805 that Cathlapotle, the third largest town on the lower Columbia, had about 900 

inhabitants. A limited number of western red cedars were felled to supply materials for houses and 

canoes, but bottomland forests remained largely intact. People may have set fires to manage oak 

woodlands and grasslands, as was the case elsewhere in the Willamette Valley and Puget Trough. 

The Fur Trade. The pace of landscape change accelerated rapidly following Euro-American 

settlement in the 19th century. Britain’s Hudson’s Bay Company established a fur-trading post at 

Fort Vancouver in 1825. The fur trade affected populations of certain mammals harvested for fur 

and food, but no species was affected more than the beaver. Beaver were an important factor in the 

creation of wetlands, and many wetlands developed on sediments trapped by beaver dams. 

Historically, willow swamps were the second most abundant habitat (after wet prairies) in the 

Willamette Valley and probably were common in the Portland-Vancouver Basin as well, forming a 

wet landscape described by early explorers and land surveyors of the region. Many of these wetland 

complexes were maintained or enhanced by beavers. Although beavers seem common today, historic 

populations in Oregon were probably ten times larger than current. Their numbers were decimated 

first by commercial trapping prior to 1845, then by diminishing wetland acreage caused by their 

trapping, and finally by widespread agricultural drainage projects (Christy 2004). 

Agricultural Development. From the mid 1800s on, bottomland forests were gradually cleared for 

agriculture, and to supply firewood and wood products. Cottonwood harvested from Clark County 

bottomlands was made into staves and barrels (Alley and Munro-Fraser 1885) and later was used in 

paper production. Oregon ash was primarily used for firewood, but it was also made into wagon 

frames, furniture, barrel staves, and tools. Christy and Putera (1993) noted that most present day 

stands of Oregon ash on the lower Columbia River appear to have originated between 1910 and 

1930. 

Bachelor Island was settled in the 1850s (see Chapter 6, Refuge History). By the late 1800s much of 

Bachelor Island’s bottomland forest had been logged off, and the island was being used for pasture 

and for growing hay and grain. When Portland businessmen Ladd and Reed bought 1,000 acres on 

Bachelor Island in 1876, these uses were well established. In 1942, 1,120 acres of the island were 

diked. Subsequently, the original ridge-and-swale topography of the island was muted by removing 

soil on the tops of ridges and using it to partially fill the swales. In the early 1980s between 900 and 

1,000 acres of potatoes and barley were being grown on the island. By the time the refuge acquired a 

portion of Bachelor Island in 1985, the original wetlands had been filled and drained, and the original 

ash/cottonwood forest was reduced to a remnant outside the dikes. 

In 1872 James E. Carty settled on the area currently known as the Carty Unit. The Carty family 

primarily used their land for grazing. Former Refuge Manager Bruce Wiseman reported that the 

Carty family had logged cottonwood trees from the high bench ground along Lake River in what is 

now the Carty Unit. However, the Carty Unit was never diked, and habitats there remained in a 

relatively natural condition. The River ‘S’ Unit was diked in 1941, and ash forests were logged from 

the unit in the 1950s to clear land for pastures. Up to 600 cow/calf pairs, and at times hundreds of 

sheep, grazed on improved and canarygrass pastures. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-6 Chapter 4. Refuge Biology and Habitat

Livestock grazing had major effects on wildlife and habitat. Native grasses and forbs were not 

adapted to heavy grazing pressure; grazing therefore opened the door to the spread of exotic plant 

species. Exotic pasture and forage grasses were also intentionally introduced. These grasses had a 

competitive advantage under heavy grazing pressure, and permanently altered many plant 

communities. Livestock grazing in riparian areas allowed exotic reed canarygrass to invade and 

largely replace the native understory plant community. 

On the other hand, livestock grazing benefitted some native wildlife species. Until the mainstem 

Columbia River dams were built, and widespread levee construction along the lower Columbia River 

was completed, healthy and productive wetlands supported large numbers of migrating and wintering 

waterfowl. The juxtaposition of wetlands and adjacent pasture and croplands may have actually been 

favorable to geese and certain ducks that preferred short, nutritious grasses. During the 1950s and 

1960s, pastures on the present-day refuge were used heavily by migratory and wintering Canada 

geese (mostly duskys), tens of thousands of American wigeon, and other ducks. Some wildlife 

species responded to changing land uses by altering their wintering areas and migration routes. 

Bromley and Rothe (2003) discussed changes in the distribution of dusky Canada geese during the 

20th century. A summary follows. 

Until the late 1930s, dusky Canada geese apparently wintered primarily along the Oregon coast 

(Gabrielson and Jewett 1940). From the late 1930s through the mid-1940s, large dark geese, 

presumably duskys, were commonly observed spring and fall migrants and winter visitors in the 

southern Willamette Valley (Gullion 1951). Jewett (1953) reported observations and harvest of 

duskys from the Willamette Valley and Sauvie Island, Oregon, from 1931 through 1952. He noted 

that “this coastal species [is] fairly common along the ocean beaches the entire length of Oregon, but 

is becoming either better known to hunters, or is actually increasing during the fall and winter 

months in the Willamette Valley and Lower Columbia River Valleys.” Finally, Hansen (1962) 

compiled an extensive data set based on more than 1,000 recoveries of duskys banded on the Copper 

River Delta (CRD), and demonstrated that CRD duskys wintered primarily in the Willamette Valley. 

By the mid-1960s, just prior to the effective establishment of refuges in the Willamette Valley and 

the lower Columbia River, concentrations of duskys wintering in the Willamette Valley had shifted 

from the southern end of the valley, to the middle valley near Corvallis and Albany (Chapman et al. 

1969). In part, this change in distribution may have been due to both increases in pasture, and later, 

grass seed production in the Willamette Valley and lower Columbia River; and decreases in suitable 

habitat on the coast (Pacific Flyway Council 2008). 

Ornithologist Stanley Jewett published a report on waterfowl on Bachelor Island based on his 

observations during the fall and winter of 1926-1927. Jewett reported that Canvasback Lake on 

Bachelor Island “is essentially a ‘mallard lake.’ This species outnumbers all other species of ducks 

there.” He also noted that pintail, American wigeon, and green-winged teal were common; lesser 

scaup were somewhat common; and that the wood duck was both common and a permanent resident. 

Ducks which were less common, or of “irregular occurrence” included cinnamon teal, shoveller, 

canvasback, [greater] scaup−“nowhere near as plentiful as the [lesser scaup]”−ring-necked duck, and 

ruddy duck (Jewett 1927). 

While intensive agricultural development resulted in benefits to geese and certain ducks, it had 

negative effects on other native species, including salmon and trout, landbirds associated with large 

tracts of riparian forest (e.g. yellow-billed cuckoo), and large mammals. Columbian white-tailed 

deer, once common in the bottomlands, had become rare in the Ridgefield area by the 1940s. They 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-7 

did persist in the lowlands further downriver, where they were known to local farmers and sportsmen 

as “tideland, or cottontail deer” (DOI 1941). The total white-tail population on the lower Columbia 

River was estimated at 375 in 1975, with most of the population in Columbia County. The 

subspecies was present, but in very low numbers between Bonneville Dam and the Columbia County 

line. A single white-tailed deer was seen on the refuge during big game surveys in 1974-1975, “in 

grazed pasture near ash/cottonwood habitat” (Tabor 1976a). 

Historically, the upper reach of Gee Creek was used by chum and coho salmon and coastal cutthroat 

trout for spawning. By the 1940s few salmon utilized the creek, due to forest clearing and 

agricultural activities that reduced water quality, and barriers to upstream migration. An oral history 

identified a few chum salmon spawning in a tributary of Gee Creek in the 1940s. A second-hand 

story was reported about coho salmon trying to get past a barrier in the upper reach of Gee Creek, 

near Royle Road, “prior to the 1950s.” A 1951 fisheries report said that “silvers and chums utilize 

[Gee Creek]” and that “fair to good spawning areas” occurred above the lower two miles of Gee 

Creek slough. Cutthroat trout, which had been reported anecdotally in Gee Creek for many years, 

declined to very low numbers by the 1990s (Cornelius 2006). 

Hydropower Operations and Diking. Development of the Columbia River to provide flood control 

and hydroelectric power began in 1932 with the completion of Rock Island Dam. Bonneville Dam, 

56 river miles upstream from the refuge, was completed in 1938. Construction of dams made large 

scale diking projects to expand or protect farmland on the lower Columbia River feasible (see 

Chapter 3). On Bachelor Island, diking started in 1942 with the construction of five miles of levee 

protecting 1,120 acres. In the 1940s and 1950s floods damaged the levees, and landowners 

reinforced and raised the levee several times. The River ‘S’ Unit was diked in 1941 with further 

improvements in 1947, 1963, and 1964. 

Hydro operations and diking contributed to wetland loss in the lower Columbia River bottomlands, 

both through direct loss (conversion to agriculture and other uses) and altered hydrology. Flow 

regulation, along with structural modifications to river shorelines and channels, has changed patterns 

of scouring and sediment deposition. Historically, spring flooding of the Columbia River created 

tremendous annual scouring with large annual flows flushing out small fine sediments. The lack of 

scouring inhibits successional processes. For example, natural cottonwood recruitment has been 

greatly reduced, and the refuge contains mainly older even-aged stands. Likewise, Oregon ash 

forests on the refuge are older, even-aged stands. Overflow lakes formerly dominated by large 

expanses of submergent vegetation or open water were gradually overtaken by dense stands of 

emergent vegetation (cattail, bulrush) or willow. In 1993, Christy and Putera estimated that over half 

of the historic riverine wetlands in the lower Columbia River below Bonneville Dam have been lost 

or substantially degraded as a result of flow regulation, diking, draining, filling, and dredging. 

Levee construction has had severe consequences for ocean-type juvenile salmonids, for example, 

lower Columbia River fall Chinook. Historically, flows that topped the river’s bank provided 

juvenile salmonids with access to low-velocity areas they used as refugia and for rearing. Overbank 

flows also contributed key food web inputs to the ecosystem and influenced wood recruitment, 

predation, and competition in the estuary (Fresh et al. 2005). The lower Columbia River today serves 

mainly as a migration corridor to and from the Pacific Ocean for adult and juvenile salmonids.

 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-8 Chapter 4. Refuge Biology and Habitat

Sediment transport below the dams has been greatly reduced. Since the late nineteenth century, 

sediment transport from the interior basin to the Columbia River estuary has decreased by 60 percent 

and total sediment transport has decreased by 70 percent (Jay and Kukulka 2003). This reduction in 

the amount of sediment transport has affected habitat-forming processes in the Columbia River 

estuary. Food webs are also affected, since sediment provides important nutrients that support food 

production. Although the consequences of the reduced transport of sediment through the estuary are 

not fully understood, the magnitude of change is very large compared to historical benchmarks 

(Fresh et al. 2005). 

Urban and Industrial Development. Columbia River hydropower stimulated significant economic

growth in the Pacific Northwest. During World War II, electricity from the Columbia River powered 

aluminum plants and shipyards in the Portland-Vancouver area (Center for Columbia River History 

2009). Since 1948, the most notable habitat changes have occurred in the Portland/Vancouver area 

(Tetra Tech 1996). Urban and other developed habitat has increased dramatically, with a 

corresponding decrease in wetland, riparian scrub-shrub, coniferous forest, broadleaf forest, and 

agricultural habitat. 

Although the refuge itself maintained its rural character, lands along its eastern boundary have 

largely been converted from farm and pasture land to residential development, with the pace of 

development increasing dramatically in the 1990s. The refuge’s relatively small size, along with 

adjacent residential and commercial development, and the presence of manmade barriers to dispersal 

(e.g., roads and railroads along the eastern boundary of the refuge), affects the refuge’s future 

potential to support some native wildlife species, especially those requiring large contiguous blocks 

of habitat, or with limited dispersal ability. Water quality is an ongoing issue associated with urban 

and industrial development both immediately adjacent to the refuge and in the Columbia River 

corridor (see Chapter 3).

The Columbia River is a major transportation corridor for barges carrying grain and other products 

from the interior northwest to worldwide markets. Because of the 40-foot-deep shipping channel in 

the lower river, ocean freighters can navigate up the Columbia and Willamette rivers to Portland. 

Navigation locks on Columbia and Snake River dams, and slackwater lakes behind the dams, allow 

barges to transport goods more than 465 miles from the Pacific to the inland port of Lewiston, Idaho. 

Not only does shipping have direct effects on habitat (e.g. shoreline hardening and channel dredging) 

but waves from commercial and recreational boats cause bank erosion. This had been a particular 

problem for the refuge on the Carty Unit along Lake River. As the site is located near the Port of 

Ridgefield and a marina, boat traffic is heavy and the damage significant. This site suffered 

significant impacts from floods in 1996 which exacerbated the continuing problem of boat wakes. 

Large cottonwood trees which protected the site were ripped out of the bank. As of 2004, the steep 

cutbank along the site’s western edge was eroding rapidly (USFWS 2004) and riprap had to be 

placed to stabilize the shoreline. Lake River is also eroding Bachelor Island and closing up its own 

outlet into the Columbia River (Oftedahl 2005). 

The combined effects of Columbia River hydropower operations, bank hardening and stream 

channelization, industrial and agricultural activity, introduction of exotic species, and urbanization, 

have led to dramatic changes in historic habitats and associated wildlife of the Columbia River and 

its floodplain. The refuge now provides habitat for wildlife in a highly altered system.

 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-9 

4.1.3 History of Refuge Management

By the 1960s, reduction in waterfowl habitat (and therefore, waterfowl hunting opportunities) on the 

lower Columbia River was noted by the Migratory Bird Conservation Commission (MBCC). The 

MBCC noted the limited winter range of the dusky Canada goose and the need for protection of 

wintering areas. These two factors were the major justifications for the establishment of the refuge 

(MBCC 1964). 

River S, Roth, Ridgeport Dairy, and Carty Units. The Service acquired its first Ridgefield Refuge 

property in 1965. This property, the River ‘S’ Unit, had historically been a ranch, with extensive 

improved and canarygrass pastures, which the MBCC noted were in an overgrazed condition. The 

Carty Unit was acquired in 1966 and had also been used primarily for grazing. Until 1972, 

management activities in these units did not change substantially from management under prior 

ownership. Grazing pressure was historically heavy on the Carty Unit, but was reduced considerably 

after the lands were acquired by the Service. However, the unit was still accessible to cattle, 

especially during the periods of low water. On the River ‘S’ Unit grazing was used to maintain both 

improved (grass-legume) and reed canarygrass dominated pastures in short-grass conditions that 

favored both Canada geese and American wigeon. The 1970 refuge report stated that the “majority 

of pintails and wetland populations” used Sauvie Island for “its flooded croplands, while the refuge 

provides for the migration of wigeon, swans, and dusky Canada geese” (USFWS 1996a). 

Grazing continued as a management tool for maintenance of short-grass habitat for foraging geese 

and waterfowl until 1972, when flooding destroyed most of the improved pastures on the River ‘S’ 

Unit. At that time, the River ‘S’ dike failed, and for the next 3 years the entire unit flooded annually. 

Due to funding constraints, the dike remained open until late 1974 when repairs were completed by 

an Army Construction Battalion from Fort Lewis, Washington. The prolonged flooding destroyed 

the improved pastures and the unit became severely infested with weeds, especially thistle and tansy. 

After the dike was repaired, more then 600 acres of pasture on River ‘S’ were rehabilitated. Farming 

grains and hay for waterfowl and geese on 600-700 acres of the River ‘S’ Unit was implemented 

until the early 1980s. Annual winter grains were planted by cooperative farmers to reduce noxious 

weeds prior to planting a pasture mix. This planting was minimally successful because geese 

destroyed most of the fall plantings. Corn was then introduced to provide an economically viable 

crop for cooperative farmers while at the same time providing weed control and winter waterfowl 

feed. 

As the Flyway’s populations of ducks and geese changed, habitat management practices on the 

refuge were modified to meet needs identified by flyway managers. Between 1965 and 1972, habitat 

management was dominated by grazing to provide short grass for dusky Canada geese and wigeon. 

Because objectives for dusky populations were being met in the late 1970s, refuge management 

objectives were rewritten in an attempt to increase habitat and food production for dabbling ducks.

During 1980-1981, dusky populations began another serious decline; and a low of 10,100 birds was 

recorded in the lower Columbia River and Willamette Valley in the winter of 1983-1984. Clover and 

alfalfa were planted in 1983 to provide forage for geese. Grazing was reinitiated on the River ‘S’ 

Unit in 1984 and maintained until 1996 to provide short-grass habitat for foraging ducks and geese 

through grazing reed canarygrass areas. Grazing was also the primary pasture management tool on 

the Roth and Carty Units until 1996. Between the early 1980s and 1996, cattle were turned out about 
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4-10 Chapter 4. Refuge Biology and Habitat

April 15 and removed during October/November. Cattle were rotated through several pastures. 

Mowing was used to reduce weeds and excessive growth not removed by grazing. Water levels were 

drawn down by mid-April to enable cattle to begin grazing in reed canarygrass wetlands. In a 1996 

habitat review, the review team found that grazing was an appropriate management tool to provide 

short green browse for Canada geese, cranes, and other waterfowl. However, they noted several 

problems with the grazing program, including impacts to riparian areas (loss of understory 

vegetation, loss of tree recruitment, bank erosion, and declining water quality in Gee Creek); 

disturbance to wildlife in fall; cattle and geese competing for forage in late spring; promotion of 

monotypic stands of reed canarygrass; and other weed problems. 

As a result of recommendations made by the habitat review team in 1996, a number of modifications 

to the grazing program were made. Grazing on the Carty Unit was phased out; no grazing has 

occurred on the Carty Unit since 2001. Grazing on the Ridgeport Dairy Unit was phased out in 1996. 

Grazing was removed from all wetland units on the River ‘S’ Unit following the summer of 1999. 

Some grazed areas on River ‘S’ were recontoured as wetlands while other pastures were improved. 

Most uplands on the River ‘S’ Unit are now mowed to maintain goose browse, and wetlands are 

drawn down later in the season (or receive supplemental inundation) to suppress reed canarygrass 

growth. A very limited cooperative grazing program was reinstated on the River ‘S’, Bachelor 

Island, and Ridgeport Dairy units in 2003. A 2004 wildlife and habitat management review 

recommended that limited grazing be used to maintain desirable conditions in managed pastures. In 

2009 236 head of cattle and horses were grazed between May and October on approximately 1,700 

acres of the refuge. 

The River ‘S’ Unit has 25 wetlands. Prior to 1998, these wetlands were lacking in effective water 

control capabilities, and had an inefficient water delivery system. Little vegetation management 

occurred. As a result these wetlands were not meeting their potential to provide quality habitat for 

migratory birds and associated wetland flora and fauna. Between 1998 and 2000, both the River ‘S’ 

and Ridgeport Dairy units underwent massive wetland restoration efforts to produce and maintain 

better functioning wetlands near sustainable pastures. These activities included construction and/or 

rehabilitation of contour dikes, rehabilitation of the main delivery canal, installation of water control 

structures, disking of almost 450 acres of reed canarygrass, and installation of 6,500 feet of PVC 

pipeline with 5 delivery valves. A new pump station providing approximately 15 cubic feet per 

second (cfs) of water to the River ‘S’ wetlands via the PVC pipe was installed in July 1999. A new 

30 hp expulsion pump was installed during the 2000 field season. This was tied to the western 

expulsion pump that is capable of recirculating water out of Bower Slough into Plantain Marsh. As a 

result of this rehabilitation, water depths on most wetlands increased. Irrigation within the River ‘S’ 

Unit was typically initiated four to five weeks prior to the opening day of duck season. However, 

with current low river levels, irrigation has started five to six weeks prior to the hunting season to 

ensure there are adequate sanctuary wetlands within optimal target levels. In most cases, the initial 

irrigation is adequate until late spring when additional inundation is needed to suppress reed 

canarygrass growth. Disking to control reed canarygrass was discontinued on the River ‘S’ Unit 

when ricefield bulrush was discovered in 2002 (see section 4.5). 

Historically, the refuge provided a variety of winter foods for waterfowl and cranes (clover, alfalfa, 

corn, potatoes, winter grains, orchard grass, and perennial ryegrass) through the use of cooperative 

farming. As of 1996, several different crops were grown on the River ‘S’ Unit, including corn, 

winter wheat, alfalfa, and clover. A small amount of grain was grown on the River ‘S’ Unit until 

2003, when this was discontinued due to baiting issues. By 2009, less than 50 acres of corn were 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-11

grown on the refuge, (15 acres on Bachelor Island, 2 acres planted on the River ‘S’ Unit, and 30 

acres on the Ridgeport Dairy Unit). Declines in sandhill crane use of the River ‘S’ Unit from the late 

1990s on may have been linked to loss of corn and other crops. 

Bachelor Island Unit. In 1985 the Bachelor Island Unit was purchased from the Zimmerly family. 

The island was cooperatively farmed until the end of 1999. When the land was purchased, the 

primary crops of potatoes and grain (mostly barley) were grown on approximately 900 acres of 

cropland. After harvest, waste grain and potatoes provided feed for thousands of ducks, geese and 

swans. Within weeks, the birds would strip the fields bare and move on. The entire island was 

essentially winter fallowed. 

Between the mid 1980s and the mid 1990s, goose populations increased by three to four times on the 

refuge (USFWS 1996b), concurrently, with the northward shift in the winter range of cackling geese 

from California to the Willamette Valley. Canada goose management again became the primary 

management objective for the refuge (at that time cackling geese were considered a subspecies of 

Canada goose). Beginning in 1986, the refuge began to incorporate grasses and clovers into the 

cooperative farming program to provide additional green forage to meet Canada goose objectives. 

The long range (10 year) goal was to convert most of the farmed acres (1,000 acres) to crops that 

would provide sustained green forage for geese. Potatoes were phased out by 1992 and red clover 

was planted in their place. In 1994, the refuge began to convert crops to approximately 800 acres of 

clover and 100 acres of grass (orchard grass, annual and perennial ryegrass). Some wheat and barley 

was grown as well. As of 1996, more than half the Bachelor Island fields were planted in clover and 

the rest were in permanent pasture. 

The refuge was also under increasing pressure to provide additional forage to reduce goose 

depredation on surrounding private lands. The Northwest Oregon-Southwest Washington Canada 

Goose Agricultural Depredation Control Plan (Pacific Flyway Council 1998) mandated that the 

refuge provide sustained green forage for Canada geese. In 1998 the refuge converted the 800 acres 

of short-lived clover to more sustainable crops of perennial ryegrass and pasture mixes. This 

decision led to the cooperative farmer terminating his obligations after the 1999 field season. By 

2003, the clover fields had been converted to permanent pasture; however, three fields were planted 

in corn. The refuge experimented with barley, corn, and pea-barley crops in the late 1990s and early 

2000s, but budget limitations eliminated this management regime from the 2004 field season. By 

2009, acres planted in corn on Bachelor Island had dropped to 15, with two acres planted on the 

River ‘S’ Unit and 30 acres on the Ridgeport Dairy Unit. After the cooperative grazing program was 

reinstated in 2003, the refuge had one cooperative grazer who grazed a few pastures with 12-16 head 

of cattle and hayed approximately 400 acres on Bachelor Island, River S, and Ridgeport Dairy units. 

In 2009, 236 head of cattle and horses grazed on approximately 1,700 acres (total for the three units), 

between May and October. 

In 1996, floods breached the Bachelor Island dike, causing significant damage to infrastructure and 

facilities. In 1998, the refuge worked cooperatively with Ducks Unlimited to restore approximately 

350 acres of wetlands on the Bachelor Island Unit, with the installation of a pumping facility and 

earthwork/water control structures made possible through a North American Wetlands Conservation 

Act (NAWCA) grant. However, pumping costs and efficacy of the delivery system are major 

limiting factors. Natural factors including soils, precipitation, elevation, tides, and river levels 

impose additional limitations to water delivery and retention on Bachelor Island wetlands. Eight of 
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4-12 Chapter 4. Refuge Biology and Habitat

these wetlands, totaling approximately 145 acres, exhibit good to excellent water holding tendencies, 

and have proven to be successful in providing necessary loafing and watering areas in close 

proximity to productive pastures. Five wetlands have failed to adequately hold water upon irrigation, 

four exhibited poor water holding capabilities, and three exhibited fair capabilities. Some of these 

wetlands are incapable of retaining water until river levels approach 13 feet Mean Sea Level (MSL). 

For these wetlands to cost effectively maintain optimal water levels, the Bachelor Slough staff gage 

reading must reach 7.00; this has not happened since 2000. 

Water retention improves in late winter (despite low river levels) in some wetlands, probably due to 

complete soil saturation and regular precipitation, but retention is generally short term. With the 

current trend of low river levels, irrigating wetlands with fair to poor water holding capabilities is not 

cost effective. However, a rain event in February 2003 irrigated Bachelor Island wetlands to optimal 

levels in two to three days (this would have taken weeks to a month of pumping). Currently, five

wetlands totaling approximately 70 acres on Bachelor Island are irrigated. Wetlands with fair to poor 

water holding tendencies fill naturally with rainwater and are managed as seasonal wetlands or wet 

meadows. 

Wetlands on the Bachelor Island Unit have been primarily managed through water management with 

minimal disking of a few designated wetlands prior to 2001. In the summer of 2001 intensive 

disking occurred on nine wetland units. In 1999, ricefield bulrush was introduced to one borrow site 

(wetland 011) on Bachelor Island as part of a supplemental seeding. The spread of ricefield bulrush 

on Bachelor Island has been minimal, with 43 plants detected in 2003. However until the refuge staff 

is confident that ricefield bulrush is contained, disking on Bachelor Island will be limited to select 

wetlands. 

4.1.4 Changes in Wildlife Populations after Refuge Establishment

Canada and Cackling Geese. Wintering Canada and cackling goose populations in the lower 

Columbia River and Willamette Valley have changed significantly since the refuge was established. 

At the time of refuge establishment, the dusky Canada goose (B. canadensis occidentalis) was the 

most abundant goose subspecies on the refuge. Total numbers of Canada geese in the Willamette 

Valley and lower Columbia River were estimated at 20,000-30,000 (mostly duskys) in the mid 

1960s. Although the effects of the 1964 Alaska earthquake on dusky breeding habitat would not be 

apparent for a decade; managers were already concerned about duskys due to their limited winter 

range and loss of wintering habitat. 

Historically, nearly all cackling geese (B. hutchinsii minima) wintered in California’s Central Valley. 

Between the late 1960s and the late 1970s, cackler populations declined from more than 400,000 

birds, to less than 50,000. A record low count of less than 26,000 cackling geese was tallied in the 

fall of 1984. The steady decline likely resulted from the combined effects of spring subsistence 

hunting in Alaska, and sport harvest primarily in California. Since then, cooperative conservation 

efforts have restored the cackling goose population to about 200,000 birds. Since the early 1990s, 

the majority of cacklers have wintered in western Oregon and southwest Washington. Today 

cacklers are by far the most abundant goose wintering in the Willamette Valley and lower Columbia 

River. The number of Taverner’s geese (B. hutchinsii taverneri) and lesser Canada geese (B. 

canadensis parvipes) wintering in the Willamette Valley increased in the 1980s. The population of 

resident western Canada geese (B. canadensis moffitti) increased steadily. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-13

Historically, midwinter population indices for the dusky goose increased from less than 10,000 in the 

early 1950s to over 26,000 in 1975, largely as a result of cooperative harvest management, expansion 

of winter foraging habitats, and creation of refuges in southwest Washington and western Oregon. 

The population declined steeply in the early 1980s, falling below 10,000 in 1984 and 1985, as effects 

of the 1964 Alaska earthquake accelerated changes to breeding ground habitats. The result was an 

increase in the elevation of the breeding grounds used by dusky Canada geese. Rapidly expanding 

shrubs and trees were favorable to brown bears and other mammalian predators that significantly 

increased predation on nests and adult geese. During the 1990s, low levels of production and a 

gradual decline in breeding birds resulted in a moderately stable population of about 15,000 duskys. 

Over the past five years, annual production has remained low, now primarily from nest predation by 

bald eagles, but the population has been maintained by a couple of productive years. In 2009 the 

population fell to fewer than 10,000; the total estimated population was 6,709 birds and the threeyear running average was 8,682 birds (USFWS 2009). As a result, Action Level 2 management 

actions were initiated, as described in the Pacific Flyway Management Plan for the Dusky Canada 

Goose (USFWS 2008). With ongoing forest succession on the Copper River Delta and associated 

predation on geese, impaired production will likely limit the population of dusky geese for the long 

term.

In addition to concerns about the diminished population, management of dusky geese on their 

wintering grounds is complicated by the concurrent use by other goose subspecies, including lesser, 

Vancouver, and western Canada geese; and Taverner’s, cackling, and Aleutian cackling geese. Large 

numbers of mixed white-cheeked geese cause problems in conducting winter inventories, designing 

optimal harvest regulations, controlling crop depredation, and assessing carrying capacity of winter 

habitats for all geese. 

Between 1970 and 2000, peak numbers of geese using the refuge in winter increased by more than 10 

times. As in the Willamette Valley, most of this increase was due to a large influx of cackling geese. 

In 1970, weekly surveys documented peak counts of approximately 3,300 geese, of which 60 percent

(approximately 2,000 birds) were duskys. In 1976, surveys estimated a total of 13,000 geese 

wintered in the area between Bonneville Dam and river mile 79, eight miles north of the refuge

(Tabor 1976). Goose surveys on the refuge from 1999 to 2000 identified peak numbers of 

approximately 35,000 geese in mid-November and 45,000 in mid-April, 79 percent of which were 

cacklers. Approximately 16 percent were Taverners and lessers, and only 3 percent were duskys 

(also see Section 4.3, Waterfowl.) 

Other Waterfowl. In 1927, Stanley Jewett noted that the mallard was by far the most common duck 

on Bachelor Island wetlands; pintail, American wigeon, and green-winged teal were also common 

(Jewett 1927). By the time the refuge was established in the 1960s, American wigeon was the most 

common duck and the most abundant species harvested on the refuge by hunters. The expansion of 

pasture lands on the Ridgefield bottomlands since Jewett’s time favored this species. In the 1960s it 

was not uncommon to see flocks of 10,000-20,000 wigeon feeding on the grazed pastures of the 

River ‘S’ Unit. In 1970, wigeon accounted for 62 percent of duck use days on the refuge, while 

mallard and pintail made up only 14 percent and 10 percent respectively (USFWS 1973). With the 

dike failure in 1972, the subsequent elimination of grazing, and conversion of weed-infested pastures 

to croplands, wigeon numbers declined significantly. By 1994 only 124,000 wigeon use days were 

recorded, compared to over 900,000 in 1966. 
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4-14 Chapter 4. Refuge Biology and Habitat

Waterfowl surveys of the lower Columbia River from Bonneville Dam to river mile 79 estimated that 

250,000 waterfowl wintered in the area (Tabor 1976); most were on Sauvie Island but the refuge was 

also an important area. The top two species were pintail (58,000 or 23 percent), wigeon (55,000 or 

20 percent), and mallard (35,000 or 14 percent). For waterfowl trends in recent years, see Section 

4.3 below. 

4.1.5 Influx of Exotic and Invasive Species

One of the most striking features of the refuge is the extent to which invasive plants and animals 

have taken hold. Invasive plant species displace native vegetation, altering the composition and 

structure of vegetation communities, affecting food webs, and modifying ecosystem processes (Olson 

1999), resulting in considerable impacts to native wildlife. 

Exotic Plants in Upland Habitats. The spread of invasive plant species in upland habitats was 

facilitated by the rapid increase in land clearing and grazing that followed Euro-American settlement. 

By 1825 there was a small herd of cattle at Fort Vancouver; by 1836, the herd had increased enough 

to allow cattle to be killed for beef for the first time. In 1839, the Hudson’s Bay Company imported 

cattle and sheep from California with the objective of exporting wool, hides, and tallow. Herds 

expanded rapidly in the 1850s, and by 1860 there were nearly 200,000 cattle in Oregon and the 

territory of Washington (Galbraith and Anderson 1971). Cattle have been grazed on Bachelor Island 

since the 1850s and the Carty Unit since the 1870s. During the first half of the 20th century, dairy 

farming became an important industry in the Ridgefield area. Livestock grazing is a major factor in 

habitat change, because native grasses and forbs were not adapted to heavy grazing pressure and soil 

disturbance. This gave exotic grasses and forbs a competitive advantage over native species. 

Exotic pasture and forage grasses were also intentionally introduced. Today, most grasses on the 

refuge are introduced “tame” pasture grasses, for example perennial ryegrass, orchardgrass, and 

fescues. These grasses do, however, provide benefits to native wildlife. Short grazed or mowed 

pasture grasses are extensively browsed by Canada geese and are the most important winter food 

source for Canada and cackling geese on the refuge. Of the intentional grass introductions, reed 

canarygrass has been by far the most problematic. It has become thoroughly entrenched in wetland 

and riparian habitats throughout western Oregon and Washington (see below). 

State-listed noxious weeds occurring on refuge’s uplands include Canada thistle (Cirsium arvense), 

tansy ragwort (Senecio jacobaea) and poison hemlock (Conium maculatum). These weeds are 

commonly found in pastures, old fields, roadsides and dikes, especially on the south end of the 

refuge. These invasives are a major concern for the Clark County Weed Management Program and 

the adjacent landowner. Although not classified as a noxious weed, Himalayan blackberry (Rubus 

armeniacus) is an introduced species with major impacts to refuge uplands. Repeated treatments 

(mechanical and chemical) are required to keep it from encroaching into pastures. It has also become 

a problem in some woodland areas, especially on the Carty Unit. Horsetail (Equisetum) and common 

rush (Juncus effusus) are considered undesirable in pastures and are a problem in some fields, even 

though they are native species. 

Exotic Plants in Riparian and Wetland Systems. Exotic plants that have proliferated in riparian 

and wetland areas include reed canary grass (Phalaris arundinacea), yellow flag iris (Iris 

pseudacorus), fragrant water lily (Nymphaea odorata ssp. tuberosa), and false indigo or indigobush 

(Amorpha fruiticosa) which was introduced to the upper Columbia River for bank stabilization and 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-15

has migrated downstream with floods. Indigo bush now lines the majority of suitable shoreline 

around the refuge. Purple loosestrife (Lythrum salicaria) was brought onto the refuge in 1993, 

probably as seed on hunters’ boots. The plants were removed in 1994 (USFWS 1996). Purple 

loosestrife has been detected in low numbers in Bull Lake, a small wetland on the River ‘S’ Unit, 

since 1997. As of 2004, 20-30 plants were hand-pulled and sprayed each year (USFWS 2004). 

Scattered Japanese knotweeds (Polygonum cuspidatum) were first noted in the Carty Unit along Gee 

Creek in 2000. While numbers on the refuge are low, it is a significant problem in the upper Gee 

Creek watershed. Aquatic areas likely host the invasive submergent, Eurasian water milfoil 

(Myriophyllum spicatum) and curly pondweed (Potamogeton crispus). 

Reed canarygrass is the most abundant invasive plant on the refuge, typically forming dense 

monocultures in seasonally-flooded wetlands, wet pastures, and the understory of open canopy 

riparian forests. Based on generalized vegetation mapping conducted in 1997, approximately 390 

acres of seasonally- and semi-permanently-flooded wetlands, 530 acres of wet meadows, and 200 

acres of riparian forest support dense stands of reed canarygrass. Reed canarygrass is native to the 

Pacific Northwest but its distribution was originally limited to river systems in Montana, Idaho, and 

Wyoming. It is likely that the reed canarygrass that is ubiquitous today in low-lying areas of the 

Pacific Northwest descends from European cultivars. Reed canarygrass trials and plantings began in 

Oregon as early as 1918 for pasture and erosion control (Tu 2004). By the time of refuge

establishment this species was well entrenched on bottomlands throughout the lower Columbia 

River. 

Reed canarygrass is highly competitive in shallow, seasonal wetlands, posing a major threat to native 

vegetation. This species often forms monocultural stands in suitable areas. Once established, its 

creeping rhizomes typically form a thick sod layer which excludes all other plants (Tu 2004, Kilbride 

and Paveglio 1999). Some native wetland plants, for example, common spikerush (Eleocharis 

palustris), cattail (Typha latifolia), marsh speedwell (Veronica scutellata), and Columbia sedge

(Carex aperta) can survive within canarygrass infestations, but wetlands without canarygrass tend to 

have a much higher diversity of native species. Reed canarygrass does provide some benefit to 

wildlife, for example thermal and nesting cover. Short, mowed or grazed reed canarygrass has some 

value as goose browse. However it is not preferred by geese and they utilize it less than other pasture 

grasses. 

On the lower Columbia River, the native riparian understory has been almost completely supplanted 

by reed canarygrass, and it is impossible to reconstruct the species composition of native understory 

with any degree of certainty (Christy and Putera 1993). Until 1996 grazing occurred in riparian areas 

of the refuge. This allowed reed canarygrass to become established in the understory. Following the 

1996 habitat review, grazing was discontinued in riparian areas. 

Ricefield bulrush, also known as bog bulrush or pointed bulrush (Schoenoplectus mucronatus) is 

another introduced species that has had substantial impacts on refuge management. In 1999, ricefield 

bulrush was introduced to the refuge as part of a supplemental seeding. In conjunction with a 

wetland rehabilitation project on the refuge, rice screenings from California’s San Joaquin Valley 

were applied to approximately 51 acres in eight wetlands on the refuge (six on the River ‘S’ Unit and 

one each on the Bachelor Island and Ridgeport Dairy units). Rice screenings are primarily composed 

of moist soil plant seeds and non-rice vegetation remaining after cleaning and processing rice. These 

screenings typically contain wild millet and smartweeds which are considered high quality waterfowl 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-16 Chapter 4. Refuge Biology and Habitat

foods. These screenings were intended to replenish the seed source lost during wetland expansion 

and construction. During the spring/summer of 2000, the seeds germinated in refuge wetlands. 

Subsequent identification of ricefield bulrush in refuge wetlands was attributed to the applications of 

rice screenings. Because this species had not been previously recorded in the Pacific Northwest, this 

infestation represented the introduction of a new invasive species in the region. After its accidental 

introduction to eight refuge wetlands, ricefield bulrush had expanded to 14 new wetlands by August 

2002. The total extent of ricefield bulrush on the refuge was 78 acres in 2002 (USFWS 2003). 

Control efforts, including water level management, hand pulling, and herbicide application began in 

2003. As of 2009, ricefield bulrush was common in two wetlands and present in five other wetlands. 

The refuge will continue to monitor all 22 wetlands originally infested to ensure that the seedbank is 

depleted and that there are no new occurrences. 

Mammals. Nutria (Myocastor coypus) is a large nonnative, semi-aquatic rodent that is native to 

South America. This species was reportedly introduced or escaped into the Pacific Northwest via the 

fur farming business during the 1930s to 1950s, and now resides along the Columbia River upriver to 

at least to the Bonneville Dam and northward into the Puget Sound. It also has a disjunct distribution 

in the Columbia Basin. Although nutrias are known to occur on all of the refuges managed by the 

Ridgefield Refuge Complex, there have been no surveys conducted to document actual numbers. In 

Washington, nutria are considered a nonnative, prohibited aquatic animal (WAC 220-12-090). 

This species is semi-aquatic, constructing den systems in the sides of stream embankments and dike 

systems which it enters from beneath the water surface. These large den excavations can contribute 

to erosion problems and pose significant maintenance and budget issues on refuges through dike and 

road damage, unintended water diversions, and structural damage to water-control facilities. These 

problems also pose significant safety hazards to staff and refuge visitors due to dike and roadway 

collapse. Nutria burrows can undermine roadbeds, stream banks, dams, and dikes, which may 

collapse when the soil is saturated or when subjected to the weight of heavy objects on the surface, 

such as vehicles, farm machinery, or grazing livestock (LeBlanc 1994). 

Nutrias are extremely prolific, breeding year-round and producing two to three litters per year. 

Normal litter size is 4.5 young, but depending on conditions, up to 13 young per litter has been 

recorded. They eat tremendous quantities of herbaceous vegetation, plant stems, roots and rhizomes, 

both in wetlands and along the shorelines. At high densities, nutrias can damage stands of desirable, 

wetland vegetation used by native wildlife. The destruction of wetland vegetation and decline in 

general marsh health caused by nutria has been documented throughout the United States. In some 

cases, nutria-caused damage to marsh vegetation and soils is so severe that these resources are 

permanently lost (APHIS 2005). Nutrias have also been implicated in the destruction of seedling 

trees and shrubs planted for habitat restoration purposes. Nutrias have been documented to cause 

significant damage to croplands in some parts of the country. The nutria’s aggressive behavior can 

also eliminate or greatly reduce native muskrat populations where nutrias are established (Bounds 

2000, and Evans 1970). 

Eastern gray squirrels are a nonnative species that occur in oak woodland and mixed coniferousdeciduous forest on the refuge. They compete with native western gray squirrels and are considered 

to be a factor in the decline of this species (Linders and Stinson 2007). Opossum and eastern 

cottontail are common nonnative mammals on the refuge. Opossums prey on native ground-nesting 

birds (Altman and Holmes 2000). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-17

Birds. Nonnative bird species occurring on the refuge include house sparrow, rock dove, and 

European starling. House sparrows and starlings are both cavity nesting species, and compete with 

native wildlife for nest locations. As resident species, house sparrows and starlings select nesting 

territories early in the breeding season. Native cavity nesting birds often arrive from migration to 

find prime cavities occupied and breeding territories aggressively defended by these species. 

Recently, house sparrows have been linked with the spread of human diseases and may be a vector in 

the transmission of West Nile virus (Pimentel et al. 1999). Control of nonnative birds has not been 

conducted on the refuge. 

Reptiles and Amphibians. Bullfrogs (Rana catesbeiana), native to the eastern United States, were 

introduced to the Pacific Northwest in the 1920s or 1930s to be raised as food. Bullfrogs prey on 

native amphibians, turtle hatchlings, and even ducklings. Bullfrogs introduced in the western United 

States have been implicated in localized declines of a number of native amphibian species through 

predation and competition (Bury and Whelan 1984, and Kupferberg 1997). A recent study by Pearl 

et al. (2005) in the Willamette Valley found little evidence supporting negative effects of the 

presence of breeding populations of bullfrog on native amphibians. However, bullfrogs are a known 

predator of, and threat to the State endangered western pond turtle (Hays et al. 1999). Skink tails 

have been found in the stomach contents of bullfrogs captured on the refuge. Control of bullfrogs 

has not been conducted on the refuge. 

Fish. Between 1880 and 1930, at least 15 species of exotic, warm water fish species (e.g. bluegill, 

crappie, bass, carp) were introduced to the Columbia River and its backwater lakes and sloughs, with 

the original intent of providing food for human consumption, forage for other fish, biological control 

of animal or plant pests, or sport-fishing opportunities (Wydoski and Whitney 2003). Mainly 

transplanted from eastern North America, most of the exotics have been extremely successful in the 

relatively warm, slow, backwater habitats of the lower river. The backwater aquatic system has also 

been greatly altered in the past 150 years. Diking and mainstem dams on the Columbia River greatly 

reduce seasonal flooding and create conditions that are extremely attractive to exotic fish (Li et al. 

1987). These fish may prey directly on adults or juveniles of native species, or compete with them 

for food. Pearl et al. (2005) found that the occurrence of two native amphibians, the Pacific chorus 

frog (Pseudacris regilla) and long-toed salamander (Ambystoma macrodactylum), was best predicted 

by the absence of nonnative fish. Largemouth bass also prey on western pond turtle hatchlings. 

Nonnative fish are abundant within the waterways of the refuge. Nonnative species found in surveys 

of Gee Creek from 1993 on, include brown bullhead (Ameiurus nebulosus), bluegill (Lepomis 

macrochirus), pumpkinseed (L. gibbosus), largemouth bass (Micropterus salmoides), smallmouth 

bass (M. dolomieu), black crappie (Pomoxis nigromaculatus), and goldfish (Carassius auratus). In 

addition, carp, black bullhead, mosquitofish, white crappie, walleye, and yellow perch have been 

reported in Gee Creek (Cornelius 2006). Nonnative species found in fish surveys of Campbell 

Slough in 2007-2008 include carp, yellow perch, banded killifish, crappie, largemouth bass, bluegill, 

and American shad. 

The common carp (Cyprinus carpio), originally native to Eurasia, was introduced as a food fish in 

the Pacific Northwest in the late 1800s. It is widespread in the lower Columbia River, and is a major 

pest in wetlands. Carp consume vegetation and invertebrates, competing with native wildlife for 

food. Their foraging activities degrade water quality by increasing turbidity (Wydoski and Whitney 

2003). This has negative effects on both native fish and waterfowl. Carp are especially abundant on 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-18 Chapter 4. Refuge Biology and Habitat

the refuge during the spring, as they congregate in Gee Creek and Campbell Slough seeking shallow, 

warm habitat for spawning. Little control of nonnative fish has been conducted on the refuge; 

however, Post Office Lake was drawn down in the summer of 2000 to control carp and other rough 

fish, and allow submergent vegetation to re-establish.

Invertebrates. Exotic mollusks carried in ship ballast (Asian clam, New Zealand mudsnail, zebra 

mussel) are a potential threat to wetlands connected to the Columbia River. The Asian clam

(Corbicula fluminea) was introduced to the Columbia River in 1938; it is abundant in some areas of 

the refuge. The New Zealand mudsnail (Potamopyrgus antipodarum) was established in the lower 

Columbia River by 2002 (Benson and Kipp 2010), however, it has not been documented on the 

refuge. To date, the zebra mussel (Dreissena polymorpha) and the quagga mussel (Dreissena 

bugensis) have not invaded the Columbia River basin, but could be introduced via trailered boats; 

this is a threat of high concern to river managers. 

Control Efforts. In accordance with Service policy 7 RM 14 (Pest Control), wildlife and plant pests 

on units of the Refuge System can be controlled to assure balanced wildlife and fish populations in 

support of refuge-specific wildlife and habitat management objectives. An Integrated Pest 

Management (IPM) approach is used, which includes a variety of tools: prevention of new 

introductions or the spread of established pests to areas not infested, mechanical or physical control 

methods, cultural methods, biological controls, pesticides, and habitat restoration/maintenance. The 

current draft IPM program for the refuge is included as Appendix K. Control efforts are planned 

annually and Pesticide Use Proposals (PUPs) are submitted to regional and/or national IPM

coordinators for approval. 

Reed Canarygrass. In the 1990s a study of reed canarygrass control methods was conducted on 

refuge wetlands (Kilbride and Paveglio 1999). The authors evaluated mechanical disking or 

mowing, chemical applications (Rodeo®), and combinations of disking and chemical methods, along 

with water-level manipulation, for three growing seasons. Canarygrass was reduced most by 

spraying and disking with a follow-up application of Rodeo during the next growing season. Disking 

with a follow-up application of Rodeo during the next growing season generally provided a similar 

level of control. Canarygrass that germinated and grew from viable rhizomes following drawdown 

after the initial Rodeo application or disking made a follow-up treatment with herbicide imperative 

for effective control. They recommended that, in order to prevent canarygrass re-infestation, 

treatments should not be initiated until managers have the ability to manage consistent water levels in 

wetlands throughout the winter and early spring. 

Before 2003, management and restoration of wetlands to control canarygrass included water 

drawdowns by May 1, followed by disking and rototilling. After ricefield bulrush was accidentally 

introduced (see below), this rotation regime for wetlands was discontinued to reduce the potential of 

spreading ricefield bulrush. Consequently, canarygrass infestations in the refuge’s wetlands have 

increased, especially in those units with bulrush. 

Ricefield Bulrush. Significant refuge resources have been diverted to fighting this weed since its 

discovery in 2002. Control methods to date have included hand pulling, spraying with herbicide, and 

altering water management in wetlands. Since 2003, the refuge has been using staff and volunteers 

to search for and control ricefield bulrush. A volunteer-based control program was initiated in 2004 

that consisted of searches, mapping ricefield bulrush occurrences, and hand pulling nearly 44,000 

plants. In addition, herbicide was applied to four wetlands. Hand pulling has been successful in 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-19

eradicating small satellite populations, and therefore, containing spread of ricefield bulrush into new 

areas, but the technique is inadequate to control larger infestations. 

Test plots were established in 2007 to identify effective herbicide treatments, and significant 

herbicide treatments were initiated in 2009. In 2009, almost 15,000 plants were pulled (down from 

nearly 44,000 in 2004). Three wetlands had sufficient populations that herbicide applications were 

conducted. Starting in 2010, wetlands with large populations (Wetland #6 and Canvasback Lake in 

the River ‘S’ Unit) will be treated with herbicide, disked, and re-sprouting plants sprayed again in an 

attempt to rapidly deplete the seed bank. These efforts will be continued aggressively for several 

years, since ricefield bulrush propagules exhibit long-term seedbank viability. The refuge is also 

monitoring outfalls and adjacent areas in the Columbia River in the vicinity of the refuge to ensure 

that this species does not escape the River ‘S’ Unit and infest other habitats. This monitoring will 

continue annually until the seedbank is depleted and the species eradicated. The refuge has hired a 

seasonal volunteer coordinator to organize searching and hand-pulling efforts. These efforts are 

coordinated with refuge staff members, who oversee herbicide applications and water level control. 

Himalayan Blackberry. Repeated treatments (mechanical and chemical) are required to keep 

blackberry from encroaching into pastures. Mowing following by spraying with glyphosate or 

triclopyr has been used to control this species. 

Canada Thistle, Poison Hemlock, Tansy Ragwort. Canada thistle (Cirsium arvense), poison hemlock 

(Conium maculatum), tansy ragwort (Senecio jacobaea), and bull thistle (Cirsium vulgare) have been 

designated Class B noxious weeds in Washington, and control of these species is mandatory in Clark 

County. Mowing prior to seed set, or a combination of mowing and spraying with 2,4-D and Garlon 

3A herbicides have been used successfully. Biological control of these weeds was attempted in the 

early 1990s. Insects introduced for biological control were thistle stem gall fly (Urophora cardui) 

for Canada thistle; seedhead weevil (Larinus planus) for Canada thistle; poison hemlock moth 

(Agonopterix alstroemeriana); thistle-feeding shield beetle (Cassida rubignosa); and cinnabar moth

(Tyria jacobaeae) for tansy ragwort (USFWS 1996c). No releases of biological control agents have 

been made since 2000. Seedhead weevil and cinnabar moths are still present on the refuge, but not in 

sufficient numbers to significantly reduce the infestation. 

Nutria. The refuge has used nonlethal measures, such as dike sloping, to help reduce erosion and 

dike damage caused by nutria, but this is only effective in limited areas and is associated with loss of 

wetland area. In addition, nonlethal methods do not address habitat degradation or competition with 

and displacement of native wildlife. Shooting by trained staff members has been used in the past to 

reduce the population where substantial dike damage has occurred, while not creating a safety 

hazard. In April 2008 a categorical exclusion was signed to reinitiate nutria control throughout the 

Ridgefield Refuge Complex. Control activities include shooting and carcass removal by staff and 

refuge-authorized agents, such as professionals of the U.S. Department of Agriculture’s Wildlife 

Services Division (USDA), and the development and initiation of innovative reduction technologies 

by USDA. Carcasses, including pelts, are to be disposed of on-refuge to allow scavenging by native 

wildlife such as vultures, raptors, and coyotes. No carcasses or pelts are be removed from the refuge 

or utilized for economic purposes. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-20 Chapter 4. Refuge Biology and Habitat

4.2 Selection of Priority Resources of Concern

4.2.1 Selection Process 

Early in the planning process, the planning team cooperatively identified 15 priority species for the 

refuge, as recommended under the Service’s Habitat Management Planning policy (620 FW1). 

These priority resources of concern (ROCs) frame the development of goals and objectives for 

wildlife and habitat. Resources of concern may be species, species groups, or features that the refuge

will actively manage to conserve and restore over the life of the CCP; or species that are indicators of 

habitat quality for a larger suite of species (see “Other Benefitting Species,” Table 4.1). Negative 

features of the landscape, such as invasive plants, may demand a large part of the refuge management 

effort, but are not designated as resources of concern. 

 

The main criteria for selecting priority ROCs included the following requirements. 

• The resource must be reflective of the refuge’s establishing purposes and the Refuge System 

mission. 

• The resource must include the main natural habitat types found at the refuge; 

• The resource must be recommended as a conservation priority in the Wildlife and Habitat 

Management Review (2004); and 

• The resource must be federally or State listed, a candidate for listing, or a species of concern. 

Other criteria that were considered in the selection of the resources of concern included the 

following. 

• Species groups and/or refuge features of special management concern. 

• Species contributing to the biological diversity, integrity and environmental health of the 

lower Columbia River ecosystem. 

• Species where it is feasible to estimate population size (needed for future monitoring and 

adaptive management).

Table 4-1 displays the resources of concern that were selected and are the main focus of this CCP, as 

well as other species that will benefit from management of habitat for the ROCs. 

Table 4.1 Priority Resources of Concern for the CCP

Focal Species Habitat Other Benefitting Species

Dusky Canada 

goose 

Improved (agricultural) 

pastures of small patch 

size, with adjoining 

water

Other Canada geese, American wigeon, great blue heron, 

American pipit, streaked horned lark, short-eared owl, 

raptors, coyote, great egrets, sandhill crane, black-bellied 

plover, semipalmated plover, Wilson’s phalarope

Wet meadow American wigeon, mallard, rails, herons, snipe, stilt, 

shorebirds 

Cackling goose

(Branta 

hutchinsii 

minima)

Improved (agricultural) 

pastures—large patch 

size

Other cackling geese, Canada geese, great blue heron, 

American pipit, streaked horned lark, short-eared owl, 

raptors, coyote, great egret, sandhill crane, black-bellied 

plover, semipalmated plover, Wilson’s phalarope

Savannah

sparrow 

Old fields/buffers (tall 

grass/forbs, nonnative)

Northern harrier, short-eared owl, gray-tailed vole, western 

meadowlark, streaked horned lark, Oregon vesper sparrow, 

Upland (dry) prairie western pond turtle, lazuli bunting, nesting waterfowl 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-21

Focal Species Habitat Other Benefitting Species

Northern 

harrier

Bottomland (wet)

prairie

Common yellowthroat, American bittern, nesting 

waterfowl, dusky Canada goose, rare plant species 

(Bradshaw’s lomatium, Nelson’s checkermallow), shorteared owl, savannah sparrow, common snipe, song 

sparrow, western meadowlark

Mallard Seasonal emergent 

wetlands 

Other dabbling ducks, tundra swans, western painted turtle, 

yellow-headed blackbird, common snipe, long-billed 

dowitcher, black-necked stilt, rails

Tundra swan Semi-permanent 

emergent wetlands 

(Rest Lake, Mantrap 

Lake)

Mallard, trumpeter swan, wapato, amphibians, turtles, 

yellow-headed blackbird 

Lesser scaup Permanent wetlands 

(Post Office Lake, 

Carty Lake)

Ring-necked duck

Canadian 

sandhill crane 

(Grus canadensis rowani) 

Tidal wetlands (Boot 

Lake, Campbell Lake, 

Fowler Lake)

Coho (Lower Columbia ESU), Chinook salmon (Lower 

Columbia ESU), geese, herons, shorebirds, all dabbling 

ducks, swans 

Agricultural Croplands Canada geese, American wigeon, mallard

Water howellia 

(Federal 

Threatened)

Ephemeral vernal 

ponds, Carty Unit 

Amphibians

Coastal 

cutthroat trout 

(SW WA/ 

Columbia 

River ESU)

Riverine/Instream 

habitats (tidally 

connected−Gee Creek, 

Campbell Slough) 

Coho (Lower Columbia ESU), Chinook salmon (Lower 

Columbia ESU), Pacific lamprey, western brook lamprey, 

steelhead, bald eagle (foraging) 

Willow 

flycatcher

Early successional 

floodplain forest 

(willow, red-osier 

dogwood)

Yellow warbler, song sparrow

Swainson’s 

thrush

Mid-late successional 

floodplain forest (black 

cottonwood, Oregon 

ash) (Fraxinus latifolia/

Populus trichocarpa/ 

Cornus stolonifera/ 

Urtica dioica)

Song sparrow, Bewick’s wren, house wren, pileated 

woodpecker, downy woodpecker, black-headed grosbeak, 

red-eyed vireo, Pacific-slope flycatcher, tree swallow, great 

blue heron, bald eagle 

Bewick’s wren Oregon ash floodplain 

forest (Fraxinus latifolia/Carex deweyana/ 

Urtica dioica)

Slender-billed white-breasted nuthatch, western woodpeewee, house wren, tree swallow, song sparrow, downy 

woodpecker, pileated woodpecker 

Slender-billed

white-breasted 

nuthatch 

Oregon white oak 

woodland 

Western pond turtle, Bewick’s wren, western skink, 

northern alligator lizard, western gray squirrel, house wren

Orangecrowned 

warbler

Upland mixed forest Rufous hummingbird, Wilson’s warbler, MacGillivray’s 

warbler, willow flycatcher, Bewick’s wren, song sparrow, 

spotted towhee
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-22 Chapter 4. Refuge Biology and Habitat

4.2.2 Analysis of Priority Resources of Concern 

Wildlife and habitat goals and objectives were designed directly around the habitat requirements of 

species designated as “priority resources of concern.” (Resources of concern are called conservation 

targets in conservation planning methodologies used by other agencies and NGOs). In developing 

objectives, the team followed the process outlined in the Service’s−Identifying Resources of Concern 

and Management Priorities for a Refuge: A Handbook (USFWS 2008). While this document was

still in draft form while this CCP was being developed, it had been adopted by the Service as the 

process to develop wildlife and habitat goals and objectives for CCPs. 

As defined in the Service’s Policy on Habitat Management Plans (620 FW 1), resources of concern 

are:

“all plant and/or animal species, species groups, or communities specifically identified in refuge 

purpose(s), System mission, or international, national, regional, State, or ecosystem conservation 

plans or acts. For example, waterfowl and shorebirds are a resource of concern on a refuge whose 

purpose is to protect ‘migrating waterfowl and shorebirds.’ Federal or State threatened and 

endangered species on that same refuge are also a resource of concern under terms of the respective 

endangered species acts (620 FW 1.4G).” 

The Handbook goes on to say that “Habitats or plant communities are resources of concern when 

they are specifically identified in refuge purposes, when they support species or species groups 

identified in refuge purposes, when they support NWRS resources of concern, and/or when they are 

important in the maintenance or restoration of biological integrity, diversity, and environmental 

health.” Therefore, resources of concern for a refuge may be a species or species group, or the 

habitat/plant community that supports a priority species/species group. 

In developing its listing of Priority Resources of Concern, the planning team selected not only 

species mentioned in establishing documents for the refuge, but also species that captured the 

ecological attributes of habitats required by larger suites of species. The team analyzed the 

ecological attributes of habitats that are necessary to meet the life history requirements of ROCs, and 

are therefore, critical to sustain the long-term viability of the ROC and other benefitting species. 

Ecological attributes of habitats include vegetation structure, species composition, age class, and 

seral stage; patch size and/or contiguity with other habitats; hydrologic regime; and disturbance 

events (e.g. flooding, fire). These provide measurable indicators that strongly correlate with the 

ability of a habitat to support a given species. Tables listing the desired conditions for habitat types 

found on the refuge are included in the following sections of this chapter. “Desired” conditions were 

based on scientific literature review and team members’ professional judgment. These desired 

conditions for specific ecological attributes were then used to help design habitat objectives, as 

presented in Chapter 2. However, not all ecological attributes or indicators were deemed ultimately 

feasible or necessary to design an objective around. Other factors, such as feasibility and the 

refuge’s ability to reasonably influence or measure certain indicators, played a role in determining 

the ultimate parameters chosen for each habitat objective. Thus, ecological attributes should be 

viewed as a step in the planning process. The ultimate design of objectives was subject to further 

discussion and consideration. 

Limiting factors were also considered in developing objectives. A limiting factor is a threat to, or an 

impairment or degradation of, the natural processes responsible for creating and maintaining plant 

and animal communities. In developing objectives and strategies, the team gave priority to
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-23

mitigating or abating limiting factors that presented high risk to ROCs. In many cases limiting 

factors occur on a regional or landscape scale and are beyond the control of individual refuges. 

Therefore, objectives and strategies may seek to mimic, rather than restore, natural processes. For 

example pumps and water control structures may be used to control water levels in wetlands in areas 

where natural hydrology has been altered by hydropower operations and dike construction. The 

structure of plant communities utilized by ROCs can be created, rather than restoring the original 

native species composition. For example, mowing and/or grazing may be used to maintain a 

desirable vegetation structure, when restoring native grassland communities may be impractical. 

4.3 Waterfowl and Supporting Habitat-Improved Pasture and 

Croplands

4.3.1 Description and Location

Thousands of waterfowl use the refuge during fall, winter, and spring. Abundant wintering species 

include Canada geese, cackling geese, tundra swan, mallard, American wigeon, gadwall, northern 

shoveler, northern pintail, and green-winged teal. The refuge also attracts significant numbers of 

diving ducks largely ring-necked duck, lesser scaup, and bufflehead. Tundra swans are also a 

wintering species on the refuge with peak populations of up to 3,000 birds observed. 

Western Canada geese are the only resident goose on the refuge. All other geese spend the winter 

months on the refuge and migrate to nesting areas for the spring and summer. Public use is restricted 

on the refuge from October 1 to May 1 to limit disturbance to wintering waterfowl. Informal staff 

observations of migrating geese since 1994 have noted arrival, departure, and peak migration dates 

for select waterfowl. Annually, these dates have been variable but are subsequently expressed as an 

average date to suggest typical dates for migrational events. The average arrival date for cackling 

geese has been September 24 and the average departure date has been May 6. The average date for 

the peak of goose use on the refuge has been November 1 and again on April 20. Dusky Canada 

geese have a slightly shorter wintering period on the refuge. The average arrival and departure dates 

for dusky Canada geese are October 11 and April 11, respectively. Tundra swans have a wintering 

period that is generally November to March. Arrival and departure trends for other migrating 

waterfowl are not monitored and are presumably variable by species, weather patterns, and other 

climatic conditions. 

The refuge also has several species of duck that nest on the refuge in limited numbers. The most 

common nesting waterfowl species include wood duck, mallard, blue-winged teal, and cinnamon 

teal. Additionally, nesting has been confirmed for gadwall, American wigeon, northern shoveler, 

hooded merganser, common merganser, and ruddy duck. Production levels are not presumed to be 

high compared to other breeding areas along the flyway, but there is little data on this aspect. 

4.3.2 Condition and Trends

Regular wintering goose surveys were conducted by refuge personnel from 1998 to 2003. Primarily, 

these surveys supported regional efforts to obtain information about geese that had been captured and 

fitted with coded plastic neck collars. However, data from these surveys were also used to assess 

flock compositions, peak populations, average populations, and goose utilization of individual 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-24 Chapter 4. Refuge Biology and Habitat

wetland/field units. These goose surveys have counted an average of more than 13,000 geese on the 

refuge during the wintering periods of 1998 to 2003. Peak numbers occur as geese stage on the 

refuge during fall and spring migration. Goose surveys during 1999 and 2000 identified peak geese

numbers of 34,747 in mid-November and 45,500 in mid-April. The composition of the goose flock 

was calculated using the older naming convention of one Canada goose species with five subspecies 

(cackling, Taverner’s, lesser, dusky, and western) commonly found on the refuge. 

Surveys from the winter of 1999 to the spring of 2000 determined the subspecies composition of 

geese examined on the refuge to consist of 3.0 percent dusky Canada geese, 2.3 percent Taverner’s 

Canada geese, 0.7 percent lesser Canada geese, 79.3 percent cackling Canada geese, 1.3 percent 

western Canada geese, and 13.3 percent that were not differentiated between Taverner’s or lesser 

Canada geese. With the current naming convention for geese, the cackling and Taverner’s 

subspecies are treated under the species of cackling geese. The lesser, dusky, and western subspecies 

still belong with Canada geese. Recalculation of this data to represent the new naming convention 

would be complicated with the large percentage of undifferentiated lesser and Taverner’s Canada 

geese, which are currently considered separate species. 

Geese in the lower Columbia River have shown a significant change in wintering habitat use patterns 

and distribution. Documents relating to the establishment of the refuge describe dusky Canada geese 

as the primary subspecies. An annual narrative from 1970, noted the composition of dusky Canada 

geese on the refuge, which consisted of the Carty and River ‘S’ Units, had risen to about 60 percent 

in 1970. Refuge surveys from the fall of 1999 to the spring of 2000 determined that dusky Canada 

geese comprised approximately 3 percent of the total flock, and cackling geese more than 79 percent. 

This data shows that cackling geese are more prevalent on the refuge while dusky Canada geese are 

less prevalent. This trend is partly due to the shift in migration patterns by cackling geese. Since the 

early 1990s cackling geese shifted from wintering in California and the Klamath basin to wintering in 

the Willamette Valley and lower Columbia River (Harb and Trost 1995). Therefore, throughout 

western Oregon and Washington, cackling geese now represented a larger proportion of the overall 

goose composition largely due to the influx of wintering cackling geese that formerly wintered 

elsewhere. Refuge narrative reports also suggest that fewer dusky Canada geese utilize the refuge

than historically recorded. Weekly surveys conducted during the winter of 1970 documented peak 

counts of wintering dusky Canada geese of more than 2,000 birds on the refuge, comprising 

approximately 3,000 acres. The average number of dusky Canada geese observed during the surveys 

of 1998 to 2003 was 267 birds on the refuge, comprising approximately 5,200 acres.

Midwinter waterfowl surveys have been regularly conducted on the refuge since the 1980s. These 

surveys count waterfowl populations utilizing the refuge and surrounding area. Since waterfowl are 

highly migratory and can change wintering locations quickly and frequently, the data generated from 

these surveys represent a snapshot of the numbers of waterfowl using the refuge on that particular 

day of survey and do not represent total refuge wintering populations. The cumulative data taken 

over the years may provide an index to the numbers of waterfowl the refuge has attracted and their 

trend over time. The midwinter waterfowl data set contains considerable detail about distribution of 

birds at various scales from specific refuge unit to overall region. Figure 4.2 identifies the overall 

number of geese, dabbling ducks, swans, and diving ducks counted on the entire refuge during a 

single flight in January of each particular year. The data for 2004 is an anomaly to the data set. 

Weather in 2004 kept the aerial survey from occurring. Therefore, the 2004 data set represent a 

ground based count which may not have adequately surveyed remote locations of the refuge. 

Additionally, it should be noted the data could not be located for the 2005 survey. The midwinter 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-25

waterfowl survey data set shows that the refuge has counted over 33,000 ducks on the refuge during 

one flight. Calculating the average number of birds counted since 1998 suggests an average 

midwinter population of 1,595 diving ducks, 9,791 dabbling ducks, 8,069 geese, and 1,619 swans. 

Figure 4.2 Midwinter Waterfowl Populations at Ridgefield Refuge. Source: Midwinter 

Waterfowl Survey data, 1985–2007

Contribution to Flyway Management Plans. The Ridgefield Refuge contributes to several 

waterfowl management plans developed by the Pacific Flyway Council. A summary and the major 

goals/objectives of each of the following plans are described in Chapter 1. 

• Northwest Oregon/Southwest Washington Canada Goose Agricultural Depredation Plan 

(1998) 

• Pacific Flyway Management Plan for the Cackling Canada Goose (1999) 

• Pacific Flyway Management Plan for the Dusky Canada Goose (2008) 

• Pacific Flyway Management Plan for the Pacific Population of Western Canada Geese (2000) 

The 2004 Strategic Guidance (NAWMP Committee 2004), a 15-year plan, does contain speciesspecific population targets as a step-down from the NAWMP and evaluations of whether the 

continental population is currently short or over the target. There are also flyway goals for 

production by species. Annually there are population reports available based on the spring breeding 

surveys in the northern U.S. and Canada. According to the NAWMP Strategic Plan, pintail and 

scaup are decreasing at the flyway level. The western population of tundra swans exceeds the 

population objective by about 22,000. Population objectives have not been established for most of 

the Pacific Flyway’s Canada geese subspecies. However consistent with the Pacific Flyway 

Management Plan for the Cackling Canada Goose (1999), the population objective for cackling 

Canada geese in the 2004 Strategic Guidance is 250,000 birds (autumn population). Dusky Canada 

geese have no numeric population objective within the 2004 Strategic Guidance. Rather, the stated 

objective of the plan is to avoid listing of dusky Canada geese under the Endangered Species Act. 

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

1985198719891991199319951997199920012003

NA

2007

Year

Midwinter Waterfowl Surveys

Diving Duck

Swans

Dabbling Duck

Geese
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-26 Chapter 4. Refuge Biology and Habitat

4.3.3 Habitats Utilized

Wetlands. Waterfowl are a diverse group of birds with widely divergent habitat requirements 

throughout the year. Waterfowl utilize both lacustrine and palustrine wetland habitats on the refuge. 

(For detailed information on management, habitat conditions and trends of refuge wetlands, see 

section 4.5 of this chapter.) Generally, lacustrine habitats support invertebrates and/or submergent 

vegetation and are utilized by select diving ducks. Diving ducks can utilize food resources in the 

deeper water associated with lacustrine wetlands. Select dabblers may consume invertebrates and 

vegetation high in the water column within lacustrine wetlands, but these conditions are not 

considered optimal for foraging. With their deep open water, lacustrine wetlands offer long sight

distances and are free of mammalian predators. Therefore, they provide important loafing, resting, 

and roosting habitats for wintering waterfowl. 

Healthy and productive refuge palustrine wetlands host a rich diversity of emergent wetland plants 

including smartweeds, bulrushes, wapato, sedges, rushes, wild millet, bur-reed, cattail, and water 

plantain. Additionally, floating aquatics such as duckweed and water fern are valuable waterfowl 

food resources produced within palustrine wetlands. Waterfowl both directly consume wetland 

vegetation and selectively consume portions of plants including seeds, tubers, rhizomes, and roots. 

The detritus and submerged microclimates formed by seasonally flooded, emergent vegetation create 

an important substrate for the production of aquatic invertebrates. Consumption of invertebrates for 

protein and lipid content is seasonally significant to female ducks for egg development and laying 

(Fredrickson and Reed 1988). 

Appropriate water depths are important for effective waterfowl management. Geese, especially 

dusky Canada geese, frequently forage in shallow wet meadow conditions or sheet water conditions 

with less than six inches of water. Management of seasonal wetlands is valuable for producing 

emergent wetland vegetation that is a primary food resource for wintering waterfowl. These 

wetlands are generally slowly drawn down through the spring, with the intent of creating moist soil 

areas where the seeds of annual emergent plants, such as millet and smartweed, can germinate. Once 

these plants are mature, the basins are reflooded or allowed to flood naturally with rainwater. Water 

depths of 2-10 inches are optimal for foraging by dabblers, allowing them access to seed heads. 

Various duck species have preferred foraging depths within this range; for example preferred water 

depths for mallards are 2.75-5.5 inches, while northern shovellers prefer depths of 6.3-9.5 inches 

(Frederickson 1991). 

Swans feed on wapato and other aquatic tubers. For successful feeding, water depths must allow 

swans to reach the submerged tubers with their bills. Conversely, divers including ring-necked ducks 

and lesser scaup are capable of locating food resources throughout the water column, from near the 

surface to depths of many feet. 

Managed Pasture. An establishing purpose of the Ridgefield Refuge is to provide migration and 

wintering habitat for waterfowl, especially dusky Canada geese. Additionally, the refuge is 

identified within several Flyway goose management plans for its role in attracting and supporting 

wintering Canada and cackling geese. To meet these goals, a primary strategy at Ridgefield is 

managing short pastures or grasslands. Wintering geese frequently graze upon large, short-grass

pastures. Presumably, these conditions afford the geese access to young green plants and forbs, 

improved sight distances for predator detection, reduced concealment cover for predators, and clear 

flight paths for escape. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-27

The refuge achieves short grass conditions for wintering geese through multiple strategies including 

haying, grazing, and mowing. Haying and grazing are achieved by initiating Cooperative Land 

Management Agreements. In exchange for the grazing and haying the refuge, the cooperator repairs 

fences, maintains infrastructure, controls weeds, and mows additional fields. Ultimately, the refuge

achieves short grass conditions and additional improvements without the cost of performing these 

activities. The amount of grazing and haying is annually variable upon the number of cooperating 

farmers participating with the program and their annual business obligations. In all the refuge

manages up to 1,432 acres of pastures within 55 fields on all units of the refuge. Generally, refuge

fields are mowed after July 15 to avoid conflicts with ground nesting birds. While late mowing is 

favorable for ground nesting birds, it also leaves heavy residual thatch and coarse stems after 

mowing. Eventually the fields green up during the fall and spring, but initially upon the return of 

wintering geese the conditions are not optimal for goose browse. Select fields that are considered 

core dusky Canada goose wintering habitat are targeted for either grazing or repeat mowing during 

the spring and summer. These techniques keep the fields low and green, recycle nutrients into the 

field, and reduce heavy thatch accumulations. 

Subtle differences exist between the utilization of managed grasslands between cackling geese and 

Canada geese. These differences are likely greatest between cackling geese and dusky Canada 

geese. Generally, cackling geese use large short-grass pastures. Cackling geese often favor highly 

manipulated green fields including cow pastures, golf courses, soccer fields, and open parklands. 

These habitats are large open fields with minimal trees and shrubs. In many instances, these areas 

are used by cackling geese during poor weather or off hours when the public is absent. At the refuge

cackling geese use large open fields but have acclimated to vehicular traffic. Cacklers will feed in 

close proximity to the auto tour route and often will pick grit off of the road when the road is vacant. 

Like cacklers, dusky Canada geese will join into mixed flocks of Canada and/or cackling goose 

subspecies in large open fields and croplands. However, dusky Canada geese will use small fields in 

relatively close proximity to shrub and trees. Duskys frequent habitat highly influenced by water 

and water features, such as wet meadow, sheet water, and shorelines. Duskys utilize mosaics of 

shallow water and roughly cut vegetation, reed canarygrass, and spikerush stubble, below six inches 

in height. In spring, dusky Canada geese can be found in shallow flooded reed canarygrass, and it is 

surmised that duskys forage on young green spring growth of canarygrass. 

Croplands. A limited amount of croplands are annually planted to provide forage for Canada geese 

and sandhill cranes. Generally, the refuge manages approximately 175 acres of croplands, planting 

between 50 and 150 acres of crops annually. These crops may include barley, wheat, corn, oats, and 

clover. Cropping has included field planting and inter-seeding of small grain into existing pastures. 

Interseeded crops are left for geese to consume during the growing season. Field crops, especially 

corn, are planted in the spring and allowed to grow into the fall. Corn is then mowed in blocks 

during fall and winter allowing geese, ducks, and cranes access to the downed ears. Cropped fields 

must be carefully placed on the refuge to avoid baiting violations in both the refuge’s and 

surrounding hunt areas. Cropped lands we intend to mow between September and February to 

expose waterfowl food must be selected in a manner that does not attract birds to hunted areas. 

Cooperative farming was largely practiced on the Bachelor Island and River ‘S’ units until 1996, 

with the objective of providing grain and green feed to migrating and wintering waterfowl. In 1996 

approximately 718 acres of winter wheat, corn, clover, and alfalfa were planted by cooperative 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-28 Chapter 4. Refuge Biology and Habitat

farmers from the refuge. The crops grown in all the cooperatively farmed fields were mutually 

agreed upon by the refuge and farmer, with the refuge receiving shares (usually 20 percent). The 

refuge’s shares were made up of grains and green forage, as determined by the refuge to meet 

wildlife objectives, while maintaining a viable cooperative agreement. The refuge received 

additional wildlife benefits, although not counted as refuge shares, through the availability of waste 

grains, green forage, and the growth of understory crops (e.g. clover) following the harvest of the 

cooperator’s portion of the crops. Over time the refuge’s farming capacity grew with large 

investments in tractors, seeders, sprayers, mowers, tillers, and disks. The refuge also constructed a 

bridge to Bachelor Island, eliminating the need to ferry supplies and equipment to the island. 

Collectively, the investment in equipment and construction of the bridge allowed the refuge to plant, 

manage, and maintain its own pastures and crops. All cropping is now done through force account. 

Due to the relatively high cost and inputs required to grow corn, only a small acreage is planted. 

4.3.4 Key Ecological Attributes

Table 4.2 Habitat Attributes, Indicators, and Condition Parameters for Waterfowl* 

Key Ecological 

Attributes Indicators Desired Conditions 

Upland Food 

Availability 

(Improved 

Pasture, 

Croplands)

• Green browse

• Crops (corn, small grains, 

legumes)

• Crops provided off-refuge

• See Table 4.3 below for pasture habitat attributes

• Mix of corn, small grains, legumes; normal 

planting, harvest, and post-harvest manipulation

• Corn provided on nearby State wildlife areas 

(Shillapoo, WA; Sauvies Island, OR). 

Water depth 

and 

hydroperiod

• Variety of water depths to accommodate swans, dabblers and divers; incremental 

floodup and drawdown to promote waterfowl foraging within entire basin 

• Provide managed seasonal wetlands (moist soil units) with water depths of 4-12 

inches during initial floodup (Oct-Nov); 24-30 inches late Jan. to May; achieve 

drawdown by June 15 

• Also see Wetlands Table 4.6 below

Vegetation 

Diversity, 

Structure

• Wet meadows with mix of desirable, palatable grasses, sedges and rushes; if reed 

canarygrass is present, mow to shorter than 6 inches 

• Managed seasonal wetlands (moist soil units) with more than 60% cover of moistsoil annuals (e.g., smartweeds, wild millet, water plantain), wapato, and nutsedges 

• Semipermanent and permanent wetlands with less than 40% cover of native 

emergent species (e.g., cattail, hardstem bulrush, wapato, bur-reed) and more than 

60% open water and native submergent vegetation

• Minimal woody vegetation (e.g. willow, spirea) 

Invertebrate 

diversity

• Macroinvertebrate abundance and diversity preferably high; invertebrate diversity 

will partially be determined by hydroperiod.

Invasive 

plants and 

animals 

• Limit or exclude habitat-altering species (e.g. carp, nutria)

• Limit or exclude exotic vegetation (e.g. reed canarygrass, yellow flag iris, purple 

loosestrife) that form persistent monocultures.

Human 

Disturbance

• Minimize disturbance to preferred waterfowl feeding, roosting, and nesting areas; 

provide waterfowl sanctuary area during hunt season

Source: Planning Team, Fredrickson and Drobney 1979, Fredrickson and Reed 1988, Frederickson1991, Korschgen and 

Dahlgren 1992

*Note: For the preceding and following tables, not all ecological attributes or indicators were 

deemed ultimately feasible or necessary to design a habitat objective around. While the ecological 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-29

attribute identifies a desired condition for most indicators, other factors, such as feasibility and the 

ability to reasonably influence certain indicators, played a role in determining the ultimate 

parameters and condition levels chosen for habitat objectives (Chapter 2). 

Table 4.3 Habitat Attributes, Indicators, and Condition Parameters for Improved Pasture 

(managed for dusky and cackling geese).

Key Ecological 

Attributes Indicators Desired Conditions 

Community 

Structure 

• Average grass height

• Thatch

• Shrub cover 

• Field/wetland interface 

• Shorter than 6 inches by October 1 

• Minimal

• No encroaching woody vegetation

• Short vegetation along interface 

Patch Size

-Dusky pasture

-Cackler pasture

• 2-45 acres (duskys)

• 35 acres or more (cackling geese)

Security • Area clear of tall/

woody vegetation to 

allow for predator 

detection 

• Human disturbance

• Predator detection width 250 feet (duskys) 

• Predator detection width 450 feet (cackling geese)

• Minimal disturbance in sanctuary areas Oct 1-

April 1 (duskys)

• Minimal disturbance in sanctuary areas Oct 1-

May 1 (cackling geese)

Connectivity Distance to accessible 

wetlands

400 feet or less (duskys)

Plant Species • Mix of desirable 

palatable grasses and 

forbs

• Invasive species 

• Perennial ryegrass, orchardgrass, fescues, clover

• Less than 20% cover of invasive species(e.g. 

Canada thistle, buckhorn plantain, tansy ragwort, 

teasel); no false indigo or poison hemlock

Source: Planning Team

4.3.5 Threats 

The lower Columbia River provides important habitat for migrating and overwintering waterfowl 

that use the Pacific Flyway. Other threats are associated with breeding and migration areas in 

Canada and Alaska, and are treated in detail in other documents. Threats to wetland habitat are 

discussed in section 4.5. Threats to waterfowl and their associated habitats in the lower Columbia 

River region follow. 

• Loss, degradation, or fragmentation of wetland and grassland habitat (see section 4.4 below). 

• Development of grasslands or conversion to less suitable or unsuitable agricultural habitats. 

• Human disturbance to key foraging and roosting areas. 

• Wildlife diseases.

Specific threats to improved pasture on the refuge include: 

• Lack of ability to fully utilize prescribed fire or cooperative grazing and haying as 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-30 Chapter 4. Refuge Biology and Habitat

management tools, leading to encroachment by woody plants, thatch accumulation, and 

increased prevalence of invasive and noxious weeds that reduce food availability and 

palatability for geese; and

• Invasive and noxious weeds, which compete with or exclude desirable grasses and forbs 

utilized by waterfowl. 

4.4 Native Grasslands

4.4.1 Description and Location

Due to changes caused by conversion to agriculture (diking, draining, and logging of bottomlands; 

soil disturbance; grazing; and introduction of exotic grasses), grasslands on the refuge are highly 

altered from presettlement conditions. Before Euro-American settlement, most of the refuge was 

covered by a mosaic of floodplain forest, wetlands, sedge meadows, and wet prairie. Upland (dry) 

prairie likely occurred only in small patches of well drained soils in oak woodland, while wet 

meadow or prairie likely covered larger tracts of seasonally inundated ground. 

Reconstructing the species composition of the refuge’s historic grassland and prairie habitats is 

difficult due to their early conversion to agriculture. Early survey notes recorded patches of “wet 

prairie or meadow” on lower Columbia River bottomlands. Some of these were likely Columbia 

sedge meadows (Christy 2004). Another possible vegetation type was native wet prairie dominated 

by tufted hairgrass (Deschampsia cespitosa) (Christy 2004). 

Small patches (approximately 10 acres total) of unmanipulated upland (dry) grassland occur as 

openings in oak woodland habitat in the Carty Unit. These grassland patches occur on shallow, well 

drained soil. Characteristic grasses associated with this habitat type include red fescue (Festuca 

rubra) and California oatgrass (Danthonia californica) (Christy 2004, and Altman and Holmes 

2000). These small patches are dominated by introduced grasses, for example, poverty brome 

(Bromus sterilis) and orchardgrass (Dactylis glomerata); however, native wildflowers such as camas 

and Nuttall’s larkspur occur in these grassy openings. 

When the refuge was established, much of the area of former riparian forest and wetland had been 

converted to pastures, hayfields, and croplands. Many wetlands were restored on the refuge, but 

agricultural lands continued to be managed as such. Today, most of these lands are managed as 

improved pasture. These pastures are dominated by introduced “tame” pasture grasses such as 

perennial ryegrass, orchardgrass, and fescues, and are managed to provide short browse for Canada 

and cackling geese. Winter wheat, alfalfa, and/or clover have been planted in select areas as cover 

crops to rehabilitate pastures and to provide additional forage for geese and sandhill cranes. 

Management emphasis has been to manipulate vegetation structure through mowing, managed 

grazing, and other techniques. Ecological attributes, indicators, and condition parameters for 

improved pastures and croplands are discussed in Section 4.3 (Waterfowl). Some areas (old fields 

and buffers) have been left unmowed to provide nesting habitat for grassland-dependent birds, such 

as savannah sparrow and western meadowlark. The refuge currently contains approximately 400 

acres of this “old field” habitat (see Table 4.5 below). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-31

4.4.2 Condition and Trends

Only small remnants of native grassland still exist in western Oregon and Washington. Less than 1

percent of Willamette Valley grassland and savannah habitat remains. In western Washington, only 

about 8 percent of the original prairie still supports grassland vegetation and about 2-3 percent is still 

dominated by native prairie vegetation (Stinson 2005). More than 99 percent of the prairies in Clark, 

Lewis, and Cowlitz Counties have been converted to agriculture and other uses (Caplow and Miller 

2004). As is the case elsewhere in the region, little remains on Ridgefield’s native grassland plant 

communities. However, there has been some expansion of suitable habitat for grassland birds 

through the creation of agricultural grassland habitat where grasslands did not previously exist. This 

occurred primarily from extensive wetland draining, which converted wetlands and floodplain forest 

into agricultural lands. This also occurred on the refuge; upland grassland has increased as a habitat 

type compared to historic conditions due to human modifications of the habitat prior to refuge

establishment (logging followed by diking, draining, introduction of nonnative pasture grasses, 

grazing, and cropping). The refuge currently manages these lands as improved pasture (see section 

4.3, Waterfowl) with some areas left unmowed as habitat for grassland-nesting birds (see table 4.5 

below). Columbia sedge meadows, likely a common refuge habitat type historically, have been 

almost completely replaced by nonnative reed canarygrass. These areas are mowed to provide short 

browse for geese. There is currently no known occurrence of native wet prairie on the refuge. 

In select areas, habitat conditions may favor restoration of native grassland. However, such habitat 

restoration would be expensive, limiting the size of restored areas; and maintaining small patches of 

native grassland in a “sea” of pasture dominated by nonnative grasses is problematic. Approximately 

30 acres of nonnative pasture areas on Bachelor Island were planted to native grasses in 2002. 

Wetland 8A (12 acres) and the southern portion of Wetland 8 (3.2 acres) were planted to a native 

moist soil grass community; and Smith Lake Field and a small portion of South Warehouse (13.5 

acres) were planted in a native dry prairie grass community (blue wildrye 60 percent, red fescue 30 

percent, and California brome, 10 percent). (Note: Portions of Wetlands 8 and 8A and Hundred Acre 

Field were later included in 8 Spit Field (24 ac), under the “old field” habitat designation.) The 

native grass plantings on 8 Spit Field and Smith Lake did not persist and were not replanted. In 2007 

experimental plantings of Nelson’s checkermallow, a species native to wet prairie in the Willamette 

Valley, were conducted in Smith Lake Field and Hundred Acre Field. Vegetation inventories and 

test plantings presented in Chapter 2 Objectives 7.7a and 7.7b, will help identify areas with the best 

potential for and feasibility of restoration. 

4.4.3 Associated Wildlife

Birds. About 100 bird species can occur in grassland habitats in western Washington and Oregon. 

Of these, 44 species are highly associated breeding species in grasslands (Altman 1997; and Altman 

and Holmes 2000). Examples of obligate grassland species include western meadowlark, savannah 

sparrow, Oregon vesper sparrow, streaked horned lark, grasshopper sparrow, common nighthawk, 

western bluebird, lazuli bunting, northern harrier, western kingbird, killdeer, and short-eared owl. 

Many of the species have shown declining trends for decades, and are State listed or candidate 

species in Oregon and/or Washington. However, the savannah sparrow has shown an increasing 

trend (Altman and Holmes 2000). Many other birds occur in grasslands, but are not dependent on it,

for example, predator birds (red-tailed hawk) attracted by rodents; generalist or edge species such as 

song sparrows; or open-country aerial foragers such as barn swallows (Altman 1997). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-32 Chapter 4. Refuge Biology and Habitat

Grassland-associated birds known to occur on the refuge are northern harrier, killdeer, short-eared 

owl, common nighthawk, western kingbird, streaked horned lark, western bluebird, vesper sparrow, 

savannah sparrow, lazuli bunting, and western meadowlark. These species utilize improved pasture 

and old fields. Of these species, only northern harrier, killdeer, and savannah sparrow are common 

and are known to breed on the refuge. Western meadowlark is uncommon but is a confirmed 

breeder. The remaining species are occasional to rare, and breeding has not been confirmed. 

Mammals. Limited data is available on mammals occurring in this habitat. The refuge occurs 

within the historic range of the Mazama (western) pocket gopher (Thomomys mazama), Brush Prairie 

(northern) pocket gopher (Thomomys talpoides douglassii), and gray-tailed vole (Microtus 

canicaudus), however, data on their occurrence is lacking. Further work to gather baseline data on 

small mammals is needed.

4.4.4 Key Ecological Attributes

Tables 4-4a, b, and 4-5 describe key ecological attributes of grasslands and old fields, and associated 

indicators. For each indicator, the conditions that would represent “good” or better are shown. 

Table 4.4a Upland (Dry) Prairie Ecological Attributes, Indicators, and Condition 

Parameters

Key Ecological 

Attributes Indicators Desired Conditions 

Vegetation 

structure

• Average grass/forb heights

• Percent grass/forb cover

• Percent woody vegetation 

cover

• Variable grass heights 6-30 in tall

• More than 50% but variable, with areas of bare or 

sparsely vegetated ground and areas of dense (e.g. 

more than 80%) grass cover (western meadowlark)

• Shrub-tree cover less than 10%

Native plant 

composition 

Roemer’s fescue, red fescue, California oatgrass, California brome, blue wild rye, 

western bittercress, American vetch, western wood strawberry, spring beauty, 

chickweed, Nuttall’s larkspur, camas

Invasive 

species

Less than 20% cover of invasive/undesirable nonnative grasses (e.g. poverty brome), 

forbs (e.g., ox-eye daisy, thistle and trefoil), and shrubs (e.g. blackberry)

Soils Well drained soils 

Disturbance 

Events

• Fire intensity

• Fire return interval

• Grazing

• Human disturbance 

• Low

• Frequent (2-5 years) after July 15; fire is the 

preferred tool to maintain habitat where feasible

• Light to moderate non-uniform grazing to meet 

desired conditions

• Minimize management and recreational activities 

during the breeding season, April 15-July 15. 

• Delay mowing, haying until after July 15

Patch Size/

Connectivity

• Patch size 

• Contiguity with 

agricultural grasslands 

(e.g., fallow fields, 

pastures, hayfields) 

• Larger than 25 ac

• Larger than 200 ac (western meadowlark)

Source: Altman and Holmes 2000 (Grassland-Savannah Conservation Strategies, pp. 36-40; Biological Objectives for Western 

Meadowlark, pp 40-43; Oregon vesper sparrow, p 50), Christy 2004, USFWS 1993, Wilson et al. 1998a, Altman 1999
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-33

Table 4.4b Bottomland (Wet) Prairie Ecological Attributes, Indicators, and Condition 

Parameters 

Key Ecological 

Attributes Indicators Desired Conditions 

Vegetation 

Structure 

• Average grass/forb heights

• Percent grass/forb cover

• Percent woody vegetation 

cover 

• Short to medium (6-36 inches); mosaic of 

vegetation heights

• More than 50%

• Less than 5%; no willows 

Native plant 

composition 

• Native grass and forb species

• Native shrub/tree species

• Mix of grasses and forbs including tufted 

hairgrass, rushes, sedges, camas, Bradshaw’s 

lomatium, Nelson’s checkermallow.

• Scattered shrub component e.g. Douglas’ spirea

Invasive 

species

Less than 20% cover of invasive/undesirable nonnative grasses (reed canarygrass), 

forbs, and shrubs

Soils/

Hydrology 

• Poorly drained (hydric) soils

• Seasonal flooding; water depths range from moist soil to 4 inches from December 

through at least March

Disturbance 

Events

• Fire intensity

• Fire return interval

• Grazing

• Human disturbance 

• Low

• Frequent (2-3 times every 6 years needed to 

maintain viability of Bradshaw’s lomatium 

• No grazing to light rotational grazing depending 

on vegetation and soil conditions. Limit grazing 

during spring and early summer in areas where 

harriers are nesting to protect nests from trampling

• Minimize or avoid agricultural field operations 

and recreational activities during breeding season; 

April 15-July 15. Delay mowing/haying until 

after July 15.

• Provide a no activity buffer of more than 400 feet 

around harrier nests

Patch Size/

Connectivity

• Patch size 

• Contiguity with wetland, wet 

meadow and old field 

habitat 

• 200 ac (northern harrier, short-eared owl)

• Maintain mosaic of wetland, wet meadow and 

non-managed field in greater than 400 acre blocks

farther than a quarter mile from human 

development or recreational activities

Source: Altman and Holmes 2000 (Grassland-Savannah Conservation Strategies, pp. 36-40; Biological Objectives for northern 

harrier, pp 54-56). Christy 2004, USFWS 1993, Wilson et al. 1998b, Altman 1999
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-34 Chapter 4. Refuge Biology and Habitat

Table 4.5 Old Field Ecological Attributes, Indicators, and Condition Parameters 

Key Ecological 

Attributes

Indicators Desired Conditions 

Vegetation 

structure 

• Average grass/forb heights

• Shrub cover 

• Grass/forb cover

• Unmanipulated residual 

cover

• 6-24 inches 

• Less than 10%

• More than 80%

• More than 60% remaining annually (residual duff is 

preferred for nesting habitat)

Plant species 

composition 

• Mix of desirable native and/or nonnative grasses (e.g., perennial ryegrass, 

orchardgrass, fescues) and forbs (e.g. clover)

Invasive 

species

• Less than 30% cover of invasive species (e.g. Canada thistle, buckhorn plantain, 

tansy ragwort, teasel); no false indigo or poison hemlock

Disturbance 

Events

• Fire intensity

• Fire return interval

• Mowing/Grazing 

• Human disturbance 

• Frequent 

• 2-5 years

• May be used as management tool after nesting 

season; no mowing before July 15; light to moderate 

rotational grazing 

• Minimize or avoid agricultural field operations 

(mowing, tilling, spraying) and recreational activities 

during breeding season; April 15-July 15. 

Patch Size/

Connectivity

• Minimum Patch Size

• Connectivity 

Contiguity with wetland or 

agricultural grasslands 

(fallow fields, pastures, 

hayfields)

• 5 ac 

• Within or adjacent to managed pasture, croplands, or 

wetlands 

• Within 200 acre contiguous mosaic of native and 

agricultural grasslands

Source: Planning Team, Altman and Holmes 2000

4.4.5 Threats 

The following threats to native prairie and agricultural grassland habitat are summarized from 

Altman and Holmes (2000): 

• Direct habitat loss from urban, residential, and agricultural development; 

• Altered fire regimes and intensities, leading to habitat issues such as encroachment by woody 

plants, thatch accumulation, and increased prevalence of exotic plant species;

• Invasion by introduced plant species, which compete with or exclude native plants and alter 

vegetation structure (e.g., percent cover, vegetation height); 

• Conversion of agricultural grasslands (e.g., fields dominated by exotic grasses and usually 

managed for a crop or for grazing) to less suitable or unsuitable agricultural habitats;

• Habitat fragmentation of remaining grasslands to sizes that may be insufficient to maintain 

healthy populations of birds; 

• Proximity to agricultural and residential areas that may have a high density of nest parasites 

(brown-headed cowbird), exotic nest competitors (European starling) and predators 

(opossums), and domestic predators (cats), and may be subject to high levels of human 

disturbance; and 

• Timing and extent of agricultural practices (e.g. mowing, haying, grazing, tilling, pesticide 

application) that results in direct and indirect reproductive failures of grass-land-nesting birds.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-35

4.5 Wetlands and Deepwater Habitats

For the purposes of the CCP, wetlands are defined according to the classification system (Cowardin 

et al. 1979) used by the National Wetlands Inventory (NWI), but exclude all riparian habitats which 

might be included under this classification, that is, those areas dominated by woody perennial shrubs 

or trees. Deepwater habitats are permanently flooded lands lying below the deepwater boundary of 

wetlands. According to Cowardin et al. (1979) wetlands are lands transitional between terrestrial and 

aquatic systems where the water table is usually at or near the surface, or the land is covered by 

shallow water. A positive indicator of wetland status requires the presence of one of the following: 

• hydrophytic plants; 

• hydric soils; or 

• saturated or flooded soils during part of the growing season. 

The key divisions of the NWI classification relevant to the refuge include the lacustrine, palustrine, 

and riverine systems. Lacustrine wetlands are generally permanently flooded and are identified as 

those areas lacking trees, shrubs, or emergent vegetation with greater than 30 percent areal coverage 

and measuring greater than 20 acres. Smaller areas can be defined as lacustrine if the water depth in 

the deepest part of the basin exceeds 6.6-feet at low water. Palustrine areas may or may not be 

permanently flooded, but they are typically recognized by the presence of trees, shrubs, or 

herbaceous emergent vegetation. Under the NWI classification, shallow marsh includes the 

following palustrine types:

• Class = Aquatic bed (water regime modifier = permanently flooded) 

• Class = Aquatic bed (water regime modifier = semipermanently flooded) 

• Class = Emergent wetland (water regime modifier = semipermanently flooded)

• Class = Emergent wetland (water regime modifier = seasonally flooded) 

• Class = Emergent wetland (water regime modifier = temporarily flooded) 

• Class = Emergent wetland (water regime modifier = seasonal-tidal)

Aquatic bed wetlands are wetlands that are dominated by vegetation that is floating and/or 

submerged and can be either palustrine or lacustrine; however, the refuge contains only the palustrine 

type. See the glossary for a complete definition of these three system types according to the NWI. 

4.5.1 Description and Location 

Permanent Wetlands. Permanently flooded wetlands occupy approximately 600 acres of the 

refuge. Three of these wetlands fall into the Lacustrine System under the NWI based on size (larger 

than 20 acres), and lack of persistent woody or emergent vegetation (less than 30% cover): 

• Campbell Lake (189 acres) on the Roth Unit; 

• Post Office Lake (74 acres) on the Ridgeport Dairy Unit; and 

• Fowler Lake (36 acres) on the Carty Unit. 

Lacustrine habitats support fish, aquatic invertebrates and/or submergent vegetation and are utilized 

by diving ducks and various fish-eating birds. With their deep open water, lacustrine wetlands offer 

long sight distances and are free of mammalian predators. Therefore, they provide important loafing, 

resting, and roosting habitats for wintering waterfowl. Other permanent wetlands fall into the 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-36 Chapter 4. Refuge Biology and Habitat

Palustrine category based on vegetation types. These include Carty Lake (52 acres) on the Carty 

Unit and Wigeon Lake (25 acres) on the Bachelor Island Unit. Two other large permanent palustrine 

wetlands on Bachelor Island, Canvasback Lake and Turtle Lake, lie mostly or entirely off Serviceowned lands. 

Approximately 450 acres of permanent wetlands lie outside the dikes on the Roth, Ridgeport Dairy, 

Carty, and Bachelor Island units, and therefore, are tidally influenced. The refuge has no 

management control of water levels in these wetlands. These include Campbell Lake (189 acres) and 

Campbell Slough (30 acres) on the Roth Unit; South Campbell Lake (15 acres) on the Ridgeport 

Dairy Unit; wetlands in the Gee Creek system on the Carty Unit (approximately 100 acres total); and 

Canvasback Lake-West (52 acres) and Wigeon Lake (25 acres) on Bachelor Island. All of these 

wetlands have an unconsolidated bottom, with the exception of Wigeon Lake which is classified as 

an aquatic bed in the NWI. 

Campbell Lake is a floodplain wetland with direct connection to the Columbia River via Campbell 

Slough. Campbell Slough is considered a permanent tidal riverine system in the NWI. Wigeon Lake 

and Canvasback Lake West are connected to the Columbia River via Canvasback Lake. Gee Creek 

winds through the Carty Unit in a network of sloughs, channels and open lakes before emptying into 

the Columbia River. The larger wetlands in this unit include Fowler Lake (36 acres), Beaver Pond 

(18 acres), Middle Lake and its channel (19 acres), and Quarry Lake (20 acres). The degree and 

timing of inundation of these wetlands depends upon tides, river levels, and rainfall. 

Permanent nontidal wetlands on the refuge include approximately 150 acres of wetlands and slough 

remnants historically connected to the Columbia River, but cut off from the river by dikes and/or 

cessation of major flooding events. These wetlands currently include Post Office Lake (74 acres) on 

the Ridgeport Dairy Unit, Carty Lake (52 acres) on the Carty Unit, and Bower-Mallard Slough on the 

River ‘S’ Unit. Bower Slough was originally a backwater slough of the Columbia River, but was cut 

off from the river by diking and is now filled through precipitation and pumping. It is part of the 

water delivery system for managed wetlands on the River ‘S’ Unit. Post Office Lake formerly had a 

tidal connection to the Columbia River, but this ceased when a stop log structure was installed in the 

mid 1990s. However, the County-owned dike separating Post Office Lake from the Columbia River 

is deteriorating and will likely breach in the next major flood event. 

The refuge may or may not have some minimal water management capabilities on these permanent, 

nontidal wetlands. These wetlands rarely dry completely via evaporation during the summer, though 

significant reduction in surface area and depth may occur. It appears that water retention in these 

wetlands is in part a function of the current water levels within the Columbia River system, probably 

due to seepage/ground water levels. Post Office Lake has partial water management capabilities in 

that it has a water control structure on its drain. Post Office Lake was also fitted with a ‘duckbill’ 

tide gate in 1999, to prevent floodwater from backfilling into the basin and avoid fish entrapment 

within the wetland. The Service’s ability to manage Post Office Lake is limited because a portion of 

the lake is privately owned. Outside of their extensive use by waterfowl and other migratory birds, 

little is known about the submerged vegetation and other aquatic species inhabiting Carty and Post 

Office Lakes. Bower Slough contains abundant woody debris and gets heavy use by hooded 

mergansers, wood ducks, and waterfowl broods. It is a summer refugium for painted turtles and 

amphibians. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-37

Semipermanent and Seasonal Wetlands. Most semipermanent and seasonal wetlands on the 

refuge are classified as palustrine emergent wetlands in the NWI. Timing and depth of inundation 

depends on basin depth, rainfall, soil characteristics, and water delivery capabilities. Semipermanent 

and seasonal wetlands occupy approximately 1,100 acres of the refuge and offer high habitat values. 

These values include productive foraging habitat for seed-eating waterfowl, breeding habitat for 

waterfowl, and in the spring, muddy exposed substrates which support shorebirds. These wetlands

can be highly productive for various invertebrates because of temperature and water fluctuation 

cycles and decaying vegetation. They include approximately 650 acres of managed seasonal and 

semipermanent wetlands (mostly on the River ‘S’ Unit), 150 acres of nonmanaged seasonal wetlands 

(mostly on Bachelor Island), and 300 acres of wet meadow (mostly on the River ‘S’, Roth, and 

Ridgeport Dairy Units). 

Managed Seasonal and Semipermanent Wetlands. Refuge waters inside diked areas of the River 

‘S’, Bachelor Island, and Ridgeport Dairy units are managed to mimic natural disturbance 

mechanisms, providing and maintaining the cyclical aging and renewal processes of wetlands over 

time. By maintaining open shallow marsh through artificial means such as mechanical and 

hydrological operations, the refuge can provide a diversity of early successional vegetation stages 

that increase overall biodiversity and prevent wetland loss over time. Managed seasonal and 

semipermanent wetlands have existing infrastructure (pumps, culverts, water control structures) to 

manipulate water levels on a seasonal basis, relatively independent of water conditions in the 

surrounding watershed. Because of the widely divergent habitat requirements of waterfowl and 

waterbirds throughout the year (see section 4.3.3 above), refuge wetlands are managed to provide a 

range of water depths. Water depths, surface area, and hydroperiods within these managed wetlands 

can generally be independently regulated with a network of pumps, ditches, and water control 

structures. In all, the refuge has the ability to manipulate water within 48 individual wetland basins 

and over 971 surface acres. Generally, managed wetlands are irrigated in the fall and winter to 

desired depths and surface areas. These elevations are maintained until spring. Periodically, spring 

water depths within managed wetlands are increased to negatively impact reed canarygrass. Select 

basins may be dewatered in early spring to facilitate management actions including dike repair, or 

invasive species control measures. 

Most of the River ‘S’ wetlands are seasonally flooded with water pumped from Bachelor Slough, 

which serves as the reservoir for filling most of the wetlands. Water availability can be limited 

during low tides. In recent years, water has been pumped into the wetlands to achieve desired water 

depths for the waterfowl hunting program by mid-October. When winter rains commence, the 

wetlands can become over-full and water must be pumped off the unit. Since the River ‘S’ Unit is 

generally sloping from south to north, water is expulsed from pumps on the north end of the unit. 

(For detailed information on water control infrastructure, see Chapter 5). The largest wetland on the 

River ‘S’ Unit, Rest Lake (86 acres) is classified as a semipermanent emergent wetland, but has 

generally been managed as a permanent wetland. However, it may be drawn down when needed for 

management purposes (for example, it was drawn down in 1999 for restoration and disking). 

The River ‘S’ Unit contains most of the refuge’s managed seasonal wetlands, which provide food for 

migrating and overwintering waterfowl. Managed seasonal wetlands are generally slowly drawn 

down through the spring to create moist soil areas where the seeds of annual emergent plants (e.g., 

smartweeds, wild millet, and water plantain) can germinate in summer. In fall, the wetland basins 

are reflooded or allowed to flood naturally with rainwater. Water depths of 2-10 inches are optimal 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-38 Chapter 4. Refuge Biology and Habitat

for foraging by dabbling ducks. Preferred water depths for foraging waterfowl range from 2.75 to 

5.5 inches for mallard and 6.3 to 9.5 inches for northern shoveller (Frederickson 1991). 

The wetland system on Bachelor Island was largely redesigned in 1998. New wetlands were created, 

other wetland basins were expanded, and several steep banked wetlands were recontoured. 

Additional improvements were made to the water delivery and control systems. There are 21 

wetland basins on Bachelor Island with water management potential. At full capacity, the refuge

could manage nearly 400 acres of wetlands on Bachelor Island. However, due to a soil structure of 

alternating sandy and clayey layers, some wetland basins only hold water during high river levels, 

when water can percolate through the sand layers. When river levels are low, water percolates out 

through these same layers, draining the wetlands. The cost of pumping water into these wetlands is 

prohibitive. Therefore, active irrigation on Bachelor Island is reserved for wetlands with proven 

water retention capabilities, and where good water control capability exists. Most Bachelor Island 

wetlands are not actively managed (see below, “Nonmanaged Seasonal Wetlands”). 

Wetland improvements were initiated on the Ridgeport Dairy Unit in 1998 with the recontouring and 

disking of the Hillocks, Fingers, and Dusky marshes, and the installation of a pump station and water 

delivery system for these marshes. These three basins, totaling 80 acres represent the managed 

wetlands of the Ridgeport Dairy Unit. A water control structure on the south end of Campbell Lake 

facilitates drainage for the Hillocks and Fingers marshes. These shallow wetlands are classified as 

wet meadow. 

Nonmanaged Seasonal Wetlands. Unmanaged or nonmanaged seasonal wetlands are those that are 

typically dry in summer (June-September) and fill with rainwater in fall. Most of this wetland type 

(approximately 120 acres) occurs on the Bachelor Island Unit. Some small seasonal wetlands 

(approximately 20 acres total) occur on the Carty Unit, and one 16-acre seasonal wetland is on the 

Carty Unit (River ‘S’ Point). Seasonal wetlands on Bachelor Island are generally not supplemented 

with pumped water, and there are no capabilities to supplement wetlands on the Carty Unit. The 

small seasonal wetland basins in the Carty Unit may be inundated during unusually high water events 

(Columbia River floods) but otherwise are disjunct from the daily fluctuations of the Columbia River 

and Gee Creek wetland systems. 

Most of Bachelor Island is maintained as managed pasture, however, a series of linear, generally 

north-south trending basins contain seasonally flooded emergent wetlands. Formerly, these were 

filled by spring floods from the Columbia River and by rainwater in winter. These basins are 

shallower at present than they were historically. In the 1940s and 1950s the low ridges between the 

basins were partially leveled to facilitate farming. Soil from the ridge tops was used to partially fill 

the basins. This decreased the depth of seasonal wetlands on Bachelor Island and probably affected 

their water-holding capabilities as well. Because the cost of pumping water into these wetlands is 

prohibitive, the Columbia River’s level, seasonal rainfall, and soil characteristics of each wetland 

basin dictate the overall acreage of wetlands on Bachelor Island. Most wetland basins on Bachelor 

Island collect water from seasonal rainfall, with approximately 250 acres of wetlands by mid-winter. 

Wet Meadows. Wet meadows are shallowly flooded wetland edges with little to no slope. On the 

refuge they occur within both managed and unmanaged units. Due to the generally short duration 

and shallow flooding of these sites, reed canarygrass proliferates, and little if any native wet meadow 

vegetation (e.g. Columbia sedge) persists. However, wet meadow is a favored habitat of dusky 

Canada geese, and high use of these areas has been documented despite the dominance of reed 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-39

canarygrass. The largest contiguous tracts of wet meadow are on the Roth Unit (113 acres) and the 

Ridgeport Dairy Unit (60 acres). As noted above, the refuge has water management capabilities on 

the Ridgeport Dairy wetlands. The River ‘S’ Unit contains about 85 acres of wet meadows, broken 

up among several small (10 acres or less) tracts. There is also about 20 acres of this habitat on the 

Carty Unit, in the overflow plain north of Carty Lake, but this area receives little goose use.

Howellia Wetlands. Howellia wetlands are generally small, isolated basins that fill with rainwater 

in fall and dry during the summer months, providing habitat for the endangered water howellia 

(Howellia aquatilis). Drying to a mudflat stage in the late summer or early fall is essential for 

successful germination of howellia seed. These wetlands cannot be supplemented with pumped 

water or artificially dewatered. The Carty Unit contains several small (less than 1 acre) perched 

wetlands that contain water howellia. These small wetlands generally contain open water (shallower 

than 1 foot) from November through June, with sparse emergent and submergent vegetation, e.g. 

aquatic grasses, sedges, pondweeds, and burreeds. The refuge’s howellia ponds occur in a matrix of 

dense forest vegetation, typically Oregon ash with a well-developed shrub component of red-osier 

dogwood and Douglas’ spirea. Howellia does not persist in wetlands overgrown with emergent 

vegetation or woody plants. Deeper ponds that remain wet for the majority of the growing season 

may undergo succession to cattail, which eventually excludes howellia; where howellia occurs with 

cattail, populations are less vigorous (Shelly and Moseley 1988). With increasing sedimentation and 

accumulation of organic matter, and the lowering of the water table, shallower ponds eventually 

develop into seasonal emergent wetlands dominated by sedges and grasses, and howellia is not 

present. Because howellia habitat is ephemeral, the availability of clusters of closely adjacent ponds 

in a variety of successional stages, with corridors between ponds for animal movement to facilitate 

seed dispersal, is essential for the persistence of this species (Roe and Shelly 1992). 

4.5.2 Condition and Trends

Construction of dams and levees caused several significant changes in wetland habitats along the 

lower Columbia River. Natural fluvial processes that occurred along the river were lost, such as 

seasonal flooding and scouring that helped maintain river-associated wetlands by setting back 

succession. The timing of seasonal flows were also severely altered, which prior to the dams, 

included high water flows during spring and summer and low flows during fall and winter (see 

Chapter 3). Under this highly altered system, refuge wetlands lack natural renewing processes and 

will age in terms of succession, unless they are actively managed to set back succession. Diversity in 

vegetation structure (e.g. a mix of submergent and emergent plants) will gradually give way to 

dominant monocultures of tall, persistent emergent plants, that when combined with sedimentation, 

causes the infill and eventual loss of shallow wetlands. 

Permanent Tidal Wetlands. Although some wetlands at the refuge retain tidal connections to the 

Columbia River, water levels are lower than they were historically due to lower river levels and 

altered flooding regimes. The presence of nonnative fish, especially carp, has decreased water 

quality for native salmonids that use these habitats for rearing, and has probably negatively impacted 

the native mussel community. The decline of wapato in permanent wetlands is probably due to a 

combination of altered hydrology and the foraging activities of carp and nutria. 

Campbell Lake and Slough (Roth Unit). Campbell Lake supports large numbers of migratory and 

overwintering waterfowl, as well as being an important roost for migrating sandhill cranes. Carp 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-40 Chapter 4. Refuge Biology and Habitat

enter Campbell Lake via Campbell Slough by the thousands during the breeding season. However, 

despite the presence of carp, Campbell Lake still supports a reasonably high-quality native plant 

community and receives high waterfowl use. Average year-round water levels within Campbell 

Lake appear to be consistently lower since the 1996-1997 flood seasons, when Campbell Lake was 

predominantly a nonvegetated, exposed mudflat. Since then, tall emergent plants have colonized 

much of the shallow wetlands and mudflats once utilized by roosting cranes. The middle and 

southern portions of the lake are still relatively open; however, water levels may be too deep for 

roosting. This habitat change in Campbell Lake may account for the shift in roosting to Canvasback 

Lake on Bachelor Island from 2003 on. If the current vegetation trend continues, the site may lose its 

value as roosting habitat. 

Canvasback Lake (Bachelor Island Unit). Historically, Canvasback Lake was a large, shallow lake 

heavily used by mallard and other dabbling ducks (Jewett 1927). The lake retains some hydrologic 

connection to the Columbia River; however, with lower average river levels and cessation of annual 

spring flooding, the condition of the lake has been gradually deteriorating. The deepest area of the 

lakebed holds water year-round, and lies on private land. The shallower south end of Canvasback 

Lake (approximately 60 acres total) is on refuge land. Because most of the lake, and a small dike and 

water control structure, is on private land, the Service does not have management control of this lake. 

Without the ability to control water levels, the southern portion is now becoming a water smartweed 

(Polygonum amphibium) monoculture, and yellow flag iris has begun to invade. The southernmost 

portion of the wetland is currently in a degraded, weedy condition. Habitat improvement, 

specifically the creation of shallow open water areas, could increase waterfowl and crane use.

Wigeon Lake (25 acres) is connected to Canvasback Lake and is dependent on Columbia River 

levels. It is not actively managed at this time. Although it has an independent water delivery system, 

a hydraulic and topographic survey is needed. The primary vegetation is water smartweed and 

spikerushes. The area surrounding Wigeon Lake is currently in degraded, weedy condition. 

 

Permanent Nontidal Wetlands. Due to the loss of connection permanent nontidal wetlands once 

had with the Columbia River system, their functionality has been reduced, particularly with respect 

to anadromous fish rearing habitat, wapato beds, and native mussel beds. 

Post Office Lake (Ridgeport Dairy Unit). For many years Post Office Lake was managed as a 

permanent wetland with little submergent vegetation. A “duckbill” tide gate was installed in 1999, 

and in 2000 the lake was drawn down to control carp and other rough fish. It was hoped that this 

would allow submergent vegetation to re-establish and improve habitat quality for swans, diving 

ducks, and wading birds. A biological survey is needed to determine the success of the restoration 

effort. Formerly, the lake was grazed to the shoreline, which had negative impacts to water quality 

but the short, grazed grass did encourage heavy wigeon use. Currently, the lake is surrounded by a 

“fence” of tall vegetation which makes the lake less attractive to waterfowl and cranes. 

Carty Lake (Carty Unit). Carty Lake formerly contained a large wapato bed; currently, wapato is 

confined to small areas of the lake. As with other permanent wetlands on the refuge, water quality 

and aquatic plants have been negatively impacted by carp. Restoring a tidal connection could 

improve habitat conditions; however, contaminants present in sediment (see Chapter 3) limits 

management options. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-41

Managed Seasonal and Semipermanent Wetlands. Between 1998 and 2000, many refuge

wetlands on the River ‘S’, Bachelor Island, and Ridgeport Dairy units were restored. Basins were 

recontoured, and water control infrastructure was repaired or added. An improved water control 

infrastructure enhanced the refuge’s ability to manage for desirable, moist-soil plants, and also 

control reed canarygrass, which had been a persistent management issue since the refuge was 

established. The most effective control techniques for reed canarygrass involve dewatering wetland 

basins, followed by disking and multiple herbicide treatments. Extensive disking of wetland basins 

was conducted to control reed canarygrass between 1999 and 2002, including 450 acres on the River 

‘S’ Unit. In many cases, wetland basins responded positively with decreased reed canarygrass cover 

and an increase in desirable moist-soil plants. 

The accidental introduction of ricefield bulrush forced the refuge to change the reed canarygrass 

control regime. After ricefield bulrush was discovered in 2002, disking was discontinued in most of 

the refuge’s managed wetlands (including most wetlands on the River ‘S’ Unit) to prevent the spread 

of this plant. Water management was also changed to prevent the spread of bulrush seed through 

delivery/drainage ditches. Where possible, water was not pumped off but rather allowed to recede 

only through evaporation, transpiration, or ground water seepage (USFWS 2003). To control reed 

canarygrass, water was held in wetland basins for extended periods (until at least June). While this is 

an effective control method, it also creates deeper water conditions unfavorable for the production of 

moist-soil plants. 

In addition, water was pumped onto the managed wetlands of the River ‘S’ Unit in early fall 

(September) to ensure that hunt units were flooded by mid-October. As winter rains added more 

water to these wetlands, it was necessary to pump the water off to avoid flooding refuge roads, and 

other infrastructure. Because out-pumping generally could not keep pace with inflow from rains, this 

pumping regime created relatively deep-water conditions for most of the fall through spring season. 

These depths are not conducive for most foraging waterfowl. The combined effects of water 

management for the waterfowl hunt program and invasive species control have made conditions less 

favorable for dabbling ducks. This has been reflected in an increase in species that prefer deeper 

water for foraging or are adept at gleaning food from the water’s surface (e.g. northern shoveller, 

green-winged teal, American coot, and ringneck ducks) and a decrease in dabbling ducks that prefer 

shallower water (e.g. mallard, American wigeon). 

Nonmanaged Seasonal Wetlands. Since these wetlands vary in water-holding capability and are 

not actively managed, habitat conditions vary. In general, those with fair to poor water holding 

capability have a higher abundance of reed canarygrass, while those that hold water for longer 

periods have a higher abundance and diversity of moist soil plants. Four Bachelor Island wetlands 

with very poor water retention are now classified as wet meadows (see below) and two (Wigeon No 

Man’s Land and Canvasback Lake south) are classified as old fields and are in rank, weedy 

condition. In some cases, shallow wetland benches are undergoing succession to riparian forest. 

Ricefield bulrush was introduced to Wetland 11 on Bachelor Island in 1999 and discovered in 2002; 

since then the wetland has been managed as a semipermanent wetland.

Wet Meadows. Due to the generally short duration and shallow flooding of these sites, reed 

canarygrass proliferates and little if any native wet meadow vegetation persists. However, areas of 

short mowed or grazed reed canarygrass do receive high use by dusky Canada geese. Three seasonal

wetlands on the Ridgeport Dairy Unit (the Hillocks, Fingers, and Dusky Marshes, 60 acres) have 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-42 Chapter 4. Refuge Biology and Habitat

water management capabilities, but hold water poorly at low river levels. The Dusky and Fingers 

marshes quickly become dominated by reed canarygrass without frequent disking and rototilling

treatments, while native wetland plants (e.g. knotgrass and nodding beggartick) remain common in 

Hillocks. Ricefield bulrush was introduced into Fingers Marsh in 1999; subsequent control efforts 

favored the dominance of reed canarygrass. The Dusky and Hillocks marshes have been important 

loafing and foraging areas for dusky Canada geese in recent years. Several Bachelor Island wetlands 

(approximately 30 acres total) with shallow basins and poor water holding capacity are currently 

classified as wet meadows; reed canarygrass dominates in these wetlands.

Howellia Wetlands. Currently, one of the refuge’s four howellia ponds has been largely taken over 

by reed canarygrass. Woody vegetation (Douglas’ spirea) is encroaching on another pond. 

4.5.3 Associated Wildlife

Birds. Thousands of waterfowl representing more than 30 species use the refuge during winter or as 

stopover sites during spring and fall migrations. Twelve species of waterfowl breed on the refuge. 

The deeper semipermanent wetlands on the River ‘S’ Unit (Rest Lake and Mantrap Lake) are well 

known foraging and roosting sites for tundra swans (For detailed information on waterfowl use of 

wetlands, see section 4.3 of this chapter). 

Campbell Lake on the Roth Unit is a regionally significant roosting site for sandhill cranes; as many 

as 1,500 cranes may use this site in early fall (see section 4.9.2). Refuge wetlands provide both 

nesting and foraging habitat for marsh birds such as pied-billed grebe, American bittern, American 

coot, Virginia rail, and sora. Common songbirds breeding in refuge wetlands include marsh wren, 

common yellowthroat, red-winged blackbird, and yellow-headed blackbird. Refuge wetlands get 

limited use by migrating shorebirds (dunlin, western and least sandpipers, yellowlegs, and long-billed 

dowitcher). However, killdeer, black-necked stilt, spotted sandpiper, common snipe, and Wilson’s 

phalarope are known breeders on the refuge. Other common waterbird species that use refuge

wetlands primarily for foraging and/or resting include double crested cormorant, great blue heron, 

great egret, ring-billed gull, California gull, Thayer’s gull, and glaucous-winged gull. 

Fish. A number of nonnative warmwater fish are present in the refuge’s permanent wetlands. They 

enter Campbell Lake through Campbell Slough, and are also common throughout the Gee Creek 

system in the Carty Unit. Common introduced fishes include common carp, largemouth bass, brown 

bullhead, mosquitofish, black crappie, white crappie, bluegill, and yellow perch. It is likely that 

refuge lakes with tidal connections were historically used as rearing habitat by juvenile salmonids. A 

recent survey (June 2007) found juvenile Chinook salmon (most without fin clips, indicating a wild 

origin) in Campbell Slough. 

Mammals. American beaver (Castor canadensis), muskrat (Ondatra zibethicus), mink (Mustela

vison), and river otter (Lutra canadensis) inhabit wetlands on the refuge. Nonnative nutria 

(Myocastor coypus) are the most commonly observed mammal on the River ‘S’ Unit and cause 

considerable damage to dikes. 

Reptiles and Amphibians. Species known to occur in suitable habitat include the nonnative 

bullfrog (Rana catesbeiana), northern red-legged frog (Rana aurora), western chorus frog 

(Pseudacris regilla), northwestern salamander (Ambystoma gracile), long-toed salamander

(Ambystoma macrodactylum), and western painted turtle (Chrysemys picta). Red-legged frogs 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-43

require relatively long wetland inundation (November-June) while long-toed salamanders and 

western chorus frogs utilize wetlands with a shorter hydroperiod (3-4 months inundation). 

Wapato is a good indicator of suitable red-legged frog breeding habitat since it requires a similar 

water depth and hydroperiod. Permanent wetlands could provide suitable habitat, however, habitat 

value is limited by the presence of nonnative warmwater fish, e.g. bluegill and pumpkinseed, and 

bullfrogs. Three wetlands on the River ‘S’ Unit have been historically significant in terms of 

amphibian production: Southeast Lake, a 14-acre managed semipermanent wetland; Bull Lake, a 15-

acre managed seasonal wetland; and Middle Lake, a 23-acre managed seasonal wetland (USFWS 

2004). Southeast Lake is well known for producing large numbers of red-legged frog egg masses. 

Bull Lake has produced northwestern salamanders and red-legged frogs, although northwestern 

salamander breeding was low as of 2000 (Beale and Akins 2001). 

Painted turtles use permanent ponds and waterways on the refuge; however, they require sandy areas 

with good sun exposure for nesting. Therefore, scouring events are important in maintaining turtle 

nesting habitat. Currently, most western painted turtle nesting occurs on Turtle Lake on Bachelor 

Island, which is owned by WDNR. 

Plants. The refuge’s large permanent and semipermanent wetlands support stands of persistent 

emergent vegetation such as cattail and softstem bulrush. Wapato was formerly abundant in refuge

wetlands but habitat conditions do not favor this species at its former abundance. Some stands of 

wapato can be found in permanent and semipermanent wetlands, including Carty Lake and other 

Carty Unit wetlands, and Mantrap Lake on the River ‘S’ Unit. Common and widespread species in 

the refuge’s shallower seasonal wetlands include spikerushes (Eleocharis acicularis, E. palustris, E. 

ovata), water smartweed, swamp smartweed, nodding beggartick, Mexican mosquitofern, and 

common duckweed. Common species in particular wetland basins include (introduced species are 

noted with an *): American waterplantain, common mare's-tail, toad rush, knotgrass, spotted 

ladysthumb*, bur-reed, spike bentgrass*, wild millet*, rice cutgrass, western marsh cudweed, marsh 

cudweed*, skullcap (or marsh) speedwell, creeping jenny (or moneywort)*, and marsh seedbox (or 

false loosestrife). Good quantified information on submerged plants is lacking. 

4.5.4 Key Ecological Attributes

Table 4.6a Wetland Ecological Attributes, Indicators, and Condition Parameters

Key Ecological 

Attributes Indicators Desired Conditions 

Hydrology • Natural fluvial cycle approximating natural hydrograph (annual spring flooding with 

overbank flows; flood waters peaking in June) or direct artificial manipulation that 

mimics this cycle 

• Major flood events every 10+ years deposit sediment or rework sediment to create 

depressions or use of mechanical techniques (e.g., drawdown, disking, mowing) to 

set back succession

Water depth 

and 

hydroperiod

• Wet meadows

• Seasonal wetlands

• Moist soil to shallow sheet water (0-4 inches) Dec-March

• Early-season flooding and summer drying (June-Sept.). 

Incremental floodup; 4-12 inches during initial floodup 

(Oct.-Nov.); winter depth 4-18 inches over 75% of wetland; 

drawdown by June 15
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-44 Chapter 4. Refuge Biology and Habitat

Key Ecological 

Attributes Indicators Desired Conditions 

• Semi-permanent 

wetlands 

• Permanent wetlands 

(nontidal) 

• Permanent wetlands 

(tidal)

• Seasonal fluctuations in water levels; 24-30 inches by late 

Jan; summer depths several inches; no more than 60-80% of 

wetland bottoms dry by Oct. 1. 

• Maximum water depths 24-36 inches with potentially 

increased depths in winter due to precipitation; natural 

drying in summer may reduce depth and area of wetlands 

• Perennial water flows, wetlands connected to Columbia 

River irrigated by daily freshwater tides; hydroperiod and 

depth variable with river. 

Vegetation 

Diversity, 

Structure

• Wet meadows

• Seasonal wetlands

• Semi-permanent 

wetlands 

• Permanent wetlands 

(nontidal, tidal)

• All types

• Native grasses and forbs, e.g. Columbia sedge, tufted 

hairgrass, camas; less than 5% cover of native shrubs; less 

than 20% cover of invasive plants (other than mowed/grazed 

reed canarygrass); reed canarygrass if present is mowed 

(preseason) to shorter than 6 inches. 

• More than 60% cover of moist-soil annuals (e.g., smartweeds, wild millet, water plantain), wapato, and nutsedges; 

less than 20% cover of tall persistent emergent species (e.g., 

cattail, hardstem bulrush)

• 60%-80% cover of desirable and native wetland plants 

including moist-soil annuals and submergent plants (e.g., 

pondweeds); 20%-40% cover of tall persistent emergent 

species (e.g., cattail, hardstem bulrush, wapato, bur-reed)

• Open water and native submergent vegetation covering more 

than 70-75% of wetland basin during peak water elevations; 

less than 25% cover of native emergent vegetation

• Minimal woody vegetation (e.g. willow, spirea) 

• Avoid monocultures of tall persistent emergent vegetation 

and aggressive smartweeds (e.g. Polygonum amphibium)

Optimal patch 

size or 

contiguity 

with wetland/

riverine 

habitat

• Maintain mosaic of wetland, wet meadow and non-managed field in greater than 

400-acre blocks. 

• Wet meadow patch size ranges from 2 to 45 acres with a minimum predatordetection width of 250 feet. 

• Barrier-free fish passage between permanent tidal wetlands and Columbia 

River/main sloughs

Invertebrate 

diversity

• Macroinvertebrate abundance and diversity preferably high; invertebrate diversity 

will partially be determined by hydroperiod. 

Invasive 

plants and 

animals 

• Limit or exclude habitat-altering species, e.g. carp, nutria. Carp in permanent 

wetlands less than 200 lbs/acre.

• Less than 40% cover of invasive plants (e.g., reed canarygrass, ricefield bulrush) in 

wet meadows and seasonal wetlands. 

• Less than 20% cover of undesirable/invasive plants (e.g., reed canarygrass, ricefield 

bulrush) in semipermanent wetlands. 

• Less than 10% cover of invasive plants (e.g., reed canarygrass, milfoil) in permanent 

wetlands. 

• No purple loosestrife and false indigo present. 

• Limit or exclude exotic vegetation (e.g. reed canarygrass, yellow flag iris) that form 

persistent monocultures.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-45

Key Ecological 

Attributes Indicators Desired Conditions 

Water quality • Water temperature

(permanent tidal 

wetlands)

• Turbidity

(permanent tidal 

wetlands)

• Toxics (all 

wetlands)

• 7-DAD Max temperature ≤22°C (71.6°F) and the 1-day 

maximum (1-DMax) temperature of 23°C (73.4°F) or less to 

protect juvenile salmonids from acute lethality*. 

• Maximum turbidity less than 70 NTU (Threshold for 

avoidance by juvenile coho salmon). 

• Toxic substances below levels that would cause acute or 

chronic toxicity to the most sensitive biota

Source: Planning Team, Frederickson1991, Fredrickson and Drobney 1979, Fredrickson and Reed 1988, Kilbride and Paveglio 

1999, Christy 2004, Altman 2000, Wilson 1998, Washington Dept. of Ecology 2006

**WDOE Criterion in water bodies designated for salmonid spawning, rearing and migration unless otherwise specified 

Table 4.6b Ecological Attributes, Indicators, and Condition Parameters for Ephemeral 

Ponds (Howellia ponds) 

Key Ecological 

Attributes Indicators Desired Conditions 

Hydrologic 

Regime

• Small (<1 acre) perched wetlands (pothole ponds) 

• Ephemeral ponds filled by rain; Water depths range from saturated soils to 20 

inches in winter (November-June); dry in late summer/early fall

• Depth generally <36” in spring, but occasionally up to 6 ft (2 m) deep 

Plant 

Community 

Structure and 

Composition 

• Cover: water 

ratio

• Canopy cover 

• Open water without dense emergent vegetation (e.g. cattail)

• 80% open water with Howellia and other native submergent 

plants, e.g. pondweeds; less than 20% cover of emergent 

wetland plants, e.g. cattail, aquatic grasses, sedges, and 

burreeds; minimal woody species (e.g., spirea) within ponds 

• Greater than 30% canopy cover, predominately Oregon ash 

with well-developed shrub component (e.g. red-osier 

dogwood, Douglas’ spirea); maintain forested buffers of 300 

feet around ponds

Disturbance 

Events

• Fire

• Grazing

• Logging, Brush 

Clearing

• Fire early in the growing season may offset organic mat 

build-up in ponds, benefiting the population. 

• No grazing 

• Minimize logging and vegetation disturbing activities within 

300 feet of ponds

Invasive 

species

No noxious weeds, e.g. purple loosestrife, reed canarygrass

Habitat 

connectivity 

• Maintain clusters of closely adjacent ponds in a variety of successional stages

• Create and maintain corridors between ponds for animal movement to facilitate 

seed dispersal between ponds 

Source: Planning Team, Shelly and Moseley 1988, Roe and Shelly 1992, Lesica 1992, USFWS 1994, 1996, Washington Natural 

Heritage Program 1999, Center for Plant Conservation 2009 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-46 Chapter 4. Refuge Biology and Habitat

4.5.5 Threats 

Because of the numerous dams along the length of the Columbia River, and the construction of 

levees to protect private landowners along the lower Columbia River, the natural fluvial processes of 

a free-flowing riverine system have been eliminated. Diking and filling, in conjunction with 

agricultural development, have been a primary cause of decreases in tidal wetland area in the 

Columbia River estuary. These actions eliminated most of the natural, tidal exchange of water, 

materials, and organisms between the Columbia River and the adjacent floodplain forests and 

shallow overflow lakes; however, limited exchange occurs through tide gates. An estimated 90 

percent of tidally influenced freshwater wetlands in the lower Columbia River region have been lost 

(Floberg et al. 2004). Exchange is important not only for the access and use of these habitats by fish, 

but also for maintenance of habitat-forming processes such as sedimentation and erosion. Even 

where tidal connections persist, water levels in refuge wetlands are lower than they were historically 

due to lower river levels and altered flooding regimes. 

Altered plant and animal community composition was identified as a very high stress to refuge 

wetland systems. Invasive plants limit native plant production and cause impacts to food, nesting, 

and cover for wildlife. Invasive plants in wetlands reduce waterfowl food availability during the 

migration and wintering periods. Reed canarygrass, in particular, out-competes native wetland 

vegetation in seasonally flooded areas, often forming dense monotypic stands (see page 15). Lack of 

staffing and funding to contain the expansion of invasive species and reduce infested acreage has 

been an ongoing issue with all wetland habitats on the refuge. 

Carp, which are widespread in permanent wetlands on the refuge, are a high threat to the ecological 

functions of the wetland system, due to their impacts on submergent vegetation and water quality. 

Carp uproot and eliminate submerged vegetation, increase turbidity, and decrease the overall 

abundance and diversity of the invertebrate community (Miller 2006). Some invasive mollusks (e.g 

Asian clam) have been present in the Columbia River basin for decades and have probably decreased 

the abundance or species richness of native mollusks. Other species, such as zebra and quagga 

mussels, have not been reported to date but represent a serious potential threat in the Columbia River 

basin. 

4.6 Riparian and Floodplain Forests

4.6.1 Description and Location

Riparian and floodplain forest habitats occupy the edges of some wetlands and sloughs, the Columbia 

River shoreline of the refuge, and most of the Roth Unit. These habitats total approximately 1,060 

acres of the refuge. Oregon ash (Fraxinus latifolia), black cottonwood (Populus trichocarpa), 

Pacific willow (Salix lasiandra ssp. lucida), other willows (Salix spp.), red-osier dogwood, red alder, 

Nootka rose, cascara, western red cedar, snowberry, rose (Douglas’) spirea, and red elderberry are 

the primary tree and shrub species. The three major types include early successional floodplain 

forest dominated by Pacific willow and other willow species (willow flycatcher was selected as the 

ROC for this habitat); mid to late successional floodplain forest dominated by Oregon ash and black 

cottonwood (Swainson’s thrush was selected as the ROC); and Oregon ash floodplain forest 

(Bewick’s wren was selected as the ROC). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-47

The CCP team identified several blocks of riparian and floodplain forest habitat on the refuge that 

merit high consideration for conservation and restoration during the life of the CCP. Criteria for 

consideration included adjacency to other blocks of riparian habitat; being able to establish 

contiguous riparian corridors; contribution to stream conditions that enhance salmonid habitat; 

structural condition; size or width; and/or degree of exotic invasion. 

4.6.2 Condition and Trends

Woody riparian habitats, interspersed with sloughs, overflow lakes, sedge meadows, and wet prairie 

originally covered a large portion of the lower Columbia River floodplain. Prior to 1900, riparian 

and floodplain habitats occupied a large percentage of bottomlands in the Portland-Vancouver Basin 

and Willamette Valley (Christy 2004). Clearing, diking and draining for agricultural development 

are primarily responsible for the decline (Altman and Holmes 2000). Likewise, riparian and 

floodplain forests occupy a smaller portion of the refuge than they formerly did, due to agricultural

development prior to refuge establishment. 

The condition of the remaining riparian habitat and floodplain forest on the refuge has deteriorated 

compared to historic conditions. Most stands on the refuge are second growth following clearing, 

although some Oregon ash trees are unquestionably older. Historically, Columbia sedge (Carex 

aperta) and stinging nettle (Urtica dioica) were dominant understory species in Oregon ash 

floodplain forests; these have been almost entirely replaced by reed canarygrass (Christy and Putera 

1993). Stands of Oregon ash and black cottonwood suffer from poor recruitment due to the 

diminishing of flood events caused by dam operations, and therefore, the dynamic changes that occur 

in natural fluvial systems are being reduced. As a result, ash and cottonwood are represented mainly 

by dense, even-aged stands. Cottonwood recruitment requires new mineral soil deposited by 

flooding events (Braatne and Jamieson 2001), but can be stimulated by other means. For example, 

cottonwoods and willows recruited naturally in Wetland 008 on Bachelor Island (28 acres), following 

soil disturbance (disking associated with a wetland restoration project in 1999). 

Early successional floodplain forest has also regenerated in the area west of Wigeon Lake South 

(“Wigeon Scrub” approximately 20 acres). North Rookery Field (33 acres) was a thick 

cottonwood/ash/ willow forest in the 1960s but was cleared prior to acquisition by the Service. By 

2004 the extreme western portion had reverted to forest. Smaller areas of regeneration on Bachelor 

Island have occurred in Shop Pond, the south and east side of Wetland 11, and the northwest edge of 

Wetland 12. Natural regeneration and high survivorship of willow was noted in the Sand Pit Ponds 

(14.4 acres) on the Ridgeport Dairy Unit in 2004. Intensive wetland and pasture management on the 

River ‘S’ Unit has largely precluded riparian from establishing, however, the nonmanaged River ‘S’ 

Point wetland (16 acres) has been undergoing succession to forest. Willows regenerated naturally in 

Long Lake after a 2000 drawdown. A small willow stand has established in North Quigley Lake, and 

ash trees established naturally in the southwest section of West Hall Pasture, near the Millet Marsh 

levee, in 2003-2004. 

The refuge has also undertaken a number of riparian and floodplain forest restoration projects since 

1995. The purposes of these projects have included bank stabilization along Bachelor Slough and 

Wapato Portage; expanding riparian corridors along Gee Creek, Lake River, and the Columbia River; 

expanding nesting habitat for great blue herons and bald eagles; and buffering public use areas. 

Successful plantings include Wetland 14 and Great Horned Owl Field on Bachelor Island; North 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-48 Chapter 4. Refuge Biology and Habitat

River Pasture, Borrow Field, Sora Marsh East and Teal Marsh on the River ‘S’ Unit; and Gee Creek 

on the Carty Unit. The largest tract of Oregon ash floodplain forest is in the Roth Unit, it is 

approximately 300 acres. The Oregon ash on the refuge are second growth and not especially old, 

but if current trends continue, it is likely that older mature trees will not be replaced by new growth. 

At higher elevations there is a well developed understory of native shrubs, e.g. snowberry, Nootka 

rose, and oceanspray, with some nonnative blackberry invading the margins (USFWS 2004). 

However, due to past grazing practices, the understory of lower areas is dominated by reed 

canarygrass (Phalaris arundinacea), which has almost completely replaced native understory 

vegetation.

4.6.3 Associated Wildlife

Birds. The refuge’s riparian and floodplain forests host large numbers of breeding landbirds. 

Common breeding species in these habitats include downy woodpecker, northern flicker, western 

wood-pewee, Pacific slope flycatcher, tree swallow, common bushtit, Bewick’s wren, American 

robin, Swainson’s thrush, cedar waxwing, common yellowthroat, Wilson’s warbler, spotted towhee, 

song sparrow, and black-headed grosbeak. The nest-parasitic brown-headed cowbird commonly

occurs in riparian habitats during spring and summer. As many as 50 bald eagles have been sighted 

using riparian trees on or near the refuge for roosts from December through March, and up to 6 pairs 

nest on or near the refuge. Until 2009, cottonwood forest on Bachelor Island supported one of the 

largest nesting colonies of great blue heron on the Columbia River. 

Riparian areas are disproportionately important to bird species (Johnson and O’Neil 2001). Fortynine native species are considered to be highly associated breeding species in riparian forest and 

shrub habitats in the Conservation Strategy for Landbirds in Lowlands and Valleys of Western 

Oregon and Washington (Altman and Holmes 2000). The following 11 species are considered by 

Altman to be focal species (those species highly associated with important attributes within each 

habitat and used to represent highly functioning ecosystems) for riparian woodland and shrub habitat 

in western Oregon and Washington (Table 4.2). Nine of the 11 species occur on the refuge and five 

are confirmed breeders. 

Table 4.7 Focal Species for Riparian Woodland and Shrub Habitat in Western Oregon 

and Washington (adapted from Altman and Holmes 2000)

Habitat Type Habitat Attribute Species Status on Refuge

Riparian 

Shrub 

dense shrub layer Willow flycatcher (D)* B, S, F

dense shrub layer Yellow-breasted chat S

Riparian 

Woodland 

large canopy trees Red-eyed vireo B, S, F

large canopy trees Bullock’s oriole (D) S, F

subcanopy, tall shrub foliage Yellow warbler B, S

dense shrub understory Swainson’s thrush** (D) B, S, F

dense shrub understory Wrentit (D) Not confirmed

snags Downy woodpecker B, R

Large, structurally diverse patches Yellow-billed cuckoo Historically present in 

area; not confirmed

Large, structurally diverse patches Red-shouldered hawk S, F, W

Large, structurally diverse patches Cooper’s hawk R

*Selected as Priority ROC for early successional floodplain forest. **Selected as Priority ROC for mid-late successional 

floodplain forest. D=Significantly declining population trend in the Southern Pacific Rainforest BBS Physiographic Region.

Refuge Status: B= Confirmed breeder on Refuge; S,F=Spring/fall migrant; W= winter; R=resident
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-49

A Monitoring Avian Productivity and Survivorship (MAPS) station operated on Bachelor Point 

between 1993 and 2003 (also see section 4.10, Research). This station sampled birds in floodplain 

forest habitat (cottonwood/ash forest), and was a relatively productive station with capture rates and 

number of species captured well above the average for stations in the region (DeSante et al. 2004). 

A diverse suite of landbirds was captured at this site, included habitat generalists, species associated 

with early-successional or disturbed sites, and species highly associated with lowland riparian 

habitat, such as Swainson’s thrush, Bullock’s oriole, and willow flycatcher. These three species are 

considered to be focal species for riparian woodland and shrub habitat in western Oregon and 

Washington (Altman 2000). The data suggest that although riparian and floodplain forest on the 

refuge is degraded compared to historic conditions, it nevertheless retains significant value as habitat 

for riparian obligate species. 

Table 4.8 Mean annual capture rates of target landbird species at Bachelor Point MAPS 

Station, 1993-2003. 

Species Mean Annual Capture Rate

(1993-2003)

Population Trend

(Southern Pacific Rainforest BBS 

Region) 

− = Declining, + = Increasing

Significance Level in ( )

Willow Flycatcher 8.00 − (0.01<P≤0.05)

“Western” Flycatcher 4.11 − (0.05<P≤0.10)

Bewick's Wren 9.00 − (P>0.10)

House Wren 13.33 − (P>0.10)

Swainson's Thrush 31.22 − (P>0.10)

American Robin 16.22 − (P>0.10)

Common Yellowthroat 9.56 +

Wilson's Warbler 7.89 − (P≤0.01)

Spotted Towhee 4.67 +

Song Sparrow 47.89 − (P>0.10)

Black-headed Grosbeak 8.22 +

Brown-headed Cowbird 4.67 − (P>0.10)

Bullock's Oriole 6.56 − (P≤0.01)

House Finch 6.33

American Goldfinch 21.00 − (P>0.10)

Total Number of species: 15

Number of target species: 14

Total capture rate 198.67. Capture 

rate of target species: 192.34

Species shown in bold are focal species in PIF Bird Conservation Plans in one or more states. Data from DeSante et al. 2004.

Mammals. The most common large mammal occurring on the refuge is the mule deer. Riparian 

areas provide both forage and cover for this species and other mammals. Historically, Columbian 

white-tailed deer occurred on the refuge. Carnivores such as coyote (Canis latrans), raccoon 

(Procyon lotor), and striped skunk (Mephitis mephitis) are frequently seen on the refuge. An 

occasional cougar (Felis concolor) may visit the refuge. 

Reptiles and Amphibians. Red-legged frogs (Rana aurora) use mid to late successional riparian 

and floodplain forest habitat, especially cottonwood with a relatively sparse, low understory 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-50 Chapter 4. Refuge Biology and Habitat

structure, within 1-2 km of suitable breeding habitat. Many red-legged frogs were noted near the 

Bachelor Point MAPS station when it was in operation. 

4.6.4 Key Ecological Attributes

Table 4.9 Early Successional Floodplain Forest Ecological Attributes, Indicators, and 

Condition Parameters

Key 

Ecological 

Attributes

Indicators Desired Conditions 

Vegetation 

structure 

and cover 

• Mean canopy closure 

• Canopy tree heights 

• Shrub layer cover (woody veg 

3-12 feet tall)

• Openings 

• Age classes

• Less than 20% 

• Taller than 12 feet 

• 30%-80% 

• Scattered openings with herbaceous vegetation

• Persistent early successional shrub

Native plant 

composition 

• Trees

 

• Shrubs 

• Herbaceous vegetation

• Primarily Pacific willow; also red-osier 

dogwood, young cottonwood. 

• Red-osier dogwood, willow, snowberry, 

Douglas’ spirea, serviceberry, red elderberry, 

Indian-plum, cascara, rose. 

• Columbia sedge, green-sheathed sedge, wooly 

sedge, retrose sedge, stinging nettle.

Invasive 

species

Less than 30% cover of invasive plants (e.g. reed canarygrass, false indigo, and 

blackberry in understory/herbaceous layer)

Hydrologic 

Regime

• Fluvial processes, timing

• Water table height

• River and floodplain functions and processes

intact or maintained artificially with structures; 

timing follows natural flooding hydrograph 

(historically, overbank flooding in spring with 

floodwaters persisting through summer) 

• Scouring and deposition of silts by floods; 

deposition occurs in patterns mimicking natural; 

no perched floodplain.

• Water table available to trees and shrubs for most 

of the year

Disturbance 

Events

• Flooding 

• Public use 

• Grazing

• Management activities

• Historically floods were major disturbance event’ 

major floods every 10+ years 

• Restricted in breeding season (April 15-July 31) 

• None 

• Conduct habitat restoration, exotics control/eradication outside nesting season (April 15-July 31)

Patch Size/

Connectivity

• Patch size or contiguity with 

other riparian/floodplain forest

• Riparian width 

• Distance from 

urban/residential areas 

• Larger than 50 acres

• Greater than 100 feet 

• Greater than 0.6 miles from urban/residential 

areas and greater than 3 miles from high-use 

cowbird areas 

Source: Altman and Holmes 2000 (Biological Objectives for Willow Flycatcher, pg 87; General Conservation Strategies for 

Riparian Habitat, pp 82-83 ), Altman 1999, Chappell et Al. 2001, Guard 1995.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-51

Table 4.10 Mid-late Successional Floodplain Forest Ecological Attributes, Indicators, and 

Condition Parameters. 

Key Ecological 

Attributes Indicators Desired Conditions 

Vegetation 

structure and 

cover 

• Mean canopy closure 

• Dominant tree heights

• Understory (shrub layer) 

cover

• Snags and woody debris

• Age classes

• Vertical structural complexity

• Greater than 50% (Swainson’s thrush)

• Mean canopy tree height of 50 feet (Bullock’s 

oriole)

• Greater than 50%

• More than 1.2 snags/ha (3/ac) greater than 30 cm 

(12 in) dbh and >6 m (20 ft) high (above water) 

(Purple martin)

• Mature forest or a mix of early successional and 

older forest

• Distinct canopy, subcanopy, understory layers, 

with a well developed understory shrub layer 

comprised primarily of native species

Native plant 

composition

• Canopy tree species

• Subcanopy trees

• Native shrub understory

• Black cottonwood, Pacific willow, Oregon ash

• Black hawthorn, vine maple, big leaf maple, 

willow, ninebark, hazelnut, and young canopy 

trees.

• More than 75% native species in shrub layer, 

including red-osier dogwood, snowberry, 

Douglas’ spirea, serviceberry, red elderberry, 

Indian-plum, cascara, Nootka rose, willow, red 

alder, and saplings of native canopy trees. 

Invasive 

Species

Less than 30% cover of invasive plants (e.g. reed canarygrass, blackberry) in 

understory/herbaceous layer

Hydrologic 

Regime

• Fluvial processes, timing

• Water table height

• As in Early Successional Riparian

Disturbance 

Events

• Flooding

• Public use

• Grazing

• Management activities

• Historically floods were major disturbance event; 

major floods every 10+ years create areas of bare 

mineral soil needed for cottonwood recruitment 

• Low impact recreational activities that are not 

likely to adversely affect wildlife; prohibit public 

use in key areas (e.g. heron rookeries) during 

breeding season

• None

• Conduct habitat restoration, exotics control/

eradication outside the nesting season (i.e., April 

15 - July 31)

Patch Size/

Connectivity

• Patch size or contiguity with 

other riparian/floodplain

forest

• Riparian width

• Greater than 100 acres, or greater than 0.5 miles 

in length (yellow-billed cuckoo)

• Width of riparian woodland and shrub vegetation 

zone greater than 330 feet (yellow-billed cuckoo)

Source: Altman and Holmes 2000 (Biological Objectives for Swainson’s thrush, pg 94; yellow-billed cuckoo, page 98; Bullock’s 

oriole, page 90; purple martin, page 85 ); Chappell et al. 2001, Guard 1995.
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4-52 Chapter 4. Refuge Biology and Habitat

Table 4.11 Oregon Ash Floodplain Forest Ecological Attributes, Indicators, and Condition 

Parameters. 

Key Ecological 

Attributes Indicators Desired Conditions 

Vegetation 

structure and 

cover 

• Mean canopy closure 

• Dominant tree heights

• Understory (shrub layer) 

cover

• Snags and woody debris 

• Age classes

• Vertical structure complexity

• >50% 

• >12 ft. overstory, large Oregon ash >12” DBH 

• <20% 

• Snags or old ash trees with cavities in or 

adjacent to open water (wood duck, tree 

swallow, purple martin); >5 snags/ac >6 in dbh 

and >6 ft tall; of these >2/ac should be >10 in 

dbh (downy woodpecker) 

• Mix of mature and young Oregon ash 

• Overstory of Oregon ash with sparse shrub 

layer

Native plant 

composition 

• Canopy tree species

• Native species in understory

(shrub layer) 

• Herbaceous vegetation

• Oregon ash is dominant species

• Native floodplain species such as Douglas’ 

spirea, red-osier dogwood, snowberry, Nootka 

rose, and young (recruitment) sapling ash 

• >50% native species (e.g. stinging nettle, 

Columbia sedge, green-sheathed sedge, wooly 

sedge, retrorse sedge)

Invasive 

species

<30% cover of invasive plants (e.g. reed canarygrass, false indigo, and blackberry in 

understory/herbaceous layer)

Hydrologic 

Regime

• Fluvial processes, timing

• Water table height

• As in Early Successional Riparian

Disturbance 

Events

• Flooding

• Public use 

• Grazing

• Management activities 

• Historically floods were major disturbance 

event; major floods every 10+ years 

• Low impact recreational activities that are not 

likely to adversely affect wildlife

• None 

• Conduct habitat restoration, exotics control/

eradication outside the nesting season (April 

15-July 31)

Patch Size/

Connectivity

• Patch size or contiguity with 

other riparian/floodplain forest

• Riparian width

• >50 acres

• >100 feet 

Source: Altman and Holmes 2000 (Biological Objectives for downy woodpecker, pg 96; purple martin, page 85; General 

Conservation Strategies for Riparian Habitat, pp 82-83), Altman 1999, Chappell et al. 2001, Christy 2004, Guard 1995.

4.6.5 Threats 

The primary threats to riparian and floodplain forests are a nonfunctioning floodplain, combined with 

intensive development of the floodplain. Historically, flooding was the primary natural disturbance 

regime in lower Columbia River bottomlands. Overbank flooding occurred annually in spring, and 

major spring floods occurred at longer intervals. Floodwaters scoured some areas, creating bare soil 

suitable for recruitment of black cottonwood, and deposited sediment in other areas. This dynamic 

system created a patchy mosaic of late and early-successional shrub and forest habitat. Hydropower 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-53

operations have changed the hydrograph of the Columbia River so that major spring floods no longer 

occur, and dikes and levees have nearly eliminated overbank flows. Other threats include grazing, 

invasive species that compete with native plants and bind soil, habitat fragmentation, and proximity 

to sources of predators and nest competitors. The following threats to riparian and floodplain forest 

are summarized from Altman and Holmes (2000): 

• Direct habitat loss due to clearing for farmland and urban development; 

• Habitat alteration from (1) hydrological diversions and control of natural flooding regimes 

(e.g., dams) resulting in reduction of overall area of riparian habitat, loss of vertical 

stratification in riparian vegetation, and lack of recruitment of young cottonwoods, ash, 

willows, etc.; and (2) stream bank stabilization (e.g., riprap) which narrows stream channel, 

reduces the flood zone, and reduces extent of riparian vegetation habitat;

• Invasive exotic plants such as reed canary grass and blackberry, which compete with or 

completely exclude native understory plants and reduce recruitment of canopy tree saplings; 

• Habitat degradation from overgrazing which can widen channels, raise water temperatures, 

reduce understory cover, and lead to exotic species replacing native understory vegetation; 

• Fragmentation and loss of large tracts necessary for area-sensitive species such as yellowbilled cuckoo; 

• Reductions in riparian corridor width which decreases habitat suitability for some species and 

may increase encroachment of nest predators and nest parasites to the interior of the stand; 

• Proximity to agricultural and residential areas, may have high density of nest parasites 

(brown-headed cowbird), exotic nest competitors (European starling), and domestic predators 

(cats), and be subject to high levels of human disturbance; 

• Recreational disturbances, particularly during nesting season of sensitive species such as 

great blue herons; and 

• Increased use of pesticides and herbicides associated with agricultural practices, which may 

reduce insect food base for many landbirds. 

4.7 Oregon White Oak Woodlands, Upland Mixed Woodlands

4.7.1 Description and Location

Oak Woodland. Oak woodlands can be found on the Carty Unit, including the Blackwater Island 

RNA. Oak woodlands are found in areas above the floodplain, 20 foot elevation and above, on welldrained Olympic stony clay loam overlying basalt outcrops (Wiberg and Greene 1981). The refuge’s 

oak woodlands are classified as the Oregon white oak/ovalleaf viburnum/poison oak plant 

association (Chappell 2006). This habitat occupies approximately 70 acres of the refuge. 

The Carty Unit’s varied topography and soils creates a mosaic of plant communities and habitat 

types. Gee Creek winds its way through the Carty Unit in a series of tidally influenced, shallow 

lakes. The lakes are surrounded by seasonally flooded willow lowlands, bordering Oregon white oak 

stands on basalt islands. There is a narrow belt of Oregon ash between the willow and white oak 

stands. The basalt islands also contain ephemeral ponds and small patches (approximately 10 acres 

total) of grassland. The grassland patches occur on thin, well drained soil, and are dominated by 

introduced species, for example, poverty brome (Bromus sterilis) and orchardgrass (Dactylis 

glomerata). Some ephemeral ponds are habitat for the water howellia (Howellia aquatilis), federally 

listed as threatened in 1994 (Wiberg and Greene 1981; and USFWS 1994). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-54 Chapter 4. Refuge Biology and Habitat

Two plant species listed as sensitive in Washington occur in Oregon white oak woodlands: the 

smallflower wakerobin (Trillium parviflorum) and tall bugbane (Cimicifuga elata). T. parviflorum

has been found on the refuge, but tall bugbane has not. The slender-billed white-breasted nuthatch

(Sitta carolinensis aculeata), a candidate for listing in Washington, occurs in this habitat. Wiberg 

and Greene (1981) also listed the western gray squirrel (Sciurus griseus) as likely to occur here, but 

its presence has not been confirmed. 

Upland Mixed Forest. A small tract (approximately 15 acres) of upland mixed forest occurs on the 

refuge’s Carty Unit. The forest type corresponds to the low elevation western hemlock forest of 

Franklin and Dyrness (1988). However, western hemlock typically does not become dominant or 

codominant until late successional stages; typical of early successional forest of this type, Douglas fir 

is the dominant conifer in this stand. Also typical of low elevation early to mid successional forest of 

this type, canopy trees are a mix of conifers (Douglas fir, western red cedar) and deciduous trees (e.g. 

bigleaf maple, red alder, and Oregon white oak, depending on site conditions). This forest has a well 

developed subcanopy of shrubs and smaller trees. 

4.7.2 Condition and Trends

In western Washington, Oregon white oak woodland is a plant community of major conservation 

concern. Oak woodlands have declined in extent and have been significantly degraded by land 

conversion, fire suppression and subsequent conifer invasion, grazing, and invasion of nonnative 

plant species. The Oregon white oak/ovalleaf viburnum plant association was classified as a Priority 

1 (endangered) ecosystem in the Washington Natural Heritage Plan (WDNR 2007). With the 

inclusion of the 115-acre Washougal Oaks Natural Area Preserve/Natural Resource Conservation 

Area in the Washington Natural Areas Program in 2008, this plant association was reclassified to 

Priority 2 (WDNR 2009). 

Until the early 1800s, anthropogenic fire of various frequencies was probably characteristic of this 

habitat. Fire reduced encroachment by conifers and other competing species. Fire also opened up 

the understory, enhancing establishment and survival of oak saplings. In areas with short fire 

intervals the oak canopy was more open and the understory was dominated by grasses, while areas 

with longer intervals had a denser canopy and shrub understory. Historically, this area probably had 

had a relatively long fire interval compared to oak woodlands in the Willamette Valley. Fire has 

been absent from the Carty Unit for many decades, and possibly well over 100 years. As a 

consequence, Douglas fir has become more prevalent in the overstory. 

The major disturbance to oak woodlands on the Carty Unit has been from livestock grazing. Grazing 

pressure was historically heavy but was reduced considerably after the refuge was established. 

Within the Carty Unit, lands within the Blackwater Island RNA received the least grazing pressure, 

but even this area was still accessible to cattle during periods of low water. Grazing was phased out 

on the Carty Unit starting in 1996, and has not occurred on the unit since 2001. Grazing resulted in 

changes to oak woodlands through decreased oak recruitment, reduction or loss of plant species not 

adapted to heavy grazing pressure, and the spread of exotic species, especially Himalayan 

blackberry, in the understory. Encroachment by blackberry is a major issue in upland mixed forest 

habitat as well. In some areas it dominates the shrub layer, excluding native shrubs and forbs. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-55

4.7.3 Associated Wildlife

The refuge’s oak woodlands are known to provide habitat for a suite of oak-associated landbird 

species that are now rare in western Washington, including the slender-billed white-breasted 

nuthatch, western scrub jay, and house wren. Other landbird species found in this habitat include 

Bewick’s wren, western wood-pewee, downy woodpecker, and common bushtit. Refuge oak 

woodland may provide habitat for western gray squirrel, although the presence of this species has not 

been confirmed. Oak woodland is also utilized by reptiles such as northern alligator lizard and 

western skink. It potentially could provide habitat for the sharp-tailed snake, although its presence 

has not been confirmed. The Carty Unit’s patchy mix of oak woodland, grassy openings, and ponds 

could provide suitable habitat for western pond turtles. Upland mixed forest provides habitat for 

landbirds associated with deciduous trees in multi-layered mature coniferous forests, such as orangecrowned warbler, Wilson’s warbler, MacGillivray’s warbler, Bewick’s wren, song sparrow, spotted 

towhee, and rufous hummingbird. 

4.7.4 Key Ecological Attributes

Table 4.12 Oregon White Oak Woodland Ecological Attributes, Indicators, and Condition 

Parameters

Key Ecological 

Attributes Indicators Desired Conditions 

Vegetation 

structure 

• Total canopy closure 

• Oak size

• Shrub layer cover

• Other

• 40-80%, primarily Oregon white oak

• Mean dbh larger than 21 inches with 20% of 

oaks larger than 28 inches; young subcanopy 

oaks present

• Greater than 40% 

• Large oaks with cavities

Native plant 

composition 

• Non-oak cover in canopy 

• Shrub understory species 

• Less than 10%; conifer cover less than 5% 

• Snowberry, poison oak, rose, Douglas’ spirea, 

oval-leafed viburnum 

Invasive 

species

Less than 20% cover of invasive plants (e.g., reed canarygrass, blackberry); less than 

10% blackberry cover in shrub layer

Animal species Presence of acorn dispersing animals (e.g., squirrels, scrub jays)

Patch Size Contiguous minimum stand size 100 acres

Disturbance 

Events

• Fire frequency and 

severity

• Public use 

• Herbivory/grazing

• Ground disturbance 

• Management activities

• Frequent (e.g. return interval approx. 5 years) 

low intensity fire; moderate or mosaic pattern 

• Low impact recreational activities that do not 

compromise oak regeneration and are not likely 

to adversely affect wildlife

• No grazing or low density grazing for limited 

periods (Larsen and Morgan 1998)

• None; leaf litter supports acorn germination 

• No thinning/brush removal during nesting season

Source: Altman and Holmes 2000, pp 61-63, 65-68* (Biological Objectives for White-breasted Nuthatch), Chappell et al. 2001, 

Larsen and Morgan 1998, Planning Team
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-56 Chapter 4. Refuge Biology and Habitat

Table 4.13 Upland Mixed Forest Ecological Attributes, Indicators, and Condition 

Parameters. 

Key 

Ecological 

Attributes

Indicators Desired Conditions 

Vegetation 

structure 

• Canopy cover

• Subcanopy cover 

• Ground cover (forbs, 

ferns)

• Snags

• Downed woody debris 

• Age classes

• Vertical structural 

complexity

• Greater than 50%

• Greater than 30% cover deciduous shrubs and 

small trees (smaller than 15 feet tall)

• Greater than 30% 

• For pileated woodpecker: Greater than 0.2 

snag/acre greater than 30 inches dbh, and 12 

foraging snags/acre greater than 10 inches dbh 

• 4 down logs per acre greater than 24 inches dbh for 

winter wren

• Mix of mature forest and openings/edges in earlier 

successional stages

• Multi-layered forests; well developed understory 

of shrubs and small trees

Native plant 

composition 

• Canopy tree species

• Subcanopy tree species 

(in addition to above) 

• Shrub species 

• Ground cover species 

(forbs and ferns)

• Mixed deciduous trees and conifers, e.g. Douglasfir, western red cedar, grand fir, Oregon white oak, 

Oregon ash and bigleaf maple. 

• Black hawthorn, vine maple, beaked hazelnut. 

• Native species including poison oak, snowberry, 

rose, spirea, oval-leafed viburnum, native Rubus

spp, ninebark, Indian-plum, tall Oregon grape, 

elderberry). 

• Major native component of flowering perennial 

herbaceous plants (e.g. Solomon’s seal, trillium, 

lilies, columbine, sanicle) 

Invasive 

species

• Less than 20% cover of invasive plants (e.g., reed canarygrass, blackberry) in 

understory layer

Patch Size • Patch size • More than 74 acres for varied thrush, winter wren, 

brown creeper; 1,500 acres within 60% of 

landscape as suitable habitat for pileated 

woodpecker

Disturbance 

Events

• Fire 

• Drought 

• Public use 

• Grazing

• Management activities

• Infrequent

• Not frequent or severe 

• Low impact recreational activities that are not 

likely to adversely affect wildlife

• None 

• No thinning/brush removal during nesting season 

Source: Altman 1999, Planning Team
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-57

4.7.5 Threats 

Oak Woodland. The two most significant threats to oak woodland communities are habitat loss 

from rural, residential, and urban development, and habitat loss and degradation due to fire 

suppression (Altman and Holmes 2000). Oak habitats were formerly maintained by fires of various 

frequencies which reduced encroachment by conifers and other competing species, and increased 

establishment and survival of oak saplings. Over the past 150 years, fire suppression has led to 

conifer encroachment, canopy closure, and reduced oak recruitment. Fire suppression has also 

promoted the spread of exotic shrubs (e.g. Himalayan blackberry) in the understory of oak woodland 

habitat, which results in decreased recruitment of young oaks. Overgrazing of oak seedlings by 

livestock also leads to reduced oak recruitment. Today, conifer and mixed deciduous/coniferous 

forests occupy large areas of former oak woodland habitat. These forests are often dominated by an 

overstory of Douglas fir, and an understory of exotics such as Himalayan blackberry. 

Much oak woodland habitat is in private ownership, and the current distribution of oak woodland is 

patchy and discontinuous, with variable-sized patches of different quality. Oak woodland in close 

proximity to agricultural and residential areas may have a high density of nest parasites (brownheaded cowbird), exotic nest competitors (European starling), and domestic predators (cats), and be 

subject to high levels of human disturbance. Competition with European starlings for nest cavities 

may reduce reproductive success of species such as white-breasted nuthatch and western bluebird 

(Altman and Holmes 2000). Oak diseases such as anthracnose disease (Gnomonia quericina), which 

has caused significant damage to white oaks in Washington, are a potential concern (Campbell 

2004). Reed canarygrass encroachment and canopy closure are the major threats to ephemeral ponds 

that support the federally threatened water howellia. 

Free roam hiking is a potential source of soil and vegetation disturbance, reducing recruitment of oak 

seedlings, and spreading introduced plants. Free roam hiking is allowed on the Carty Unit, but 

current use appears to be low (public use on the Carty Unit accounts for only 15 percent of total 

refuge use). An increase in this use is expected if facility improvements and linkages to local trail 

systems are made; therefore, impacts to habitat will need to be monitored, and if the use is causing 

undesirable impacts to habitat, refuge management adjustments will be made. 

Mixed Coniferous-Deciduous Forest. Much low-elevation coniferous forest in western 

Washington has been lost or greatly altered due to growth and expansion of urban, residential, and 

agricultural areas. Forest practices that truncated succession at rotation age (40-70 years) have 

resulted in a landscape dominated by early and mid-successional forests, with limited amounts of 

late-successional forests (Bunnell et al. 1997). Deciduous vegetation increases structural 

heterogeneity and vegetative diversity of early successional habitats (Morrison and Meslow 1983), 

which in turn increases overall biodiversity. A number of landbird species use the deciduous 

component of mixed coniferous-deciduous stands for foraging or nesting (Altman 1999). In 

managed forests, deciduous vegetation has been traditionally managed against, and as a result, some 

bird species highly associated with deciduous vegetation in early-successional habitats, such as 

orange-crowned warbler, rufous hummingbird, and MacGillivray’s warbler, have significantly 

declining populations in western Oregon and Washington. Currently, invasive plants are the most 

significant threat to upland mixed forest habitat on the refuge. Plants such as English ivy and 

Himalayan blackberry compete with native understory plants and forbs for light and space and may 

completely exclude them if left unchecked.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-58 Chapter 4. Refuge Biology and Habitat

4.8 Instream Habitat 

4.8.1 Description and Location

Gee Creek is a low-elevation, 4th order tributary of the Columbia River and occupies a watershed 

basin of approximately 12,000 acres, and empties into the Columbia River approximately a quarter 

mile upstream from the mouth of the Lewis River in Clark County, Washington. The drainage 

consists of a mainstem of approximately 11.5 miles in length, which branches into headwater 

tributaries, and a small mid-reach tributary locally named Tee Creek. The headwaters of Gee Creek 

are located in the southernmost portion of the watershed, just west of the Interstate 5 freeway (I-5). 

The creek crosses under I-5 several times before heading west-northwest toward the City of 

Ridgefield and the Columbia River (Clark County 2008). Gee Creek enters the Columbia River 

floodplain on the refuge’s Carty Unit. The lower 3.75 miles of Gee Creek winds its way through the 

refuge in a series of lakes and ponds before emptying into the Columbia River. The lower reach of 

Gee Creek is tidally influenced. The creek joins the Columbia River between the mouth of Lake 

River and the mouth of the Lewis River, at approximately river mile 87. 

Campbell Slough, which connects Campbell Lake to the Columbia River, was originally a backwater 

slough of the Columbia River. The slough is approximately 2.6 miles long and lies entirely within 

the refuge. Campbell Slough retains its connection to the Columbia River and is considered a 

permanent tidal riverine system.

4.8.2 Condition and Trends

Gee Creek’s overall health is ranked as poor (Clark County 2004), reflecting 170 years of 

concentrated land use in the watershed that have reduced the quality and complexity of instream 

habitat. The primary land-use activities responsible for habitat degradation include forest clearing, 

agriculture, road building, and development. Much of the level and mildly sloping areas in the Gee 

Creek watershed were probably cleared for agriculture in the late 1800s and early 1900s. Forest 

cover in the lower (refuge), middle, and upper Gee Creek subwatersheds are 38 percent, 29 percent, 

and 18 percent respectively, all well below the threshold of 50 percent for a nonfunctioning 

watershed (Clark County 2008). Forest cover in the watershed is generally limited to narrow bands 

along streams. Since the 1950s the watershed has become increasingly developed, from mostly 

agricultural lands to a mix of agriculture, residential development, and industry. Portions of Gee 

Creek were straightened and culverts installed as part of various road projects (see Chapter 3). 

Collectively, these activities have increased water temperatures and turbidity, reduced woody debris, 

and changed run-off patterns (flashier flows in winter and reduced stream flow in summer). 

Flooding has probably increased in severity compared to historic conditions, as forest cover was 

reduced and impervious surface area in the basin increased (Clark County 2008). 

Data from two monitoring stations at Abrams Park in Ridgefield, approximately one stream mile 

upstream of the refuge, indicate that Gee Creek has significant water quality issues related to 

temperature, dissolved oxygen, turbidity, and fecal coliform bacteria (see Chapter 3, Water Quality). 

The biological integrity of the benthic macroinvertebrate community measured at Abrams Park was 

on the low end of the moderate range (Clark County 2008); invertebrate assessments have not been 

conducted for the refuge portion of Gee Creek. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-59

Gee Creek currently gets very limited use by anadromous fish and has been given a low regional 

recovery priority. The presence of nonnative warmwater fish is a significant issue in both Gee Creek 

and Campbell Slough (see section 4.1.5). Poor water quality in Gee Creek, including high turbidity 

and summer water temperatures, gives these fish a competitive advantage over native species. 

Cutthroat trout surveys in reaches of Gee Creek above the refuge (2002-2005) yielded low cutthroat 

numbers and high populations of warmwater fish, an unusual situation compared to other streams 

studied (Cornelius 2006). A report by the Bureau of Reclamation also identified a sediment barrier at 

the mouth of Gee Creek and channel disconnection/aggradation as significant issues (BOR 2004). 

Restoration Efforts. In the spring of 2006, the Service and Washington State University’s Clark 

County Extension initiated the Gee Creek Watershed Restoration Project to improve instream and 

riparian habitat throughout the Gee Creek watershed. Cooperators in the project included the Lower 

Columbia River Estuary Partnership, the Friends of Ridgefield National Wildlife Refuge, the City of 

Ridgefield, area schools, and local residents (WSU 2009). Funding for in-stream work on the refuge, 

other than site assessments and preliminary planning activities, has not been available. Most of the 

restoration work currently consists of invasive species control (primarily Japanese knotweed, 

Himalayan blackberry, and fragrant water lily) and streamside and floodplain plantings to increase 

forest cover and reduce stream temperature and bank erosion. 

4.8.3 Associated Wildlife

Anecdotal evidence indicates that coho and chum salmon historically spawned in the upper reach of 

Gee Creek, but the last reported spawning was in the 1940s (Cornelius 2006). Although Gee Creek 

is heavily impacted by agricultural and urban development, it does provide some rearing habitat for 

juvenile salmonids, and year-round habitat for coastal cutthroat trout. A 1993 survey found juvenile 

Chinook salmon, and 1995-1997 surveys yielded juvenile Chinook, coho, and steelhead. A few 

juvenile coho salmon have been found in recent years (2002-2005) in the mid-lower reaches of the 

creek and juvenile Chinook salmon have recently been documented in the lower reaches during 

downstream migration (Cornelius 2006). 

Coastal cutthroat trout have been reported for decades in Gee Creek and continue to use it in low 

numbers. In a recent Service study, juvenile coastal cutthroat were trapped in three lower Columbia 

River tributaries (2002-2004), including a 5-mile (8-km) stretch of Gee Creek, and fitted with 

Passive Integrated Transponder (PIT) tags to monitor their movements (Johnson et al. 2008). The 

study found that coastal cutthroat were an order of magnitude less abundant in Gee Creek than the 

two other streams sampled (only 132 cutthroats were captured over three seasons, compared to more 

than 1,000 in each of the other streams). Other native fish documented in Gee Creek during surveys 

conducted in the 1990s included northern pikeminnow, threespine stickleback, Western brook 

lamprey, largescale sucker (Catostomus macrocheilus), and sculpins (Cottus spp.) (Cornelius 2006). 

Other native fish that have been found in Gee Creek include Pacific smelt (eulachon), redside shiner, 

peamouth, speckled dace, longnose dace, and warmouth. Gee Creek also provides foraging habitat 

for bald eagle, osprey, river otter, and mink. 

In general, during fish surveys of Campbell Slough conducted by NOAA/NMFS in 2007-2009, the 

most abundant species collected were carp, threespine stickleback, banded killifish, yellow perch, 

American shad, and juvenile Chinook salmon. Most of the juvenile salmon lacked fin clips, 

indicating a wild origin. Both juvenile Chinook and chum salmon were captured in 2008. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-60 Chapter 4. Refuge Biology and Habitat

Several species of native anadromous salmonids, including Chinook and coho salmon, use waters 

adjacent to the refuge (Columbia River, Lake River, and Bachelor Slough) during their migrations 

upstream to spawning areas and downstream to the Pacific Ocean. Other native fish that use waters

adjacent to the refuge include green and white sturgeon, Pacific lamprey, mountain whitefish, 

chiselmouth, longnose sucker, and bridgelip sucker. 

4.8.4 Key Ecological Attributes

Intact riparian forest and total forest cover within watersheds are the most critical factors contributing 

to the quality of instream habitat. Research in the Pacific Northwest has shown that when forest 

cover declines below approximately 65 percent, watershed forming processes become degraded 

(Booth and Jackson 1997). These include reduced riparian shade, less delivery of woody debris to 

streams, increased storm water runoff, and increased fine sediment delivery. Riparian forest prevents 

erosion, keeping sediment loads in streams low; provides shade, reducing water temperatures in 

summer; provides a food source for aquatic invertebrates; and is a source for large woody debris. 

Large woody debris plays an important role by creating deep, low-velocity pools, providing fish 

cover, and trapping spawning gravel. 

Table 4.14 Instream Ecological Attributes, Indicators, and Condition Parameters (Gee 

Creek, Campbell Slough) 

Key Ecological 

Attributes Desired Conditions 

Hydrologic Regime • Perennial water flows, tidal and periodic flooding. 

• Open, generally flowing water. 

Habitat connectivity • Connectivity between spawning areas, rearing areas, and ocean migration 

routes.

Habitat complexity 

(structure within the 

aquatic habitat) 

• Large quantities of large woody debris in stream channel throughout the 

watershed. 

• High channel sinuosity. 

• Off-channel areas and/or large pools (larger than 50 square yards and deeper 

than 6 feet) available as rearing and adult holding areas for salmonids 

(WDFW 2000).

Water 

depth/velocity

• Velocities should not scour redds.

• Egg deposition optimally is within a range of depths/velocities that 

minimizes risk of desiccation as water levels recede. 

• Multiple low velocity areas available as refugia for salmonid rearing during 

periods of high flow.

Water temperature • 17.5°C (63.5°F) or colder, 7-day average of daily maximum temperatures 

(7-DADMax) *

• 7-DADMax temperature 22°C (71.6°F) or colder and the 1-day maximum 

(1-DADMax) temperature 23°C (73.4°F) or colder to protect adult and 

juvenile salmonids from acute lethality*

Dissolved oxygen

(DO)

• 1 day minimum DO 8.0 mg/L* (6.5 mg/L for rearing and migration only)* 

Channel stability • Gravels with low concentrations of fine sediments and organic materials are 

important for salmon spawning and incubation.

Turbidity • Less than 5.5-7 NTU (Likely criterion for Gee Creek based on State 

standard for salmonid spawning, rearing and migration; Clark County 2008); 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-61

Key Ecological 

Attributes Desired Conditions 

Less than 10.5-12NTU for rearing and migration only.

• Maximum turbidity less than 70 NTU (Threshold for avoidance by juvenile 

coho salmon) 

• Fine sediments should not impact developing redds or negatively change the 

composition of invertebrates and other prey for salmonids. Sediment levels 

should not be high enough to cause salmon to delay or abandon spawning 

runs. 

pH • 6.5–8.5 units, with a human-caused variation within the above range of less 

than 0.5 units *

Toxics • Toxic substances below levels that would cause acute or chronic toxicity to 

the most sensitive biota.

Riparian vegetation 

cover 

• Intact mid-late successional riparian corridor. 

• Stream shading of 70% or more (moderately shaded).

Benthic 

macroinvertebrate 

diversity

• B-IBI (Benthic Macroinvertebrate Index of Biological Integrity) (Karr 1998) 

25 or more (moderate biological integrity). 

Nonnative fish and 

invertebrates

• Limit or exclude nonnative warmwater fish, including members of the 

sunfish family, bass, and crappie. 

• Limit or exclude habitat altering exotic fish and invertebrates, e.g. carp, 

zebra mussel.

Sources: EPA 1986, WDOE 2006, Clark County 2008, Bjornn and Reiser 1991, Karr 1998, WDFW 2000, Bisson and Bilby 1982

*WDOE Criterion in water bodies designated for salmonid spawning, rearing and migration unless otherwise specified

4.8.5 Threats 

The most significant threats to instream habitat are upstream activities (forest clearing, residential 

and commercial development, and farming) that reduce water quality. Threats to instream habitat 

identified in Clark County’s Steam Health Report (2004) include: 

• Flashier runoff due to forest clearing, impervious surfaces of roads and buildings; 

• High summer water temperatures and low dissolved oxygen, due to loss of riparian 

vegetation;

• High nitrogen and phosphorus levels, due to livestock, croplands, landscaped areas, broken 

sewer lines, and failing septic systems;

• E. coli and fecal coliform bacteria, due to livestock, broken sewer lines, and failing septic 

systems;

• Increased sediment in streams, due to land clearing, bare fields, construction projects, and 

channel erosion; and

• Toxic substances from urban areas and agricultural activities. 

Increases in fine sediment in streams in the watershed have decreased survival of cutthroat trout eggs 

and alevins, reduced stream productivity and ultimately food availability, and decreased size and 

depth of pools which are important rearing and adult holding areas for cutthroat trout (WDFW 2000). 

A major erosion event in 2004, caused by insufficient erosion controls at a subdivision construction 

project a mile upstream of Abrams Park in Ridgefield, caused lasting damage to Gee Creek (WDOE 

2008). A manure spill in 2001 caused a major fish kill in the creek (Cornelius 2006). Other threats 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-62 Chapter 4. Refuge Biology and Habitat

to instream habitat are barriers to upstream spawning and rearing habitats, reduced structural 

complexity of habitat (due to channel straightening and lack of large woody debris), and presence of 

nonnative fish (see above). 

4.9 Threatened, Endangered, and Sensitive Species

4.9.1 State or Federally Listed Species Known to Occur on the Refuge

One goal of the Refuge System is “To conserve, restore where appropriate, and enhance all species 

of fish, wildlife, and plants that are endangered or threatened with becoming endangered.” In the 

policy clarifying the mission of the Refuge System, it is stated “We protect and manage candidate 

and proposed species to enhance their status and help preclude the need for listing.” In accordance 

with this policy, the CCP planning team considered species with Federal or State status, and other 

special status species, in the planning process. Since the refuge occurs within the Willamette-Puget 

Trough ecoregion of Oregon and Washington, species listed in both states are included. Tables 4-15 

through 4-19 list special status species known to occur on or historically occupy the refuge. 

Discussion follows the tables in section 4.9.2. 

Table 4.15 Special Status Bird Species Known to Occur or Likely to Have Occurred on the 

Refuge Historically

Species Federal WA OR Current Occurrence on Refuge

Aleutian Canada 

goose 

BCC T (Rec. 

for State 

delisting)

Present fall-spring in very low numbers, in mixed 

flocks of geese. Observed on refuge in 1995, 2002-

2003, 2005

American white 

pelican

E Infrequently seen Jan.-July; wintering and migrant 

birds; nonbreeding subadults

Bald eagle T T 30-50 eagles winter on or near the refuge; 6 pairs 

nest on or near the refuge

Band-tailed 

pigeon

BCC Occasional year-round. 

Caspian tern BCC Infrequent observations

Common loon S Rare, Fall/winter/spring

Golden eagle C Rare

Lewis’s 

woodpecker

BCC C S-Critical Rare, fall/winter/spring.

Loggerhead 

shrike

BCC C SVulnerableRare, spring.

Long-billed 

curlew

BCC Rare

Merlin C Occasional observations

Northern 

goshawk

BCC C Rare

Olive-sided 

flycatcher 

BCC SVulnerable Occasional seasonal migrant, spring/summer/fall. 

Oregon vesper 

sparrow

BCC C S-Critical Rare, spring/fall.

Peregrine falcon, 

American

BCC S E Occasional observations, all seasons; displaced 

birds reared on refuge
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-63

Species Federal WA OR Current Occurrence on Refuge

Pileated 

woodpecker

C Resident and nests on refuge

Purple martin C Uncommon, spring/summer/fall. Breeding; 15 pairs 

nest on refuge.

Rufous 

hummingbird

BCC Nests on refuge

Sandhill crane, 

Canadian 

(G. c. rowani) 

E The refuge and Sauvie Island, Oregon is a 

significant migration and wintering area. Fall roost 

averages 1,700 birds; winter population 700-800. 

Occasionally seen in summer. Unconfirmed 

breeding record from Bach. Island, late 1970s. 

Short-billed 

dowitcher

BCC Rare

Slender-billed 

white-breasted 

nuthatch

BCC C Resident, nests on refuge. Mainly confined to 

Vancouver vicinity, especially the refuge.

Streaked horned 

lark 

BCC, C E S-Critical Rare, fall.

Vaux’s swift C Seasonal migrant; Uncommon summer/fall; 

occasional winter

Western 

bluebird

Monitored SVulnerableRare, spring.

Western grebe C Occasional, fall/winter/spring

Western 

meadowlark

S-Critical 

(WV)

Occasional summer; uncommon fall-spring. Breeds 

on refuge

Willow 

flycatcher (ssp 

brewsteri)

BCC SVulnerable Uncommon spring/summer/fall. Breeds on refuge.

Yellow-breasted 

chat

BCC S-Critical Rare, spring/summer. 

Key to Codes: E=Endangered, T=Threatened, C=Candidate, S=Sensitive, BCC=Birds of Conservation Concern, 

Table 4.16 Special Status Mammals Known or Likely to have Occurred on the Refuge

Historically

Species Federal WA OR Current Occurrence on Refuge

Brush Prairie (Northern) 

pocket gopher (Thomomys

talpoides douglassii)

C A subspecies known to Clark County, not 

confirmed on refuge

Columbian white-tailed 

deer

E E SVulnerableHistorically occurred on refuge; last confirmed 

sighting on refuge 1974-75 (Tabor 1976)

Gray-tailed vole

(Microtus canicaudus)

C A species known to Clark County, not confirmed 

on refuge

Mazama (Western) 

pocket gopher (Thomomys 

mazama)

C T A species historically present in Clark County; 

probably extinct in southwest Washington

Townsend’s big-eared bat 

(Pacific ssp.)

SC C S-Critical Within range of species; not confirmed on refuge
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-64 Chapter 4. Refuge Biology and Habitat

Species Federal WA OR Current Occurrence on Refuge

Western gray squirrel

(Sciurus griseus)

SC T S-Undet.

status

The refuge is in historic range and contains 

suitable oak habitat; not confirmed on refuge. 

Two or more reliable reports in Clark County in 

the last 5 years (Linders and Stinson 2006).

Yuma myotis SC Within range of species; not confirmed on refuge

Key to Codes: E=Endangered, T=Threatened, C=Candidate, S=Sensitive, SC=Species of Concern

Table 4.17 Special Status Reptiles and Amphibians Known to Occur or Likely to Have 

Occurred on the Refuge Historically

Species Federal WA OR Current Occurrence on Refuge

Western painted turtle S-Critical Occurs on the refuge, common

Western pond turtle SC E S-Critical Refuge in historic range, contains suitable habitat. 

Single adult found in 2005.

Western toad SC C S-Vulnerable Refuge in historic range. No documented 

occurrences in Clark Co. after 1984.

Northern red-legged 

frog

SC S-Vulnerable

(WV)

Occurs on refuge, uses suitable wetland and riparian 

habitat

Oregon spotted frog C E S-Critical Refuge in historic range. No documented 

occurrences in Clark Co. after 1984. 

Key to Codes: E=Endangered, T=Threatened, C=Candidate, S=Sensitive, SC=Species of Concern, WV=Willamette Valley

Table 4.18 Special Status Fishes Occurring on the Refuge and in Surrounding Waters

Species Federal WA OR Current Occurrence on Refuge

Bull trout T SC Records from Clark County, use of refuge unlikely

Chinook 

salmon (Lower 

Columbia ESU) 

T C SCriticalColumbia River migration takes fish past refuge. Refuge 

waterways may be utilized for rearing habitat. Juveniles 

trapped in Gee Creek in 1990s but not in 2002-2005 surveys. 

Juveniles trapped in Campbell Slough June 2007.

Chum salmon 

(Col R ESU)

T C (Lwr 

Col R)

SCriticalRefuge not utilized. Columbia River migration takes fish past 

refuge. Reported in Gee Creek in 1940s; extirpated. 

Coastal cutthroat trout

(SW WA/Col R 

DPS)

SC SCriticalSpawning documented in Gee Creek. Gee Creek utilized for 

rearing habitat.

Coho salmon

(Lower 

Columbia ESU)

T E Refuge waterways may be utilized for rearing habitat. Juveniles 

trapped in Gee Creek in 1990s and 2002-2005 surveys. 

Spawning not known in watersheds adjoining the refuge.

Sockeye 

salmon (Snake 

R ESU)

E C Refuge not utilized. Columbia River migration takes fish past 

refuge. 

Steelhead trout

(Lower 

Columbia ESU) 

T C SCriticalRefuge not utilized. Columbia River migration takes fish past 

refuge. Spawning not known in watersheds adjoining the 

refuge. Juveniles trapped in Gee Creek in 1990s, not in 2002-

2005 surveys.

Pacific smelt

(Southern DPS)

T Present in Gee Creek in low numbers; Columbia River 

migration takes fish past refuge

Western brook 

lamprey

SC Large numbers of adults and ammocetes trapped in Gee Creek, 

1995-1997; no adults and only 2 larvae in 2005

Key to Codes: E=Endangered, T=Threatened, C=Candidate, S=Sensitive, SC=Species of Concern
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-65

Table 4.19 Special Status Plants Known to Occur or Likely to have Occurred on the 

Refuge Historically

Species Federa

l 

WA O

R 

Current Occurrence on Refuge

Bradshaw’s desert 

parsley (Lomatium 

bradshawii) 

E E E Two known locations in Washington, both in Clark County; not 

documented on refuge. Experimental plantings on refuge in 

2007. Habitat: Wet, seasonally flooded prairies and grasslands 

around creeks and small rivers. Associated species include 

tufted hairgrass, slender rush, sawbeak sedge, and one-sided 

sedge.

Golden paintbrush

(Castilleja levisecta) 

T E E Historic record from Clark County; not documented on refuge. 

Habitat: Open grasslands, esp. glacial soils; often associated 

with Festuca idahoensis and F. rubra (Wentworth 2000).

Nelson’s checkermallow (Sidalcea 

nelsoniana) 

T E T Occurs in Cowlitz and Lewis counties; not documented on 

refuge. Experimental plantings on refuge in 2007. 

Habitat: A variety of open of habitats that undergo periodic 

flooding or soil saturation for extended periods of time; 

associated with tall fescue, common velvet grass, common 

rush, oxeye daisy, sweet vernal grass, and Canada thistle.

Pale larkspur

(Delphinium 

leucophaeum) Syn: D. 

nuttallii ssp.

ochroleucum

SC E E One record from Lewis County. D. nuttallii noted on refuge

(Wiberg and Greene 1981) but subspecies not noted. 

Habitat: Undisturbed sites on dry bluffs, open ground, and 

moist lowland meadows; now mostly confined to roadsides 

Smallflower

wakerobin

(Trillium parviflorum) 

Syn: T. chloropetalum

S Occurs on refuge. 

Habitat: Moist shady environments at upper elevations of 

riparian zones. Found in association with hardwoods, 

especially under ash, alder; and in Oregon white oak/oval leaf 

viburnum/poison oak plant association (Chappell 2006).

Tall bugbane

(Cimicifuga elata var. 

elata) 

SC S Occurs in Clark County, not documented on refuge.

Habitat: Openings in or margins of mixed, mature or old 

growth stands of mesic coniferous forest, or mixed coniferousdeciduous forest. Associated species include Douglas fir, 

western red cedar, bigleaf maple.

Water howellia

(Howellia aquatilis) 

T T Occurs in small vernal ponds in the Carty Unit (only Clark 

County record). 

Habitat: Vernal pools and seasonal ponds

Wheeler’s bluegrass

(Poa nervosa) 

S Three known locations in Washington, in Clark and Cowlitz

counties; not documented on refuge. 

Habitat: Rock outcrops and sparsely vegetated sites in woods 

that are dominated by Douglas fir, bigleaf maple, and Oregon 

white oak.

Key to Codes: E=Endangered, T=Threatened, C=Candidate, S=Sensitive, SC=Species of Concern. Source: Washington Natural 

Heritage Program
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-66 Chapter 4. Refuge Biology and Habitat

4.9.2 Condition and Trends of Washington State and Federally Listed Species 

and Habitats Utilized on the Refuge

Birds

Aleutian cackling goose (Branta hutchinsii leucopareia). The Aleutian cackling goose (formerly 

named Aleutian Canada goose) was delisted by the Service in 2001 and by the State of Oregon in 

2005. The subspecies is still listed as threatened in Washington State but is recommended for 

delisting. Aleutian cackling geese migrate along the coastline of the Pacific Ocean. Washington 

provides stopover habitats for Aleutians during the fall and spring migration. The principal stopover 

location in Washington is Willapa National Wildlife Refuge and the fields surrounding Willapa Bay. 

Peak numbers of Aleutians are associated with the fall migration with up to 380 birds observed in 

November 1996 (Hays 1997). Infrequently, Aleutians have been observed inland at the Ridgefield 

Refuge. Occurrences of Aleutians in the vicinity of Ridgefield are most often several birds mixed 

within a larger flock of geese. Documented observations of Aleutians at Ridgefield Refuge include 

one neck-collared bird in 1995, four unmarked birds during the winter of 2002-2003, and two 

unmarked birds during the spring of 2005. In 1994, three Aleutians were shot during the State’s hunt 

season. One bird was shot on Ridgefield Refuge and the other two were harvested from private lands 

near the refuge (Pitkin and Lowe 1995). 

American white pelican (Pelecanus erythrorhynchos). American white pelicans are seen 

infrequently in southwest Washington with observations ranging from single birds to small flocks. 

Since the mid-1990s, pelicans have been observed on the refuge from January into July. All current 

and historic breeding colonies for American white pelicans have been documented on the east side of 

the State. The presence of pelicans at the refuge relates to wintering, migrant, or nonbreeding 

subadult birds. 

Bald eagle (Haliaeetus leucocephalus). The bald eagle was delisted from threatened status by the 

Service in 2007, but is still listed by the State as threatened. Six pairs of bald eagles nest on the 

refuge or on adjoining private and public lands. Territories utilized by these nesting pairs 

presumably overlays portions of the refuge. Summer populations are comprised primarily of nesting 

birds, their offspring, and a few nonbreeding subadults. During the fall and winter, bald eagle 

populations at Ridgefield increase as migrant birds move into the area to feed on waterfowl and a 

variety of fish, including salmon and smelt. The nonbreeding population of eagles is not monitored 

at the refuge, however, bald eagles are commonly found throughout the fall and winter months, with

an estimated 30 to 50 eagles spending portions of the migration and winter periods on or near the 

refuge. Many of these migrant eagles forage on salmonids during the period when fish are entering 

the Lewis River and Gee Creek. Bald eagles have been observed foraging along the major 

waterways around the refuge including Gee Creek, Lewis River, Bachelor Slough, Lake River, and 

the Columbia River. Eagles are observed regularly roosting in trees along these waterways. Eagles 

regularly roost along the section of Lake River between the River ‘S’ bridge north to the Ridgefield 

marina. Bald eagles also forage extensively on waterfowl within refuge boundaries. 

Canadian sandhill crane (Grus canadensis rowani). All subspecies of sandhill cranes are listed as 

endangered in Washington State. Sandhill cranes on the refuge belong to a population that breeds in 

coastal British Columbia and southeast Alaska and migrates west of the Cascades. Morphometric 

and migration studies support assigning these birds to the Canadian subspecies (Grus canadensis 

rowani) (Littlefield and Ivey 2002; and Ivey et al. 2005). The lower Columbia River region is the 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-67

only major stopover site for Canadian sandhill cranes between their northern breeding areas and 

wintering sites in California’s Central Valley. Cranes generally forage primarily on corn crops and 

loaf along wetland edges. Canvasback Lake, on the Roth Unit, is an especially important roost site. 

In recent years, up to 4,273 cranes have been counted in the area of Ridgefield Refuge and Sauvie 

Island, Oregon, during early fall (Littlefield and Ivey 2002). Local migrant populations peak from 

early to mid-October, with peaks of 1,500 cranes utilizing the refuge at this time. The only wintering 

areas for sandhill cranes in Washington are long the Columbia River between Woodland and 

Vancouver. Since the mid-1990s the number of wintering cranes on the lower Columbia River has 

been increasing. In the 1980s approximately 100 sandhill cranes wintered on the refuge and nearby 

Sauvie Island. That number has increased to a current level of approximately 700 to 800 birds. 

There are no historical accounts of breeding sandhill cranes in southwest Washington. However, 

periodically cranes have been noted during the summer months on Ridgefield Refuge. The 

occasional presence of cranes on the refuge during the nesting season is presumed to be nonbreeding 

subadult birds. However, an unconfirmed breeding record of a nesting pair raising one chick was 

noted on Bachelor Island from the late 1970s (USFWS 1980). 

The taxonomic status of the Canadian sandhill has been debated. Recent studies of crane genetics do 

not support a separate subspecies designation for rowani, and one study suggests that rowani is a 

hybrid of greater and lesser sandhill cranes (tabida and Canadensis) (Peterson et al. 2003). On the 

other hand, the “Canadian” sandhill differs from other subspecies in a variety of ways, including 

morphology, migration routes and timing, and chick development rates. Its breeding distribution is 

also distinct from the other subspecies (Ivey et al. 2005). 

While some argue that the true “endangered” population in Washington is breeding greater sandhills 

(G. c. tabida), the Canadian sandhill is nevertheless of conservation concern due to its limited 

numbers, distinct coastal migration path, and habitat issues at breeding, staging, and wintering areas 

(Ivey et al. 2005). If Ivey’s conclusions of G. c. rowani using the lower Columbia River are correct, 

then staging counts may represent the entire population nesting in coastal B.C. and southeast Alaska. 

Peregrine falcon (Falco peregrinus): The peregrine falcon was delisted from threatened status by 

the Service in 1999 and is considered a Bird of Conservation Concern. However, peregrines are still 

State listed as endangered. Falcons are not known to nest on the refuge, but they are known to nest 

on cliffs in the Columbia River Gorge, and multiple bridges in the Portland metropolitan area. 

Peregrine falcons may utilize the refuge throughout the year, but occur more frequently from fall 

through spring as migrants move into the area to hunt for waterfowl and other prey. 

Periodically, bridge repair and maintenance projects coincide with falcon nesting season. When 

conflict with a bridge project is imminent, falcon eggs are removed from the nest and hatched at a 

local wildlife care facility. In support of the falcon conservation project, a peregrine falcon hack 

tower was constructed on the refuge during spring 2003 by the Portland Audubon Society and other 

partners. As the young falcons mature, they are transported to an enclosure from which they are 

slowly acclimated and released to the wild, a process called hacking. Once the birds are mature 

enough to fly, the enclosure is opened and the falcons are allowed to fledge. In 2003, five peregrine 

falcons were hacked from the tower. In 2004, osprey nested on top of the hack tower and peregrines 

were released from an alternate location. No releases have been conducted on the refuge since 2003. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-68 Chapter 4. Refuge Biology and Habitat

Mammals

Of 23 verified species of mammals on the refuge, none are federally or State listed. However the 

refuge lies within the historic range of one federally listed and one State listed species and may 

provide suitable habitat.

Columbian white-tailed deer (Odocoileus virginianus leucurus). Columbian white-tailed deer (CWT 

deer) occurred historically on the refuge. A 1971 survey reported that the subspecies was present in 

Columbia River bottomlands between Bonneville Dam and the Columbia County line in very low 

numbers. A single CWT deer was sighted on the refuge, in “grazed pasture near ash/cottonwood 

habitat” during a large mammal survey in 1974-1975 (Tabor 1976a). The revised recovery plan for 

the CWT deer noted that the refuge “may also have potential as a transplant site, although the 

existing habitat has not been evaluated for CWT deer suitability” (USFWS 1983). A feasibility study 

for the reintroduction of CWT deer, which will include an evaluation of habitat suitability, is part of 

this CCP. 

Western gray squirrel (Sciurus griseus). The refuge lies within the historic range of the western gray 

squirrel and contains suitable habitat; however, its presence has not been confirmed. Western gray 

squirrels have been extirpated from much of their historic range due to habitat loss and competition 

with nonnative eastern gray squirrels. 

Reptiles and Amphibians

Of 13 verified species of amphibians and reptiles on the refuge, none are federally or State listed. 

However, the refuge lies within the historic range of two State listed species and may provide habitat. 

Western pond turtle (Actinemys marmorata) (Syn: Clemmys marmorata): The refuge lies within the 

historic range of the western pond turtle. The Carty Unit features a relatively large area of suitable 

habitat: Wetlands interspersed with uplands and islands of basalt rock. The thin, well-drained soils 

on the uplands support plant communities that typify the best pond turtle nesting habitat (Oregon 

white oak, wild rose, snowberry and poison oak with a limited amount of nonnative blackberry). 

Western pond turtles have been extirpated from much of their historic habitats in the lower Columbia 

River due to over-exploitation for food, habitat loss, altered river hydrology, invasive plants (which 

impede turtle migration between ponds), and introduction of nonnative, warmwater game fish and 

bullfrogs that prey upon turtle hatchlings and juveniles (Hays et al. 1999). A single turtle was 

captured by a refuge volunteer in fall 2005. In the summer of 2006, WDFW biologists attempted to 

locate western pond turtles on the refuge without success. Therefore, it is unclear if the single turtle 

was a relic of the original population or a released pet. The WDFW supports reintroduction of 

western pond turtles on the refuge due to the presence of suitable habitat.

Oregon spotted frog (Rana pretiosa). The refuge lies within the historic range of the Oregon spotted 

frog. Oregon spotted frogs have been extirpated from at least 78 percent of its historic range due to 

wetland loss, invasive plants such as reed canarygrass that reduce the value of wetland habitat, and 

introduced warmwater game fish and bullfrogs, which compete with or directly prey upon spotted 

frogs. This species has not been documented in Clark County since a specimen was collected in 

Brush Prairie, Washington, in 1962 (McAllister and Leonard 1997). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-69

Fish

Because the refuge is located along the lower Columbia River, listed anadromous fish from upstream 

Evolutionary Significant Units (ESUs) may be present adjacent to the refuge in the Columbia River, 

Lake River, or Bachelor Slough at certain times of year. An ESU is a distinct population segment 

which is substantially reproductively isolated and represents an important component in the 

evolutionary legacy of the biological species.

Gee Creek, Campbell Slough, and Campbell Lake maintain connectivity to the Columbia River and 

may provide spawning or rearing habitat for federally listed and state listed species of fish (Table 

4.17). Surveys of Gee Creek have documented use by salmonids and western brook lamprey during 

rearing and migration. Pacific smelt have also been documented in Gee Creek in low numbers. In 

June 2007, juvenile Chinook salmon were trapped in Campbell Slough. However, the suitability of 

this habitat for native fish, and the degree of utilization, has not been fully assessed. Fish are 

excluded from both the River ‘S’ Unit and Bachelor Island. The units are diked and lack designs to 

accommodate fish egress back to the Columbia River. Ingress of fish into these units is precluded by 

fish screens maintained on all input pumping stations.

Bull trout (Salvelinus confluentus). Bull trout occur in the mainstem of the Columbia River, but the 

species has not been found in refuge waterways. Habitat conditions apparently preclude spawning by 

bull trout and would not support an anadromous or resident population. 

Chinook salmon (Oncorhynchus tshawytscha) Lower Columbia River ESU. The lower Columbia 

River Chinook salmon is the only Chinook ESU with the potential of occurring in refuge waters. 

Most of the ESU is represented by fall-run fish; it is unclear if any spring Chinook of natural origin 

still exist in this ESU. Other Chinook salmon ESUs migrating in the Columbia River include Snake 

River fall-run, Snake River spring/summer-run, and Upper Columbia River spring-run. In the late 

1990s juvenile Chinook were sampled in Gee Creek by screw trap and electrofishing, however, 

electrofishing from 2002-2005 failed to locate any juveniles (Cornelius 2006). In June 2007, 

juvenile Chinook were trapped in Campbell Slough; these appeared to be of natural origin because 

only one had a clipped fin. No adult spawning occurs on the refuge; therefore, these juvenile 

Chinook were rearing in Campbell Slough rather than produced within the watershed. 

Chum salmon (Oncorhynchus keta) Columbia River ESU. Chum salmon were historically abundant 

in the Lewis River basin and presumably, nearby tributaries of the Columbia, including Gee Creek. 

Historical adult populations produced from the Lewis Basin (including the mainstem, North, and East 

Forks of the Lewis River) are estimated from 120,000-300,000. Current natural spawning is 

estimated at less than 100 fish (Lower Columbia Fish Recovery Board 2004). The Lower Columbia 

Salmon Recovery and Fish and Wildlife Subbasin Plan (2004) lists chum use as “presumed” in the 

lower reach of Gee Creek and “potential” in the upper reach. There are historic accounts of chum 

and possibly coho spawning in Gee Creek prior to the 1950s (Cornelius 2006). The Columbia River 

ESU is known to migrate in the Columbia River past the refuge, but recent surveys have not 

indicated any use in refuge waters. Habitat conditions within refuge waters are apparently not 

suitable for chum salmon. 

Coho salmon (Oncorhynchus kisutsch) Lower Columbia River ESU. A second-hand story was 

reported about coho salmon trying to get past a barrier in upper Gee Creek, near Royle Road, “prior 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-70 Chapter 4. Refuge Biology and Habitat

to the 1950s” (Cornelius 2006). A 1951 fisheries report said that “silvers and chums utilize [Gee 

Creek]” and that “fair to good spawning areas” occurred above the lower 2 miles of Gee Creek 

slough. Coho juveniles are known to use Gee Creek within the refuge; it is also possible that they 

use the pond complex within the Carty Unit as rearing areas. In the late 1990s juvenile coho were 

sampled in Gee Creek by screw trap and electrofishing. Electrofishing during 2002-2005 also 

located juvenile coho in Gee Creek (Cornelius 2006); however, numbers were low compared to two 

other streams sampled on the lower Columbia. These coho are of uncertain origin. The absence of 

adult coho during surveys and lack of habitat within Gee Creek suggests that these juvenile coho 

were rearing in Gee Creek rather than produced within the watershed. 

Sockeye salmon (Oncorhynchus nerka) Snake River ESU. The Snake River ESU is known to migrate 

in the Columbia River past the refuge, but surveys have not indicated any use of refuge waters.

Steelhead (Oncorhynchus mykiss) Lower Columbia ESU. Both adult and juvenile steelhead may be 

present year-round within the Columbia River, its tributaries, and adjoining aquatic habitats. The 

Upper Columbia River, Middle Columbia River, and Snake River Basin ESUs are known to migrate 

in the Columbia River past the refuge, but have not been collected on the refuge. Transient steelhead 

may enter lower Gee Creek from the Columbia during periods of juvenile freshwater rearing. In the 

late 1990s juvenile steelhead were sampled in Gee Creek by screw trap and electrofishing, however, 

electrofishing in 2002-2005 failed to locate any juveniles (Cornelius 2006). No adult spawning 

occurs on the refuge. All steelhead found within Gee Creek are assumed to be transient and spawned 

from another watershed. 

Pacific smelt (Thaleichthys pacificus) Southern DPS. Pacific smelt were historically abundant in 

tributaries of the lower Columbia River. Like salmon, smelt are anadromous, returning to the 

Columbia at 3, 4, and 5 years of age, to spawn in the mainstem and its tributaries downstream of 

Bonneville Dam. Peak tributary abundance is usually in February, with variable abundance through 

March. Smelt typically spawn every year in the Cowlitz River, with inconsistent runs and spawning 

events occurring in the Grays, Elochoman, Lewis, Kalama, and Sandy rivers (Columbia Basin 

Bulletin 2009). Presumably, spawning occurred historically in Gee Creek as well. Smelt also 

migrate in the Columbia River past the refuge. Pacific smelt have been found in low numbers in 

surveys of Gee Creek (Cornelius 2006). Smelt abundance dropped precipitously in 2005 and has 

remained low since, prompting Federal listing of the species’ southern population, which ranges from 

the Mad River in Northern California to the Skeena River in British Columbia (NOAA 2010). 

Plants 

Water howellia, Nelson’s checkermallow, and Bradshaw’s desert-parsley are the only listed plants 

known to occur on Ridgefield Refuge. Bradshaw’s desert-parsley and Nelson’s checkermallow may 

have been present historically; and experimental plantings were conducted in 2007. The refuge 

occurs within the historic range of the State-listed pale larkspur (see Table 4.18 above) however, its 

presence has not been verified. 

Water howellia (Howellia aquatilis). This aquatic annual was discovered in 1897 by Thomas and 

Joseph Howell on Sauvie Island, Oregon. Water howellia is found in California, Washington, Idaho, 

and Montana, with over 150 known occurrences (since its discovery, it has become extinct in 

Oregon). However, the entire species occupies a total area of less than 200 acres of a very particular, 

ecologically fine-tuned, and easily disrupted habitat (Center for Plant Conservation 2009). The 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-71

species is restricted to small pothole ponds or orphaned river oxbows that are seasonally inundated 

yet dry out in late summer or early fall. This annual inundation may help keep competing vegetation 

from becoming too well established (Washington Natural Heritage Program 1999). In Washington, 

water howellia has a limited distribution with remnant populations in the Columbia Basin and Puget 

lowlands. Water howellia was documented in several small ponds in the Carty Unit in the late 1970s 

(Wiberg and Greene 1981). This area is a complex mix of oak woodland, Oregon ash, and shrub. 

Reed canarygrass encroachment is a threat to water howellia in these ponds. 

Bradshaw’s desert-parsley (Lomatium bradshawii). This perennial plant was formerly common in 

native prairies of the Willamette Valley and the Puget Trough, and likely occurred on or in the 

vicinity of Ridgefield Refuge. Bradshaw’s desert-parsley reproduced only by seed which germinates 

soon after falling from the flower; therefore, seed persistence in the soil is low. Frequent (2-3 times 

every 6 years) low intensity burns are required to maintain viability of this species (USFWS 1993). 

Restoration of historic wet meadow or prairie habitat would benefit this species. Experimental 

plantings were conducted in February 2007, with an additional planting of seedlings in the winter of 

2007-2008. 

Pale larkspur (Delphinium leucophaeum) Syn: D. nuttallii ssp. ochroleucum. This species is State 

listed as endangered in both Washington and Oregon. In Washington, there is one record of this 

species from Lewis County (Washington Natural Heritage Program 2005). D. nuttallii was noted as 

occurring on the refuge’s Carty Unit by Wiberg and Greene (1981) but the subspecies was not noted. 

The habitat for this species includes undisturbed sites on dry bluffs, open ground, and moist lowland 

meadows. It is now mostly confined to roadsides. Threats to this species include land conversion to 

agriculture, grazing, and introduced species. Updated plant surveys are needed to confirm which 

Delphinium species occur on the Refuge. 

4.9.3 Condition and Trends of Sensitive Species and Habitats Utilized on the 

Refuge

Great Blue Herons. The Bachelor Island Unit contains riparian (cottonwood) forest that for many 

years was home to the largest heron colony on record in Washington, and one of the largest on the 

Columbia River. Other refuge habitats, including seasonal and permanent wetlands, managed 

pastures, and grasslands, provide year-round foraging areas for herons. A 1972 survey found more 

than 500 nests in the colony, with an estimated production of 975 young (Tabor 1976). In 1973 the 

Bachelor Island colony reportedly had 773 active nests. The 2001 observation for this colony on file 

with WDFW reports 557 active nests (P. Thompson WDFW pers. comm. in Vennesland and Norman 

2006). The rookery had 96 nests in 2009, but no adults were present during the survey and it is 

unclear if any young were fledged this year. Given the reduction in heron use, the refuge is 

minimizing trips into the site and not collecting fledgling rate data. Additional active colonies were 

located on the Ridgeport Dairy Unit during the summer of 2009 and will be monitored in 2010 to 

confirm use. 

The most significant sources of stress to nesting great blue herons include human disturbance, 

predation by bald eagles and corvids (which can be exacerbated by human disturbance and habitat 

fragmentation), loss of foraging areas, and environmental contaminants (Vennesland and Norman 

2006). Great blue herons are extremely sensitive to human disturbance during the nesting period, 

from nest initiation in February through fledging in late July. Herons may temporarily abandon nests 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-72 Chapter 4. Refuge Biology and Habitat

in response to disturbance, which increases risk of predation by bald eagles and corvids. In some 

cases, wholesale colony abandonment may occur. Proximity to nesting bald eagles can also cause 

colony abandonment. Potential impact to great blue herons from recreational disturbance and 

recreation-induced habitat modification on adjacent WDNR land on Bachelor Island has been a 

concern. 

Condition and Trends of Nesting Habitat. The primary great blue heron rookery on Bachelor 

Island was depleted in 2009 compared to the past 30 years, with only 96 active nests recorded during 

the spring survey. It is not yet known whether the colony will reform or the birds have relocated to 

another site. Rookeries at the north end of Bachelor Island and the west side of Carty Unit had six 

and seven nests respectively. At least two other small colonies (6 to 12 nests) were located in the 

Ridgeport Dairy Unit during the summer of 2009 and will be monitored for use in 2010. 

Table 4.20 Ecological Attributes, Indicators, and Condition Parameters for Great Blue 

Heron Nesting Colonies and Associated Foraging Areas 

Key 

Ecological 

Attributes 

Indicators Desired Conditions 

Security • Distance from human 

activity

• Timing of public use 

• Amount/type of public use 

• Bald Eagles

• An 820–985-foot buffer between outer edge of 

colony and human activity from nest initiation (Feb 

15) through fledging (July 31) (WDFW 2004). 

Herons are most sensitive to disturbance during nest 

initiation and early incubation. 

Size • Acres

• Proximity to alternate 

nesting sites

• 10 acres or more

• Several alternate forest stands at least 10 acre in size 

with dominant trees at least 56 feet tall within 2.5 

miles of nesting colonies (Colonies with more than 

50 nests will require a greater number of stands) 

(WDFW 2004)

Vegetation 

structure

• Tree height, structure, 

species

• Dominant trees at least 56 feet tall (WDFW 2004)

• Trees of suitable size to provide nest platforms 6.6-

100 feet (2-30 meters) above the ground (Butler 

1997) 

• Open branch structure to provide access by adult 

birds; black cottonwood, bigleaf maple, and Douglas 

fir preferred

Food 

availability 

• Proximity to foraging sites 

(wetlands, 

instream/riverine, 

improved pastures)

• Less than 9.3 miles (15 km) from suitable foraging 

areas (Butler 1991, 1992, and 1997) 

Sources: WDFW 2004, Vennesland and Norman 2006, Quinn and Milner 2004

4.9.4 Key Ecological Attributes and Threats

Key ecological attributes and threats differ for each listed species, and are not described here in the 

interest of space. Federal and State recovery plans and other species specific documents are the best 

source for in-depth information on these species. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 4. Refuge Biology and Habitat 4-73

4.10 Wildlife and Habitat Research and Monitoring Efforts

A number of research and monitoring projects have been conducted at the refuge since it was 

established. Many are collaborative efforts between the refuge and other Service programs, other 

agencies, nongovernment organizations (NGOs), and universities. A number of refuge-specific 

monitoring projects were discontinued in 2004 due to cuts in staffing and funding. 

4.10.1 Waterfowl Surveys

Mid-winter Waterfowl Surveys (1985-present). The refuge has participated in the Mid-winter 

Waterfowl Surveys every year since 1985, with the exception of 2004, when weather prevented 

aerial surveys from occurring. These surveys count waterfowl populations utilizing the refuge and 

surrounding area. Surveys are conducted by the Migratory Bird Management Office (MBMO) with 

the Refuge Biologist serving as an aerial observer. Data from the annual surveys go to the MBMO, 

which calculates a flyway population total. The flyway totals do not provide a picture of local trends. 

However, the midwinter waterfowl data set contains considerable detail about distribution of birds at 

various scales, from a specific refuge unit to overall region. Even though the data generated from 

these surveys represent a snapshot of the numbers of waterfowl using the refuge on the particular day 

of the survey, and not total refuge wintering populations, the cumulative data taken over the years 

may provide an index to the numbers of waterfowl on the refuge and their trends over time. For 

midwinter counts of waterfowl on the refuge, see Figure 4.2. 

Dusky Canada Goose Surveys (1999-present). The refuge has participated annually in regional 

dusky Canada goose surveys conducted by the MBMO. This consists of weekly surveys conducted 

between October and March or April, done in conjunction with goose collar surveys. While these 

surveys provide a population index for the entire population, they are inadequate to discern 

population shifts on a local level. Updated information is needed on seasonal use patterns and 

distribution of Canada geese and cackling geese in Oregon and southwest Washington to understand 

how dusky Canada geese are redistributing themselves in wintering areas. 

Canada and Cackling Goose Surveys (1993-2004). In an effort to discern local trends, wintering 

Canada and cackling geese were surveyed on the refuge between 1993 and 2004. Monitoring was 

modified in 1999 to collect additional data on all refuge geese and their habitat use. These surveys 

supported regional efforts to obtain information about geese that had been captured and fitted with 

coded plastic neck collars. Data from these surveys were also used to assess flock compositions, 

peak populations, average populations, and goose utilization of individual wetland/field units. 

However, these goose surveys were suspended after 2004, due to funding declines that resulted in the 

loss of the biological technician position needed to conduct the daily surveys. 

Multi-agency Goose Projects−Canada Goose Collar-reading Project (usually funded by MBMO) 

(1999-present): Canada goose collar surveys have been conducted since 1999 on the refuge and 

consist of weekly surveys from October to March. Volunteers survey the majority of the refuge’s 

goose habitat, recording numbers of each subspecies, the number of collared birds, and collar 

numbers/letters if readable. Data is submitted to the MBMO and reviewed by refuge staff to improve 

goose management on site. 
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4-74 Chapter 4. Refuge Biology and Habitat

4.10.2 Surveys for Listed Species and Other Species of Management Concern

Lower Columbia River Sandhill Crane Roost Survey (1991-present). The refuge has partnered 

with The Nature Conservancy of Oregon to conduct sandhill crane roost surveys since 1991. The 

surveys are conducted in early October. A number of other crane surveys, studies and banding 

projects were terminated between 1998 and 2002 due to lack of staff. 

Ridgefield Refuge Great Blue Heron Rookery Survey (1990-2009). This survey is performed by 

volunteers in March. Bachelor Island had recently provided nesting habitat for over 400 pairs of 

great blue herons and great egrets. In 2009, the rookery was largely abandoned, and it is not clear if 

the birds will return or whether they have relocated. Heron colonies are quite sensitive to human 

disturbance, as well as availability of prey species, presence of raptors, water management, and 

presence of contaminants in river waters and sediments. Therefore, heron populations will continue 

to change and provide a good barometer of habitat integrity. Natural succession and habitat 

management regimes also affect these species’ utilization of the refuge for foraging, roosting and 

nesting. Monitoring the rookery is essential for early identification of issues that may impact these 

populations. 

Bald Eagle Nest Monitoring (1990-2009). The refuge provides nesting and/or summer foraging 

habitat for up to 7 pairs of bald eagles. The reproductive success of these eagles has been monitored 

since 1990, by the Oregon Cooperative Fish and Wildlife Research Unit at Oregon State University 

as part of larger, cooperative, state-wide surveys that are still being conducted. Although the bald 

eagle has been delisted, monitoring of current nest sites and expansions on the refuge should 

continue, to ensure compliance with the Bald Eagle Protection Act, and to identify potential issues 

that may jeopardize nesting eagles.

Water Howellia Surveys (1995, 1998, annually since 2005). Water howellia (Howellia aquatilis) 

was surveyed in 1995 and again in 1998. The 1995 surveys located two new populations. This 

species is resurveyed every year to verify species presence and assess habitat issues such as reed 

canarygrass encroachment. 

Purple Martin Nest Monitoring (1998-present). The refuge maintains four purple martin nest 

structures with 12 artificial nests (gourds). Volunteers set up the nests and report on any incidental 

observations. Nest occupancy has been more than 75 percent, achieving 100 percent most years. 

4.10.3 Habitat and Vegetation Inventories, Surveys, and Monitoring

Pasture Vegetation Monitoring (1995-2003) and Wetland Plant Surveys. Vegetation monitoring 

in goose pastures was conducted using various techniques between 1995 and 2003. Loss of staff 

positions and funding has prevented collection of data on goose use and vegetation since 2003. 

Wetland plant surveys were conducted annually until the ricefield bulrush issue arose in 2002; it has 

never been summarized adequately. 

Lower Columbia River Natural Area Inventory (1993). Plant communities of several sites on the 

refuge (Blackwater Island RNA, Canvasback Lake, Campbell Lake, and the outlet of Campbell 

Lake) were described by Christy and Putera as part of their inventory of remnant native habitats on 

the floodplain of the lower Columbia River (river miles 0-143). As part of this study, sites were 

ranked by relative importance for use in setting priorities for protection. 
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Chapter 4. Refuge Biology and Habitat 4-75

Columbia River Riparian Habitat Inventory (1976). Tabor (1976 a, b) surveyed riparian plant 

communities and associated wildlife of the refuge (including large and small mammals, and birds) as 

part of a habitat inventory along the Columbia and Snake rivers.

Blackwater Island Research Natural Area Vegetation Descriptions (1973 and 1981). A 

vegetation description of the Blackwater Island RNA was developed by an undergraduate student 

from Portland State University (Morrison 1973). Subsequently, Wiberg and Greene (1981) 

published a description of the physical environment and plant communities of the RNA. The RNA is 

known to contain rare habitat types (Oregon white oak/ovalleaf viburnum/poison oak woodland and 

overflow plains) and support rare and sensitive species such as the threatened water howellia, and the 

slender-billed white breasted nuthatch, which is a Federal species of concern and a candidate for 

listing in Washington. Updated inventories are needed. 

4.10.4 Habitat Restoration and Monitoring (Multi-agency coordination projects)

Gee Creek Restoration Project (2006-present). In the spring of 2006, the Service and Washington 

State University’s Clark County Extension initiated a joint effort to fund expanded watershed 

enhancement efforts, including the Gee Creek Watershed Restoration Project. Cooperators in the 

project include the Lower Columbia River Estuary Partnership (LCREP), the Friends of Ridgefield 

National Wildlife Refuge, the City of Ridgefield, area schools, and local residents. These partners 

work to maintain and enhance water quality and habitat conditions in Gee Creek by educating 

watershed residents about best management practices and identifying, prioritizing and developing 

watershed restoration projects; and by executing on-the-ground restoration, including tree plantings, 

stream habitat restoration, invasive plant control, water quality monitoring, and field assessments 

(WSU Clark County Extension 2009). Restoration project volunteers planted trees along Gee Creek 

on the refuge in 2006, 2007, and 2008, and have also conducted invasive plant control on the refuge. 

Bachelor Slough Project (2003). The refuge and the U.S. Army Corps of Engineers (ACE)

partnered to evaluate channel improvements to Bachelor Slough that would improve channel flushing 

and the ability of the refuge to use the south Bachelor Island pump station. Elevation survey data 

were collected, but the project was not funded, and therefore, it was not implemented. 

4.10.5 Invasive Species Monitoring and Studies of Control Techniques

Ricefield bulrush Monitoring and Eradication (2002-2009). A volunteer-based control program 

was initiated in 2004 that consisted of searching, identifying, and mapping ricefield bulrush 

occurrences, and hand-pulling with some herbicide applications. Test plots were established in 2007 

to identify effective herbicide treatments resulting in initiating significant herbicide treatments in 

2009. These efforts will be continued aggressively for several years, since ricefield bulrush 

propagules exhibit long-term seedbank viability. It is expected that surveys and control efforts will 

be required at some level for years until the seedbank is depleted and the species is eradicated. 

Reed Canarygrass Control Techniques (1994-1997). Service biologists studied reed canarygrass 

control techniques on the refuge from 1994 to 1997 (Paveglio and Kilbride 2000, Kilbride and 

Paveglio 1999). Treatments (mowing, disking, herbicide application plus disking, and both single 

and multiple herbicide application), were performed in select seasonal wetlands in 1994 and 1995. 

Mean densities of reed canarygrass (stems per square meter) were monitored in the treated areas for 
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4-76 Chapter 4. Refuge Biology and Habitat

three seasons (1995-1997). The authors concluded that the most effective treatment was a 

combination of herbicide (Rodeo) and disking, with a follow-up herbicide application during the next 

growing season.

4.10.6 Baseline Inventories of Major Fish and Wildlife Groups

Landbird Banding (1995-2003). Winter banding of songbirds occurred for many years between 

1995 and 2003, providing information on species composition and some habitat use information. 

Reptile and Amphibian Surveys (1995-2001). The refuge conducted pitfall trapping for 

amphibians (frogs and salamanders) and small mammals from 1995 to 1997 in selected habitats, 

which provided a good idea of what species occur and what habitats they use. However, not all 

species are sampled adequately by pitfalls, so gaps remain. The refuge also conducted frog breeding 

surveys on the River ‘S’ Unit in 2001; this provided additional information on habitats utilized for 

breeding as well as some data on other amphibian species. Painted turtle trapping occurred from 

1996 to 2000; painted turtle telemetry was conducted in 2001. These studies provided data on turtle 

populations and habitat use on the River ‘S’ and Bachelor Island units. Information on nesting sites 

and production is lacking. Only the amphibian breeding information has been analyzed with a report 

written.

Fish Surveys (1993-2009). Surveys for fish have occurred over the past 15 years in part through 

specific fisheries studies conducted by the Columbia River Fisheries Program Office (CRFPO). 

These studies have occurred primarily on the Carty Unit within the Gee Creek system. Fish surveys 

were conducted for Gee Creek in 1993, 1995-1997, and 2002-2005 (Cornelius 2006). These surveys 

showed that while Gee Creek hosts primarily warm-water, nonnative species, it also supports rearing 

habitat for salmonids such as coho and Chinook salmon, and cutthroat trout. The National Marine 

Fisheries Service (NMFS) conducted general fish surveys in Campbell Slough in 2007, 2008, and 

2009. Juvenile Chinook salmon (most without fin clips, indicating a wild origin) were found in the 

2007 and 2008 surveys, and juvenile chum were found in 2008, as well as many species of 

introduced warmwater fish. 

Inventory of Odonates for the Ridgefield Refuge Complex. Dennis Paulson (Slater Museum of 

Natural History, University of Puget Sound) and Jim Johnson (a local entomologist) collected 

odonates (dragonflies and damselflies) on the refuge. 

4.10.7 Experimental Reintroductions

Experimental Reintroduction of Bradshaw’s Lomatium and Nelson’s Checkermallow (2007-

2008). The Washington Natural Heritage Program has partnered with the Service’s Ecological 

Services Office located in Lacey, Washington, to evaluate the feasibility and techniques for 

introducing two endangered Willamette Valley plants, Bradshaw’s lomatium and Nelson’s 

checkermallow. The refuge was identified as a site with good potential for reintroduction. An 

experimental planting design was developed for Bradshaw’s lomatium (Arnett 2007). Test plantings 

were conducted in February 2007, with an additional planting of seedlings in the winter of 2007-

2008. In fall 2007, 1,000 Nelson’s checkermallow seedlings were outplanted on the refuge. 

Subsequent plantings were conducted in following years. During surveys conducted in 2009, plants 

were found on three sites on the refuge. A fourth site was surveyed, but no surviving plants were 

located. An evaluation of the refuge indicated that some marginal habitat for Bradshaw’s lomatium 
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Chapter 4. Refuge Biology and Habitat 4-77

was present along the Auto Tour Route, and seeding occurred in 2007. No plants have been detected 

during subsequent visits and no replanting has occurred.

4.10.8 Other Research Projects

Monitoring Avian Productivity and Survivorship (MAPS) (1993-2003). Monitoring Avian 

Productivity and Survivorship (MAPS) is a research program created by the Institute for Bird 

Populations to assess and monitor the vital rates and population dynamics of North American 

landbirds. Partners in the MAPS program include the Service, the USDA Forest Service, the 

National Park Service, the U.S. Geological Survey’s Biological Resources Division, the Department 

of Defense Legacy Resource Management Program, the National Audubon Society, and the 

International Neotropical Migratory Bird Conservation Initiative’s Partners in Flight. The MAPS 

Program utilizes constant-effort mist netting and banding at hundreds of banding stations throughout 

North America. Analyses of MAPS data provide critical information relating to the ecology, 

conservation, and management of North American landbird populations and the factors responsible 

for changes in their populations. A MAPS station was maintained on Bachelor Point on the refuge

for 10 years (1993-2003). This station sampled birds in lowland riparian habitat (cottonwood/ash 

riparian forest), one of five priority habitats in the region indentified in Partners in Flight Bird 

Conservation Plans. 

A study of MAPS stations on national wildlife refuges (DeSante et al. 2004) showed that the 

Bachelor Point station was one of the most productive and diverse within the Pacific Northwest. The

mean annual capture rate (199 adults per year) was well above the average of 90 adults per year, and 

the number of species captured annually (15 per year) was also well above the average (9), second 

only to William Finley Refuge in Oregon. Because of the relatively large number and species 

diversity of birds captured, the authors recommended that the Bachelor Point station be reinitiated if

funding becomes available.

Study of Paternity in American Kestrels (2004-2006). This study, conducted by students at 

Warner Pacific College in Portland, Oregon, examined paternity patterns of American Kestrels 

nesting on the refuge during the 2004-2006 breeding seasons (Alston et al. 2006, and Smith et al. 

2006). Nest boxes were placed on the refuge in 2004 and 2006. Adult birds and chicks were banded, 

standard morphometric data was collected, and blood samples were collected. A DNA analysis was 

then conducted to determine the paternity of chicks. 

Malformed Amphibian Study. Frogs were collected on the refuge in 2000 as part of a nationwide 

survey to determine the extent of abnormal frogs on national wildlife refuges (Hayes et al. 2001). 

Simple first-tier assessments of frog abnormalities were conducted in ponds, wetlands, puddles, and 

other water bodies on more than 145 refuges in 47 states (USFWS 2008). Analysis of data from this 

study may demonstrate trends that will help focus additional studies.

4.10.9 Contaminants Studies

Study of Food-chain Effects from Contaminants in the Columbia River (Buck 2004). The 

purposes of this study were to: 

• Determine and compare contaminant concentrations in sediment, aquatic invertebrates, fish, 

and bird eggs within various segments of the Columbia River (the lower Columbia River, 
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4-78 Chapter 4. Refuge Biology and Habitat

below Bonneville Dam, and the mid-Columbia River associated with Umatilla Refuge); 

• Compare concentrations in biota to guidance or reference levels, to identify primary 

contaminants of concern and resources at risk; and 

• Derive biomagnification factors (BMFs) and target fish concentrations (TFCs, or 

concentrations in fish that would be protective of fish-eating birds) for persistent, 

bioaccumulative compounds. In 1990 and 1991, sediment, invertebrates (crayfish and 

clams), fish, and eggs of piscivorous and nonpiscivorous birds were collected from various 

river segments to determine contaminant concentrations, identify concentrations in biota that 

exceed guidance or reference levels, and derive apparent biomagnification factors (BMFs) for 

persistent, bioaccumulative compounds. Fish (carp, peamouth, and suckers), invertebrates 

(clams and crayfish), and sediment were sampled at the refuge in 1991. The author 

concluded that although bioaccumulative contaminants were near or below detection limits in 

sediment and invertebrates, the biomagnification of some organochlorines would likely result 

in adverse impacts to some piscivorous bird species. 

Contaminants Studies of Carty Lake and Lake River (Kleinfelder 1993, Ecology and 

Environment 1996, Buck 2000, ongoing monitoring of groundwater wells). These studies 

documented contamination of groundwater and sediments resulting from operations of the Pacific 

Wood Treating (PWT) facility from 1964 to 1993. A Resource Conservation and Recovery Act 

(RCRA) facility investigation conducted for the PWR Corporation (Kleinfelder1993) documented 

wood-treating chemicals in sediment and water in and around surface water outfalls in both Carty 

Lake and Lake River. Contaminants documented onsite included PCP, volatile and semi-volatile 

organics, copper, chromium, and arsenic. A study conducted for EPA concluded that contaminants 

originating from the PWT site had migrated off-site and into refuge lands, including Carty Lake and 

adjacent wetlands (Ecology and Environment 1996). Groundwater in wells installed on the border of 

the refuge and the site at Carty Lake contained high levels of PCP. 

A Preliminary Contaminants Assessment was conducted by the Service (Buck 2000). The objective 

of this study was to document environmental contaminants which may have entered the refuge from 

the adjacent PWT site through groundwater or surface water. The investigation included chemical 

analysis of sediment and fish collected adjacent to the PWT site and on the refuge. The main 

contaminants looked at in this study were PCP and trace elements, but it also looked at 

organochlorine pesticides, total PCBs, and chlorphenoxy herbicides. Sediment and fish samples 

were collected from Carty Lake, Bachelor Slough, Lake River, and a reference area near the refuge in 

June and July 1999. The data indicated that PCP and the trace elements arsenic, chromium, copper, 

and possibly lead and zinc were elevated on the refuge as a result of contaminant migrations from the 

PWT site.

Several monitoring wells have been installed in and around the PWT site to collect baseline data and 

monitor movement of contaminants off the PWT site during the steam-injection cleanup process. In 

the fall of 2000, EPA installed three clusters of monitoring wells (three wells per cluster) in the south 

end of Carty Lake. The Service installed three new wells in the fall of 2001, two approximately 82 

feet (25m) north of the EPA well clusters, and one south of the EPA wells and closer to the PWT 

site. Baseline data was collected from the wells in January 2002, and wells were sampled on a 

quarterly basis thereafter, until September 2003. 

Bald Eagle Productivity Study (USFWS 1999). This study examined the productivity of bald 

eagles nesting along the lower Columbia River, including pairs nesting on the refuge, and 
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Chapter 4. Refuge Biology and Habitat 4-79

contaminant levels in eggs collected in 1994 and 1995. Although total productivity increased due to 

the success of new nesting pairs moving into the region, results indicated that organochlorine 

contaminants were continuing to impact the breeding success of eagles in the lower Columbia River. 

The Service, in cooperation with Oregon Cooperative Wildlife Research Unit at Oregon State 

University and the Lower Columbia River Estuary Program, planned to continue monitoring these 

eagles to see if the conditions of the Columbia River are improving for all species. 

Effects of Contaminants on Great Blue Herons (Thomas and Anthony 1999). The purpose of this 

study was to determine whether great blue herons would serve as a good monitoring species for 

contaminants in piscivorous (fish eating) birds from the Columbia and Willamette basins. A good 

indicator species should have a wide distribution, high food-chain status, nest fidelity, and low 

sensitivity to contaminants. Great blue herons on the lower Columbia and Willamette rivers meet all 

four criteria. Heron eggs were collected from six colonies in Oregon and Washington during 1994 

and 1995, including the Bachelor Island colony. Eggs were analyzed for organochlorines (DDE),

PCBs, dioxins, furans, and trace elements. Heron reproductive success (number of chicks fledged 

per occupied nest) was also studied. The authors concluded that contaminants do not impair great 

blue heron reproduction at the colony level in the Columbia and Willamette rivers, only at the 

individual level. The study demonstrated that herons can be used as an indicator species of 

environmental contamination.

4.10.10 Other Monitoring

Mosquito Population Surveillance. The Clark County Mosquito Control District, which has 

responsibility for mosquito control in the local area, has an annually renewed Special Use Permit 

with the refuge that allows mosquito crew members to visit the refuge to monitor larvae at specific 

sites and during specific time periods during the year. Monitoring consists of collecting dip samples 

from target wetlands. 

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Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

4-92 Chapter 4. Refuge Biology and Habitat
Chapter 5. Refuge Facilities and

Public Use Programs

Wildlife observation, wildlife photography, waterfowl hunting, and

environmental education are popular public uses on the Refuge/

USFWS
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 5. Refuge Facilities and Public Use Programs 5-1 

Chapter 5. Refuge Facilities and Public Use Programs

5.1 Infrastructure and Administrative Facilities

The infrastructure and facilities discussed in this section include boundary fences and markers, 

entrances, roads, trails, administrative buildings, easements and rights of way, and water-related 

structures. 

5.1.1 Boundary Fences and Markers 

The Ridgefield Refuge encompasses 5,218 acres. Its boundary is marked with Service boundary 

signs. Generally, the refuge’s perimeter borders sloughs, creeks, and the Columbia River. It is the 

intent to accurately post the refuge’s boundary; however, in select locations the boundary may be 

posted slightly inside the actual property line on high ground or dikes to avoid the potential loss of a 

sign due to flooding and bank erosion. Periodically, boundary signage is checked to identify and 

replace damaged and missing signs. Because much of the refuge’s perimeter borders waterways, 

boundary fences are not maintained. Select fencing for the refuge’s grazing program has been 

erected and is maintained. In portions of the Roth, River ‘S’, and Carty units, cattle fences may 

coincide with the refuge’s boundary. 

Entrances and Access Points. There are three official entrances to the refuge. Boating of navigable 

water surrounding the refuge is common; however, accessing the refuge from these waters is not 

allowed and constitutes trespass beyond the refuge boundary. 

Carty Unit. The Carty Unit is accessed from Main Avenue approximately one mile north of the town 

of Ridgefield. The entrance is posted with a standard double-sided brown entrance sign with a footer 

board printed with the unit name. The sign was new in the summer of 2008 replacing a badly faded 

entrance sign with a bullet hole. Access to the Carty Unit is limited to daylight hours which are 

seasonally variable and announced on the refuge’s website. Additionally, gate closure times are 

physically posted on the gate to avoid entrapments. Access is regulated by an automatic 

programmable gate off of Main Avenue at the road entrance to the Carty Unit. 

 

Ridgeport Dairy Unit. The Ridgeport Dairy Unit is accessed from northwest Lower River Road 

approximately eight miles northwest of Vancouver, Washington. Formerly, Lower River Road (a 

State road) entered the refuge and terminated approximately 1.25 miles into the refuge boundary at a 

turn-around. Through an agreement with the State, the refuge was allowed to construct an automatic 

programmable gate at the boundary to preclude access to road segments bordering the refuge after 

dusk. The road was constructed on top of a flood control dike offering elevated overlooks over the 

Columbia River and refuge. Within the refuge, the road offered three parking lots for wildlife 

observation. These lots were additionally popular with anglers that used them to access the shore of 

the Columbia for sturgeon fishing. In 2004, erosion along the river’s edge had narrowed the dike 

width to the road’s edge. By July 2004, the road was collapsing and in 2005 the State closed the last 

1.25 miles of road at the refuge’s boundary with signage and concrete barriers. The former entrance 

is posted with a standard single-side brown entrance sign. This sign has been subject to considerable 

vandalism and is in poor condition. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

5-2 Chapter 5. Refuge Facilities and Public Use Programs

River ‘S’ Unit. The River ‘S’ Unit is accessed from S. 9th Avenue (Hillhurst Road) approximately 

one mile southeast of Ridgefield, Washington. The entrance is posted with a standard double-sided 

brown entrance sign with a footer printed with the unit name. The sign was new in the summer of 

2008 replacing an older single-sided sign facing the north. The single-sided sign facing south was 

stolen and had been missing for several years. Access to the River ‘S’ Unit is limited to daylight 

hours which are seasonally variable and announced on the refuge’s website. Additionally, gate 

closure times are physically posted on both the gate and on a secondary sign near the start of the auto 

tour route to prevent entrapments. Access to the River ‘S’ Unit is regulated by an automatic 

programmable gate off of 9th Avenue across the entrance road. 

Roads and Parking Areas 

Carty Unit. There are 0.3 miles of gravel roads maintained for public access on the Carty Unit. Prior 

to 2005, the road was a loop road of approximately 0.2 miles. The road and parking lot was 

expanded in the spring of 2005 to accommodate additional parking needs for Cathlapotle Plankhouse 

events and relocation of the refuge complex’s headquarters to the Carty Unit. The Carty Unit has 

two parking areas accessible from the public roads. The lower parking lot serves the restroom 

facilities, Cathlapotle Plankhouse, and Oaks to Wetlands trailhead. The upper parking lot functions 

as overflow parking for the lower lot and serves as parking for the headquarters. Three gates regulate 

public access from public roads within the Carty Unit. The primary gate is at the refuge’s entrance 

off of Main Avenue allowing public access during daylight hours by means of an automatic 

programmable gate. Another gate precludes public access to the Carty Unit from the parking area 

above the BNSF railroad tracks, while allowing vehicular access for railroad, refuge, refugeapproved, and public safety personnel. A third gate accommodates easement-granted access to 

adjoining private land while routing general public access through the automated programmable 

entrance gate.

Ridgeport Dairy Unit. Until 2005, the public had access to the Ridgeport Dairy from Vancouver, 

Washington, along Lower River Road (SR 501). The State closed Lower River Road at the refuge’s 

boundary due to road failure in July of 2005. In January 2006, the State abandoned its right of way 

from milepost (MP) 11.40 to MP 12.72, and transferred jurisdiction for that road segment to Clark 

County. Prior to the closure, Lower River Road offered elevated views of both the Columbia River 

and refuge. The paved road was utilized by the public for driving, hiking, and biking. The refuge

maintained three parking areas along the margins of the road for wildlife observation. The parking 

areas were additionally popular with anglers, for accessing to the Columbia River. 

Prior to the Lower River Road closure, the refuge maintained four gates along the terminal 1.25-mile 

segment of the road that bordered the Ridgeport Dairy Unit. Three of these gates restricted public 

access from Lower River Road to Service-owned roads, fields, facilities, and closed areas within the 

Ridgeport Dairy Unit. The fourth gate was an automatic programmable gate that limited access to 

the Ridgeport Dairy Unit to daylight hours. With the road closure, only one of three parking areas is 

functional along Lower River Road. All other parking areas are beyond the road closure. The 

automatic gate has fallen to disrepair and road access is blocked near the boundary by concrete 

barriers the State installed.

River ‘S’ Unit: The River ‘S’ Unit has a graveled 4.3-mile auto tour route open to the general public 

year-round. The auto tour route is restricted to vehicle traffic from October 1 to April 30, with foot 

traffic additionally allowed from May 1 to September 30. The auto tour route has three developed 

parking areas. The first parking area near the beginning of the auto tour route serves the visitor 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 5. Refuge Facilities and Public Use Programs 5-3 

contact station, restroom, and entrance fee collection kiosk. The next lot is paved and allows yearround access to a restroom, short trail, and observation blind. The last parking lot of the auto tour 

route offers seasonal, May 1 to September 30, access to the Kiwa hiking trail. The auto tour route 

also has several established turnouts to facilitate safe passage for faster moving vehicles. Off of the 

auto tour route, all service and hunter access roads are gated or cabled to prevent access into closed 

areas of the unit. Access to the River ‘S’ Unit is allowed during daylight hours and regulated by an 

automatic programmable gate off of 9th Avenue. The remaining road segment open to the general 

public is a road easement that connects 9th Avenue to the auto tour route. This 0.4-mile road segment 

parallels a forested canyon, crosses an easement over the railroad tracks, and accesses the River ‘S’ 

Unit by bridge. 

Approximately one mile into the auto tour route, a programmable gate regulates access to the River 

‘S’ Unit’s waterfowl hunt area and hunter check station. The gate only allows hunter access to the 

hunt area on refuge hunt days during the general waterfowl hunting season, currently Tuesdays, 

Thursdays, and Saturdays from mid-October to late January. Within the hunt area, there are 

approximately 2.8 miles of graveled road and 7 parking areas developed to serve the hunting area. In 

addition, a programmable gate near the hunter check station limits access at the Bachelor Island 

Bridge to refuge staff and authorized volunteers. 

Trails 

Carty Unit. Starting near the headquarters office is the 2-mile Oaks to Wetlands Trail. The Oaks to 

Wetlands trail starts with a pedestrian bridge over the BNSF railroad tracks and passes the 

Cathlapotle Plankhouse. Beyond the Plankhouse, the route is a series of braided trails that transect 

coniferous forests, oak woodlands, wetlands, and basalt outcroppings. With numerous loop options 

the trail can range from flat and developed to steep and rustic, as the visitor gets farther from the 

trailhead. The trail surface ranges from asphalt at the trailhead, to compacted gravel up to the 

Plankhouse, to native soil beyond the Plankhouse. The trail is open year-round during daylight hours 

except the north loop. The north loop is located on private property and is open with permission 

from the landowner from March 1 to September 30. The trail closure is posted along the trail during 

the winter months. The Oaks to Wetlands Trail was recognized by the Department of the Interior in 

June 2005 as a National Recreation Trail in the National Trail System. 

River ‘S’ Unit. The River ‘S’ Unit offers several trail options. The primary trail of the River ‘S’ 

Unit is the 1.1-mile Kiwa Trail. The Kiwa Trail is a loop trail open to the public seasonally from 

May 1 to September 30. The trail surface is flat consisting of compacted gravel and two short 

boardwalks and is well suited for visitors of all abilities. The trail provides visitors opportunities to 

view wildlife in a mix of floodplain habitats, including emergent wetlands, grasslands, and Oregon 

ash forests. Visitors are also currently allowed to seasonally hike the auto tour route from May 1 to 

September 30. Generally, the seasonal use of the auto tour route by pedestrians is for short walks 

from parked cars or parking lots to facilitate wildlife observation and photography. The length of the 

route, seasonal dust, and distraction of vehicles likely limits the use of the auto tour route as a major 

hiking trail. The other trail open to the general public on the River ‘S’ Unit is a short year-round 

asphalt trail through a gallery of Oregon ash connecting the observation blind to the parking area. 

Within the River ‘S’ Unit’s fee hunt area a trail network is seasonally mowed by refuge staff to 

provide waterfowl hunters access to designated hunting blinds. These trails are several miles in 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

5-4 Chapter 5. Refuge Facilities and Public Use Programs

length and to the fullest extent possible utilize secondary maintenance roads and internal dikes to 

reduce annual trail maintenance needs. 

Administrative Facilities 

Bachelor Island Unit. The Bachelor Island Unit contains the majority of the infrastructure associated 

with refuge maintenance and operations. The island has a large maintenance shop with four offices 

for refuge staff and partners. Other structures to support refuge maintenance include an equipment 

storage building, a hazmat building, a pump house, and fueling stations. Within the compound 

containing these facilities is one small government-owned farmhouse that serves as temporary 

quarters for refuge staff and volunteers. 

Carty Unit. The refuge’s headquarters is located off of Main Avenue one mile north of downtown 

Ridgefield. The headquarters currently consists of a prefabricated building with five offices 

accommodating seven staff members including contractors. The only other structure on the Carty 

Unit is the Cathlapotle Plankhouse, a replica Native American longhouse. The Plankhouse serves a 

primary environmental education function for the refuge, providing a tangible educational experience 

for sharing information about the refuge’s valuable cultural and natural resources. 

Roth Unit. The Roth Unit is undiked and remains in the floodplain of the Columbia River. 

Therefore, construction of permanent facilities has been limited. With the acquisition of Roth Unit 

parcels, the refuge acquired a small barn. Due to its remote location, the barn is not particularly 

functional and is generally not used by the Refuge. 

Ridgeport Dairy Unit. The Ridgeport Dairy Unit had a government-owned residence that provided 

living quarters for refuge staff and volunteers. The closure of Lower River Road limited access to 

this location and precluded residential use. Once the house was vacated, it became a frequent target 

of vandalism and break-ins. Evidence of illicit and criminal activities prompted the Service to 

demolish the building in 2008. 

River ‘S’ Unit. There are several administrative facilities on the River ‘S’ Unit. Largely, these 

structures are used for storage. They include a nine-bay shed, a three-bay covered area, and two 

small storage sheds. Near the entrance to the River ‘S’ Unit is a small building that serves as the 

visitor contact station. This building is staffed by refuge volunteers offering visitor information and 

orientation. The other administrative site on the River ‘S’ Unit is the hunter check station that serves 

as a seasonal office for a temporary check station employee. 

Easements and Rights-of-Way

The Service has been granted several important easements critical to accessing various units of the 

refuge. The 0.4-mile road that provides access to the River ‘S’ Unit from 9th Avenue is an easement

that was granted when the unit was acquired. Additionally, River ‘S’ access is achieved via an 

easement for at-grade crossings over the railroad tracks east of the River ‘S’ Bridge. Access to the 

Carty Unit for visitors is achieved via an easement for a pedestrian bridge over the railroad tracks. 

At-grade crossings over the railroad tracks to the Carty Unit are allowed by easement, but crossings 

are to be controlled by a locked gate. Other right-of-ways on record relate to water intake or 

discharge over second class tidelands in State jurisdiction, and utilities (phone/electric) crossing the 

refuge to serve refuge facilities. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 5. Refuge Facilities and Public Use Programs 5-5 

Dikes, Irrigation, and Water Control Structures 

Bachelor Island Unit. The wetland system on Bachelor Island was largely redesigned in 1998. New 

wetlands were created, select wetland basins were expanded, and several steep banked wetlands were 

re-contoured. Additional improvements were made to the water delivery and control systems 

including two new intake pumps, buried delivery pipes, delivery valves, and water control structures. 

There are 21 wetland basins on Bachelor Island with water management potential, including water 

control structures and water delivery capability. At full capacity, the refuge could manage nearly 400 

acres of wetlands on Bachelor Island. Realistically, the Columbia River’s water level, seasonal 

rainfall, and soil characteristics of each wetland basin dictate the overall acreage of wetlands 

managed on Bachelor Island. Most wetland basins on Bachelor Island collect water from seasonal 

rainfall, with approximately 250 acres of wetlands by mid-winter. Active irrigation of wetlands on 

Bachelor Island is reserved for select wetlands with proven water retention capabilities. All Bachelor 

Island wetlands drain with the island’s natural topography to the north, eventually feeding to a 

common drainage pond equipped with a series of expulsion pumps. 

Carty Unit. The Carty Unit is part of the Columbia River floodplain with no water management. 

Roth Unit. The Roth Unit is part of the Columbia River floodplain with no water management. 

Ridgeport Dairy Unit. Wetland improvements were initiated on the Ridgeport Dairy Unit in 1998 

with the re-contouring and disking of the Hillocks, Fingers, and Dusky marshes. The water system 

was improved with the installation of a pump station, delivery pipes, valves, and water control 

structures on the marshes. The three marshes (or basins) represent the managed wetlands of the 

Ridgeport Dairy Unit, designed with water delivery structures and dewatering infrastructure to 

regulate water levels. 

Campbell Lake has a water control structure on its south end that facilitates drainage for the Hillocks 

and Fingers marshes, but this structure is not intended to manage levels within Campbell Lake. 

Campbell Lake is still a floodplain wetland with direct connection to the Columbia River via 

Campbell Slough. Post Office Lake has partial water management capabilities in that it has a water 

control structure on its drain. Water delivery to the lake could be achieved by routing water through 

Dusky Marsh. The inefficiencies of this delivery mechanism coupled with the size of Post Office 

Lake make this water delivery option tenuous. Post Office Lake is additionally fitted with a 

‘duckbill’ tide gate to prevent floodwater from backfilling into the basin and fish entrapment within 

the wetland. 

River ‘S’ Unit. The River ‘S’ Unit is generally sloping from south to north. Water is expelled from 

the unit by pumps on the north end. Water intake is achieved through three pumps at two pumping 

stations. Both pump stations take water from Bachelor Slough. Tides impact operation of both 

pump stations limiting water availability during low tides. The northern pump station supplies a 

network of pipes and valves designed to either independently deliver water to four wetlands or to 

supplement water delivery to the main fill ditch. The southern pump station directly fills the main 

fill ditch. Water delivered to the main fill ditch gravity feeds into Bower Slough. When filled, 

Bower Slough serves as the water reservoir for filling most of the wetlands of River ‘S’ Unit. 

Earthen dikes and ditches from Bower Slough fitted with water control structures supply water to the 

wetland network.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

5-6 Chapter 5. Refuge Facilities and Public Use Programs

5.2 Recreation Overview

5.2.1 Open and Closed Areas

Open Areas. The Carty Unit is open year-round during daylight hours for wildlife-dependent 

recreation with most use occurring along the Oaks to Wetlands Trail. The auto tour route of the 

River ‘S’ Unit is open to vehicles year-round during daylight hours for wildlife observation and 

photography. Off of the auto tour route, the observation blind is open year-round for pedestrian 

access from the parking lot to the blind. 

Seasonally Open Areas. The Kiwa Trail and auto tour route on the River ‘S’ Unit are both open for 

hiking from May 1 to September 30 during daylight hours. The refuge was established primarily to 

offer wintering habitat for waterfowl, particularly dusky Canada geese. The selection of trail dates 

on the River ‘S’ Unit is strategic to separate pedestrians from wintering concentrations of waterfowl 

utilizing the area. The refuge provides a regulated, spaced-blind waterfowl hunt program on 

approximately 760 acres of the River ‘S’ Unit. Access to the 21-blind hunt area is permitted three 

days a week by fee during the regular State waterfowl season (mid-October to late-January). Hours 

for waterfowl hunter access in the hunting area are extended sufficiently before and after daylight to 

accommodate check-in and check-out procedures and provide hunting opportunities during all 

hunting hours. 

Closed Areas. Refuge-owned portions of the Bachelor Island, Ridgeport Dairy, and Roth Units are 

closed to public use. 

5.2.2 Annual Recreation Visitors

In close proximity to the refuge is the Portland metropolitan area with a combined population of over 

2 million people. During the 2007 fiscal year, the refuge had an estimated 93,241 visitors. Overall 

annual visitation of the refuge is rapidly growing. Figure 5.1 shows visitation trends expressed in 

averages for each decade since the refuge was established. Admittedly, the means and methods of 

reporting visitation data have been variable over the years, but the graph suggests a significant 

increase in public use with time. The data shows that the average annual visitation in the 1960s was 

just over 8,800 visitors. Visitation in the 1980s had grown to 22,000 visitors annually. The average 

number of visitors annually from 2000 to 2007 has been more than 162,000. The apparent decline in 

visitation in 2007 relates to both different methodologies in reporting visitation and to the closure of 

the end of Lower River Road. From 2000 to 2005, the public had access to the south end of the 

refuge from Vancouver, Washington. Recreational opportunities occurring along Lower River Road 

bordering the refuge formerly included wildlife observation, photography, hiking, jogging, fishing, 

and biking. The road closure in 2005 closed a popular access point to refuge parking areas and 

overlooks for multiple recreational opportunities and has reduced overall reported refuge visitation in 

recent years. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 5. Refuge Facilities and Public Use Programs 5-7 

Ridgefield National Wildlife Refuge

Average Annual Visitation

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

1960's 1970's 1980's 1990's 2005-

2007

Range of Years

Figure 5.1 Average annual visitation to Ridgefield Refuge, 1965-2007 

5.2.3 Annual Recreation Visits 

Recreational visits differ from overall annual visitors. A visitor is a member of the public coming to 

the refuge to participate in an activity. In most instances, a visitor may engage in multiple activities. 

For example, one visitor may watch birds along the Oaks to Wetlands Trail, visit the Plankhouse, and 

drive the auto tour route on their trip home. In this example, the visitor actually visited three distinct 

locations. The activities of the visitor are considered visits. One visitor can register multiple visits in 

one trip and the annual sum of visits is always more than the number of visitors. Visits are measured 

by a variety of direct and indirect methods. Trail and vehicular visits are measured by counters 

installed along these routes. Plankhouse, educational, hunting, and special event visits are directly 

counted by staff or volunteers conducting these activities. Other visit numbers may be estimated by 

staff and volunteers via informal observations of the frequency of an activity. The overall Ridgefield 

Refuge visit trends for Fiscal Year 2007 are exhibited in Figure 5.2. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

5-8 Chapter 5. Refuge Facilities and Public Use Programs

Fiscal Year 2007 Ridgefield National Wildife Refuge 

Visits 

0

10000

20000

30000

40000

50000

60000

Fishing

Waterfowl Hunt 

Environmental Education

Special Events

Photographic

Visitor Contact Stations

Talks/Interpretation

Kiwa Trail

Plankhouse

Oaks to Wetland Trail

Auto Tour Route

Activity or Facility

Visits

Number of Visits

Figure 5.2 Recreational visits to Ridgefield Refuge in fiscal year 2007, by type of visit 

5.2.4 Recreation and Entrance Fee Program 

The Federal Lands Recreation Enhancement Act authorizes Entrance and Recreation Fees for 

national wildlife refuges. The Ridgefield Refuge implemented a recreation fee of $3.00 per hunter 

for waterfowl hunting in 1976. The fee increased to $5.00 per hunter in 1980. From 1980 to 2006, 

the recreation fee for waterfowl hunting experienced some minor programmatic changes such as fees 

for the reservation lottery, annual waterfowl hunting passes, and a minimum blind fee. In October 

2006, the recreation fee for waterfowl hunting increased to $8.00 per hunter or $10.00 per blind, 

whichever sum is greatest. With a maximum capacity of three, a typical hunting blind may cost from 

$10.00 to $24.00. Using a Golden Age Passport, Golden Access Passport, Interagency Senior Pass, 

or Interagency Access Pass issued under the National Parks and Federal Recreation Lands Annual 

Pass program will reduce the recreation fee for waterfowl hunting for the individual passholder. The 

refuge offers an annual pass that covers the recreation fee for the passholder for the entire waterfowl 

season. Waterfowl hunters may optionally enter a lottery for reservations to hunt the refuge. The fee 

for lottery picks is $1.00 per date selected with a maximum of 30 potential picks per person per 

season.

The refuge added an entrance fee to its fee program in October 2006. The daily entrance fee for the 

refuge is $3.00 per vehicle. Additionally, an annual pass was established for entrance to the refuge

for $15.00. The refuge pass was priced comparably to a Federal Duck Stamp, which waives the 

entrance fee at any national wildlife refuge. Consistent with the Federal Lands Recreation 

Enhancement Act, the refuge additionally honors passes from the National Parks and Federal Lands 

Pass Program including the Interagency Annual Pass, Interagency Senior Pass, Interagency 

Volunteer Pass, Interagency Access Pass, Golden Age Passport, and Golden Access Passport. Fees 

collected under authority of the Federal Lands Recreation Enhancement Act are to be used by the 

refuge for very specific expenditures including visitor services, visitor information, signs, 

interpretation, law enforcement, visitor facility maintenance/enhancement, and habitat restoration 

directly related to wildlife-dependent recreation. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 5. Refuge Facilities and Public Use Programs 5-9 

5.2.5 Accessibility of Recreation Sites and Programs for People with 

Disabilities

The refuge contains facilities that are accessible to persons with disabilities. Some of the facilities 

are for persons with permanent disabilities who qualify under WAC 232-12-828. A brief description 

of accessible facilities follows.

Hunt Program Accessibility. Blinds 1A and 8 are accessible to persons with disabilities, as are 

restrooms within most parking lots in the hunt area. Blind 1A is reserved exclusively for persons 

with permanent disabilities who qualify under WAC 232-12-828. Non-disabled hunters may only 

access blind 1A as a hunting companion of a disabled hunter. Disabled hunters with reservations 

may select blind 1A without any competition for this blind. Multiple disabled hunters, who do not 

possess reservations, may compete in a random lottery specifically for blind 1A; hunters who do not 

win a spot for blind 1A may re-enter the general lottery to vie for blind 8. Blind 8, while accessible, 

is not specifically reserved for persons with disabilities and is subject to the reservation/lottery 

system imposed on the general waterfowl-hunting public. 

Accessibility of Wildlife Observation and Photography. The public use facilities on the River ‘S’ 

Unit have been designed for accessibility. The auto tour route is designed for wildlife observation 

from the comfort and safety of one’s personal vehicle. The two permanent restrooms along the auto 

tour route are of modern accessible design with paved approaches to the facilities. The parking lot 

for the River ‘S’ observation blind is paved with an asphalt trail connecting the lot to the ramps of the 

blind. Lastly, the Kiwa Trail consists of compacted fine aggregate and wood boardwalks over flat 

terrain suitable for visitors with disabilities. 

Accessibility of Interpretive Programming at the Cathlapotle Plankhouse. The Plankhouse is 

designed to be fully accessible for persons with disabilities. Visitors with permanent disabilities, 

who qualify under WAC 232-12-828, may request an accommodation to access the Cathlapotle 

Plankhouse by contacting the refuge headquarters. For special programming and events at the 

Plankhouse qualified flaggers are secured to facilitate railroad crossings in private vehicles to provide 

access to the Plankhouse. 

5.2.6 Law Enforcement

The refuge receives law enforcement coverage from a Service Zone Officer to support major public 

events, peak visitation periods, and hunting seasons. Zone Officers are assigned to multiple refuges 

and large geographic regions. They enforce special refuge regulations via periodic patrols of refuge

lands, protect resources, and maintain public safety. With the loss of law enforcement officers 

stationed on the refuge, there has been a reduction of field patrols and officer presence. 

The most common law enforcement issues encountered are violations of refuge closures (trespass 

into closed areas, present on the refuge after hours, and out of vehicles along the auto tour route 

during seasonal restrictions), waterfowl hunting violations (bag limit violations, taking birds out of 

season, and failure to check-out), vandalism (defaced signs), littering, trash dumping (household and 

commercial), and Entrance Fee Program noncompliance. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

5-10 Chapter 5. Refuge Facilities and Public Use Programs

5.3 Waterfowl Hunting

The National Wildlife Refuge System Improvement Act, passed by Congress in 1997, identified 

hunting as a wildlife-dependent, priority public use for the National Wildlife Refuge System. At the 

Ridgefield Refuge the waterfowl hunting program is operated in a manner that is consistent and 

compatible with the refuge’s purposes and goals, and provides a quality experience for the hunter. 

This program contributes to the continuation of America's traditions and heritage in wildlife 

conservation and outdoor recreation. 

The refuge’s waterfowl hunting program is designed to maintain hunt quality by regulating hunter 

density, while affording equal opportunity to all participants. The refuge has provided a public 

waterfowl hunting area since it was established. When the Migratory Bird Conservation 

Commission approved the establishment of the refuge on May 18, 1965, they included a provision 

that the refuge would provide “substantial public shooting” opportunities (see Chapter 1, Refuge 

Purposes). The establishing documents defined the public shooting opportunity as waterfowl 

hunting. The refuge’s waterfowl hunting program represents the only spaced–blind public hunt area 

in the local area. Currently, the refuge’s waterfowl hunting program permits the hunting of ducks, 

geese, and coot on approximately 790 acres, from 21 spaced blinds. The refuge continues to provide 

a prominent waterfowl hunting program in southwest Washington. Thirty-three percent of all ducks 

and 20 percent of all geese harvested in Clark County from 2002 to 2006 were harvested on the 

refuge (analysis compared to statistics reported in the State of Washington, Migratory Waterfowl and 

Upland Game Seasons, 2007-2008 Pamphlet Edition [WDFW 2007]). 

Please note: The following hunting statistics and program descriptions are inclusive of the 2006/2007 

hunting season, but do not capture more recent hunting datasets. 

Facilities. The refuge operates 12 box blinds and 10 pit blinds within its hunting area. There are a 

maximum of 21 blinds assigned on any particular hunt day. Blind 7 has both a pit or box option, 

allowing hunters to select between the blind styles based upon their preference. Due to proximity, it 

is not safe for a hunting party to split between the box and pit at blind 7. Blind 15 is a field blind best 

suited for hunting of geese and is typically not made available until the opening of goose season. 

Blinds 1A and 8 are accessible for people with disabilities. Blind 1A is reserved exclusively for 

persons with qualified permanent disabilities. Hunter volunteers and the Washington Waterfowl 

Association Lower Columbia Chapter have conducted annual maintenance on the refuge’s hunt 

blinds. The refuge conducts annual preparations for the hunt blinds, including mowing in areas 

surrounding the blinds to create open water, and managing water to flood the hunt area. 

Supporting access to the hunting blinds is a network of seasonally mowed trails, covering 

approximately 3.25 miles. These trails are mowed by refuge staff to provide waterfowl hunters 

access to designated hunting blinds. This trail network attempts to utilize secondary maintenance 

roads and internal dikes to reduce annual trail maintenance efforts. Sign maintenance to orient 

hunters to the designated blinds is conducted annually by hunter volunteers. Hunting facilities 

additionally include approximately 2.8 miles of graveled road and 7 parking areas utilized to support 

the hunting program. These roads are periodically graded, graveled, cleared, and mowed by refuge 

staff. The refuge owns 3 standard portable restrooms and 3 accessible portable toilets that are placed 

at major parking lots. Twice a month during the hunting season, these facilities are cleaned and 

maintained by a contractor. 
"j "

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Unit River S

Unit

Roth

Unit

Ridgeport

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Unit

S a u v i e

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Post

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Campbell

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Auto

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River S

Entrance

SR501 - Pioneer Street

To I-5

Oregon

Washington

122°45'0"W

45°45'0"N 45°45'0"N

T 4 N

T 3 N

T 4 N

T 3 N

R 1 W R 1 E

Produced in the D ivision of R ealty & R efuge Inform ation

Portland, O regon

Data C urrent to: 03/09/09

M ap D ate: 08/19/10

Basem ap: ES R I S H A D ED R E LIE F

M eridian: W ILLA M E TTE

File: 10-178-6.M XD

UT M ZO N E 10

NA D 83

Legend

Refuge Units Open to the Public

(See Regulations about Closed Areas within

these Units)

Refuge Units Closed to the Public

"

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Refuge Waterfowl Hunt Area

(Consult Refuge Office for Regulations)

Refuge Headquarters

"j Parking

"

_ Restrooms at Carty Unit, River 'S' Unit

and Observation Blind Parking Lots

"

[ Observation Blinds

Oaks to Wetlands Hiking Trail (2-miles)

Open Year Round

Kiwa Seasonal Hiking Trail (~1.5 miles)

Open May 1 - Sept.30

"

6 Cathlapotle Plankhouse

4.2-mile Auto Tour Route (Open Year Round)

Kayak/Canoe/Boat Route

(No Launching Facilities or Routes Located

on the Refuge.)

0 1 2 0.5

M iles

0 2.5 1.25

Kilometers

1:38,000

__________________________________________________________________________________________________________________________________ 

Chapter 5. Refuge Facilities and Public Use Programs 5-11
5-12
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 5. Refuge Facilities and Public Use Programs 5-13

The refuge staffs and operates a hunter check station within the hunting area of the River ‘S’ Unit 

during the waterfowl hunting season. To accomplish daily check station functions, a seasonal 

employee is hired to manage daily operations including sales of passes and duck stamps, blind 

assignments, reservations, fee collection, material and information distribution, and harvest and 

hunting data collection. 

Hunt Program History. Since the establishment of the refuge hunt program, measures have been 

implemented to manage the number of hunters and frequency of hunting to increase hunt quality. In 

1965, hunting occurred on Saturday, Sunday, and Wednesday. A maximum of 50 hunters were 

allowed on the hunt unit at any given time. There were no developed blinds and hunters constructed 

blinds from natural materials in the immediate landscape. During the 1967 to 1968 season the refuge

modified the hunt program by implementing a reservation/permit system for waterfowl hunting. This 

programmatic change was derived from issues associated with the previous first-come, first-served 

format that caused overnight ‘sweat’ lines, hunter confrontations, and vehicles parked on the onelane bridge and railroad crossing. Starting the 1967 to 1968 season, hunters possessing reservations 

were given priority for access to the hunt area over other hunters. Additionally, hunter distribution 

was regulated by the assignment of blind locations and the installation of 15 permanent blinds. 

Blinds were filled with two hunters either by partners appearing on the reservation card or forced 

pairings of single hunters on the day of the hunt. By 1969, the number of blinds had increased to 31, 

located approximately within the footprint of the current hunt unit of about 790 acres. 

The hunting program changed significantly in 1972 when flooding breached the River ‘S’ dike and 

destroyed the infrastructure of the hunt unit. During this hunt season, the hunt area became an open 

hunt replacing a controlled reservation hunt. During the 1972 season, the staff noted a loss of 

traditional hunters with an influx of inexperienced hunters and a general decline in hunting quality. 

After the season, the refuge received two petitions from hunting groups to rebuild the hunting 

infrastructure, restore habitat, and return to a controlled hunt. In 1974 a reservation system was 

reinstated and hunt areas had implemented requirements for steel shot. In 1975 the refuge started to 

restrict the number of shells that an individual hunter could possess and shoot on a particular hunt 

day to 25. Since the 1975 season, the number of shells had been limited to 20 to 25 shells per hunter, 

and a trial period of either a 12- or 20-shot limit depending upon the blind selected. 

The refuge’s hunt days have included a three-days-per-week schedule (including Saturday/Sunday/ 

Wednesday, Tuesday/Thursday/Saturday, and Monday/Wednesday/Saturday) and an alternating day 

schedule. The total number of hunting days has ranged from 29 to 46. Variability in the number of 

hunt days in a particular season may be subject to many elements, including length and framework of 

annual seasons, number of hunting days per week, holiday closures, severe weather events, and 

habitat conditions. In 1976, hunting did not occur until October 30th due to insufficient water in the 

hunt unit. 

Since the 1967-1968 season the refuge has regulated hunter distribution and density through blind 

assignments, except from 1972 to 1974 when infrastructure was lost to flooding. The number of 

blinds on the refuge has ranged from 31 to 19 over the years. Designated blinds have included a 

variety of styles including box blinds, stilt blinds, pit blinds, and ‘natural’ blinds concealed by 

surrounding vegetation. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

5-14 Chapter 5. Refuge Facilities and Public Use Programs

Number of hunters and harvest statistics. The refuge waterfowl hunting program has maintained 

hunter visit statistics over the years. The annual number of hunting visits is influenced by the 

number of hunt days in an individual season, which has ranged from 29 to 47 days since 1965. 

Additionally, annual visitation is also subject to the number of blinds available and maximum blind 

occupancy, which has been variable over the years. In an extreme situation, the refuge program 

could accommodate over 5,000 hunt visits in a single season. This would represent all blinds filled 

to capacity on every hunt day, with the refuge vacating hunters from the blinds midday for 

occupation by new hunt parties. Figure 5.3 shows the annual number of hunt visits to the refuge. 

This graph shows high visitation during the 1972 flood event that destroyed the infrastructure of the 

hunt program. 

Annual Number of Hunter Visits

0

500

1000

1500

2000

2500

3000

3500

4000

1960 1970 1980 1990 2000 2010

Figure 5.3 Annual number of hunter visits to the refuge, 1965-2007. 

During 1972 to 1974 the reservation system was suspended while infrastructure was being repaired, 

and the refuge hunt temporarily became an open free range hunt program. During this time, there 

was a general concern that the quality of the hunt program had declined. There was a dip in hunt 

visits during the mid 1980s, probably reflecting lower hunt participation during a period of poor 

nesting conditions and a consequent continent-wide depression in duck populations. Hunting 

participation increased as duck populations recovered and hunters returned to the field. 

Currently, the number of annual hunter visits to the refuge is approximately 2,000. This level of 

visitation represents a season ranging from 41 to 45 hunt days, a typical hunting party of 2 persons, 

selecting from up to 21 blinds (one blind is reserved for disabled hunters), and approximately 25 to 

30 blind assignments on each hunt day. Should every blind be selected on a hunting day, there 

would be 21 blind selections for that day. Therefore, 25 to 30 blind assignments suggests that most 

blinds were selected for a morning hunt and choice blinds that became vacant throughout the day 

were refilled. Refuge hunting statistics from the 1997 to 2001 hunt season show that 80 percent of 

the blinds were occupied during the morning draw and 65 percent of the blinds were occupied 

sometime after 10:00 am. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 5. Refuge Facilities and Public Use Programs 5-15

Figure 5.3 also shows a stable to increasing number of hunting visits to the refuge’s waterfowl 

hunting program over time, despite declining participation in waterfowl hunting statewide (Moore 

2007). The stability in hunting visitation relative to statewide declines may reflect diminishing 

public waterfowl hunting opportunities in the area. It could be inferred that as public hunting areas 

have become fewer, hunters become concentrated into the remaining areas. 

A 2003 projection for future participation in outdoor recreation in Washington State identifies a 15

percent decline in the number of participants in hunting and shooting activities from current levels 

over the next 10 years, and a 21 percent decline over the next 20 years (IAC 2003). In addition, 

fewer young hunters are being recruited into the sport. These statewide trends may eventually be 

reflected in a decline in numbers of hunters using the refuge, but no sign of decline has been noted to 

date.

Harvest Information: Review of annual refuge narrative reports and hunting reports show harvest 

trends for the refuge’s waterfowl program. While the harvest trends may suggest patterns, many 

complex variables may be governing the annual harvest of waterfowl. The harvest trends do not 

account for variability in Flyway populations, daily bag limits, seasonal closures, weather patterns, 

migration patterns, cropping regimes, and changes in hunt program and/or refuge management. 

These variables individually, or in tandem, may profoundly change the harvest trends over time. As 

an example, the daily bag limits for cackling geese has ranged from zero to four in the past decade. 

During this period, annual harvest of cackling geese was largely governed by annual hunting 

regulations, rather than the abundance or distribution of geese. The information reported in this 

section is used to estimate the size, scope, and nature of the refuge hunt program. Only simple data 

computations have been completed to show simple trend, user, and harvest statistics. Hunting 

statistics over the years have been gathered and reported in various formats. Incomplete data sets or 

breaks in the data reported have been omitted from the graphs. 

 

Over the years, the annual harvest of waterfowl has been recorded as birds harvested (ducks and 

geese) per hunter visit. The refuge’s average harvest since 1966 has been 1.46 birds per hunter. 

Since the 2000 hunt season, the annual harvest has been 1.56 birds per hunter. The range of annual 

harvest has been 0.7 birds per hunter in 1966 to 2.1 birds per hunter in 1969. The annual harvest of 

birds per hunter is shown in Figure 5.4. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

5-16 Chapter 5. Refuge Facilities and Public Use Programs

Figure 5.4. Annual harvest of birds per hunter at Ridgefield Refuge, 1965-2007. 

Over the years, the refuge’s waterfowl hunters have harvested an average of 2,376 ducks per year. 

Figure 5.5 shows the annual harvest of ducks at the refuge gathered from multiple reports and 

narratives. Data was not available for all years and has been omitted from the figure. The annual 

duck harvest has ranged from 1,256 ducks in 1986 to 4,425 ducks in 1969. Generally, the harvest of 

ducks has been increasing since the mid-1990s. Recently, the program averaged 3,928 ducks per 

year since the 2000 season. 

Annual Number of Ducks Harvested 

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Figure 5.5 Annual number of ducks harvested at the Ridgefield Refuge, 1965-2007. 

Annual Harvest of Birds per Hunter

0

0.5

1

1.5

2

2.5

1960 1970 1980 1990 2000 2010

Year
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 5. Refuge Facilities and Public Use Programs 5-17

The refuge waterfowl hunt program harvests a variety of duck species. Most of the ducks harvested 

from the refuge are dabbling ducks. Northern shoveler, northern pintail, mallard, American wigeon, 

green-winged teal, and gadwall are the most commonly harvested species. Select diving ducks are 

harvested on the refuge, most commonly including ring-necked ducks, buffleheads, and lesser scaup. 

Figure 5.6 shows the composition of most commonly harvested duck species from the refuge’s 

waterfowl hunt program over time. Data was not available for all years and has been omitted from 

the figure. The figure shows that shoveler, pintail, mallard, and wigeon collectively comprise 

roughly 75 percent of the ducks harvested. The relative distribution of the species harvest has 

changed over time. From 1966 to 1972, American wigeon represented 36 percent of all ducks 

harvested. Since the 2000 season, wigeon have comprised only 12 percent of all birds harvested. 

During the same time periods, harvest of shoveler has increased from 11 percent to 32 percent of the 

birds harvested. Mallard harvest has ranged over the years from 10 percent to 37 percent with an 

average harvest over the years of 20 percent of all birds harvested. Pintail harvest has ranged from 

13 percent to 19 percent with an average harvest over the years of 13 percent. Over the years bag 

limits and seasonal closures have been implemented to protect mallards and pintails from 

overharvesting. Changes in these annual regulations have an influence on the overall annual harvest 

of these species. 

Harvested Duck Species Composition 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

19661968197019721984198619881990199219971999200120032005

Year

Northern Shoveler

Northern Pintail

Mallard

American Wigeon

Figure 5.6 Species composition of ducks harvested at Ridgefield Refuge, 1966-2007. 

Prior to 2004 Canada geese were considered to be one species that was subdivided into numerous 

subspecies based on geographic range and variability in plumage and size. In 2004, smaller-bodied 

birds were split into a separate species, called the cackling goose (Branta hutchinsii). Larger-bodied 

birds retained the name Canada goose (Branta canadensis). In the Pacific Flyway, the Aleutian, 

cackling, and Taverner’s subspecies were reassigned to the cackling goose species. The lesser, 

dusky, western, and Vancouver subspecies remained within the Canada goose species. Goose data 

collected over the years from the refuge hunt program was largely gathered when the species was 

described as the Canada goose with 7 subspecies. To re-categorize this historic data into the current 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

5-18 Chapter 5. Refuge Facilities and Public Use Programs

species nomenclature would be a considerable project. Therefore, for the purpose of the following 

discussions, the goose harvest on the refuge will utilize the older nomenclature (Canada goose with 

seven subspecies). 

The refuge’s waterfowl hunting program allows harvest of geese consistent with State regulations 

and special conditions of the Western Washington Goose Management Area 2A. Nearly all geese 

harvested on the refuge are Canada and cackling geese. The harvest of snow geese and white-fronted 

geese is very rare, with none harvested in recent years. Figure 5.7 shows the annual harvest of geese 

attributed to the refuge’s hunt program. Over time the refuge’s hunt program has had an average 

harvest of 240 geese per year. The number of geese harvested in a particular season ranged from 50 

in 1974 to 666 in 1996. Since the 2000 season, the refuge has averaged 243 geese per year. The 

number of geese harvested annually is highly dependent upon the number of goose hunting days in a 

season. The refuge’s waterfowl hunt program is within Western Washington Goose Management 

Area 2A. Management Area 2A operates a quota system to reduce harvest of dusky Canada geese. 

The refuge is currently assigned a harvest quota consistent with the Dusky Management Plan. 

Should dusky harvest exceed the refuge’s quota, the refuge is authorized to implement an emergency 

area closure to its goose hunt season. In some seasons the refuge goose season has closed after 11 

goose hunting days to avoid overharvesting dusky Canada geese. 

 

Annual Number of Geese Harvested

0

100

200

300

400

500

600

700

1960 1970 1980 1990 2000 2010

Year

Figure 5.7 Annual number of geese harvested at Ridgefield Refuge, 

1966-2007. 

Historically, the refuge’s hunt program harvested a high percentage of dusky Canada geese. During 

the 1971 and 1972 seasons, the percentage of dusky Canada geese exceeded 60 percent of the overall 

Canada goose harvest. In comparison, duskys comprised 76 percent of the geese during the 

midwinter surveys of the lower Columbia River and Willamette Valley in 1971 and 1972 (Pacific 

Flyway Council 1997). Over time, limited dusky populations coupled with population increases in 

some other subspecies of Canada and cackling geese have diluted the overall percentage of dusky 

Canada geese wintering in the region. Since the 1970s, a northwardly change in the wintering 

distribution of cackling geese to the lower Columbia River and Willamette Valley has additionally 

reduced the composition of dusky Canada geese in the local area. In 1980, surveys located more than 

99 percent of the cackling geese wintering in California and near Klamath, Oregon. In 1998, more 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 5. Refuge Facilities and Public Use Programs 5-19

than 93 percent of cackling geese were surveyed on wintering grounds in the lower Columbia River 

and Willamette Valley (Pacific Flyway Council 1999). Overall these variables have considerably 

changed the composition of geese on the refuge. In 1969 dusky Canada geese were reported to 

represent from 30 to 60 percent of the wintering geese on the refuge. Data from 1998 and 1999 show 

dusky Canada geese comprising 3.4 percent of the geese wintering on the refuge. The increase in 

other subspecies in the region, too some degree, has reduced the harvest of the dusky subspecies. 

Cackling geese have comprised 66 percent of all geese harvested on the refuge since 2000. This is 

not surprising since cacklers are both numerous and relatively identifiable. Various game 

management strategies have been utilized over the years to reduce the harvest on dusky Canada 

geese. Wintering areas for the dusky subspecies operate a quota system, that when exceeded, can 

trigger area closures for goose hunting. Hunters are required to possess goose harvest permits that 

are revoked when a hunter harvests a dusky; therefore, the individual hunter is not allowed to hunt 

geese in the management area for the remainder of the season. Hunters must take a goose 

identification course and pass a test to obtain a permit to harvest geese in the wintering range for 

dusky geese. Collectively, these management measures and changes in the composition and 

distribution of wintering Canada geese may have reduced the annual dusky harvest. Since 2000 

dusky Canada geese represent 5 percent of all geese harvests. Figure 5.8 shows the subspecies 

composition of Canada geese harvested from the refuge’s waterfowl hunt program over time. Data 

was not available for all years and has been omitted from the table. 

Subspecies Composition of Harvest Canada Geese

0%

20%

40%

60%

80%

100%

120%

1966197019721984198619881994199619982000200220042006

Cackling

Western

Taverner/Lesser

Dusky 

Figure 5.8 Subspecies composition of Canada geese harvested on Ridgefield Refuge, 

1966-2007. 

Current Hunt Program. Waterfowl hunting (ducks, geese, and coots) is permitted on 

approximately 790 acres of the Ridgefield Refuge in accordance with Washington, Federal, and 

special refuge regulations. The refuge operates 21 spaced blinds that are assigned on both a 

reservation and standby system. Hunting is allowed on Tuesday, Thursday, and Saturday (excluding 

Federal holidays) during the regular State waterfowl season. The refuge’s goose season may close 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

5-20 Chapter 5. Refuge Facilities and Public Use Programs

early if the dusky Canada goose harvest exceeds the refuge’s harvest quota. Duck and coot hunting 

will continue to the end of the regular State season, regardless of the status of the goose season. 

• Hunting Reservations. Hunters may elect to participate in a random drawing for reservations 

to hunt the refuge. The season is split into three hunt periods, with a different application due 

date for each hunt period. Each hunter may select up to 10 hunt days per hunt period for 

entry into the reservation lottery. Each date picked for the lottery costs the hunter one dollar. 

After the due date a computer generated lottery is run for each hunt date in the hunt period. 

The computer selects 19 reserved names for each hunt date in the hunt period and a 

reservation number between 1 and 19. The reservation number corresponds to the order in 

which the hunter will select a blind on the day of the hunt, with the lowest number selecting 

first. A post card is generated for each hunter identifying their reservation date(s) and 

reservation number. During the 1997/1998 hunt season, the refuge received between 350 and 

400 applications per hunt period. 

• Program Operations. The gates to the hunt area open two hours before legal shoot time on 

refuge hunt days. Reservations are valid until 1 hour and 45 minutes before legal shooting 

hours on the reservation date. All hunters present must record their name and address by 1 

hour and 45 minutes before shooting time on a register. After a brief orientation, blind 

selection commences with the reservation hunter holding the lowest reservation number for 

that day selecting a blind first. The reservation holder may invite hunting partners up to the 

blind’s capacity of 3 persons. This process continues until all reservation holders have 

selected blinds. Typically, about half of the reservation holders attend for a particular hunt 

day leaving blinds available for other hunters. 

• Standby Hunters. Hunters present at 1 hour and 45 minutes before legal shooting time with 

their information recorded on the register may vie for unoccupied blinds during the morning 

hunt. Each hunt party is assigned a number that corresponds to a numbered ping pong ball. 

The balls are blindly drawn from a bucket establishing the order in which standby hunters 

will select blinds. In the event that a standby hunter does not like their blind options or all 

blinds are occupied. The standby hunter may secure a picking order on the 10 a.m. waiting 

list.

• 10 a.m. Lottery. Once blinds have been assigned in the early morning additional entry is 

allowed until 10 a.m. This allows hunters arriving early a quality hunting experience without 

additional hunters moving past their blind or throughout the hunt unit. At 10 a.m. hunters on 

the 10 a.m. waiting list may fill vacant blinds or pass on available blinds and reserve their 

picking order on the waiting list. Any new arriving hunters are subjected to an additional 

ping pong ball lottery that completes the waiting list for blinds. As blinds vacate throughout 

the day, blinds are refilled according to the order established by the waiting list. Typically, 

by midday all hunters from the waiting list and 10 a.m. lottery have selected blinds. Hunters 

arriving after the waiting list is exhausted, may select blinds on a first-come first-served 

basis. 

• Refuge Specific Regulations. The refuge imposes regulations specific to its hunt program 

with the intent of maintaining program quality, safety, and equality. These regulations are 

posted at the check station, announced during hunter orientation, printed on hunting fact 

sheets, and maintained on the refuge website.
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Chapter 5. Refuge Facilities and Public Use Programs 5-21

• Recreation User Fees. Hunting fees are assessed at $10 per blind or $8 per hunter; 

whichever sum is greater. This fee structure encourages higher occupancy in each blind, 

while potentially making more blinds available. The refuge’s hunt program additionally 

offers a season pass for hunting for $100. Golden Age Passports, Golden Access Passports, 

Interagency Senior Passes, or Interagency Access Passes issued under the National Parks and 

Federal Recreation Lands Annual Pass program will reduce the Recreation User Fee for 

waterfowl hunting for passholders by 50 percent. There is no fee for youth hunters, 15 years 

of age or younger. The Recreation User Fee was raised in 2006 from $10 per blind or $5 per 

hunter and $50 for season passes. The last major change in the fee structure was in 1980. 

With increases in costs for staff, maintenance, and supplies the fee increase in 2006 was 

required to make the program fiscally self-sustaining. 

• Youth Waterfowl Hunt. A youth hunt waterfowl hunting day is offered one day a year at 

Ridgefield Refuge. Hunting is free to all participants in the youth waterfowl hunting day. 

Reservations are accepted for the youth hunt by postcard early in the season. Reservations 

are generated by random drawing and selected youth are assigned a reservation number that 

determines the order in which they select blinds on youth hunt day. In 2007, the refuge

received 21 requests for participation in youth hunt day, all of which were issued 

reservations. A total of 17 youth participated in the program. To improve hunting success, 

the youth waterfowl hunting day is conducted in late October or November. Because of the 

low water levels on the refuge during the typical September youth hunts, the refuge could not 

offer a quality hunting experience during September. The youth hunt day is typically offered 

on a Sunday to avoid conflicting with both the refuge’s regular hunting schedule and school 

events.

5.4 Fishing

Fishing is allowed in areas open to the public on the Carty Unit, consistent with State fishing 

regulations. Under the CCP, the refuge will modify the existing Lake River Bridge in the River ‘S’ 

Unit to create a fishing pier from which anglers can access the State-owned waters of Lake River. 

Any other permanent or semi-permanent wetlands within the River ‘S’ Unit are within closed areas. 

Fishing in the Carty Unit occurs in various permanent water bodies throughout the unit. The lack of 

a significant native fishery on the refuge largely limits angling opportunities to warm water species 

including carp, bullhead, bass, and crappie. Fishing for salmon, steelhead, sturgeon, and other cold 

water fish is popular in the waters of the Columbia River. Fishing from boats and along the 

shorelines of Lower River Road and Bachelor Island is very popular seasonally. This use is adjacent 

to refuge lands utilizing either navigable waters or shorelines under State jurisdiction. 

5.4.1 Number of Visits

Staff estimates that the refuge has 260 fishing visits annually. This is a remarkable decline from 

when the refuge was established. From 1966 to 1970 the refuge narratives report an average of 2,343 

annual fishing visits accounting for approximately 25 percent of all recreational visits. During these 

years the average number of fishing and hunting visits were approximately the same. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

5-22 Chapter 5. Refuge Facilities and Public Use Programs

5.4.2 Facilities 

Salmon, steelhead, and sturgeon fishing is very popular in the region. Angling for these cold water 

species requires direct access to the Columbia River or its tributaries and shorelines. Multiple 

agencies in the area have developed facilities supporting this type of angling, including boat 

launches, cleaning stations, docks, parking areas, restrooms, and trails within very close proximity to 

the Columbia River. Within 10 aerial miles of the refuge boundary there are 9 public boat launches 

into the Columbia or its tributaries in Washington State. Additionally, there are many more public 

recreation sites with shoreline or dock-based public fishing facilities within close proximity of the 

refuge. The refuge has no developed facilities specifically for fishing. The parking lot and restroom 

facilities at the River ‘S’ Unit entrance serve shoreline anglers of Lake River. Similarly, the Carty 

Unit parking lot, restrooms, and footbridge facilitate fishing of this portion of the refuge. 

5.5 Wildlife Viewing and Photography

5.5.1 Number of Visits

Most visits associated with wildlife observation and photography occur along the 4.3-mile auto tour 

route. Currently, the auto tour route has about 55,000 visits per year. Visitors to the auto tour route 

have year-round access to the observation blind for wildlife viewing and photography. Additionally, 

The auto tour route provides seasonal access (May 1 to September 30) to the 1.1-mile Kiwa Trail, 

which has approximately 6,500 annual visits. The Carty Unit’s Oaks to Wetlands Trail is open yearround for wildlife observation. Visitation to the Oaks to Wetlands Trail is estimated at 

approximately 25,000. 

Currently, the number of photographic visits is estimated at 4,030. Photographic visits are difficult 

to quantify since visitors engaged in hunting, fishing, education, or wildlife observation may 

additionally be taking pictures. Without extensive surveys, the number of photographic visits is a 

rough estimate based on staff observations. It seems apparent in recent history, that the development 

of digital photographic equipment has increased wildlife photography visits on the refuge. More 

frequently, visitors have cameras or camera phones as part of their recreational equipment. 

Increasingly, the refuge has been attracting professional or serious recreational photographers using 

window mounts, high-power lenses, and digital single-lens reflex camera equipment along the auto 

tour route. The auto tour route provides photographers and wildlife observers access to a mix of 

habitats, close proximity to wildlife, and open sight lines from the shelter and comfort of their own 

vehicle. 

5.5.2 Facilities 

The auto tour route, Oaks to Wetlands Trail, and Kiwa Trail are maintained to accommodate wildlife 

observation and photography. The River ‘S’ Unit’s observation blind is an additional facility 

designed to offer wildlife viewing over sanctuary areas. In 2006 the aging observation blind was 

demolished, redesigned, and replaced by refuge and community partners as a memorial of a long 

time refuge advocate. In addition to the viewing opportunities from the designated facilities 

mentioned above, informal wildlife viewing and photography is also available from the parking lot at 

the end of Lower River Road. Wildlife observation and photography can occur from open 

undeveloped portions of the Carty Unit. The refuge is bordered by navigable rivers attracting a 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 5. Refuge Facilities and Public Use Programs 5-23

growing number of canoeists and kayakers. Staff-led access to closed areas for wildlife observation 

and photography is granted for special events and tours, including BirdFest. 

5.6 Environmental Education

5.6.1 Number of Visitors

The environmental education program at Ridgefield provides programs to more than 3,100 students 

and adults annually. 

5.6.2 Facilities

Educational visits are primarily served on the Carty Unit. Select schools will elect to drive the auto 

tour route enroute back to school. The Plankhouse and Oaks to Wetlands Trail is the primary 

attraction for educational visits. Most schools elect to divide their groups to alternate visitation 

between the trail and the Plankhouse. Other simple necessities utilized by educational visits include 

parking lots and restrooms. 

5.6.3 Environmental Education Program Details

The refuge’s support groups−the Friends of Ridgefield National Wildlife Refuge and the Friends of 

the Cathlapotle Plankhouse (Friends groups)−have significantly contributed to the development and 

support of the education program. They have also raised transportation funds to reimburse schools 

for bussing costs to the refuge. The Friends groups have been instrumental in scheduling and 

conducting teacher workshops. They have offered specific training for volunteers working with 

educational visits and have formed a committee to improve the refuge’s education program to better 

align with grade levels and State standards. Collectively, the Friends groups are working to supply 

interpretive and educational equipment, supplies, and materials. They have additionally funded a 

Plankhouse Coordinator position for two years. The Plankhouse Coordinator has been invaluable in 

scheduling educational visits, developing activities/content, and directly working with students. 

For cost and logistical efficiencies, schools frequently send an entire grade to the refuge in a single 

visit. This might consist of 3 or 4 classes of 75 to 120 students. Staffing such visits is problematic. 

Typical staffing for these groups draws upon the Plankhouse Coordinator, the refuge’s Instructional 

Systems Specialist, and volunteers. The large magnitude of such a visit is difficult to program and 

compromises the quality of students’ experiences. When possible, groups of under 60 students are 

encouraged to attain a high ratio of adult chaperones to students (1 chaperone for every 10 students). 

Currently, all grades are welcome; however, we are working on revising the educator’s guide, to 

focus on specific grade level content particularly suited to a refuge visit (e.g. Native American 

Studies, Plants, Animal Adaptations). 

The cool and wet weather of the Pacific Northwest makes winter educational visits to the refuge

challenging. During the winter, the only shelter for any educational programming is within the 

Plankhouse. Because replica items, mats, and skins are stored in the Plankhouse, educational groups 

are not allowed to eat in the facility due to the potential of stains, spills, and attracting pests. 

Therefore, all other educational activities, programming, and lunch is outside without seating or 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

5-24 Chapter 5. Refuge Facilities and Public Use Programs

shelter. As a result, most education visit requests come in the spring. During 2007 56 percent of all 

educational visits during the school year were scheduled during May and June. 

5.7 Interpretation/Outreach

The refuge has produced and maintains an inventory of general brochures and wildlife checklists. 

The refuge’s Web site (www.fws.gov/ridgefieldrefuges) is managed by the Refuge Complex, current 

refuge information can be obtained at any time. Annually, the refuge produces a ‘tear-sheet’ with 

refuge regulations and a map for the waterfowl hunt program. The refuge is lacking in interpretive 

signage with most signage focused on visitor orientation (i.e. maps) and regulation. Previous 

interpretive signs at the refuge were very dated and in poor condition. They were removed several 

years ago and replaced with temporary signs produced on large format laminated paper. These signs 

were deteriorating and were removed, leaving interpretive kiosks empty. The need for interpretive 

signage will be addressed in this plan. 

Refuge volunteers staff a visitor contact station at the entrance to River ‘S’ Unit roughly 4 to 6 days a 

week. Those staffing the contact station are particularly interested in wildlife, wildlife observation, 

and photography. As a visitor service, they maintain and post significant wildlife sightings and offer 

visitor orientation. It is conservatively estimated that volunteers made 3,500 to 4,000 visitor contacts 

in 2007. 

Refuge outreach includes off-site talks and presentations upon request. These are conducted by both 

refuge staff and volunteers. The refuge annually participates in the Fourth of July Celebration in 

Ridgefield. This is a very popular event attracting thousands of people. The refuge designs a float 

for the parade and staffs a booth during the events of the day. The refuge attends other local outreach 

events like the Hometown Celebration and Night Out barbeque. Periodically, staff and volunteers 

will participate in other regional events such as the Clark County Fair, Home and Garden Ideas Fair, 

Wapato Days, and the Sturgeon Festival. 

In October the Friends of the Ridgefield National Wildlife Refuge hold a wildlife festival, known as 

BirdFest. BirdFest celebrates with National Wildlife Refuge Week and coincides with the peak 

migration of sandhill cranes through the area. The festival is in its seventh year and continues to 

grow, attracting approximately 3,500 visitors in 2007. Events are scheduled for an entire weekend 

and include guided van tours, hikes, wildlife viewing, tours of sanctuary areas, archeological/Native 

American interpretation, kayak tours, raptor shows, exhibits, and children’s activities. BirdFest has 

become a premier opportunity for the public to learn more about the refuge, wildlife, and the Refuge 

System. 

5.8 Cultural Resources Interpretation

Since its construction in 2004 the Cathlapotle Plankhouse continues to attract thousands of visitors 

annually. Over the past two years, there have been approximately 7,500 annual visits to the 

Plankhouse for interpretation. This count is actually the number of contacts made by trained 

Plankhouse docents with members of the public when the facility was open and staffed. The number 

of visits to the Plankhouse outside the hours of operation is difficult to assess. Typically, the 

Plankhouse is staffed by volunteers on Friday, Saturday, and Sunday afternoons (noon to 4:00 p.m.) 

from late March to early November for walk-in visitation by the public. This schedule is variable 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 5. Refuge Facilities and Public Use Programs 5-25

upon the availability of a minimum of 2 docents to have the facility adequately staffed. An advance 

schedule of operation is maintained by the Plankhouse Coordinator on a website 

(www.plankhouse.org). Visitors with disabilities requiring access accommodations, or groups can 

prearrange to visit the Plankhouse during other times of the week. Specially arranged group and 

educational visits continue throughout the winter months. 

Programming at the Plankhouse is quite variable. At a minimum, a walk-in visitor is able to talk 

with a trained docent and experience artifacts, replica goods, and the artwork within the facility. 

Prearranged groups will additionally have a brief presentation in the Plankhouse about cultural 

resources or related topics. To some degree, these presentations are driven by the individual group’s 

interest or expertise of the presenter. The Plankhouse Coordinator also regularly schedules Native 

American craft/skills workshops with limited enrollment for volunteer and visitor enrichment. 

Annually, content specialists offer tours and presentations for special events like BirdFest. These 

events are very popular, often attracting capacity crowds to the Plankhouse. Topics for these 

presentations include refuge archeology, local history, Native American culture, ethnobotany, 

cultural resources, and Tribal interpretation. Grants received in 2007 expanded the opportunity for 

cultural interpretation during the spring and summer of 2008. Other outreach and educational 

materials related to the Cathlapotle Plankhouse include monthly newsletters, a website, and fact 

sheets.

The Chinook Tribe was an active partner in Plankhouse since its inception. The Tribe and the refuge

work together to interpret, educate, and recover the natural and cultural history of the refuge through 

the historical-representative Chinookan Plankhouse. Creating an opportunity for the Tribe to practice 

their cultural heritage is one of the purposes of the Plankhouse, and currently, it is used by the Tribe 

for activities and cultural events. 

5.9 Nonwildlife-Dependent Recreation

5.9.1 Recreational Boating and Waterskiing

Pleasure boating, waterskiing, canoeing, and kayaking are popular activities on the navigable 

waterways adjacent to the refuge. When these activities are conducted within navigable waters of 

Lake River, Bachelor Slough, and the Columbia River, they have minor, direct impacts to the 

refuge’s wildlife resources. However, over the years the refuge is experiencing habitat loss along the 

shorelines of the Carty, Roth, and Ridgeport Dairy units as wakes from ships and recreational boats 

are eroding some high banks. Short sections of rip-rap have already been used as an armament along 

Bachelor Slough and Lake River in areas exhibiting erosion. 

5.9.2 Camping, Beach Use, and Swimming

Beach use along Bachelor Island has occurred for many years. Seasonally, the Bachelor Island 

shoreline attracts anglers, hunters, boaters, and campers. In 2007 the refuge was alerted about an 

internet blog promoting the shores of Bachelor Island as a satellite location for nudists from Sauvie 

Island, Oregon. All of the Island’s user groups access the shoreline by boat. These activities 

primarily occur on WDNR property bordering the refuge. However, trespass into sanctuary areas of 

Bachelor Island has been observed. A primary concern is disturbance of wildlife within closed areas 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

5-26 Chapter 5. Refuge Facilities and Public Use Programs

of the refuge. Additionally, no facilities are present to serve these groups and temporary ‘out houses’ 

made of tarps and driftwood are found throughout the area. Summer campers also assemble 

makeshift houses out of scrap wood and tarps. At the end of the camping season, these sites are 

abandoned along with considerable trash and discarded camping gear. 

5.9.3 Horseback Riding, Bicycling, Jogging, and Dog Walking.

Horses and horseback riding, bicycling, jogging, and dog walking were all discontinued in 1998. 

Waterfowl hunters are encouraged to use retrievers as an effective method of recovering harvested 

waterfowl. Hunting dogs must remain on a leash except when at the blind and must be under the 

control of its owner at all times. 

5.10 Illegal Uses

The Ridgefield Refuge has been negatively affected by vandalism, theft, garbage dumping, area 

closure violations, after-hours trespass, illegal shooting, drug activity, and off-road vehicle use. 

These illegal uses may occur in any location; however, a problematic site is the Ridgeport Dairy 

Unit. Illegal uses persist partly because of the remoteness of the site, inadequacy of physical barriers 

(i.e. for off-road vehicles), and limited law enforcement capability. 

5.11 Area Outdoor Recreational Opportunities and Trends

5.11.1 Nearby Recreational Opportunities

The refuge, located approximately 20 miles from the Portland Metropolitan area, is within a 

reasonable driving distance for recreational day visits. It is estimated that 66 percent of all refuge

users are from Clark County Washington and Multnomah, Clackamas and Washington counties in 

Oregon. The proximity to these population centers creates a high demand for recreational 

opportunities. Local and regional governments have developed recreation departments to support the 

recreational demand of the local citizenry. Collectively, the recreation programs for nearby 

metropolitan areas (Clark County, Vancouver, Portland, and Tualatin Hills) manage approximately 

18,000 acres of parks and 300 miles of multiple-use trails for hikers, bicyclists, and equestrians (City 

of Portland 2009; Clark County Parks and Recreation 2006 and 2007; and Metro Regional 

Government 2003 and 2009). Clark County has other significant lands managed as open public 

space by Washington Department of Fish and Wildlife, Gifford Pinchot National Forest, National 

Park Service, WDNR, State Parks, Clark County Parks, and other entities totaling over 60,000 acres 

(Clark County Parks and Recreation 2007). Other popular recreation locations within southwest 

Washington include the Mt. St. Helens National Monument and recreational sites within the 

Columbia River Gorge National Scenic Area. 

5.11.2 Outdoor Recreation Rates and Trends

A small State agency, the Recreation and Conservation Office (RCO) (formerly known as the 

Interagency Committee for Outdoor Recreation, or IAC), advises the State of Washington on matters 

of outdoor recreation. The RCO conducts an inventory of outdoor recreation sites and opportunities, 

conducts studies of recreational participation and preferences, and periodically releases the State 

Comprehensive Outdoor Recreation Plan (SCORP) and related documents. 
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Chapter 5. Refuge Facilities and Public Use Programs 5-27

Current Participation Rates. The most recent SCORP (RCO 2008) and associated recreation 

survey (Clearwater Research 2007) identified 15 major categories (activity areas) of outdoor 

recreation, subdivided into more than 170 recreational activities. Of these 15 major categories, 

surveys identified walking/hiking and nature activities as the most popular, with 73.8 percent and 

53.9 percent of Washington state residents participating in these activities, respectively. In terms of 

specific recreational activities, the RCO study indicated that walking without a pet in a park or trail 

setting was the most popular activity (47.8 percent of Washington residents participated in 2006) 

while observing/ photographing nature and wildlife was the second most popular activity, with 

participation rates of 39 percent. Table 5.1 shows participation prevalence and frequency for 

activities that are either currently allowed at the refuge or were allowed in the past but discontinued. 

Table 5.1 Participation Frequency for Selected Outdoor Recreational Activities in 

Washington State. (Table includes those recreational activities which currently or formerly 

occurred on the refuge and adjoining lands and waters.)

Source: Washington State Recreation and Conservation Office 2006 Outdoor Recreation Survey (Clearwater Research 2007)

1. Frequency is defined as the number of times the activity was performed annually, based on peak month data for that activity; 

therefore, this describes a lower bound for the activity (Clearwater Research 2007). 2. “Rural trail system” was chosen rather 

than “mountain or forest trail” as better representing the activity on the refuge. 3. Occurs on waters adjacent to the refuge

Major Activity Area

Recreational Activity

Rank

Percent of WA 

Residents 

Participating (2006)

Number of 

Participants 

(2006)

Participation 

Frequency1 

(2006)

A. Current Refuge Activities 

Walking/Hiking

- Walking without a pet, in a park or 

trail setting

1 47.8% 3,002,421 13,513,508

- Hiking in a rural trail setting2 15% 941,208 2,125,099

Nature Activities

- Visit nature/interpretive center 15.9% 999,287 1,141,213

- Observe/photograph wildlife/nature 2 39% 2,453,243 35,212,304

- Gather/collect berries/mushrooms 11.8% 742,512 1,314,800

Fishing

- Fishing from a bank, dock, jetty 

(freshwater)

13.6% 853,534 1,860,886

Hunting / Shooting

- Hunting Waterfowl 2.5% 156,729 172,810

Water Activity

- Canoeing/kayaking—freshwater3 16.2% 1,019,678 920,451

B. Past Refuge Activities

Walking/Hiking

- Walked with a pet (site not designated) 3 31.1% 1,961,279 1,961,279

Team/Individual Sports, Physical 

Activity

- Jogging/Running on a trail 17.5% 1,099,247 5,086,921

Bicycle riding

- Bicycle riding, rural trail system2 10.7% 671,723 1,589,353

Equestrian Activity

-Horseback riding, rural trail system2 2.4% 150,998 376,578
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

5-28 Chapter 5. Refuge Facilities and Public Use Programs

It must be noted that there is a major discrepancy between the estimated number of waterfowl 

hunters in 2006 as reported in the RCO study (projections based on survey data), and actual numbers 

reported by WDFW (WDFW 2007). The RCO estimated than more than 156,000 Washington 

residents participated in waterfowl hunting in 2006 while WDFW reported that approximately 27,000 

residents participated in this activity. This raises the question of whether RCO’s survey methodology 

resulted in a higher percentage of hunters being surveyed than are present in the general population, 

or whether estimated participation is higher than actual participation in multiple categories. The 

RCO survey may have captured individuals who formerly hunted but no longer do so. Still, the study 

does provide a broad basis of comparison of participation in recreational activities. 

Forecast of Future Regional Recreation Demand and Key Recreation Needs. Overall, outdoor 

recreation activity in most activities continues to increase at high growth rates. In a recent technical 

report (IAC 2003), IAC projected future participation in 13 of 14 major outdoor recreation use 

categories over periods of 10 and 20 years. Nine of these activities will experience double digit 

growth (see Table 5.2). 

These most recent estimates of recreation trends were based on the National Survey on Recreation 

and the Environment Projections for the Pacific Region (NSRE), which includes Washington. The 

NRSE’s projections were adjusted by IAC as necessary based on age group participation, estimates 

of resource and facility availability, user group organization and representation, land use and land 

designations; and “other factors” including the economy and social factors. Table 5.2 shows the 

percent change expected for Washington State by activity as reported in the 2003 IAC report. 

Many outdoor activities generally permitted on refuges are expected to show increases of 20 percent 

to 40 percent over the next 20 years. The exceptions are hunting, in which participation is expected 

to fall by about 20 percent within the next 20 years, and fishing, in which participation is expected to 

fall by about 10 percent within the next 20 years. 

Trends in Waterfowl Hunting in Washington. Note: The following discussion is based on data 

collected by the Washington Department of Fish and Wildlife (Moore 2007). Between 1962 and 

1971, there was an increase in the number of waterfowl hunters in Washington, from 70,000 to 

100,000. This increase, along with the loss of waterfowl habitat and hunting opportunities in 

southwest Washington, added weight to the MBCC’s decision to name waterfowl hunting, along with 

protection of migration and wintering habitat for waterfowl, as a refuge purpose in 1964. 

Throughout the 1970s, the number of waterfowl hunters in Washington was relatively stable at 

approximately 90,000. Beginning in 1980 there was a precipitous decline; by 1990 numbers had 

dropped to 30,000. While some ascribe the decline to more restrictive regulations and lower bag 

limits, the WDFW report notes that the decline actually began at a time of liberal regulations and bag 

limits. Other factors which could explain the decline include increasing urbanization and loss of 

waterfowl habitat in Washington, and declines in duck populations due to low nesting success in the 

mid 1980s, which caused some hunters to abandon the sport. As duck populations recovered, some 

hunters did return; this may account for the modest rise in numbers between 1990 and 1999 (from 

30,000 to 40,000). The years 2001-2005 saw continued declines, down to a low of 22,000 waterfowl 

hunters in the 2004-2005 season. Numbers increased between 2005 and 2007 to approximately 

27,000 hunters. While the number of waterfowl hunters remains low compared to historic highs of 

the 1970s, the success rate (number of ducks harvested per hunter) has actually increased. This could 

be due to lower numbers of hunters in the field, and the most dedicated and skilled hunters remaining 

in the sport. Participation in hunting is expected to decline in Washington by approximately 20 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 5. Refuge Facilities and Public Use Programs 5-29

percent by 2022 (see Table 5.2) for a number of reasons, including an increasingly urban population 

with no established hunting tradition, fewer hunt opportunities, and no recruitment of new hunters. 

While the number of waterfowl hunters in Washington State has declined greatly since 1970, the 

number of waterfowl hunt visits at the refuge has remained remarkably constant over the past 30

years, at approximately 2,000 visits annually (see page 12). This implies that with fewer public 

hunting opportunities in southwest Washington, waterfowl hunters are crowding into remaining 

areas. Convenience and ease of access may also make Ridgefield attractive to waterfowl hunters.

Table 5.2 Projected Future Changes in Participation for Selected Outdoor Recreation 

Activities

Activity

Estimated Change, 

10 years (2002-2012)

Estimated Change, 

20 Years (2002-2022)

Walking1 +23% +34%

Hiking1 +10% +20%

Nature Activities1 (includes outdoor photography, 

observing wildlife and fish, gathering and collecting, 

gardening, and visiting nature interpretive centers)

+23% +37%

Bicycle riding2,3 +19% +29%

Canoeing/kayaking3 +21% +30%

Fishing1 -5% -10%

Hunting / Shooting1 -15% -21%

Equestrian2 +5% +8%

Source: IAC (2003). 1 Use allowed on refuge in select areas. 2. Use formerly allowed on select areas of refuge but discontinued. 

3 Use not allowed on refuge but occurs or public lands or waters adjacent to the refuge

5.12 References 

City of Portland, Oregon. 2009. Portland Parks and Recreation. URL: http://www.portlandonline.com/parks/index.cfm?c=38281

Clearwater Research, Inc. August 2007. Washington State Recreation and Conservation Office 

2006 Outdoor Recreation Survey. URL: 

www.rco.wa.gov/documents/rcfb/Recreation_Trends/2006RecSurveySummary.pdf

IAC. 2002. An Assessment of Outdoor Recreation in Washington State. A State Comprehensive 

Outdoor Recreation Planning (SCORP) document 2002-2007. 

IAC. 2003. Estimates of Future Participation in Outdoor Recreation in Washington State: Technical 

Report by the Interagency Committee for Outdoor Recreation. URL: http://www.rco.wa.gov/ 

documents/rcfb/Recreation_Trends/Est_Future_Participation_Outdoor_Rec_3-03.pdf

Metro Regional Government. 2009. Regional trails and greenways system. Accessed online 

http://www.oregonmetro.gov/index.cfm/go/by.web/id=595/level=3

Metro Regional Government. 2003. Regional trails and greenways: connecting neighborhoods to 

nature. URL: library.oregonmetro.gov/files/trailsgreenways.pdf
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

5-30 Chapter 5. Refuge Facilities and Public Use Programs

Moore, Mikal. 2007. Waterfowl status and trend report: statewide winter waterfowl populations and 

harvest, in: Washington Department of Fish and Wildlife 2007 Game status and trend report. 

Washington Department of Fish and Wildlife, Olympia,WA. URL: 

wdfw.wa.gov/wlm/game/status/07trend.pdf

National Flyway Council and Wildlife Management Institute. 2006. National duck hunter survey 

2005, national report. URL: http://www.ducksurvey.com/report/ducksurvey_national.pdf

Pacific Flyway Council. 1997. Pacific Flyway management plan for the dusky Canada goose 

(Unpublished report). Dusky Canada Goose Subcomm., Pacific Flyway Study Comm. U.S. Fish and 

Wildlife Service, Portland, OR. 

Pacific Flyway Council. 1999. Pacific Flyway Management Plan for the Cackling Canada Goose. 

U.S. Fish and Wildlife Service, Portland, OR. 

Pacific Flyway Council. 2008. Pacific Flyway management plan for the dusky Canada goose 

(Unpublished report). Dusky Canada Goose Subcomm., Pacific Flyway Study Comm. U.S. Fish and 

Wildlife Service, Portland, OR. 

Trost, R.E., J.S. Gleason, T.A. Sanders. 2007. Pacific Flyway Data Book: waterfowl harvest and 

status, hunter participation and success in the Pacific Flyway and United States. U.S. Fish and 

Wildlife Service, Portland, OR. 

Vancouver-Clark Parks and Recreation Dept. 2006. Clark County Regional Trail & Bikeway 

Systems Plan. URL: www.ci.vancouver.wa.us/parks-recreation/parks_trails/trails/index.htm

Vancouver-Clark Parks and Recreation Dept. 2007. Vancouver-Clark Comprehensive Parks, 

Recreation, and Open Space Plan. Prepared by MIG Inc., Eugene, OR. URL: 

http://www.cityofvancouver.us/parks-recreation/parks_trails/planning/pdf/compplan.pdf

Washington Dept of Fish and Wildlife (WDFW). 2007. State of Washington, Migratory Waterfowl 

and Upland Game Seasons, 2007-2008 Pamphlet Edition. WDFW, Olympia, WA. 

U.S. Fish and Wildlife Service (USFWS), and U.S. Census Bureau. 2003. 2001 National Survey of 

Fishing, Hunting, and Wildlife-Associated Recreation: Washington (revised 2003). U.S. Fish and 

Wildlife Service, Portland, OR. 

USFWS and U.S. Census Bureau. 2007. 2006 National Survey of Fishing, Hunting, and WildlifeAssociated Recreation. U.S. Fish and Wildlife Service, Portland, OR. 

USFWS and U.S. Census Bureau. 2007. 2006 National Survey of Fishing, Hunting, and WildlifeAssociated Recreation: State Overview, Preliminary Findings. July 2007. U.S. Fish and Wildlife 

Service, Portland, OR. 

Washington State Recreation and Conservation Office. June 2008. Defining and Measuring 

Success: The Role of State Government in Outdoor Recreation, A State Comprehensive Outdoor 

Recreation Planning Document. URL:

www.rco.wa.gov/documents/rcfb/Recreation_Trends/SCORP_2008.pdf
Chapter 6. Special Designation Lands,

Cultural Resources, and

Social/Economic Environment

A replica plankhouse gives visitors glimpses of life at Cathlapotle, a Chinookan town that stood

on the Refuge until the 1830s. /USFWS

Roots of the wapato plant were a major trade item

and a “staff of life” for the Cathlapotle Chinookans /

USFWS
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 6. Special Designations, Cultural Resources, and Social/Economic Environment 6-1 

Chapter 6. Special Designation Lands, Cultural Resources, 

and Social/Economic Environment

6.1 Special Designation Lands

This section discusses sites or areas on the Ridgefield Refuge that have been assigned special 

designations by local, county, State, Federal or international governments, and in some cases 

nongovernmental organizations, so that these sites receive special management consideration. The 

areas discussed in detail below include the Blackwater Island Research Natural Area (RNA), sites 

listed under the National Register of Historic Places, and sites identified as Important Bird Areas. 

6.1.1 National Register of Historic Places 

Established under the National Historic Preservation Act of 1966 (NHPA), the National Register 

includes nearly 77,000 districts, sites, buildings, structures, and objects that are significant in 

American history, architecture, archaeology, engineering, and culture. The register’s entries were 

identified and documented in partnership with State, Federal, and tribal preservation programs. The 

documentation provided for each property consists of photographs, maps, and a registration form 

which provides a physical description of the place, information about its history and significance, and 

a bibliography. Documentation is now available online through the National Register Information 

System at http://www.nr.nps.gov. 

The Basalt Cobblestone Quarries District, on the Refuge’s Carty Unit, was listed in the National 

Register of Historic Places on Dec 14, 1981. It includes six geographically distinct basalt quarry 

sites recorded as one site (45CL161H). An application to add the Cathlapotle Indian Town Site to 

the National Register of Historic Places is being drafted. 

6.1.2 Important Bird Areas (IBA)

The Important Bird Areas (IBA) program is a global effort to identify the most important areas for 

maintaining bird populations and focusing conservation efforts on protecting these sites. Within the 

U.S., the program has been promoted and maintained by the American Bird Conservancy (ABC) and 

the National Audubon Society (NAS). The ABC is coordinating the identification of nationally 

significant IBAs while NAS is working to identify sites in individual states. The NAS is working 

within each state to identify a network of sites across the U.S. that provide critical habitat for birds. 

This effort recognizes that habitat loss and fragmentation are the most serious threats to birds across 

North America and around the world. By working through partnerships, principally the North 

American Bird Conservation Initiative, to identify those places that are critical to birds during some 

part of their life cycle (breeding, wintering, feeding, migrating), the hope is to minimize the effects 

that habitat loss and degradation have on bird populations. The IBA program has become a key 

component of many bird conservation efforts. More information is available at 

http://www.audubon.org/bird/iba/index.html. 

In Washington, the goals of the IBA program are to: Identify the sites that are the most essential for 

long-term conservation of birds, and to take action to ensure the conservation of these sites (Cullinan 

2001). An IBA is a site that provides essential habitat for one or more species of birds. The IBA 

selection process examines sites based on: The presence and abundance of birds; and/or the condition 
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6-2 Chapter 6. Special Designations, Cultural Resources, and Social/Economic Environment

and quality of habitat. The IBAs are chosen using standard biological criteria and expert 

ornithologists’ review. All sites nominated as potential IBAs are rigorously evaluated to determine 

whether they meet the necessary qualifications. The IBAs represent discrete sites, both aquatic and 

terrestrial, that are critically important to birds during their annual life cycle (e.g. breeding, 

migration, and/or wintering periods). 

The Ridgefield Refuge is listed as a Washington State-level IBA based on large concentrations of 

migrating and wintering waterfowl (up to 45,000 geese, 20,000 ducks, and 1,000 tundra swans). 

Also cited are a significant number of bald eagles (20) and sandhill cranes (500) spending the winter 

at the refuge, a major fall sandhill crane roost (up to 1700 birds), and nesting colonies of great blue 

heron (500 pairs). The IBA criteria applicable to the refuge include: 

• Site for endangered or threatened species, or species of special concern in Washington; 

• Site containing species assemblages associated with a representative, rare, or threatened 

natural-community type in Washington; 

• Site where birds regularly concentrate in significant numbers (at least 2,000 waterfowl in 

fresh water habitats; or 5,000 waterfowl in marine/estuarine habitats for short periods during 

any season; At least 50 Great Blue Heron nests during breeding season). 

The IBA website notes that “The refuge is valuable primarily as a wintering and migration staging 

area for waterfowl, and also provides habitat for many other birds. It is a wintering area for the 

Aleutian Canada Goose, a federally threatened subspecies [delisted in 2001 but still State listed]; and 

two percent of the global population of Dusky Canada Geese winters here. Ridgefield and the 

surrounding area support Washington’s only wintering population of Sandhill Cranes, and supports a 

large concentration of wintering Bald Eagles. The refuge is important for a variety of wetlandassociated songbirds; and the oak woodlands provide habitat for an assemblage of species rare in 

western Washington, including Scrub Jay, House Wren, and the Slender-billed White-breasted 

Nuthatch, a candidate for listing as a threatened subspecies.” 

Table 6.1 Significant Concentrations of Birds Noted to Identify the Ridgefield Refuge as a 

Washington State Important Bird Area 

Species or Group Season Average Maximum

Great Blue Heron B 500 pairs --

Great Egret FM -- 100

Tundra Swan W 1,000 --

Dusky Canada Goose W 359 --

Geese W -- 45,000

Ducks W -- 20,000

Bald Eagle W 12 20

Sandhill Crane W 500 --

Sandhill Crane FM -- 1,700

Purple Martin B 15 pairs --

Source: http://wa.audubon.org/science_IBAWashington.html

6.1.3 Research Natural Area

The refuge contains one Research Natural Area (RNA), the Blackwater Island RNA (129 acres) 

located on the Carty Unit. The refuge’s RNA was established in December 1972. Activities on 

RNAs are limited to scientific and educational activities that are non-destructive, non-manipulative, 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 6. Special Designations, Cultural Resources, and Social/Economic Environment 6-3 

and maintain unmodified conditions. The purposes of RNAs are: 

• To preserve examples of major ecosystem types or other outstanding physical or biological 

phenomena; 

• To provide research and educational opportunities; and 

• To preserve a full range of genetic and behavioral diversity for native plants and animals, 

including endangered or threatened species (USFWS 1981). 

The Blackwater Island RNA exemplifies the floodplain communities of the lower Columbia River, 

with Oregon white oak occupying the basalt knolls and ridges above the flood zone. Pacific willows 

fringe the permanent lakes and channels, and a narrow belt of Oregon ash is found in the inter-flood 

zone between the Pacific willow and the oak. An herbaceous aquatic community is found along the 

shallow shorelines and in ephemeral ponds on the islands (Wiberg and Greene 1981). Ephemeral 

ponds on the RNA host the federally threatened water howellia. The RNA also contains an example 

of the Oregon white oak/ovalleaf viburnum/poison oak plant association, which is classified as a 

Priority 2 ecosystem in the Washington Natural Heritage Plan (WDNR 2009). 

6.2 Archaeological and Cultural Resources

With its strategic position on the Columbia River, the area that would eventually become the 

Ridgefield Refuge occupied an important fishing and trade route location that attracted early peoples. 

The river was a crucial link in a thriving trade network that extended inland to the Rocky Mountains, 

and as far north as Vancouver Island. The region would later attract early British and American 

explorers and traders, and eventually American settlers. This section can, therefore, serve only to 

present a brief outline of the refuge’s rich history and cultural heritage. 

Archaeological and other cultural resources are important components of our nation’s heritage. The 

Service is committed to protecting valuable evidence of plant, animal, and human interactions with 

each other and the landscape over time. These may include previously recorded or yet 

undocumented historic, cultural, archaeological, and paleontological resources as well as traditional 

cultural properties and the historic built environment. Protection of cultural resources is legally 

mandated under numerous Federal laws and regulations. Foremost among these are the National 

Historic Preservation Act (NHPA) as amended, the Antiquities Act, the Historic Sites Act, the 

Archaeological Resources Protection Act (ARPA) as amended, and the Native American Graves 

Protection and Repatriation Act (NAGPRA). The Service’s Native American Policy (1994) 

articulates the general principles guiding the Service’s relationships with Tribal governments in the 

conservation of fish and wildlife resources. Additionally, the refuge seeks to maintain a working 

relationship and consult on a regular basis with the Tribes that are or were traditionally tied to lands 

and waters within the refuge. 

Since cultural resources encompass many elements and time periods, the following simple temporal 

divisions were used to distinguish and categorize this brief review of the following resources. 

• Pre-recorded History 

• Pre-Contact Native American Traditions 

• Post-Contact Traditions (Native American, Early British and United States) 

• Recent U.S. Settlement and Economic Development Period 

• Historic and Prehistoric Sites on the Refuge
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6-4 Chapter 6. Special Designations, Cultural Resources, and Social/Economic Environment

6.2.1 Pre-recorded History 

Presence of Paleo-Indian Peoples. Although people have probably occupied the Portland Basin for 

12,000 years, evidence for ancient occupation has not been found. Rising sea levels after the last Ice 

Age and river flooding have erased or deeply buried low-elevation sites, making the discovery of 

Paleo-Indian sites in the Basin unlikely. Urban and industrial development, dredge spoils dumping, 

and construction of dikes along the Columbia River have also destroyed or buried the archaeological 

record (Gilsen 2007). 

Archaeological research has demonstrated that Native peoples have been living in the Portland Basin 

for at least 9,000 to 10,000 years (Ames 1994), although evidence of human occupation earlier than 

2,550 years before present (BP) is sparse. The earliest evidence of human presence in the area comes 

from sites that ring the outer edges of the Basin. For example, at the Burnett site (35CL96), located 

in the city of Lake Oswego, Oregon, artifacts were stylistically similar to those found in the Cascades 

and on the Columbia Plateau that date from 8000 to 10,000 BP (Burnett 1991). The Sunset Ridge 

site (45CL488), located in eastern Washougal, dates from approximately 8000 to 4500 BP (Ozbun 

and Reese 2003). 

Another site, 45CL631, located south of Ridgefield on Vancouver Lake, produced a radiocarbon date 

(C14) of about 3400 BP in association with Cascade-like points and cobble tools (Smith et al. 2005). 

The Merrybell site (35MU9) on Sauvie Island has produced C14 dates ranging from 850 to 2880 plus 

or minus 90 and 155 years respectively (Pettigrew 1981). Overlapping in age with the Merrybell 

site, the refuge’s Wapato Portage site (45CL4) preserves evidence of human occupation dating back 

at least 2,300 years. Stratified cultural deposits above the oldest dates and the presence of 19th 

century trade goods tell us that the Chinookan people used the Wapato Portage site for more than 

2,000 years (Minor and Toepel 1985). Intact, stratified sites of this age are very rare in the active 

floodplain of the Columbia River. 

The archaeological evidence shows a gradual change from a focus on big game hunting to a mixed 

gathering, hunting, and fishing economy in western Oregon and Washington. During the Middle 

Archaic period (6000-2000 BP) people began to settle into patterns that were noted by EuroAmericans when they first entered the region. Large houses, indicating higher population densities, 

and evidence of fishing technology appear, as well as an increased abundance of tools used to 

process plant foods. Evidence of an increasingly large and sophisticated trade network also appears 

in the archaeological record. 

Late Period Settlements. The Late Archaic period, beginning 2,000 years ago, shows increasing 

development of the cultural traits that culminated in the cultures and present-day tribal structures of 

the region (Gilsen 2007). Reliance on fishing (for salmon, eulachon and sturgeon), plant gathering, 

and hunting for large game is evident, as is use of larger plankhouses in more concentrated villages. 

By the time Euro-American explorers and traders arrived in the Wapato Valley, it was one of the 

most densely occupied areas of North America (Pettigrew 1981:6). Several sites from this period 

have been described in the Portland Basin, including the Cathlapotle site (45CL1) on the refuge’s 

Carty Unit (Ames et al. 1999; see section 6.2.5 below for a site description). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Chapter 6. Special Designations, Cultural Resources, and Social/Economic Environment 6-5 

6.2.2 Pre-contact Native American Traditions 

The Portland Basin, called the “Wapato Valley” by Lewis and Clark, was the site of a particularly 

rich grouping of early Native American settlements. The refuge is within the area occupied by 

Chinookan-speaking groups at the time of Euro-American contact. The term “Chinookan” refers to 

the speakers of several closely related languages who occupied the Columbia River from the 

upstream end of the Columbia Gorge (near the present town of The Dalles, Oregon), to the river’s 

mouth, and adjacent portions of the coasts of Washington and Oregon. Lower Chinook was spoken 

by peoples living on both sides of the river’s mouth, and Upper Chinook was spoken along both sides 

from the river's estuary upriver through the Gorge. Upper Chinook in turn was divided into the 

Cathlamet, Multnomah and Kiksht languages. Multnomah was spoken in the Wapato Valley, 

including Cathlapotle (Silverstein 1990). At the time of Lewis and Clark’s expedition, the Salishanspeaking Hul-lu-et-tell (Cowlitz) lived north of the entrance of the Lewis River and on the Cowlitz 

River (Hodge 1910[1]:577 in Minor et al. 2008). As traders, the residents of villages along the 

Columbia River were multi-lingual, speaking languages or dialects from both up and down river. 

There is consensus among anthropologists that prior to 1851 (when treaty negotiations began with 

the Indian tribes of the region) local Indian peoples were not organized into “tribes” (political units 

encompassing multiple villages with a common identity, sense of purpose, or territorial claim). 

Rather, it is believed people identified themselves as members of the village where they were born or 

raised (Hunn 2000). 

Villages were politically independent, headed by a chief who exercised influence through his wealth 

and personal skills. The chief, along with shamans, warriors, and traders, formed the small upper 

class. The bulk of the population consisted of “commoners,” and at the bottom of the social ladder 

were slaves, who were obtained through trade, and usually owned only by wealthy families. Slaves 

came from tribes that did not practice head flattening; their round heads distinguished them from the 

upper class and commoners (Hajda 1984:178). At different times of the year members of these 

villages might travel to areas beyond their territory. Chinookan villages consisted of one or more 

cedar plankhouses occupied by multiple extended families. Families at summer camps occupied 

temporary shelters of mats or brush (Silverstein 1990). 

Boyd and Hajda (1987) reported 16 named Chinookan villages in Portland Basin, based on Lewis 

and Clark's journals (see Figure 6.1). In the fall of 1805, Lewis and Clark estimated the population 

of the villages at 3,400 people, while they reported a figure of 8,040 during their return trip upstream 

in the spring. Boyd and Hajda believe that the lower figure represented the permanent population of 

the basin, and the higher figure reflected seasonal shifts in population during the spring, when people 

from neighboring areas moved in to share in the abundant fish runs and to collect camas in the 

upland prairies. The figure of 8,040 represent a minimum figure for the pre-epidemic permanent 

population of the Wapato Valley, since Lewis and Clark arrived after the smallpox epidemics of the 

1770s and 1801. The actual pre-epidemic population was probably closer to 12,000 to 14,000 (Ames 

1994). One of these villages listed by Lewis and Clark was “Quathlapotle” at the mouth of the Lewis 

River. The true name of the village was probably Nahpooitle, the Chinookan name for the Lewis 

River; “Cathlapotle” meant “people of the Lewis River” (Silverstein 1990). Over time, the true name 

of the village became obscured and the village was referred to as Cathlapotle. At the time of the 

Lewis and Clark expedition, Cathlapotle was the third largest Chinookan village in the Wapato 

Valley, with an estimated peak population of 900. 
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6-6 Chapter 6. Special Designations, Cultural Resources, and Social/Economic Environment

Much of the social, political, and economic culture of the Chinookan Indians focused on their role as 

traders. Cathlapotle lies at the confluence of the Columbia River, Multnomah Channel, Lake River, 

and the Lewis River, an excellent location to access natural resources and coordinate trade. 

Cathlapotle is a prime settlement location where long and continuous habitation might be expected. 

The importance of the lower Columbia River to native systems of trade is evidenced by the large 

number of strategically placed villages along major waterways, and a network of trails in areas where 

travel by water was impractical. Later, these trails would be developed by Euro-American traders 

and settlers; but their beginnings were the trails used by Native Americans for trade and travel. 

Wapato was an extremely important trade item produced by the inhabitants of the Portland Basin, 

and contributed much to their wealth. Indeed, Meriwether Lewis wrote in 1806 that “the wappetoe 

furnishes the principal article of traffic with these people which they dispose of to the nations below 

in exchange for beads cloth and various articles. The natives of the Sea coast and lower part of the 

river will dispose of their most valuable articles to obtain this root” (Moulton 1991 [7]: 26-29). 

6.2.3 Post-Contact Traditions

The Columbia River first appeared on European maps in the early 17th century when the Spanish 

explorer Martin de Aguilar described a major river near the 42nd parallel, but the river remained 

unexplored and unknown to Europeans for almost 200 years. In April 1792, the American Captain 

Robert Gray detected a strong current flowing outward near the mouth of the Columbia River. Later 

that month, Gray encountered Capt. Vancouver’s British expedition and told him that he suspected 

the existence of a major river. Vancouver, believing Gray was mistaken, continued north. Within 

two weeks, Capt. Gray became the first documented Euro-American to navigate the bar and enter the 

Columbia River. Gray gave a copy of his chart to the commander of the Spanish garrison on 

Vancouver Island, where Capt. Vancouver saw the chart and recognized his error (Oldham 2003). 

In October 1792, Vancouver sent Lt. William Broughton in the Chatham, with a copy of Gray's 

chart, to explore the Columbia River. Broughton sailed up the lower Columbia River from its mouth 

to Point Vancouver, which he named for his Captain, and back, charting and naming many features 

along the way (Oldham 2003). On October 28th, during his return trip downstream, Broughton and 

his crew met a group of Chinookan Indians at the lower end of Sauvie Island, near present day 

Warrior Rock, immediately downstream of Ridgefield Refuge. He called the site:

 

“...Point Warrior, in consequence of being there surrounded by twenty three canoes carrying from 

three to twelve persons each, all attired in their war garments and in every other respect prepared 

for combat. On these strangers discoursing with the friendly Indians that attended our party, they 

soon took off their war dress, and with great civility disposed of their arms and other articles for 

such valuables as we presented to them, but would other niether part with their copper swords nor a 

kind of battle axe made of iron.” 

From Warrior Point, Lt. Broughton described a large Indian village on the north shore. This is 

presumed to be the first written account of the Cathlapotle Chinookans: 

“At Point Warrior the river is divided into three branches; the middle one was the largest, about a 

quarter of a mile wide, and was considered as the main branch; the next most capacious took an 

easterly direction and seemed extensive; to this the name of Rushleigh’s River was given . . . On the 

banks of Rushleigh’s River was seen a very large Indian village and such of the strangers as seemed 
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to belong to it strongly solicited the party to proceed thither; and to enforce their request, very 

unequivocally represented that if the party persisted in going to the southward they would have their 

heads cut off. The same entreaties, urged by similar warnings had been before experienced by Mr. 

Broughton during his excursion, but having found them to be unnecessary cautions he proceeded up 

that which he considered to be the main branch of the river...” (Vancouver 1926:21-22) 

The next written account of the people of the “Quathlapotle nation” was from November 5, 1805, 

during Lewis and Clark’s journey down the Columbia River. On November 5, Lt. Clark described a 

substantial town of cedar plankhouses, occupying one-quarter mile of shoreline. Clark wrote: 

“...passed an Isld. Covered with tall trees & green briers Seperated from the Stard. Shore by a 

narrow Chanel at 9 [8?] miles I observed on the Chanel which passes on the Stard Side of this Island 

a Short distance above its lower point is Situated a large village, the front of which occupies nearly 

1/4 of a mile fronting the Chanel, and closely Connected, I counted 14 houses [NB: Quathlapotle 

nation] in front here the river widens to about 1/2 miles. Seven canoes of Indians came out from this 

large village to view and trade with us, they appeared orderly and well disposed, they accompanied 

us a fiew miles and returned back...” (Moulton 1990[6]:23)

On March 29, 1806, Lewis and Clark visited the town for approximately two hours. They enjoyed a 

meal of wapato and eulachon (prized for its fine flavor and high oil content), and presented gifts. 

Lewis wrote: 

“...at the distance of three miles above the entrance of the inlet on the N. side behind the lower point 

of an island we arrived at the village of the Cath [X: Quath]-la-poh-tle wich consists of 14 large 

wooden houses. here we arrived at 3 P.M. the language of these people as well as those on the inlet 

and wappetoe Island differs in some measure from the nations on the lower part of the river. tho' 

many of the words are the same, and a great many others with the difference only of accent. the form 

of their houses and dress of the men, manner of living habits custom &c as far as we could discover 

are the same. . . . 

“the floors of most of their houses are on level with the surface of the earth tho' some of them are 

sunk two or 3 feet beneath. the internal arrangement of their houses is the same with those of the 

nations below. they are also fond of sculpture. various figures are carved and painted on the peices 

which support the center of the roof, about their doors and beads [beds] . . . “ 

 “ . . . they had large quantities of dried Anchovies strung on small sticks by the gills and others 

which had been first dryed in this manner, were now arranged in large sheets with strings of bark 

and hung suspended by poles in the roofs of their houses; they had also an abundance of sturgeon 

and wappatoe; the latter they take in great quantities from the neighbouring bonds [ponds], which 

are numerous and extensive in the river bottoms and islands . . .” 

“they have a number of large symeters [scimitars, or swords] of Iron from 3 to 4 feet long which 

hang by the heads of their beads [beds]; the blade of this weapon is thickest in the center tho' thin 

even there. all it's edges are sharp and it's greatest width which is about 9 inches from the point is 

about 4 inches. the form is thus. this is a formidable weapon. they have heavy bludgeons of wood 

made in the same form nearly which I presume they used for the same purpose before they obtained 

metal. we purchased a considerable quantitiy of wappetoe, 12 dogs, and 2 Sea otter skins of these 

people. 
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“they were very hospitable and gave us anchovies and wappetoe to eat. notwithstanding their 

hospitality if it deserves that appellation, they are great begers, for we had scarcely finished our 

repast on the wappetoe and Anchovies which they voluntarily sat before us before they began to beg. 

we gave them some small articles as is our custom on those occasions with which they seemed 

perfectly satisfyed. we gave the 1st Cheif a small medal, which he soon transfered to his wife. after 

remaining at this place 2 hours we set out & continued our rout between this island, which we now 

call Cath-lah-poh-tle after the nation, and the Lard shore. at the distance of 2 miles we encamped in 

a small prarie on the main shore, having traveled 19 miles by estimate...” (Moulton 1991[7]:26-29) 

Clark described this small prairie as: 

“a butifull grassy plac, where the nativs make a portage of their Canoes and Wappato roots to and 

from a large pond at a short distance. in this pond the nativs inform us they Collect great quantities 

of wappato, which the womin collect by getting into the water, Sometimes to their necks holding by a 

Small canoe and with their feet loosen the wappato or bulb of the root from the bottom from the 

Fibers, and it imedeately rises to the top of the water. they collect & throw them into the Canoe, 

those deep roots are the largest and best roots. Great numbers of the whistling swan, Gees and 

Ducks in the Ponds. Soon after we landed 3 of the nativs came up with wappato to sell a part of 

which we purchased...” (Moulton 1991[7]:30)

Today Lewis and Clark’s campsite is known as Wapato Portage, and like Cathlapotle, it is situated 

on the refuge’s Carty Unit. 

The Fur Trade and Epidemics. After Lewis and Clark returned to the United States, EuroAmerican traders were not long in gaining a foothold on the Columbia River, which they recognized 

as key to control of the fur trade. In 1811, the Pacific Fur Company established Fort Astoria on at 

the mouth of the Columbia. Only three months later, on July 15, 1811, Canadian explorer and 

surveyor David Thompson, representing the competing Northwest Company, completed his 

“Columbia Expedition” from the Spokane House trading post to the Pacific Ocean (Oldham 2003b). 

Fort Astoria was sold to the Northwest Company in 1813, which in turn merged with the British 

Hudson’s Bay Company in 1821. The Chinookan Indians living along the lower Columbia River 

were active participants in the fur trade (Ruby and Brown 1976). Early on, the powerful traders 

successfully resisted attempts by the Americans and British to control the upriver trade. But by 

1825, with their numbers weakened by epidemics, the Chinookans were unable to stop British efforts 

to gain control of trade networks. 

The Hudson’s Bay Company established a fur-trading post at Fort Vancouver in 1825. Initial land 

claimed by the Hudson’s Bay Company extended along the Columbia to its confluence with Lake 

River. Therefore, the River ‘S’, Ridgeport Dairy, and Roth Units were once land belonging to the 

Hudson’s Bay Company. Fur traders used the same trails and water routes that had been developed 

by Native Americans for trade and travel. The Wapato Portage site visited by Lewis and Clark 

became a river crossing along the Fort Vancouver to Cowlitz Prairie Trail, constructed by the 

Hudson’s Bay Company in the 1820s. Crossing Lake River near Carty Lake, it functioned as a 

landing for cargo being transported along the trail. 

The list of early explorers, expeditions, and scientists passing through the area is large and only 

highlights can be given here. Several notable scientists visited the area during the first half of the 

19th century. David Douglas, of the London Horticulture Society, arrived at Fort Vancouver on April 
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20, 1825, in the company of the Hudson Bay Company’s chief factor, Dr. John McLoughlin 

(Douglas was familiar with the reports of Archibald Menzies, who served as surgeon and naturalist 

on Vancouver’s 1792 expedition.). That year, Douglas collected plants up the Columbia, Willamette, 

Chehalis and Cowlitz rivers, often assisted by Indian guides. He revisited the region in 1830, when 

he witnessed the terrible epidemic that swept away most of the region’s original inhabitants; and 

again in 1832-1833 (Oregon Historical Society 1905). In his 11 years as a botanist he described 250 

plant species unknown in Europe and introduced many species of Northwestern plants to British 

gardens—from the Douglas-fir which bears his name, to camas. 

In 1834, two more naturalists, ornithologist John Kirk Townsend and botanist Thomas Nuttall, 

accompanied Nathaniel Wyeth on his expedition to Oregon (Townsend 1839). Nuttall had resigned a 

professorship at Harvard to join the expedition. They explored Sauvie Island, the Willamette Valley, 

Walla Walla, and the Blue Mountains. On his arrival back in Philadelphia in 1837, Townsend sold 

93 bird specimens to John James Audubon, who described them in his Birds of America. In all, 

Townsend supplied 74 of the 508 species Audubon described (Oregon Historical Society 2002). 

Epidemics on the Lower Columbia River. Documents left by explorers, traders, and residents 

from Astoria and Fort Vancouver occasionally mention Cathlapotle and its Chinookan inhabitants. 

But increasingly, their accounts recorded disaster. Because their towns were located on the major 

trade route of the Columbia, Chinookan peoples were devastated by a series of epidemics, including 

smallpox, influenza, and malaria that killed perhaps as much as 95 percent of the precontact 

population. Smallpox epidemics started in the 1770s and continued into the next century. The worst 

of the epidemics, from the standpoint of the Chinookans, began in 1830 and continued to rage until 

1833. It hit the Wapato Valley worst of all. Described in contemporary accounts as “fever and 

ague” or “intermittent fever,” the disease was probably malaria (Boyd 1999). In a letter dated 

October 11, 1830, botanist David Douglas describes the epidemic of 1830, which began in late July 

of that year: 

“... A dreadfully fatal intermittent fever broke out in the lower parts of this river about eleven weeks 

ago, which has depopulated the country. Villages, which had afforded from one to two hundred 

effective warriors are totally gone; not a soul remains. The houses are empty and flocks of famished 

dogs are howling about, while the dead bodies lie strewn in every direction on the sands of the 

river.” (Oregon Historical Society 1905). 

Some estimate that as few as 30 to 40 Chinookan survivors were left in the Wapato Valley after the 

malaria epidemics swept through (Taylor and Hoaglin 1962). By 1840, only 280 Chinookans, 

including slaves, remained (Ruby & Brown 1976:194). This included Chinook living on the coast. 

Sometime during the 1830s, the few inhabitants of Cathlapotle that had survived the malaria 

epidemic abandoned the site. In 1833, William Tolmie, a Hudson’s Bay Company doctor, observed 

of Cathlapotle that “only its superior verdure distinguished the spot from the surrounding country.” 

However, another HBC doctor, Meredith Gairdner, claimed that Cathlapotle was still occupied in 

1835 (cited in Wuerch 1979). Ceramic trade goods found at the site indicate abandonment circa 

1834 (Kaehler 2002). 
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Figure 6.1 William Clark’s map of the “Wapato Valley,” including the site of the 

“Quathlapotle nation.” Adapted from Moulton (1983), Maps 79 and 80. Reproduced courtesy 

Center for Columbia River History. 
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Charles Wilkes, who visited the area in 1841, wrote, “I satisfied myself that the accounts given of the 

depopulation of this country are not exaggerated; for places were pointed out to me where dwelt 

whole tribes, that have been entirely swept off . . .” (Wilkes 1845). Wilkes wrote that prior to the 

epidemics, Chief Cassino (also written as Casenov or Kiesno), chief of the Multnomahs on Sauvie 

Island, was able to muster close to 500 warriors. When Wilkes met him in 1841, he was alone, “his 

land, tribe and property all departed.” The artist Paul Kane, who visited the region in 1846-1847, 

wrote that “Kattlepootle” (Cathlapotle) and other Chinookan towns of the lower Columbia River 

were “entirely extinct as villages” (Kane 1855). Nevertheless, Kane produced a record of Chinookan 

culture in his paintings and writings. In 1853 and 1854, General Land Office surveyors noted an 

“Indian lodge” on the southeastern bank of Gee Creek where it enters the Lewis River (Bureau of 

Land Management 2007). However, by that time the inhabitants may not have been Chinookan. 

As the Chinookan people living along the Columbia River were decimated by disease, survivors 

dispersed and intermarried with other groups, and other peoples moved into depopulated areas. The 

expansion of Salish-speaking Cowlitz and Sahaptin-speaking Taitnapams into the Wapato Valley 

following the decimation of Chinookan populations is well documented (Ames et al. 1999). Prior to 

the malaria epidemic, Chinookans occupied the shorelines of the lower Columbia River, while the 

Cowlitz lived further inland. But by 1834, naturalist John K. Townsend encountered “...several large 

lodges of Kowalitsk Indians, in all probably one hundred persons” on a plain below Warrior’s Point 

(Townsend 1839). William Curtis wrote in 1911 that “a few of the [Cowlitz] villages near [the 

Cowlitz River’s] mouth were partly inhabited by Chinookan people married to Cowlitz” (Curtis 

1911). 

Another group to migrate into the area following the epidemics was the Sahaptin-speaking 

Teitnapum (Taitnapam). Most 19th century writers referred to them as a branch or subgroup of the 

Klickitats. Others state that they were not originally Sahaptin speakers, but rather adopted the 

Sahaptin language through intermarriage (Ray 1966, Irwin 1994). Today they are part of the Cowlitz 

Tribe. Ethnographer and translator George Gibbs wrote, “After the depopulation of the Columbia 

tribes by congestive fever, which took place between 1820 and 1830, many of that tribe [Klickitat] 

made their way down the Kathlaputl [Lewis River], and a part of them settled along the course of that 

river . . . The present generation, for the most part, look upon the Kathlaputl as their proper country, 

more especially as they are intermarried with the remnant of the original proprietors [Chinookans]” 

(Gibbs 1877:170-171). In an 1854 letter to territorial governor Isaac Stevens, Indian agent William 

Tappan referred to “Tai tin a pams at the mouth of the Cathlapoodle” and estimated that 140 to 200 

Taitnapams were living in the valley of the Lewis River (Tappan 1854). Gibbs’s and Tappan’s 

statements were supported by relatives of Tyee Umtuch (Umtux), who is generally identified as the 

chief of the Taitnapams. Tyee Umtuch’s niece, Catherine Cosike, claimed to be a member of the 

“Cathlapodle Tribe” when she was interviewed by the Portland Oregonian in 1915 (Ruby and 

Brown 1992). 

Family histories of the Lancasters (who settled on the south bank of the Lewis River) and Shoberts 

(who ran a ferry and lodging house on Lake River) recall that they were on friendly terms with their 

Indian neighbors. Judge Columbia Lancaster even hosted Umtuch and his people in the new 

mansion he built in 1850. However they became uneasy in 1855, with reports that Indians under 

Umtuch were planning raids. They and other families fled to the blockhouse across the Columbia 

River in St. Helens, which had been built for that purpose (Standal 2009). In October of 1855, the 

U.S. Army ordered the Indians living on the Lewis River (identified as Klickitats and Umtuch’s band 

of Taitnapams) to go to Fort Vancouver for their own safety and to quiet the white settlers’ fears. 
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A group of Yakamas came to the Fort and convinced the Klickitats and Taitnapams to leave with 

them. The Army pursued, and though the Indians were persuaded to return to the fort, Umtuch was 

killed, apparently accidentally. 

After Tyee Umtuch was killed, “the remainder of his band, consisting of women and children, were 

transported to the Yakima Reservation” (Fitzpatrick 2004). However, Indian people continued to 

live in the vicinity of Cathlapotle. A local history recounts that due to the disastrous flooding along 

Lake River in 1867 and 1876, “the remaining Indians were forced to move to the mouth of the Lewis 

River” (Standal 2009). Mrs. Cosike, who was living near Battle Ground in 1915, recalled that by that 

time “this little handfull [of Cathlapodle Indians] does not number more than a dozen, although with 

their roving disposition, there are always a few of them coming and going on the trail leading to the 

Yakima Indian Reservation” (Ruby and Brown 1992). Fred Umtuch, the great grandson of Tyee 

Umtuch, was reported to have been buried in an Indian cemetery near “Cathlapoodle” (Oregonian 

1925).

Tribal Treaties. Middle Chinookans were parties to a series of treaties negotiated during the early 

1850s (all would have removed them from their homelands), but none were successfully 

implemented or ratified. In 1855, Territorial Governor Isaac Stevens held the Chehalis River 

Council with 843 Indians representing the “Upper and Lower Chehalis, Queniolts, Chenooks and 

Cowlitz.” Swan reported that 100 Indians were “all that remained of the Chenook tribe,” although it 

was unclear if all bands of the Chinook were represented (Swan 1969). Treaty negotiations were 

broken off and treaties were never signed with these tribes. Reservations were established by 

executive orders for the Upper Chehalis and Cowlitz on the Chehalis River near Oakville in 1864 and 

on northern Willapa Bay in 1866 for the Lower Chehalis, Chinooks, and others. Many Indians, 

however, refused to be moved to these reservations (Hajda 1990:514-515). 

Even though the Oregon treaties were likewise never ratified, most of the remaining Chinookans in 

the Portland Basin in Oregon were relocated either to the Grand Ronde, Siletz, or Warm Springs 

reservations (Beckham 1990). Relocations started in 1856 when Oregon Territory Superintendent of 

Indian Affairs Joel Palmer, under pressure from settlers and fearful of “Indian raids,” ordered the 

remaining Middle Chinookans to be sent to the Grand Ronde reservation (Wuerch 1979:119-139). 

Not all complied with the relocation orders and instead dispersed throughout the region, integrating 

with other Native communities such as the Yakama, Cowlitz, and Lower Chinook who resided on the 

coast, both on and off reservation (Daehnke 2006). Today Chinookan descendants are located on 

several reservations including the Shoalwater Bay, Quinault, Grand Ronde, and Chehalis 

Reservations, and on off reservation communities (BIA 2002). Tribal affiliations with lands now 

part of the refuge are shown in Table 6-2. 
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Table 6.2 Tribal Affiliations With Lands Now Part of Ridgefield Refuge

Reservation Tribes

Chinook Indian Tribe*

(No treaty; lands for Chinook allocated in the Quinault Reservation

in 1931. Quinault Reservation established by Treaty of Olympia, July 

1, 1855; expanded by Executive Order Nov 4, 1873.) (Recognized 

2001, rescinded 2002, vote on “Chinook Nation Restoration Act” 

pending in House 2010)

Chinook

Cowlitz Tribe

(No treaty) (Recognized 2002)

Lower Cowlitz, Upper Cowlitz 

(Taidnapam)

Shoalwater Bay Tribe

(Executive Order of Sept 22, 1866, under authority of Treaty of 

Olympia, July 1,1855; ratified1859)

Willapa Bay Chinook, Lower Chehalis

Confederated Tribes and Bands of the Yakama Indian Nation

(Yakama Treaty of 1855)

Yakama, Palouse, Pishquitpah. Some 

Cowlitz, Taidnapam enrolled in early 

1900s (Irwin 1994).

Confederated Tribes of the Grand Ronde Reservation

(Grand Ronde reservation established by treaty arrangements in 1854 

and 1855 and an Executive Order of June 30, 1857)

Umpqua, Molalla, Rogue River, 

Kalapuya, and Chasta. Also: Chinook 

(four Oregon bands), Tillamook, Klickitat

Confederated Tribes of Warm Springs 

(Treaty of Wasco, Columbia River, Oregon Territory with the Taih, 

Wyam, Tenino, & Dock-Spus Bands of the Walla-Walla, and the 

Dalles, Ki-Gal-Twal-La, and the Dog River Bands of the Wasco. June 

25, 1855. Ratified Mar. 8, 1859. Proclaimed Apr. 18, 1859)

Warm Springs Indians (four bands),

Wasco (Upper Chinookan speakers, two 

bands), and Northern Paiutes. 

Some Chinookans and Cowlitz moved to 

Warm Springs (Irwin 1994)

 *Nonfederally Recognized Tribe

6.2.4 Recent Settlement and Economic Development Period 

Following the first wave of American settlers to arrive via the Oregon Trail in 1843, Americans 

quickly grew to outnumber British inhabitants. The Chief Factor of Ft. Vancouver, John 

McLoughlin, aided the settlers and in doing so helped pave the way for American control of the 

region. In 1846 Britain and the United States settled on the 49th parallel as the line dividing British 

and American possessions in the Pacific Northwest. In 1849 the Hudson’s Bay Company relocated 

its Columbia Department headquarters to British territory. The town of Vancouver was incorporated 

in 1857. In 1860, the United States Army established Columbia (later Vancouver) Barracks adjacent 

to Fort Vancouver (Hanable 2004). 

The first Euro-American to settle in what would later become the town of Ridgefield was Irish 

immigrant James Carty, who took up residence on Lake River in 1839 (see “Carty Unit,” page 15). 

After Congress passed the U.S. Donation Land Claim Act in 1850, more settlers arrived. In 1849, 

bachelors Stillman Hendrick, B.O. Teal, and George Thing settled on the island across Lake River 

from Carty’s land claim, thereby giving “Bachelor Island” its name. They were followed by Arthur 

Quigley in 1852 and Frederick Shobert in 1853. Both Quigley and Shobert established mud landings 

on their properties adjoining Lake River where river steamers could offload their goods and take on 

loads of farm products. Thus, “Shobert’s Landing” became the common name for the area for the 

next 10 years. Ferry crossings were also established in the 1850s. James Carty began running a ferry 

service across Lake River in 1851 (Standal 2009). 
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The little community got its next name, “Union Ridge,” during the Civil War. According to a 

reporter who visited the area in 1875, this was because “all the settlers, save one, were outspoken 

Union men” (Standal 2009). When the first post office was established in 1865, the name became 

official. An 1886-1887 gazetteer listed Union Ridge as “a post village on Lake river . . . Settled in 

1853. Ships farm produce. Population, 65.” It had a general store and post office run by Stephen 

Shobert, and a church (Clark County Genealogical Society 2008). The post office name was changed 

to Ridgefield in 1890 at the urging of the new postmaster, S.P. Mackey, who was originally from 

Virginia, and not keen on the name Union Ridge (Standal 2009). The City of Ridgefield was 

incorporated in 1909. 

After the departure of the Hudson’s Bay Company, Clark County developed as a mostly agricultural 

area. Farming and forestry dominated land uses. Wood products manufacturing was a dominant 

industry during the first half of the 20th century, and accounted for the highest economic output in 

the county by the 1950s. As forests were cleared, farmland spread. In the 20th century, important 

farm products grown in Clark County included tree and berry fruit, potatoes, dairy, beef cattle, hay, 

and grain. County farms more than doubled from 907 in 1890 to 1,873 farms totaling 192,700 acres 

in 1900 (Hanable 2004). The number of farms continued to grow steadily from 1900 to 1950. By 

1945, there were 4,934 farms with 204,850 acres in the county. The peak year for acreage in farms 

was 1950 when the census reported that almost 220,000 acres of Clark County were in farms−about 

54 percent of the county’s total land base. By mid-century, dairy farming was the most important 

agriculture in the Ridgefield area, eclipsing potatoes in importance. Roy Garrison, a 74 year old 

Ridgefield resident who was born and raised in the Ridgefield area, recalled that in the late 1940s 

“everyone was a dairy farmer in the area at the time” (Cornelius 2006). Its prominence continued 

until the 1970s; the 1972 Clark County soil survey stated that 40 percent of farm income in Clark 

County came from dairy farming (McGee 1972). 

The region also continued to develop as a trade and transportation hub. In 1870, the Northern Pacific 

Railway connected Vancouver to Puget Sound. In the 1880s, initiation of railroad ferry service 

across the Columbia linked Vancouver with Oregon and California by rail. In 1908, a rail bridge 

replaced the railroad ferries. Following construction of a railroad through the town of Ridgefield in 

1903, the little town began to grow, reaching a population of 620 in 1920. In 1917, a highway bridge 

linked Vancouver to the Oregon side of the Columbia (Hanable 2004). Vancouver’s role in shipping 

grain, lumber, and other products from the interior Northwest to worldwide markets expanded 

throughout the 20th century. 

Until 1890, most of Washington’s population lived in Clark County: 11,000 out of a total state 

population of 18,000. Ten years later, Washington’s total population ballooned to more than 

500,000, but Clark County’s population rose only modestly, to 13,419. Two world wars brought 

additional industries and expanded population. During World War I, the U.S. government built the 

world’s largest spruce mill on the grounds of Vancouver Barracks to supply lumber for thousands of 

warplanes. The Standifer Shipyard constructed ships for the war effort, but closed in 1921. World 

War II brought the West’s first aluminum manufacturing plant, the Aluminum Company of America 

(Alcoa) and a significant shipyard, the Vancouver Kaiser Shipyard. Beginning in 1943, Clark 

County yards built 50 escort carriers, 90 other ships, and two dry docks (Hanable 2004). The 

population of Vancouver skyrocketed during World War II. In 1941, Clark County’s population was 

18,000 people. By January 1944 it was more than 95,000, as workers swarmed into the area in 

search of jobs. 
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At the end of World War I, Ridgefield had a creamery and cheese factory, shingle mill, saw mill, 

boat building factory, and a railroad tie loading plant. But the main north-south highway ran four 

miles to the east in the 1920s and 1930s, which limited growth. Between the World Wars, the town 

made practically no gain in population, and only modest growth after World War II. The 1990s saw 

rapid growth as Ridgefield became a bedroom community for Vancouver, Washington. From 1990 

to 1999, the population grew 59 percent and annexation added over 2,200 acres to the city (Standal 

2009). 

History of Refuge Units 

Carty Unit. Irish immigrant James Carty settled on Lake River in 1839. In 1851, he filed a Donation 

Land Claim on the property south of the refuge (DLC 48), and established a ferry crossing Lake 

River. He lived on the land until his death in 1873. The DLC 44, on the present-day Carty Unit, was 

settled by Charles Reed in 1854. Columbia Lancaster and his wife filed a claim on the south bank of 

the Lewis River in 1854. The Cathlapotle area may still have been occupied by Indians after these 

claims were filed. The 1853-1854 survey notes of the General Land Office (GLO) refer to an 

“Indian lodge” on the southeastern bank of Gee Creek, where it enters the Lewis River, 

approximately 800 meters north of Cathlapotle (Bureau of Land Management 2007). An 1853 GLO 

map shows a trail from Vancouver which passes directly alongside Cathlapotle. However, the 

Cathlapotle townsite is not marked on the map. 

The 1863 Washington Territory cadastral survey of T4N R1W, Willamette Meridian, shows the 

following claims on the present-day Carty Unit: William Gee (No. 44), F.A. Fowler (No. 47), and 

James Carty (No. 48). In 1873, James Carty’s nephew (also named James) acquired the DLC 48 land 

claim from his uncle, as well as DLC 44 and portions of DLC 57, including the site of the 

Cathlapotle village. At least two structures were built on DLC 44 by the Carty family. 

Archaeological site 45CL285H, recorded by Larson and Sneed (1979), is thought to be part of the 

Carty family homestead. The remains of structures associated with site 45CL285H are marked on 

the 1888 U.S. Coast and Geodetic Survey Map (Stutte and Raymond 2003). The primary land use 

during this time appears to have been as pasture for livestock, although gardens and orchards were 

also cultivated. Upon Carty’s death, the land was left to his widow and his only son William.

Beginning about 1880, basalt blocks were quarried on the present-day Carty Unit and barged upriver 

to Portland for use as paving material. The basalt was chipped into brick-shaped pieces of a standard 

size, called Belgian Block, and laid on the streets. The blocks were also used for sewer line 

construction. John (Jack) McKie operated the quarries, working under contract to the Portland 

Contracting Company. In 1885, blocks quarried from Carty’s land lined the streets of Portland on 

Front, First, and Second Streets from G to Jefferson Streets (Scott 1890). The use of Belgian Block 

paving was eventually discontinued as other paving materials became available. The quarries were 

still in operation in 1903 (Clark County 2009) and were probably abandoned circa 1909 (USFWS 

1997). 

The U-Haul Company had its beginnings on the refuge, in the winter of 1945-1946. The post World 

War II housing boom created a widespread need for do-it-yourself moving equipment. U-Haul cofounders L.S. “Sam” Shoen and his wife, Anna Mary Carty Shoen capitalized on that need. The 

Shoens launched U-Haul in the summer of 1945, after Sam was discharged from the Navy. That 

winter, Sam and Anna Mary moved to her parents’ home, the Carty ranch. Using war-surplus steel 

from a Navy yard, Sam built the first U-Haul trailer. The new trailers were a success, and the 
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6-16 Chapter 6. Special Designations, Cultural Resources, and Social/Economic Environment

business grew rapidly (U-Haul International 2009). The building where Sam Shoen built the first UHaul trailer has been moved off the Carty Unit and now stands just to the north of the Carty Unit 

parking lot (USFWS 1997). 

In 1964, the Pacific Wood Treating Company began operations on Lake River, adjacent to the 

present-day Carty Unit, on a 39-acre site leased from the Port of Ridgefield. It was one of the city’s 

biggest employers until it filed for bankruptcy and went out of business in 1993. The Port of 

Ridgefield began cleanup of toxic chemicals at the site in 1997; cleanup efforts via a steam 

remediation system were ongoing as of 2009 (see Chapter 3). 

Bachelor Island. William Clark first called Bachelor Island “Green Bryor Isd” on November 5, 1805 

(Moulton 1990[6]) but Meriwether Lewis changed the name to “Quathlahpotle Island” in his journal 

entry of March 30, 1806 (Moulton 1991[7]). Bachelor Island got its current name from three 

unmarried men who claimed land on the island from 1849 to 1850. In the 1885 History of Clarke 

County Washington Territory (Alley and Munro-Fraser 1983) the authors wrote: 

“... BACHELORS’ ISLAND. This is called Columbia Island on the maps, but is more generally 

known as Bachelors’ Island, it having received this name from the fact that its original settlers were 

three, unmarried men named S. Hendricks, B. O. Teal and George Thing, who took possession in 

1849 or 1850. In 1851 a man named Northrup took up his abode on the island, and in 1853, George 

W. Burrow, a pioneer of 1850, located on the farm now occupied by his son, John Burrow, while, in 

1854, Robert Conolly came to the place.” 

The 1863 Washington Territory cadastral survey of Bachelor Island shows five claims: George W. 

Burrows (Claim No.39), Benjamin Teel (Claim No.40), Robert Connelly (Claim No.41), S. 

[Stillman] Hendricks (Claim No.42), and George Thing (Claim No.43) (BLM 2007). An 1888 Plat 

Map for “Bachelors Island” also shows five Donation Land Claims (DLC)−the northernmost claim 

being that of G. Burrow, B. Teele, G.M. Irving, H. Hendricks, and the southernmost that of R. 

Connoly. George Burrow’s son John lived on the farm to his death in 1898. Burrow family 

members lived on the island until 1921 (Cornelius 2006). 

For more than 100 years, cattle, hay and grain were produced on Bachelor Island. Alley and MunroFraser (1885) noted that the island was owned by “John Burrow, G.E. Tyszkiewicz and Messrs Ladd 

& Reed of Portland.” Reed, Ladd, and Tyszkiewicz were wealthy businessmen from Portland who 

purchased 1,000 acres of Bachelor Island in 1876. Reed had an interest in raising purebred shorthorn 

cattle and used the island to grow grain and provide pasturage for his animals, under the supervision 

of hired farm managers (Lyman 1948). Reed built an elegant 20-room farm house, “Queen,” on the 

island, later purchased by the Zimmerly family along with other property on the island (Figure 6.3). 

They restored the house but unfortunately, it burned down in 1978 (Clark County Historical Museum 

2009). 

As the populations of Portland and Vancouver boomed during World War II, so did the demand for 

farm products. In the 1940s, numerous diking projects were undertaken to protect and expand 

farmland along the lower Columbia River. The Zimmerly family began large scale farming 

operations on Bachelor Island in the 1940s and made many improvements. In 1942, five miles of 

levee were built, protecting 1,120 acres. They grew potatoes and grains (primarily barley) until the 

refuge acquired Bachelor Island in 1985. They continued to farm cooperatively on Bachelor Island 

until 1999. 
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Chapter 6. Special Designations, Cultural Resources, and Social/Economic Environment 6-17

River ‘S,’ Roth, and Ridgeport Dairy Units. As noted above, land that would later become the River 

‘S’, Roth, and Ridgeport Dairy Units was claimed by the Hudson’s Bay Company under the treaty of 

1846. The first American settler on the unit was Arthur Quigley in 1852. The 1863 cadastral survey 

of T4N R1W, Willamette Meridian shows the Quigley claim (No. 38) and Preston Laws claim (No. 

46) on the present day River ‘S’ Unit; and the James Bowers (No. 45) and J.H. Campbell claim (No. 

47) on the present day Roth Unit (BLM 2007). 

Diking of the River ‘S’ Unit was completed in 1941, protecting 1,565 acres from floodwaters. The 

unit had historically been a ranch until its purchase in 1965. Up to 600 cow/calf pairs, and at times 

hundreds of sheep, grazed on its improved and canarygrass pastures. The resulting short grass was 

used heavily by migratory and wintering Canada geese, tens of thousands of American wigeon, and 

other ducks. The Vanport flood of 1948 provided additional stimulus for dike building. In that year, 

Congress authorized funds for flood control projects on the lower Columbia River. In June 1952 the 

U.S. Army Corps of Engineers proposed flood control projects (diking and draining) on the presentday River ‘S’ Unit (“Lake River Delta Area” 1565 acres), Bachelor Island (1883 acres), and Carty 

Unit (“Lewis River Area” 1700 acres) to prevent flood damage to existing uses and further promote 

use of these lands for agricultural production. However, detailed engineering studies concluded that 

the projects had an unfavorable benefit-to-cost ratio and they were classified as inactive (Port of 

Vancouver, 1965). 

Figure 6.2 Haying on the John Burrow Ranch on Bachelor Island, 1912. (Clark County 

Historical Society, Image No. P03.5.1)
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6-18 Chapter 6. Special Designations, Cultural Resources, and Social/Economic Environment

Figure 6.3 Farm house built by Simeon Reed and William Ladd on Bachelor Island in the 

1870s. The house burned down in 1976. (Clark County Historical Society, Image No. P15.40.1)

Refuge Establishment. In March 1962 the DOI announced that the northern portion of the 

Vancouver lowlands was under consideration as a potential wildlife refuge and hunting area. By the 

1960s, reduction in waterfowl habitat (and therefore, waterfowl hunting opportunities) on the lower 

Columbia River was noted by the Migratory Bird Conservation Commission (MBCC). In 1964, the 

population of Vancouver was 34,750 and 40 percent of Clark County was devoted to agriculture, the 

dominant land use. Agriculture was dominated by row crops, grain, hay, and pasture, which all 

provided some benefit to wildlife (Port of Vancouver, 1965). But farm acreage had been declining 

since the 1950s, and the Commission could see the writing on the wall: urban and developed areas 

would expand, while farmland and wildlife habitat would shrink. The Commission also noted the 

limited winter range of the dusky Canada goose and the need for protection of wintering areas. 

These two factors were the major justifications for the establishment of the refuge (MBCC 1964 and 

1965). 

At the time of refuge establishment, the State Department of Game provided for fishing and hunting 

on its Shillapoo Game Refuge, on Vancouver Lake, and on a tract that included the present-day 

Ridgeport Dairy Unit and a portion of the Roth Unit, therefore, most of Post Office Lake and half of 

Campbell Lake could be hunted. Adjacent State tidelands were also reserved for hunting and fishing. 
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Chapter 6. Special Designations, Cultural Resources, and Social/Economic Environment 6-19

These public hunting areas were supplemented by private hunting rights and duck clubs. In a 1965 

planning report, it was noted that “fishing and hunting use of the area is probably less extensive than 

it might be, due to the lack of easy access to much of the area” (Port of Vancouver, 1965). 

The Service acquired its first Ridgefield Refuge property in 1965. This property, the River ‘S’ Unit, 

had been a cattle ranch and was mostly pastureland. The Carty Unit was acquired in 1966 and had 

also been used primarily for grazing. In 1985, the Bachelor Island Unit was purchased from the 

Zimmerly family. Tracts of land for the Roth and Ridgeport Dairy units were purchased between 

1969 and 1995. 

6.2.5 Prehistoric and Historic Sites 

The Refuge encompasses 17 known prehistoric sites (this number includes a site on private property 

on Bachelor Island) and 11 historic sites (FWS 1997). The most significant sites documented to date 

are the Wapato portage site and the Cathlapotle Indian Town site (45CL1) in the refuge’s Carty Unit. 

Aside from the Meier site (35CO5) and the Broken Tops site (35MU57), no extensive excavations of 

a Chinookan town have occurred below the Columbia Gorge, making Cathlapotle an important 

source of archaeological information about the region. It is one of the few archaeological sites on the 

Columbia River that has not been lost to looting, development, or flooding, and may be one of the 

best preserved native town sites in the northwest United States (Ames et al. 1999). 

As Federal property, stewardship of Cathlapotle and other sites on the refuge is mandated and guided 

by Sections 106 and 110 of the National Historic Preservation Act (NHPA) as well as other relevant 

Federal cultural resource laws. As part of the stewardship program for the resource, archaeological 

work began at the site in 1991. A partnership between the Service, Portland State University, and the 

Chinook Nation soon developed, and by 1995 this partnership−the Cathlapotle Archaeological 

Program−was formally codified by a memorandum of agreement (MOA). Over the course of six 

field seasons the remains of six plankhouses, as well as thousands of artifacts, were recovered and 

catalogued (Ames et al. 1999). 

The site occurs in forested riparian habitat of the Carty Unit, 15-20 feet above mean sea level. 

Covered by stands of cottonwood, willow, alder, and ash trees, with a tangled understory of 

elderberry and stinging nettle, the site is bounded on the west by Lake River and on the east by Long 

Meadow. Radiocarbon dates indicate that the town was occupied at its current location around 1450 

A.D. (Lyman and Ames 2004). In comparison to the Meier Site, a larger proportion of European 

trade items appear to be present at Cathlapotle, suggesting that Cathlapotle was occupied well into 

the historic period, while the Meier house was not (Ames et al., 1995). Seriation of ceramic trade 

goods indicates that the Cathlapotle site was abandoned circa 1834 AD (Kaehler 2002). 

Archaeologists located 11 house depressions on the surface, laid out in two rows on a ridge running 

parallel to Lake River. The largest of the house depressions measures 200 feet by 45 feet (10m x 

63m), while the smallest is 60 feet by 30 feet. At least four are divided into compartments, as Lewis 

and Clark described when they visited the town in 1806 (Moulton 1991[7]). Other features described 

at the site include storage pits, cobble ovens, postholes marking temporary structures such as sheds 

and drying racks, middens, and debris fields. Although the site was periodically flooded, it was high 

enough not to be subject to annual flooding, and the archaeological record indicates that it was 

continuously occupied. 
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The Wapato Portage site (45CL4) is also an important site, preserving evidence of 2,300 years of 

continuous occupation. None of the 14 smaller prehistoric sites have been intensively investigated. 

Evidence from these sites, characterized as fire hearths, habitation sites, or activity stations, suggests 

that these were temporary or seasonal camps established in the course of fishing, root collecting or 

processing, hunting, or tool manufacture. 

Seven historic basalt quarry sites on the Carty Unit were placed on the National Register of Historic 

Places in 1981 as the “Basalt Cobblestone Quarries District.” Of the seven only one, 45CL113H, 

was formally recorded. The other six are grouped together, possibly under the site 45CL161H, but 

the Service does not have a site record which verifies this. The basalt cobbles from these seven 

quarries, mined from 1880 to 1903, were used for ship ballast and to pave the streets of Portland, 

Oregon. The quarries represent not only an important turn-of-the-century industry in Ridgefield, but 

also a significant step in the development of Portland from a frontier settlement to an urban and 

commercial center. 

Historic sites 45CL112H, 45CL114H, and 45CL285H are old house sites. The 45CL286H site is a 

refuse dump dating to the late 19th century. Many of these sites have been subjected to looting and 

amateur excavation. It is very likely that other unrecorded historic (and prehistoric) sites are located 

on Bachelor Island under the Lake River levee. The island is significant for its early Euro-American 

settlement, dating to the 1850s (see section 6.2.4 above).

6.3 Social/Economic Environment

6.3.1 Population, Housing, and Income

The refuge is located in Clark County, Washington approximately 15 miles north of Vancouver, 

Washington. The nearest community is Ridgefield which adjoins the refuge. Table 6.3 shows the 

population of Clark County, growth rates, and other social statistics collected by the U.S. Census. 

Some of the more striking differences between Clark County and the state as a whole are highlighted. 

Clark County has outpaced the nation in terms of both population and economic growth as it 

transitions from a small urbanized area surrounded by a rural farm population to a suburban-urban 

setting. Between 2000 and 2006 the rate of population growth was more than double the state 

average (U.S. Census Bureau). Clark County was the most rapidly developing county in the state of 

Washington in the 1990s and is one of the faster growing areas nationwide. In 1980, its 192,227 

residents accounted for 4.7 percent of the state’s population. As of April 2004, the county’s 

population had grown to 383,800, representing 6.2 percent of the state-wide total. If the recent 

growth rates of 2-3 percent annually continue, the county’s population could reach 621,763 by 2025 

(State of Washington Office of Financial Management 2001). 

Clark County is one of six counties included in the Portland-Vancouver, Oregon-Washington, 

Metropolitan Statistical Area (MSA). The other five counties are Clackamas, Columbia, Multnomah, 

Washington, and Yamhill—all in Oregon. In 2004, the metropolitan area population was 2,040,550. 

Clark County represents 18.8 percent of the total metropolitan population (Clark County 2005). 

Current growth in Clark County has mostly occurred in the cities of Battle Ground, Camas, 

Washougal, and along the urban fringe of Vancouver in areas such as Felida, Hazel Dell, Orchards, 
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Chapter 6. Special Designations, Cultural Resources, and Social/Economic Environment 6-21

and Salmon Creek. The City of Vancouver is increasing in size largely due to annexation of areas 

along the urban fringe and increases in building activity. The cities of Battle Ground, Camas, and 

Washougal and surrounding areas are also continuing to grow. 

Recently, growth has spread to rural areas where people are looking to find a more rustic and 

peaceful setting. Growth in rural areas is concentrating around small cities and towns, such as Battle 

Ground and Ridgefield, and to a lesser degree, La Center and Yacolt. The population of Ridgefield 

jumped from 1,062 in 1980 to 1,332 in 1990 and 1,510 in 1994 (The Columbian 1994). The rate of 

population growth increased in the 1990s as Ridgefield increasingly became a bedroom community 

for Vancouver. Between 1995 and 2005 the population almost doubled. Ridgefield’s population was 

projected to increase from 2,900 in 2005 to some 25,000 people in 2025, bringing some 16,000 new 

jobs to the area over that same time span (Port of Ridgefield 2005). 

Growth in Clark County can be attributed to a number of factors. Some of the key factors include 

its proximity to the Portland, Oregon metropolitan area; access to major transportation routes and 

services (including Interstates 5 and 205, the Portland International Airport, and major north-south 

and east-west railroad lines); quality schools; and quality of life. Clark County has a number of 

parks and open space areas. The opportunity to drive a few minutes and be in a rural setting is 

appealing to many. There are a number of recreational opportunities within a short drive, including 

the Cascade Mountains for skiing and other outdoor activities, the Pacific Ocean, numerous rivers 

and streams, the Columbia River Gorge, and the activities of downtown Portland. 

As the county continues to grow, the population is becoming more diversified with an increase in 

minority and ethnic groups. Although the county is still less ethnically diverse than the state as a 

whole; the white population for the county is about 90 percent. However, recent trends show an 

increase in all minority groups, particularly in the Asian and Pacific Islander, Black, and Hispanic 

origin categories, as well as an influx of eastern Europeans (Clark County 2005). 

The level of educational attainment is slightly lower than the State average. In 2000, Clark County 

had a slightly lower percentage of households in poverty than the State average, and the mean 

housing value was slightly lower than the State average. However, property values have been rising 

in recent years, which have caused repercussions for industries such as farming. 

Table 6.3 Selected Population and Associated Social Statistics, Local Counties 

Population Parameter Clark County Washington

Population, 2006 estimate 412,938 6,395,798

Population, percent change, April 1, 2000 to July 1, 2006 19.6% 8.5%

Population, 2000 345,238 5,894,121

Population, percent change, 1990 to 2000 13.9% 21.1%

Persons under 18 years old, percent, 2005 26.0% 23.6%

Persons 65 years old and over, percent, 2005 9.9% 11.5%

White persons, percent, 2005 90.2% 85.0%

Black or African American persons, percent, 2005 2.0% 3.5%

American Indian and Alaska Native persons, percent, 2005 0.9% 1.7%

Asian persons, percent, 2005 3.7% 6.4%

Native Hawaiian and Other Pacific Islander, percent, 2005 0.4% 0.5%

Persons reporting two or more races, percent, 2005 2.7% 3.0%
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6-22 Chapter 6. Special Designations, Cultural Resources, and Social/Economic Environment

Population Parameter Clark County Washington

Persons of Hispanic or Latino origin, percent, 2005 5.8% 8.8%

White persons not Hispanic percent, 2005 85.0% 77.1%

Living in same house in 1995 and 2000, percent age 5+ 44.2% 48.6%

Foreign born persons, percent, 2000 8.5% 10.4%

Language other than English spoken at home, percent age 5+, 2000 11.5% 14.0%

High school graduates, percent of persons age 25+, 2000 87.8% 87.1%

Bachelor's degree or higher, percent of persons age 25+, 2000 22.1% 27.7%

Homeownership rate, 2000 67.3% 64.6%

Housing units in multi-unit structures, percent, 2000 22.5% 25.6%

Median value of owner-occupied housing units, 2000 $156,600 $168,300

Households, 2000 127,208 2,271,398

Persons per household, 2000 2.69 2.53

Median household income 2004 $52,120 $48,438

Per capita money income 1999 $21,448 $22,973

Persons below poverty, percent, 2004 11.2% 11.6%

Source: U.S. Census Bureau, State and County QuickFacts. Data derived from Population Estimates, 2000 Census of Population 

and Housing, 1990 Census of Population and Housing http://quickfacts.census.gov/.

6.3.2 Employment and Business

Table 6.4 displays some pertinent business statistics for Clark County. In 2002, the retail sales per 

capita were 26 percent lower than the state’s average. Because median household income was 

slightly higher than the state average in 2004, it may reflect the fact that Clark County is a “bedroom 

community” and residents could be making purchases outside the county. Clark County grew rapidly 

in the period from 1994 to 2004, both in population and in the size of its economy. Although 

population increased nearly 40 percent, the local economy was able to expand to meet the demands 

of that growth. The county’s total industrial output nearly doubled in this period from just over $11 

billion in 1994 to nearly $20.3 billion in 2004. 

Labor income also nearly doubled, from $3.6 billion in 1994 to $6.8 billion in 2004. Other value 

added, which includes corporate and property income as well as taxes, increased from $2.4 billion in 

1994 to $11.2 billion in 2004 (Globalwise 2007). Table 6.5 shows relative contributions of various 

industries to the economy of Clark County. Construction is the leading contributor to the County’s 

economy, generating $1.9 billion in output in 2004. The largest employers in the county are in 

public administration, retail sales, health care, social assistance, and construction. 
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Chapter 6. Special Designations, Cultural Resources, and Social/Economic Environment 6-23

Table 6.4 Clark County Business Statistics

Business QuickFacts Clark County Washington

Private nonfarm establishments, 2004 8,936 171,529

Private nonfarm employment, 2004 102,357 2,268,913

Private nonfarm employment, percent change 2000-2004 4.5% 0.1%

Nonemployer establishments, 2004 22,757 369,860

Manufacturers shipments, 2002 ($1000) 3,320,125 79,313,884

Retail sales, 2002 ($1000) 2,946,201 65,262,333

Retail sales per capita, 2002 $7,961 $10,757

Minority-owned firms, percent of total, 2002 7.0% 10.9%

Women-owned firms, percent of total, 2002 29.2% 29.4%

Building permits, 2005 3,771 52,988

Federal spending, 2004 ($1000) 1,576,147 44,840,842

Source: U.S. Census Bureau, State and County QuickFacts. Data derived from Small Area Income and Poverty Estimates, 

County Business Patterns, 1997 Economic Census, Minority- and Women-Owned Business, Building Permits, Consolidated 

Federal Funds Report, and 1997 Census of Governments http://quickfacts.census.gov/.

Table 6.5 Clark County Output, Employment, Labor Income, and Other Value Added, 

2004 

Industry

Output

($ Millions) Employment

Labor 

Income

($ Millions)

Other 

Value

Added

($ Millions)

Construction 1,901.697 16,524 798.369 945.421

Manufacturing - Wood Products 1,624.888 3,576 274.281 468.461

Manufacturing - Miscellaneous 1,393.844 5,656 296.320 417.206

Health Care and Social Assistance 1,390.168 17,219 752.248 874.060

Utilities 1,236.136 2,213 244.167 918.282

Public Administration 1,227.031 20,039 964.597 1,102.010

Manufacturing - High Tech. and related 1,182.322 4,966 277.403 328.199

Retail Trade 1,148.239 17,229 449.525 742.002

Special Sectors 1,072.754 0 0.000 870.073

Professional, Scientific, and Tech. 

Services

1,027.755 9,293 572.895 594.621

Real Estate and Rental and Leasing 1,016.043 6,272 223.250 610.217

Wholesale Trade 870.693 5,348 327.189 595.172

Finance and Insurance 832.734 3,939 256.533 559.790

Information 783.970 2,585 172.133 384.666

Manufacturing - Food and Beverages 679.163 1,193 67.820 173.687

Other Services 658.130 10,138 262.332 375.105

Accommodation and Food Services 613.940 12,602 206.243 301.955

Transportation and Warehousing 607.462 5,230 237.046 315.057

Administrative and Support Services 577.300 10,311 274.350 347.611

Arts, Entertainment and Recreation 201.189 3,197 71.552 126.397

Forestry, Logging and Mining 108.126 582 29.940 54.632

Educational Services 59.342 1,644 25.978 35.308

Beef and Dairy Cattle 21.681 499 1.011 3.581

Crop Production 20.673 380 5.065 12.227
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6-24 Chapter 6. Special Designations, Cultural Resources, and Social/Economic Environment

Industry

Output

($ Millions) Employment

Labor 

Income

($ Millions)

Other 

Value

Added

($ Millions)

Greenhouse and Nursery Production 18.972 511 9.728 14.621

Poultry and Egg Production 14.767 82 2.265 7.155

Other Animal Production 4.039 307 0.365 0.640

Agriculture and Forestry Services 3.492 79 2.657 2.459

Clark County Totals 20,296.552 161,613 6,805.265 11,180.613

Agricultural Totals 83.624 1,858 21.091 40.683

Source: IMPLAN using 2004 Clark County data.

Over the past 50 years, the economy of Clark County has changed dramatically, from being 

dependent largely on the wood products industry and agriculture, to a diversified economic base. 

The wood products industry has declined since the early 1980s. At the same time, new industries 

located in the county. A number of high-tech companies have built plants in Clark County. These 

industries and others have diversified the employment base, stabilized the economy, and reduced the 

reliance on a single timber-dependent employment base. 

The Port of Vancouver, a major deepwater shipping port, continually handles record tonnage, as it 

expands its port facility and industrial park. As of 2008, more than 15,500 jobs were generated by 

the maritime and industrial activities at the Port of Vancouver. This included manufacturers sited on 

the port’s industrial property, and the maritime and shipping industries. It is estimated that port 

activities generate $940 million in business revenue in Clark County annually, with a total economic 

impact of $1.6 billion into the local and regional economy (Port of Vancouver 2009). In addition to 

the Port of Vancouver, the Port of Camas-Washougal and the Port of Ridgefield provide numerous 

services in their industrial parks and have experienced continual industrial growth (Clark County 

2005).

A number of business and industrial parks are situated around the county, with concentrations in east 

Clark County and along the I-5/I-205, Fourth Plain, and Mill Plain corridors, and the Ridgefield 

Junction. There are also plans for a large multiuse development on Port of Ridgefield property (the 

old Pacific Wood Treatment site) adjacent to the refuge’s Carty Unit. Given Clark County’s 

geographic location, access to major transportation routes and services, and growing population, 

economic growth is expected to continue. 

 

As Clark County has become increasingly developed, the number and acreage of farms has declined. 

The U.S. Census of Agriculture, conducted in either five or 10 year intervals between 1900 and 1954, 

showed the number of farms in the county grew steadily from 1,873 farms with 192,700 acres in 

1900 to 4,934 farms with 204,850 acres in 1945. (The census counted all entities as “farms” so long 

as there is at least $1,000 of sales.) The peak year for acreage in farms was 1950 when the census 

reported that almost 220,000 acres of Clark County were in farms. This was 54.1 percent of the 

county’s total land base. A sizeable amount of woodlands were included in the total acreage estimate 

along with cropland, pasture and grass fields. In the 1950s, small farms were characteristic of 

agriculture in Clark County. Over two thirds of all farms in the county were less than 50 acres in 

size.

By the early 1970s, about 168,000 acres (42 percent of the county) were in farmland. The 2002 

Agriculture Census reported that Clark County had 1,596 farms totaling 70,694 acres (17.6 percent of 
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Chapter 6. Special Designations, Cultural Resources, and Social/Economic Environment 6-25

the county). Although historical statistics show that Clark County has always been dominated by 

small farms, the trend has been towards even smaller farms. In 2002 the census data shows 80 

percent of all farms were less than 50 acres in the county. In 1954 the average size of farms in the 

county was 51 acres; and in 2002 the average size was 44 (Globalwise 2007). 

The types of agricultural products produced in the county have also changed. In 1957 Clark County 

was the leading western Washington orchard growing area and had a diverse agricultural economy 

including livestock, poultry, and field crops (Clark County 1957). By the early 1970s, less fruit was 

being grown, and dairy products accounted for more than 40 percent of the value of farm products 

(USDA 1972). For many years there has been a loss of the larger traditional commercial farms 

including dairies, berry farmers, fruit producers, field crops, and others. The county’s dairy industry 

has steadily declined. In 1984, there were 84 dairies in the county. As of 2007, there were only 

seven remaining. 

In recent years, Christmas trees and berries have been key crops produced in Clark County. 

Ornamental nurseries have experienced growth in recent years, propelled in large part by the growth 

in new housing. New small scale agriculture has not made up for the loss of traditional farmers and 

the total amount of land devoted to commercial agriculture continues to decrease. Many factors have 

contributed to the decline in the county’s agriculture. The most basic factor is that agricultural 

producers in other areas can grow, process, and market crops at a lower cost. Another key factor is 

the limited access to affordable, high quality agricultural land. Rapidly escalating land prices in the 

County, fueled by development, have created a major barrier for new farmers to enter the business. 

Farmers will not bid for land at prices equal to what buyers for homes and other development will 

pay (Globalwise 2007). 

The changes in local land use patterns have caused a number of management implications for the 

refuge. Fewer local acres in pasture and row crops, and more acres in housing, commercial, and 

industrial development, nurseries, Christmas tree farms, and berry farms, means that while 

depredation complaints have decreased, the refuge has an ever more important role in providing 

forage for migrating and overwintering Canada and cackling geese. Populations of birds may also 

shift as geese, in particular, seek grain and green forage. Declines in dairy and ranch operations 

mean that it has become increasingly difficult for the refuge to find cooperative grazers. Increasing 

land prices has also affected the ability of the refuge to acquire lands within its acquisition boundary. 

6.3.3 Refuge Impact on Local Economies

In 1997, and again in 2004, a national study was completed to estimate the economic effect refuges 

have on local economies. In both reports, the refuge was featured. Data from the reports showed a 

significant level of expenditures within Clark County and across the Oregon border in Multnomah 

County, stemming from recreational visits to the refuge. The following tables (6.5 and 6.6) 

summarize the level of expenditures made within the counties to support recreational visits to the 

refuge in 2004. Total expenditures during FY 2004 were $1.38 million, with nonresidents 

accounting for 56 percent of this expenditure. The majority of expenditures ($1.3 million or 95.2 

percent of the total) were attributed to nonconsumptive uses, while waterfowl hunting generated 

$60,800 (4.4 percent) and freshwater fishing accounted for $5,300, or 0.4 percent of the total. 

Spending generates jobs and multiplier effects in the economy. The total monetary effect of 

economic activity generated in the counties by refuge visitors’ expenditures totaled $2.2 million. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

6-26 Chapter 6. Special Designations, Cultural Resources, and Social/Economic Environment

This final demand generated 25 jobs, with a total employment income of $748,100. Based on the 

2004 refuge budget, we estimated the ratio of economic effects per dollar of refuge expenditure to be 

2.8. This means that for every one dollar of budget expenditures, approximately $2.80 of total 

economic effects was generated.

Although hard data like Table 6.6 is lacking, it appears that the majority of visitors are local 

residents, who do not spend as much as nonresidents when visiting the Refuge. 

 

Table 6.6 Ridgefield Refuge Visitor Recreation-related Expenditures (2004)

Activity Resident Non-Resident Total

Nonconsumptive $570.61 $743.36 $1,313.97

Hunting

 Big game $0.00 $0.00 $0.00 

 Small game $0.00 $0.00 $0.00 

 Migratory bird $25.80 $35.00 $60.80 

Total hunting $25.80 $35.00 $60.80 

Fishing $5.30 $0.00 $5.30 

Total $601.70 $778.40 $1,380.10 

Source: Caudill and Henderson (2005). All figures in thousands

Table 6.7 Ridgefield Refuge Economic Effects Associated with Visitation

Economic Effect Nonresidents Total

Final Demand $1,214,800 $2,169,100 

Jobs 13 25

Job Income $415,200 $748,100 

Source: Caudill and Henderson (2005). 

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 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix A. Appropriate Use Determinations A-1 

Appendix A. Appropriate Use Determinations 

Introduction 

The Appropriate Refuge Uses Policy outlines the process that the Service uses to determine when 

general public uses on refuges may be considered. Priority public uses previously defined as 

wildlife-dependent uses (hunting, fishing, wildlife observation and photography and environmental 

education and interpretation) under the National Wildlife Refuge System Improvement Act of 1997, 

are generally exempt from appropriate use review. Other exempt uses include situations where the 

Service does not have adequate jurisdiction to control the activity and refuge management activities. 

In essence, the appropriate use policy, 603 FW 1 (2006), provides refuge managers with a consistent 

procedure to first screen and then document decisions concerning a public use. When a use is 

determined to be appropriate, a refuge manager must then decide if the use is compatible before 

allowing it on a refuge. The policy also requires review of existing public uses. During the CCP 

process the refuge manager evaluated all existing and proposed refuge uses at Ridgefield National 

Wildlife Refuge using the following guidelines and criteria as outlined in the appropriate use policy: 

Do we have jurisdiction over the use? 

Does the use comply with applicable laws and regulations (Federal, State, tribal and local)? 

Is the use consistent with applicable Executive orders and Department and Service policies? 

Is the use consistent with public safety? 

Is the use consistent with goals and objectives in an approved management plan or 

other document? 

Has an earlier documented analysis not denied the use or is this the first the use has 

been proposed? 

Is the use manageable within available budget and staff? 

Will this be manageable in the future within existing resources? 

Does the use contribute to the public’s understanding and appreciation of the refuge’s natural 

or cultural resources, or is the use beneficial to the refuge’s natural or cultural resources? 

Can the use be accommodated without impairing existing wildlife-dependent recreational 

uses or reducing the potential to provide quality, compatible, wildlife dependent recreation 

into the future? 

Using this process and these criteria, and as documented on the following pages, the refuge manager 

determined the following use(s) are not appropriate: allowing dogs on refuge (other than dogs used 

for waterfowl hunting, bicycling, jogging, horseback riding, providing a kayak launching facility, and 

berry picking. The refuge manager also determined the following refuge use(s) were appropriate, 

and directed that compatibility determinations be completed for each use: crop production, haying 

and mowing, grazing (cattle and/or horses), research, and mosquito management. 

Appropriate Uses Justification, Attachment 1

Refuge: Ridgefield National Wildlife Refuge (NWR)

Use: Allowing Dogs 

Summary: Allowing dogs on Ridgefield NWR has been determined to be not 

appropriate because of disturbance to other users, disturbance to wildlife (especially 

waterfowl), and as a safety concern to users. 

For findings listed on FWS Form 3-2319 and if deemed necessary a justification has 

been provided below:

d. Is the use consistent with public safety? 

Wheeled access by public users is restricted to the River ‘S’ Unit Auto Tour Route, 

an established gravel roadway where popular wildlife viewing and photography 

opportunities are provided. Since 1994 when the last compatibility determination was 

made, automobile numbers on the Auto Tour Route have more than doubled. 

Because of driving habits associated with the gravel single lane road, automobile 

users are often aware of the slow moving, stop-and-go habits other automobile drivers 

exhibit. Because these same drivers are engaged in wildlife viewing activities, the 

faster moving, far less detectable and uncontrolled dogs could create an unsafe traffic 

situation. 

Pedestrian foot travel is permitted in the Carty Unit where there is no public 

automobile access. Dogs may increase conflicts between users and may pose a safety 

problem when aggressive or out-of-control dogs encounter other users. 

f. Has an earlier documented analysis not denied the use or is this the first time the 

use has been proposed?

This use had a compatibility determination completed in 1994. This determination 

collectively included seven other uses and the treatment of dogs involved two 

sentences. The use was determined to be compatible because of its infrequency. 

I. Does the uses contribute to the public’s understanding and appreciation of the 

refuge’s natural or cultural resources, or is the use beneficial to the refuge’s 

natural or cultural resources?

Dogs also elicit a greater response from wildlife than pedestrians alone (MacArthur et 

al. 1982; Hoopes 1993). In the case of birds, the presence of dogs may flush 

incubating birds from nests (Yalden and Yalden 1990), disrupt breeding displays 

Appendix A. Appropriate Use Determinations

_____________________________________________________________________________________________

A-3
(Baydack 1986), disrupt foraging activity in shorebirds (Hoopes 1993), and disturb 

roosting activity in ducks (Keller 1991). Many of these authors indicated that dogs 

with people, dogs on-leash, or loose dogs provoked the most pronounced disturbance 

reactions from their study animals. Despite thousands of years of domestication, dogs 

still maintain instincts to hunt and chase. Given the appropriate stimulus, those 

instincts can be triggered. Dogs that are unleashed or not under the control of their 

owners may disturb or potentially threaten the lives of some wildlife. In effect, offleash dogs increase the radius of human recreational influence or disturbance beyond 

what it would be in the absence of a dog. A group of Australian researchers 

determined that dog-walking can have a significant impact on avian abundance and 

species diversity, and were quite surprised by the magnitude of the impact. The team 

found that dog-walking caused bird numbers to drop by an average of 41% at each 

site studied, while the numbers of species counted fell by 35%. The results were 

similar in sites often frequented by dog-walkers and those where the practice was 

prohibited, suggesting that birds did not get habituated to the dogs’ presence, despite 

frequent encounters (Banks and Bryant 2007). 

The role of dogs in wildlife diseases is poorly understood. However, dogs host endoand ectoparasites and can contract diseases from, or transmit diseases to, wild 

animals. In addition, dog waste is known to transmit diseases that may threaten the 

health of some wildlife and other domesticated animals. Domestic dogs can 

potentially introduce various diseases and transport parasites into wildlife habitats 

(Sime 1999). 

h. Can the use be accommodated without impairing existing wildlife-dependent 

recreational uses or reducing the potential to provide quality (see section 1.6D, 

603 FW1 for description), compatible, wildlife-dependent recreation into the 

future? 

At a minimum, the quality of the visitor experience would be degraded and there 

could be direct conflicts with certain priority public uses. Disturbance to waterfowl 

and wildlife by the presence of dogs have been noted (MacArthur et al. 1982; Hoopes 

1993; Keller 1991). Due to flushing distance, a conflict may occur between users, 

resulting in the quality of the other user’s experience being impaired. This situation 

will create what Moore (1994) summarized: Trail conflicts can occur among different 

user groups, among users within the same user group, and as a result of factors not 

related to trail user activities at all. Conflict has been found to related to activity style, 

focus of trip, expectations, attitudes toward and perceptions of the environment, level 

of tolerance for others, and different norms held by different users. This loss of 

expectation of a quality wildlife dependant experience could result in use avoidance 

of the refuge by wildlife watchers and photographers who have encountered dogs 

using the same or alternate trail(s). 

______________________________________________________________________________________________

A-4 Appendix A. Appropriate Use Determinations
Literature Cited

Banks, Peter B. and Bryant, Jessica V. 2007. Four-legged friend or foe? Dog walking 

displaces native birds from natural areas. Biol Lett. 3(6): 611–613. 

Baydack, R.K. 1986. Sharp-tailed grouse response to lek disturbance in the Carberry 

Sand Hills of Manitoba. Colorado State University, Fort Collins, CO. 

Hoopes E.M. 1993. Relationships between human recreation and piping plover 

foraging ecology and chick survival. MS Thesis, University of Massachusetts, 

Amherst, MA, 106 pp. 

MacArthur, R.A., V. Geist, and R.H. Johnston. 1982. Cardiac and behavioral 

responses of mountain sheep to human disturbance. J. Wildl. Manage. 46:351-358. 

C.W. Servheen, eds. 1980. Proceedings of the Washington bald eagle symposium; 

Seattle, Washington. 

Moore. 1994. Conflicts On Multiple-Use Trails: Synthesis of the Literature and State 

of the Practice. Federal Highway Administration Report No. FHWA-PD-94-031 - 

Report Date: August, 1994.

 

Sime, C.A. 1999. Domestic dogs in wildlife habitats. Pages 8.1-8.17 in G. Joslin, 

and H. Youmans, coordinators. Effects of recreation on Rocky Mountain wildlife: A 

review for Montana. Committee on effects of recreation on wildlife, Montana chapter 

of The Wildlife Society. 

Yalden, P.E., and D.W. Yalden. 1990. Recreational disturbance of breeding golden 

plovers Pluvialis apricarius. Biol. Conserv. 51:243-263. 

 

Appendix A. Appropriate Use Determinations

_____________________________________________________________________________________________

A-5

Appropriate Uses Justification, Attachment 1

Refuge: Ridgefield National Wildlife Refuge (NWR)

Use: Bicycle Use

Summary: Use of bicycles on Ridgefield NWR has been determined to be not 

appropriate because of the disturbance to wildlife, especially waterfowl, and as a 

safety concern to users.

For findings listed on FWS Form 3-2319 and if deemed necessary a justification has 

been provided below:

d. Is the use consistent with public safety? 

Wheeled access by public users is restricted to the River ‘S’ Unit Auto Tour Route, 

an established gravel roadway where popular wildlife viewing and photography 

opportunities are provided. Since 1994, when the last compatibility determination 

was made, automobile numbers on the Auto Tour Route have more than doubled. 

Because of driving habits associated with the gravel single lane road, automobile 

users are often aware of the slow moving, stop-and-go habits other automobile drivers 

exhibit. Because these same drivers are engaged in wildlife viewing activities, the 

faster moving, far less detectable bicycles could create an unsafe traffic situation.

In the Carty Unit foot travel is permitted and there is no public access for 

automobiles. The narrow trail though wetland and forest habitats is not suitable for 

shared bicycle and pedestrian use due to line-of-sight limitations. Thus there is the 

potential for fast-moving bicyclists to collide with or disturb pedestrians. 

f. Has an earlier documented analysis not denied the use or is this the first time the 

use has been proposed?

This use had a compatibility determination completed in 1994. This determination 

collectively included seven other uses and the treatment of bicycles involved two 

sentences. The use was determined to be compatible because of its infrequency. 

h. Can the use be accommodated without impairing existing wildlife-dependent 

recreational uses or reducing the potential to provide quality (see section 1.6D, 

603 FW1 for description), compatible, wildlife-dependent recreation into the 

future? 

At a minimum, the quality of the visitor experience would be degraded and there 

could be direct conflicts with certain priority public uses. Disturbance to waterfowl 

Appendix A. Appropriate Use Determinations

_____________________________________________________________________________________________

A-7
by bicycles have been noted (Pease et al. 2005). Due to flushing distance, a conflict 

may occur between users, resulting in the quality of the other user’s experience being 

impaired. When wildlife react by moving away from a fast moving activity such as 

biking, or alter behavior by hiding, they will be less likely to be observed (Bennett 

and Zuelke 1999). This situation will create what Moore (1994) summarized: Trail 

conflicts can occur among different user groups, among users within the same user 

group, and as a result of factors not related to trail user activities at all. Conflict has 

been found to related to activity style, focus of trip, expectations, attitudes toward and 

perceptions of the environment, level of tolerance for others, and different norms held 

by different users. This loss of expectation of a quality wildlife dependent experience 

could result in use avoidance of the refuge by wildlife watchers and photographers 

who have encountered bicyclists using the same or alternate trail(s). 

Literature Cited

Bennett, KA and E. Zuelke. 1999. The effects of recreation on birds: a literature 

review. Delaware Natural Heritage Program, Smyrna, DE 1977. 

Pease, Melissa L., Rose, Robert K. and Butler, Mark J. 2005. Effects of human 

disturbances on the behavior of wintering ducks. Wildlife Society Bulletin, 

33(1):103–112 

Moore. 1994. Conflicts On Multiple-Use Trails: Synthesis of the Literature and State 

of the Practice. Federal Highway Administration Report No. FHWA-PD-94-031 - 

Report Date: August, 1994.

 

 

______________________________________________________________________________________________

A-8 Appendix A. Appropriate Use Determinations

Appropriate Uses Justification, Attachment 1

Refuge: Ridgefield National Wildlife Refuge (NWR) 

Project: Use of a private cooperator to produce crops for wildlife forage 

Summary: The refuge manages pastures, wetlands, and agricultural fields to provide a 

variety of foods that will meet the needs of wintering and migratory waterfowl. Current 

refuge farming practices include grazing, haying, and planting of crops such as cereal 

grains and clover. Agricultural crops grown on the refuge (primarily winter wheat and 

corn) are selected primarily to provide waterfowl with an easily-accessible source of 

high-energy carbohydrates. The refuge proposes to increase crop production acreages 

from the current range of 155 to 185 ac (including 55 to 85 ac in corn) to 290 to 330 acres 

(including 60 to 145 ac of corn). 

The refuge has little capacity currently to irrigate croplands and in some years rainfall 

during the growing season is insufficient to produce a successful corn crop. Corn is 

favored by both geese and cranes as a high carbohydrate food, and the 2004 Wildlife and 

Habitat Management Review recommended increasing the acreage in corn. Given the 

high costs of producing a successful corn crop, the refuge proposes to evaluate the 

feasibility of implementing a cooperative farm program for crop production, whereby a 

private farmer (cooperator) would raise a Refuge-specified crop in a designated field or 

fields, and would be entitled to a share of the harvest. As an example, 75% of the crop 

would go to the cooperator and 25% to the Refuge, although this would be negotiated 

with the cooperator as part of the development of a Cooperative Farming Agreement 

(CFA). CFAs are typically multi-year agreements that are used to implement cooperative 

programs that help achieve refuge purposes as well as an economic benefit to the farmer. 

The CFA involves a negotiated agreement between the Refuge and private farmer to 

manage lands for both parties. To benefit wildlife, the Refuge share would be left in the 

field where it would be available to wildlife. Any fields that are double-cropped (two or 

more crops raised in a single season) would be subject to the same pre-determined 

Refuge/cooperator split for each crop. 

For each of the findings listed on FWS Form 3-2319, a justification has been

provided below:

a. Do we have jurisdiction over the use?

All proposed activities would take place within refuge boundaries and under the 

supervision of refuge staff. 

b. Does the use comply with applicable laws and regulations (Federal, State, tribal, 

and local)? 

______________________________________________________________________________________________

A-10 Appendix A. Appropriate Use Determinations
The proposed activities would comply with all applicable laws and regulations and would 

be spelled out in the CFA. 

c. Is the use consistent with applicable Executive orders and Department and 

Service policies?

The proposed use would provide high energy and readily available forage for wintering 

and migrating waterfowl and cranes within close proximity to other natural food sources 

and high quality roosting habitat. Crops can provide wildlife with easily-accessible high 

energy foods, are more digestible than native plants, and can reduce foraging time 

required to meet caloric demands (Raveling 1979, Alisauskas and Ankney 1992, 

Baldassare and Bolen 2006). Because these conditions cannot be met by singularly 

managing natural foods, the production of non-genetically modified crops is consistent 

with the Service’s Biological Integrity, Diversity and Environmental Health Policy (601 

FW 3) and will help achieve the refuge purposes. 

d. Is the use consistent with public safety? 

The proposed use is consistent with public safety and would be sited in areas closed to 

the general public. 

e. Is the use consistent with goals and objectives in an approved management plan 

or other document?

The proposed use is consistent with the 2004 Wildlife and Habitat Management Review 

conducted by the Service as well as the Northwest Oregon/Southwest Washington 

Canada Goose Depredation Plan (Pacific Flyway Council 1998). 

g. Is the use manageable within available budget and staff? 

The proposed use is manageable with available budget and staff. The use of a cooperator 

may save staff time and resources and increase the reliability of successful crop 

production. 

h. Will this be manageable in the future within existing resources?

The proposed use would be manageable in the future with the existing resources and may 

save staff time and resources (see above). 

i. Does the uses contribute to the public’s understanding and appreciation of the

refuge’s natural or cultural resources, or is the use beneficial to the refuge’s natural 

or cultural resources?

The proposed use is beneficial to the refuges natural resources because crop production 

would help achieve refuge purposes by providing wintering and migrating waterfowl and 

Appendix A. Appropriate Use Determinations

_____________________________________________________________________________________________

A-11
cranes with a high energy, easily accessible food source in close proximity to natural 

foods and roosting sites. 

j. Can the use be accommodated without impairing existing wildlife-dependent 

recreational uses or reducing the potential to provide quality (see section 1.6D, 603 

FW 1, for description), compatible, wildlife-dependent recreation into the future?

The proposed use will not impair existing or future wildlife-dependent recreational use of 

the refuge. A maximum of 330 acres (approximately 6% of the refuge area) would be 

used for crop production and much of this area would be sited on Bachelor Island or Roth 

Units which are closed to the general public. 

Literature Cited

Alisauskas, R.T. and C.D. Ankney. 1992. The cost of egg laying and its relationship to 

nutritional reserves in waterfowl. Pages 30-61 in B.D.J. Batt, A.D. Afton, M.G. 

Anderson, C.D. Ankney, D.H. Johnson, J.A. Kadlec, and G.L. Krapu, eds. 

Ecology and management of breeding waterfowl. Univ. of Minnesota Press, 

Minneapolis. 

Baldassare, G.A, and E.G. Bolen. 2006. Waterfowl ecology and management. John 

Wiley and Sons, Inc. 

Pacific Flyway Council. 1998. Pacific Flyway management plan for Northwest 

Oregon - Southwest Washington Canada goose agricultural depredation control. 

Canada goose agricultural depredation working group, Pacific Flyway Study 

Comm. [c/o USFWS], Portland, OR 97232-4181. Unpubl. Rept. 31pp. + 

appendices. 

Raveling, D.G. 1979. The annual energy cycle of the Cackling Canada Goose. pages 81-

93 in R.I. Jarvis and J.C. Bartonek, eds. Management and biology of Pacific 

Flyway geese. Oregon State University, Corvallis. 

______________________________________________________________________________________________

A-12 Appendix A. Appropriate Use Determinations

Appropriate Uses Justification, Attachment 1

Refuge: Ridgefield National Wildlife Refuge (NWR) 

Project: Use of a private cooperator to graze pastures to manage and improve goose 

habitat. 

Summary: The refuge manages pastures, wetlands, and agricultural fields to provide a 

variety of foods that will meet the needs of wintering and migratory waterfowl and 

cranes. Geese in particular, use refuge pastures for most of their foraging activity, 

preferring young shoots that are higher in protein and lower in fiber than mature stems 

(Mclandis and Raveling 1981). Pasture grasses serve as an important source of amino 

acids and carbohydrates to meet the energy and nutrient requirements of geese 

(Baldassare and Bolen 2006). To provide high quality forage for wintering and migrating 

geese and cranes, the refuge uses grazing to ensure that young shoots less than 4 inches 

tall are available by early October each year and to reduce the accumulation of thatch 

(thatch can reduce the number of available shoots). Other tools used by the refuge 

include mowing and haying, which are discussed in detail in a separate appropriate use 

determination. 

The refuge provides approximately 1,450 ac of pasture in 55 fields. Of these, 

approximately 540 ac (193 head, cattle and horses combined) were grazed in 2009 to help 

achieve refuge goals. Grazing by cattle and/or horses is allowed in fields between May 1 

and October 1, subject to approval by the refuge biologist and manager, and only after 

surveys conducted by refuge staff indicate that introducing livestock to an area will not 

significantly affect grassland nesting birds. Stock is removed when the vegetation height 

is <4 inches over 90% of the pasture. 

Cooperative Land Management Agreements (CLMA) are used to implement cooperative 

farming, grazing, and haying programs that help achieve refuge purposes. The CLMA, 

signed in 2009, described the negotiated agreement between the Refuge and a private 

farmer to manage lands for both parties. The amount of stock grazed on the Refuge 

varies, but 120 to 250 of cows and horses (combined) are allowed to graze on 

approximately 740 acres, but not all acres will be grazed each year. 

For each of the findings listed on FWS Form 3-2319, a justification has been 

provided below:

a. Do we have jurisdiction over the use?

All proposed activities would take place within refuge boundaries and under the 

supervision of refuge staff. 

______________________________________________________________________________________________

A-14 Appendix A. Appropriate Use Determinations
b. Does the use comply with applicable laws and regulations (Federal, State, tribal, 

and local)? 

The proposed activities would comply with all applicable laws and regulations and would 

be spelled out in the CLMA. 

c. Is the use consistent with applicable Executive orders and Department and 

Service policies?

The proposed use would provide high quality forage for wintering and migrating 

waterfowl and cranes within close proximity to high quality roosting habitat. The use of 

a private cooperator to graze refuge pastures helps provide high quality forage and 

removes thatch that would be left behind if mowing was used as the only management 

technique. Other methods such as prescribed fire may remove thatch and mimic natural 

processes, but given local air quality concerns, the widespread and consistent use of 

prescribed fire is not practicable. Given the difficulty in using prescribed fire for pasture 

management, grazing is consistent with the Service’s Biological Integrity, Diversity and 

Environmental Health Policy (601 FW 3). 

d. Is the use consistent with public safety? 

The proposed use is consistent with public safety and would be sited in areas closed to 

the general public. Grazing would occur in hunt areas, but all livestock would be 

removed prior to the hunt seasons. 

e. Is the use consistent with goals and objectives in an approved management plan 

or other document?

The proposed use is consistent with the 2004 Wildlife and Habitat Management Review 

conducted by the Service as well as the Northwest Oregon/Southwest Washington 

Canada Goose Depredation Plan (Pacific Flyway Council 1998) and the Pacific Flyway 

Management Plan for the Dusky Canada Goose (Pacific Flyway Council 2008). 

g. Is the use manageable within available budget and staff? 

The proposed use is manageable with available budget and staff. The use of a cooperator 

may save staff time and resources. Grazing also removes thatch and therefore can 

increase the pasture habitat quality over what could be achieved by only mowing by 

refuge staff. 

h. Will this be manageable in the future within existing resources?

The proposed use would be manageable in the future with the existing resources and may 

save staff time and resources (see above). 

i. Does the uses contribute to the public’s understanding and appreciation of the

Appendix A. Appropriate Use Determinations

_____________________________________________________________________________________________

A-15
refuge’s natural or cultural resources, or is the use beneficial to the refuge’s

natural or cultural resources?

The proposed use is beneficial to the refuges natural resources because grazing would 

help achieve refuge purposes by providing wintering and migrating waterfowl and cranes 

with a high quality food sources in close proximity to roosting sites. 

j. Can the use be accommodated without impairing existing wildlife-dependent 

recreational uses or reducing the potential to provide quality (see section 1.6D, 603 

FW 1, for description), compatible, wildlife-dependent recreation into the future?

The proposed use will not impair existing or future wildlife-dependent recreational use of 

the refuge. As stated above, this activity would be sited in areas closed to the general 

public. 

Literature Cited

Alisauskas, R.T. and C.D. Ankney. 1992. The cost of egg laying and its relationship to 

nutritional reserves in waterfowl. Pages 30-61 in B.D.J. Batt, A.D. Afton, M.G. 

Anderson, C.D. Ankney, D.H. Johnson, J.A. Kadlec, and G.L. Krapu, eds. 

Ecology and management of breeding waterfowl. Univ. of Minnesota Press, 

Minneapolis. 

Baldassare, G.A, and E.G. Bolen. 2006. Waterfowl ecology and management. John 

Wiley and Sons, Inc. 

Pacific Flyway Council. 1998. Pacific Flyway management plan for Northwest 

Oregon - Southwest Washington Canada goose agricultural depredation control. 

Canada goose agricultural depredation working group, Pacific Flyway Study 

Comm. [c/o USFWS], Portland, OR 97232-4181. Unpubl. Rept. 31pp. + 

appendices. 

Pacific Flyway Council. 2008. Pacific Flyway management plan for the dusky Canada goose. 

Dusky Canada Goose Subcomm., Pacific Flyway Study Comm. [c/o USFWS], 

Portland, OR. Unpubl. rept. 38 pp.+ appendices.

Raveling, D.G. 1979. The annual energy cycle of the Cackling Canada Goose. pages 81-

93 in R.I. Jarvis and J.C. Bartonek, eds. Management and biology of Pacific 

Flyway geese. Oregon State University, Corvallis. 

______________________________________________________________________________________________

A-16 Appendix A. Appropriate Use Determinations

Appropriate Uses Justification, Attachment 1

Refuge: Ridgefield National Wildlife Refuge (NWR) 

Project: Use of a private cooperator to hay and mow pastures to manage and improve 

goose habitat. 

Summary: The refuge manages pastures, wetlands, and agricultural fields to provide a 

variety of foods that will meet the needs of wintering and migratory waterfowl and 

cranes. Geese in particular, use refuge pastures for most of their foraging activity, 

preferring young shoots that are higher in protein and lower in fiber than mature stems 

(Mclandis and Raveling 1981). Pasture grasses serve as an important source of amino 

acids and carbohydrates to meet the energy and nutrient requirements of geese 

(Baldassare and Bolen 2006). To provide high quality forage for wintering and migrating 

geese and cranes, the refuge uses mowing and haying to ensure that young shoots less 

than 4 inches tall are available by October 15 each year. 

The refuge provides approximately 1,450 ac of pasture in 55 fields that are managed by 

haying (approximately 215 ac) and/or mowing (1,235 ac); the difference being that in 

haying, cut grass stems are removed from the pasture, whereas the stems are left behind 

as thatch in mowed fields. Grazing is also used to manage some pasture lands and is 

described in a separate appropriate use determination. To reduce impacts to grassland 

nesting birds, mowing and haying are conducted after July 15, by which time most 

nesting has been completed. In most dry pastures, a single mowing or haying is 

adequate, but if the late summer precipitation is heavier than typical, a second cutting 

may need to be done. 

Cooperative Land Management Agreements (CLMA) are used to implement cooperative 

farming, grazing, and haying programs that help achieve refuge purposes. The CLMA, 

signed in 2009, described the negotiated agreement between the Refuge and private 

farmer to manage lands for both parties. The cooperator is responsible for pasture 

management, and installing and maintaining fencing. The refuge installs the 

underground water delivery system, maintains pumps, supplies fencing materials, and 

constructs and maintains access roads. The cooperator is allowed to harvest hay and raise 

stock animals for personal use. The amount of hay and stock grazed on the Refuge 

varies, but approximately 200 to 400 tons of hay are removed from approximately 1,200 

acres. 

For each of the findings listed on FWS Form 3-2319, a justification has been 

provided below:

a. Do we have jurisdiction over the use?

______________________________________________________________________________________________

A-18 Appendix A. Appropriate Use Determinations
All proposed activities would take place within refuge boundaries and under the 

supervision of refuge staff. 

b. Does the use comply with applicable laws and regulations (Federal, State, tribal, 

and local)? 

The proposed activities would comply with all applicable laws and regulations and would 

be spelled out in the CLMA. 

c. Is the use consistent with applicable Executive orders and Department and 

Service policies?

The proposed use would provide high quality forage for wintering and migrating 

waterfowl and cranes within close proximity to high quality roosting habitat. The use of 

a private cooperator to hay refuge pastures helps provide high quality forage and removes 

thatch that would be left behind if mowing was used as the only management technique. 

Other methods such as prescribed fire may mimic natural processes, but given local air 

quality concerns, the widespread and consistent use of prescribed fire is not practicable. 

Given the difficulty in using prescribed fire for pasture management, haying is consistent 

with the Service’s Biological Integrity, Diversity and Environmental Health Policy (601 

FW 3). 

d. Is the use consistent with public safety? 

The proposed use is consistent with public safety and would be sited in areas closed to 

the general public. Haying would occur in hunt areas, but this activity would be 

concluded prior to the hunt seasons. 

e. Is the use consistent with goals and objectives in an approved management plan 

or other document?

The proposed use is consistent with the 2004 Wildlife and Habitat Management Review 

conducted by the Service as well as the Northwest Oregon/Southwest Washington 

Canada Goose Depredation Plan (Pacific Flyway Council 1998) and the Pacific Flyway 

Management Plan for the Dusky Canada Goose (Pacific Flyway Council 2008). 

g. Is the use manageable within available budget and staff? 

The proposed use is manageable with available budget and staff. The use of a cooperator 

may save staff time and resources and increase the pasture habitat quality over what 

could be achieved by only haying with refuge staff. 

h. Will this be manageable in the future within existing resources?

The proposed use would be manageable in the future with the existing resources and may 

save staff time and resources (see above). 

Appendix A. Appropriate Use Determinations

_____________________________________________________________________________________________

A-19
i. Does the uses contribute to the public’s understanding and appreciation of the

refuge’s natural or cultural resources, or is the use beneficial to the refuge’s

natural or cultural resources?

The proposed use is beneficial to the refuge’s natural resources because haying would 

help achieve refuge purposes by providing wintering and migrating waterfowl and cranes 

with a high quality food sources in close proximity to roosting sites. 

j. Can the use be accommodated without impairing existing wildlife-dependent 

recreational uses or reducing the potential to provide quality (see section 1.6D, 603 

FW 1, for description), compatible, wildlife-dependent recreation into the future?

The proposed use will not impair existing or future wildlife-dependent recreational use of 

the refuge. As stated above, this activity would be sited in areas closed to the general 

public. 

Literature Cited

Alisauskas, R.T. and C.D. Ankney. 1992. The cost of egg laying and its relationship to 

nutritional reserves in waterfowl. Pages 30-61 in B.D.J. Batt, A.D. Afton, M.G. 

Anderson, C.D. Ankney, D.H. Johnson, J.A. Kadlec, and G.L. Krapu, eds. 

Ecology and management of breeding waterfowl. Univ. of Minnesota Press, 

Minneapolis. 

Baldassare, G.A, and E.G. Bolen. 2006. Waterfowl ecology and management. John 

Wiley and Sons, Inc. 

Pacific Flyway Council. 1998. Pacific Flyway management plan for Northwest 

Oregon - Southwest Washington Canada goose agricultural depredation control. 

Canada goose agricultural depredation working group, Pacific Flyway Study 

Comm. [c/o USFWS], Portland, OR 97232-4181. Unpubl. Rept. 31pp. + 

appendices. 

Pacific Flyway Council. 2008. Pacific Flyway management plan for the dusky Canada goose. 

Dusky Canada Goose Subcomm., Pacific Flyway Study Comm. [c/o USFWS], 

Portland, OR. Unpubl. rept. 38 pp.+ appendices.

Raveling, D.G. 1979. The annual energy cycle of the Cackling Canada Goose. pages 81-

93 in R.I. Jarvis and J.C. Bartonek, eds. Management and biology of Pacific 

Flyway geese. Oregon State University, Corvallis. 

______________________________________________________________________________________________

A-20 Appendix A. Appropriate Use Determinations

Appropriate Uses Justification, Attachment 1

Refuge: Ridgefield National Wildlife Refuge (NWR) 

Use: Horseback Riding

Summary: Horseback Riding on Ridgefield NWR has been determined to be not 

appropriate because of the disturbance to wildlife (especially waterfowl), impacts to 

habitat, and as a safety concern to users.

For findings listed on FWS Form 3-2319 and if deemed necessary a justification has 

been provided below:

d. Is the use consistent with public safety? 

Wheeled access by public users is restricted to the River ‘S’ Unit Auto Tour Route, 

an established gravel roadway where popular wildlife viewing and photography 

opportunities are provided. Since 1994 when the last compatibility determination was 

made, automobile numbers on the Auto Tour Route have more than doubled. The 

presence of horses on the road could create an unsafe traffic situation. 

Pedestrian foot travel is permitted in the Carty Unit, where there is no public 

automobile access, and on the Kiwa Trail on the River ‘S’ Unit. Horseback riding 

may increase conflicts between users and may pose a safety problem when horseback 

riders encounter other users. 

f. Has an earlier documented analysis not denied the use or is this the first time the 

use has been proposed?

This use had a compatibility determination completed in 1994. This determination 

included seven other uses, and the treatment of impacts from horseback riding involved a 

single sentence. The use was determined to be compatible because of its infrequency. 

g. Is the use manageable within available budget and staff?

Horseback riding has the potential to introduce exotic plants through seed dispersal from 

manure and horse equipment and forage brought onto the refuge. Soil disturbance and 

compaction caused by horses’ hooves can aid in the establishment of non-native plants 

(Beck 1993, Hammitt and Cole 1987, Bainbridge 1974, Hendee et al. 1990). The possible 

establishment of invasive exotic plant species will require staff attention and a monetary 

requirement for equipment and chemicals needed for control or elimination. With limited 

staff and resources, a need to control exotic plant species introduced as a result of 

horseback riding would compete against other priority needs on the refuge. 

______________________________________________________________________________________________

A-22 Appendix A. Appropriate Use Determinations
h. Can the use be accommodated without impairing existing wildlife-dependent 

recreational uses or reducing the potential to provide quality (see section 1.6D, 603 

FW1 for description), compatible, wildlife-dependent recreation into the future?

At a minimum, the quality of the visitor experience would be degraded and there could be 

direct conflicts with certain priority public uses. Impacts related to horseback riding 

include exotic plant seed dispersal (Beck 1993, Hammitt and Cole 1987), soil compaction 

and erosion (Bainbridge 1974, Hendee et al. 1990, Hammitt and Cole 1987), stream 

sedimentation (Wilson and Seney 1994), trail widening (Whitaker 1978), vegetation 

trampling (Nagy and Scotter 1974, Weaver and Dale 1978, Whitaker 1978), aesthetic 

concerns relative to horse manure (Lee 1975), direct wildlife disturbance (Owen 1973), 

and direct and indirect conflicts with other recreationists. Exotic plants can also be spread 

to new sites through forage (e.g., hay brought in to feed horses, which contains seeds of 

exotic plants) and manure (Beck 1993). Exotic plant establishment is further facilitated 

by increased trail disturbance, as many exotic plants gain a competitive advantage in 

highly disturbed sites. This soil disturbance is often created through soil compaction.

Additionally, hoof action tends to dig up and puncture the soil surface (McQuaid-Cook 

1978), which causes greater sediment loss than any other form of recreational trail use 

(Wilson, J.P., and J.P. Seney 1994) and increases the potential for disturbance-tolerant 

vegetation (e.g., exotic plant) establishment. Additionally, possible biological impacts of 

horseback riding are disturbance to wildlife and habitat and the reduction in quality of 

compatible wildlife dependant recreation. Wildlife can be affected through the sight and 

sound of recreationists (Boyle and Sampson 1985). Some of the effects of disturbance to 

wildlife from recreational activities include changes in foraging behavior; reduction of 

productivity; abandonment or alteration of breeding territories; alteration of animal 

distribution; alteration of flight behavior; energy depletion; and disruption of nest and 

brood rearing attentiveness (Klein 1989, Knight and Skagen 1988). 

Literature Cited

Bainbridge, D.A. 1974. Trail management. Ecological Society of America Bulletin 

55:8-10. 

Beck, K.G. 1993. How do weeds affect us all. Proceedings of the Eighth Grazing Lands 

Forum. Washington, District of Columbia. December 2, 1993, pages 5-13. 

Boyle S.A., and F.B. Samson. 1985. Effects of non-consumptive recreation on wildlife: A 

review. Wildlife Society Bulletin 13:110-116. 

Hammitt, W.E., and D.N. Cole. 1987. Wildland Recreation: Ecology and Management. 

John Wiley and Sons, New York, New York. 341 pages. 

Hendee, J.C., G.H. Stankey, and R.C. Lucas. 1990. Wilderness Management. North 

American Press, Golden, Colorado. 

Appendix A. Appropriate Use Determinations

_____________________________________________________________________________________________

A-23
Klein, M.L. 1989. Effects of high levels of human visitation on foraging waterbirds at 

J.N. “Ding” Darling National Wildlife Refuge, Sanibel, Florida. Final Report to the U.S. 

Fish and Wildlife Service. 103 pages. 

Knight, R.L., and S.K. Skagen. 1988. Effects of recreational disturbance on birds of prey: 

A review. Pages 355-359 in Proceedings of the Southwest Raptor Management 

Symposium Workshop. National Wildlife Federation, Washington, District of 

Columbia. 

Lee, R.G. 1975. The management of human components in the Yosemite National Park 

ecosystem. Yosemite National Park, California. 134 pages. 

McQuaid-Cook, J. 1978. Effects of hikers and horses on mountain trails. Journal of 

Environmental Management 6:209-212. 

Nagy, J.A.S., and G.W. Scotter. 1974. A quantitative assessment of the effects of human 

and horse trampling on natural areas, Waterton Lakes National Park. Canadian Wildlife 

Service, Edmonton, Alberta, Canada. 145 pages. 

Owen, M. 1973. The management of grassland areas for wintering geese. Wildfowl 

24:123-130. 

Weaver, T., and D. Dale. 1978. Trampling effects of hikers, motorcycles, and horses in 

meadows and forests. Journal of Applied Ecology 15:451-457. 

Whittaker, P.L. 1978. Comparison of surface impact by hiking and horseback riding in 

the Great Smoky Mountain National Park. National Park Service Management Report 24. 

Wilson, J.P., and J.P. Seney. 1994. Erosional impact of hikers, horses, motorcycles, and 

off-road bicycles on mountain trails in Montana. Mountain Research and 

Development 14(1): 77-88. 

______________________________________________________________________________________________

A-24 Appendix A. Appropriate Use Determinations

Appropriate Uses Justification, Attachment 1

 

Refuge: Ridgefield National Wildlife Refuge (NWR)

Project: Jogging on Refuge 

Summary: Jogging on Ridgefield NWR has been determined to be not appropriate, 

due to increased disturbance to wildlife and reduction of quality to other compatible 

wildlife-dependent public uses.

For each of the findings listed on FWS Form 3-2319, a justification has been 

provided below:

d. Is the use consistent with public safety?

Wheeled access by public users is restricted to the River ‘S’ Unit Auto Tour Route, 

an established gravel roadway where popular wildlife viewing and photography 

opportunities are provided. Since 1994 when the last compatibility determination was 

made, automobile numbers on the Auto Tour Route have more than doubled. 

Because of driving habits associated with the gravel single-lane road, automobile 

users are often aware of the slow moving, stop-and-go habits other automobile drivers 

exhibit. Because these same drivers are engaged in wildlife viewing activities, the 

faster moving, far less detectable joggers could create an unsafe traffic situation.

In the Carty Unit foot travel is permitted and there is no public access for 

automobiles. The narrow, muddy trail though wetland and forest habitats is not a 

good surface for jogging or running for significant portions of the year. The limited 

line-of-sight may result in conflicts between pedestrians and joggers/runners as 

described below.

f. Has an earlier documented analysis not denied the use or is this the first time the 

use has been proposed?

 

This use had a compatibility determination completed in 1994. This determination 

collectively included seven other uses and the treatment of jogging involved two 

sentences. The use was determined to be compatible because of its infrequency. 

 

h. Can the use be accommodated without impairing existing wildlife-dependent 

recreational uses or reducing the potential to provide quality (see section 1.6D, 

603 FW1 for description), compatible, wildlife-dependent recreation into the 

future? 

______________________________________________________________________________________________

A-26 Appendix A. Appropriate Use Determinations
It has been determined that animals show greater flight response to humans moving 

unpredictably than to humans following a distinct path (Gabrielsen and Smith 1995) 

and that rapid movement by joggers is more disturbing to wildlife than slower 

moving hikers (Bennett and Zuelke 1999). Burger (1981) examined the effects of 

human activity on roosting and migrating birds at a coastal bay refuge along the 

Atlantic coast. Human activities which involved rapid movements or close proximity 

to roosting birds, such as jogging even when on the pathway, caused the birds to 

flush; in comparison, slow walking bird watchers and people walking on the path 

around the ponds did not usually cause birds to flush. Wildlife learn to avoid humans 

or other stimuli when encounters result in negative interactions. Avoidance is 

influenced by a number of factors including: 1) type, distance, movement pattern, 

speed, and duration of the disturbance; 2) time of day, time of year, weather; and 3) 

food, cover, energy demands, and reproductive status (Knight and Cole, 1991). 

 

Other compatible wildlife-dependent activities such as wildlife watching, 

photography, and environmental education, will be negatively affected because of the 

expected responses by wildlife to the fast moving activity associated with jogging. 

When wildlife react by moving away from jogging activity or alter behavior by 

hiding they will be less likely to be observed (Bennett and Zuelke 1999). This 

situation will create what Moore (1994) summarized: Trail conflicts can occur among 

different user groups, among users within the same user group, and as a result of 

factors not related to trail user activities at all. Conflict has been found to related to 

activity style, focus of trip, expectations, attitudes toward and perceptions of the 

environment, level of tolerance for others, and different norms held by different users. 

This loss of expectation of a quality wildlife dependent experience could result in 

avoidance of the refuge by wildlife watchers and photographers who have 

encountered joggers using the same trail. 

Literature Cited

Bennett, KA and E. Zuelke . 1999. The effects of recreation on birds: a literature review. 

Delaware Natural Heritage Program, Smyrna, DE 1977. 

Burger, J. 1981. The effect of human activity on birds at a coastal bay. Biol. Cons. 

21:231-241

Gabrielsen, G.W. and E.N. Smith. 1995. Physiological responses of wildlife to 

disturbance. In Wildlife and Recreationists, eds., R.L. Knight and K.J. Gutzwiller, 95-

108. Washington: Island Press. 

Knight, R. L., and D. N. Cole. 1991. Effects of recreational activity on wildlife in 

wildlands. Transactions of the 56'h North American Wildlife and Natural Resources 

Conference 56:238. 

Appendix A. Appropriate Use Determinations

_____________________________________________________________________________________________

A-27
Moore. 1994. Conflicts On Multiple-Use Trails: Synthesis of the Literature and State of 

the Practice. Federal Highway Administration Report No. FHWA-PD-94-031 - Report 

Date: August, 1994.

______________________________________________________________________________________________

A-28 Appendix A. Appropriate Use Determinations

DRAFT 

Appropriate Uses Justification 

Refuge: Ridgefield National Wildlife Refuge (NWR) 

Project: Provide Kayak Launching Facility

Summary: Request to provide public with a facility where kayak users could enter 

the NWR from public waters. 

For each of the findings listed on FWS Form 3-2319, a justification has been 

provided below: 

a. Do we (USFWS) have jurisdiction over the use? 

The NWR does not have jurisdiction over lands below high water elevation and 

as such would preclude the construction of facilities on State lands. 

f. Has an earlier documented analysis not denied the use or is this the first time the 

use has been proposed? 

The development of a Kayak Launching Facility has never been proposed until 

this request. 

______________________________________________________________________________________________

A-30 Appendix A. Appropriate Use Determinations

Appropriate Uses Justification, Attachment 1

Refuge: Ridgefield National Wildlife Refuge (NWR) 

Project: Conducting research on refuge lands and waters 

Summary: The Refuge receives requests to conduct scientific research on refuge lands 

and waters. Research applicants must submit a proposal that would outline: 1) objectives 

of the study; 2) justification for the study; 3) detailed methodology and schedule; 4) 

potential impacts on Refuge wildlife and/or habitat, including disturbance (short and long 

term), injury, or mortality; 5) personnel required; 6) costs to Refuge, if any; and 7) end 

products (i.e. reports, publications). Research proposals would be reviewed by Refuge 

staff, Regional Office Branch of Refuge Biology, and others as appropriate prior to the 

refuge issuing a special use permit (SUP). Projects will not be open-ended, and at a 

minimum, will be reviewed annually. 

 

For each of the findings listed on FWS Form 3-2319, a justification has been 

provided below:

a. Do we have jurisdiction over the use?

Some or all of the proposed activities would take place within refuge boundaries. The 

refuge has jurisdiction over those research projects that are sited within refuge 

boundaries. 

b. Does the use comply with applicable laws and regulations (Federal, State, tribal, 

and local)? 

Any proposed research activities would comply with all applicable laws and regulations 

and any restrictions or qualifications that are required to comply with law and regulations 

would be specified in the SUP. 

c. Is the use consistent with applicable Executive orders and Department and 

Service policies?

Through the review of individual projects, the refuge would ensure that they are 

consistent with applicable policies, especially Research on Service Lands Policy (803 FW 

1). 

d. Is the use consistent with public safety? 

Through individual project review, the refuge will ensure that each project is consistent 

with public safety. If necessary, stipulations to ensure public safety will be included in 

the project’s SUP. 

______________________________________________________________________________________________

A-32 Appendix A. Appropriate Use Determinations
e. Is the use consistent with goals and objectives in an approved management plan 

or other document?

Research activities are approved in instances where they can provide meaningful data that 

may contribute to refuge management and public appreciation of natural resources. 

g. Is the use manageable within available budget and staff? 

The refuge receives fewer than 6 requests per year for this activity and it is manageable 

with available budget and staff. 

h. Will this be manageable in the future within existing resources?

The proposed activity at current levels would be manageable in the future with the 

existing resources (see above). 

i. Does the uses contribute to the public’s understanding and appreciation of the

refuge’s natural or cultural resources, or is the use beneficial to the refuge’s

natural or cultural resources?

The proposed use is beneficial to the refuge’s natural and cultural resources because the 

types of research projects approved are those which have the distinct likelihood to help 

achieve refuge purposes by providing information useful for the management of trust 

resources and may contribute to the public’s understanding and appreciation of natural 

and/or cultural resources. 

j. Can the use be accommodated without impairing existing wildlife-dependent 

recreational uses or reducing the potential to provide quality (see section 1.6D, 603 

FW 1, for description), compatible, wildlife-dependent recreation into the future?

The refuge will ensure that the research activities will not impair existing or future 

wildlife-dependent recreational use of the refuge during individual project review, prior 

to issuing a SUP for the project. 

Appendix A. Appropriate Use Determinations

_____________________________________________________________________________________________

A-33

Appropriate Uses Justification, Attachment 1 

Refuge: Ridgefield National Wildlife Refuge (NWR) 

Use: Berry Picking 

Summary: Berry Picking on Ridgefield NWR has been determined to be not 

appropriate because of the safety and health concern to users. 

For findings listed on FWS Form 3-2319 and if deemed necessary a justification has 

been provided below: 

d. Is the use consistent with public safety? 

 As part of the Refuge’s Invasive Species Eradication program blackberry species are 

sprayed up to multiple times per year and normally annually until control results are 

attained. Garlon 3a is the main pesticide used to accomplish blackberry control. This 

product is considered a Hazardous Chemical by OSHA also by EPA under it’s 

Hazardous Categories Under sections 311 and 312 of the Superfund Amendment and 

Reauthorization Act of 1986 and meets the following threat categories; 1) An 

immediate health hazard 2) a delayed health hazard and 3) a fire hazard. 

 Because of the toxicity to unaware berry collectors the Refuge does not allow berry 

picking. Although signs are posted where pesticides are used the public may not see 

the signs or because of language barriers not understand the warnings and will 

inadvertently put themselves in harms way. 

f. Has an earlier documented analysis not denied the use or is this the first time the 

use has been proposed? 

This use had a determination completed in 1994. This determination collectively 

included other uses and the treatment to berry picking involved two sentences. Use 

was determined to be compatible because of the infrequent use.

Literature Cited

Garlon 3a Material Safety Data Sheet (MSDS)

http://www.cdms.net/LabelsMsds/LMDefault.aspx?pd=1923 

Appendix A. Appropriate Use Determinations

_____________________________________________________________________________________________

A-35
______________________________________________________________________________________________

A-36 Appendix A. Appropriate Use Determinations
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-1 

Appendix B. Compatibility Determinations 

B.1 Introduction

The compatibility determinations (CDs) we developed during the CCP planning process evaluate 

uses as projected to occur under Alternative 2, the Preferred Alternative in the Draft EA for the 

Ridgefield National Wildlife Refuge CCP/EA, which has carried forward as the management 

direction for the Refuge in this CCP (Chapter 2). The evaluation of funds needed for management 

and implementation of each use is described in Appendix D, Implementation. Chapter 7 of the Draft 

CCP/EA also contained an analysis of the impacts of public uses to wildlife and habitats. That 

document is incorporated through reference into this set of CDs. 

B.1.1 Uses Evaluated At This Time

The following section includes full CDs for all Refuge uses that are required to be evaluated at this 

time. According to Service policy, compatibility determinations will be completed for all uses 

proposed under a CCP that have been determined to be appropriate. Existing wildlife-dependent 

recreational uses must also be reevaluated and new CDs prepared during development of a CCP. 

According to the Service’s compatibility policy, uses other than wildlife-dependent recreational uses 

are not explicitly required to be reevaluated in concert with preparation of a CCP, unless conditions 

of the use have changed or unless significant new information relative to the use and its effects have 

become available or the existing CDs are more than 10 years old. However, the Service planning 

policy recommends preparing CDs for all individual uses, specific use programs, or groups of related 

uses associated with the proposed action. Accordingly, the following CDs are included in this 

document. 

Table B-1. Summary of Compatible Use Determinations. 

Refuge Uses Page CD# Compatible? Year Due for 

Re-evaluation

Wildlife Observation, Photography, 

Interpretation, and Environmental Education—

River ‘S’ Unit

B-5 B1 yes 2025

Wildlife Observation, Photography, 

Interpretation, and Environmental Education—

Carty Unit

B-12 B2 yes 2025

Waterfowl Hunting B-19 B3 yes 2025

Recreational Fishing B-29 B4 yes 2025

Environmental Education and Interpretation—

Cathlapotle Plankhouse 

B-34 B5 yes 2020

Crop Production B-49 B6 yes 2020

Haying and Mowing B-56 B7 yes 2020

Grazing B-63 B8 yes 2020

Research B-70 B9 yes 2020

Mosquito Management B-76 B10 yes 2020
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-2 Appendix B. Compatibility Determinations

B.1.2 Compatibility–Legal and Historical Context

Compatibility is a tool Refuge managers use to ensure that recreational and other uses do not 

interfere with wildlife conservation, the primary focus of Refuges. Compatibility is not new to the 

Refuge System and dates back to 1918, as a concept. As policy, it has been used since 1962. The 

Refuge Recreation Act of 1962 directed the Secretary of the Interior to allow only those public uses 

of Refuge lands that were “compatible with the primary purposes for which the area was 

established.” 

Legally, Refuges are closed to all public uses until officially opened through a compatibility 

determination. Regulations require that adequate funds be available for administration and protection 

of Refuges before opening them to any public uses. However, wildlife-dependent recreational uses 

(hunting, fishing, wildlife observation and photography, environmental education, and interpretation) 

are to receive enhanced consideration and cannot be rejected simply for lack of funding resources 

unless the Refuge has made a concerted effort to seek out funds from all potential partners. Once 

found compatible, wildlife-dependent recreational uses are deemed the priority public uses at the 

Refuge. If a proposed use is found not compatible, the Refuge manager is legally precluded from 

approving it. Economic uses that are conducted by or authorized by the Refuge also require 

compatibility determinations.

Under compatibility policy, uses are defined as recreational, economic/commercial, or management 

use of a Refuge by the public or a non-Refuge System entity. Uses generally providing an economic 

return (even if conducted for the purposes of habitat management) are also subject to compatibility 

determinations. The Service does not prepare compatibility determinations for uses when the Service 

does not have jurisdiction. For example, the Service may have limited jurisdiction over Refuge areas 

where property rights are vested by others; where legally binding agreements exist; or where there 

are treaty rights held by tribes. In addition, aircraft overflights, emergency actions, some activities 

on navigable waters, and activities by other Federal agencies on “overlay Refuges” are exempt from 

the compatibility review process.

 

New compatibility regulations, required by the National Wildlife Refuge System Improvement Act 

of 1997 (Improvement Act), were adopted by the Service in October, 2000 (http://Refuges.fws.gov/ 

policymakers/nwrpolicies.html). The regulations require that a use must be compatible with both the 

mission of the System and the purposes of the individual Refuge. This standard helps to ensure 

consistency in application across the Refuge System. The Act also requires that compatibility 

determinations be in writing and that the public have an opportunity to comment on most use 

evaluations. 

The Refuge System mission emphasizes that the needs of fish, wildlife, and plants must be of 

primary consideration. The Improvement Act defined a compatible use as one that “. . . in the sound 

professional judgment of the Director, will not materially interfere with or detract from the 

fulfillment of the mission of the System or the purposes of the Refuge.” Sound professional 

judgment is defined under the Improvement Act as “. . . a finding, determination, or decision, that is 

consistent with principles of sound fish and wildlife management and administration, available 

science and resources . . .” Compatibility for priority wildlife-dependent uses may depend on the 

level or extent of a use. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-3 

Court interpretations of the compatibility standard have found that compatibility is a biological 

standard and cannot be used to balance or weigh economic, political, or recreational interests against 

the primary purpose of the Refuge (Defenders of Wildlife v. Andrus [Ruby Lake Refuge]). 

The Service recognizes that compatibility determinations are complex. For this reason, Refuge 

managers are required to consider “principles of sound fish and wildlife management” and “best 

available science” in making these determinations (House of Representatives Report 105-106). 

Evaluations of the existing uses on the Ridgefield National Wildlife Refuge are based on the 

professional judgment of Refuge and planning personnel including observations of Refuge uses and 

reviews of appropriate scientific literature. 

In July 2006, the Service published its Appropriate Refuge Uses Policy (603 FW1). Under this 

policy, most proposed uses must also undergo a review prior to compatibility. Uses excepted from 

the policy include priority wildlife-dependent recreational uses, and uses under reserved rights – see 

policy for more detail. Appropriate uses reviews are included in Appendix A. 

Compatibility Determinations for Ridgefield National Wildlife Refuge 

This section contains Compatibility Determinations for the following uses on Ridgefield National 

Wildlife Refuge:

• Wildlife Observation, Photography, Interpretation, and Environmental Education 

(River ‘S’ Unit) 

• Wildlife Observation, Photography, Interpretation, and Environmental Education 

(Carty Unit) 

• Waterfowl Hunting 

• Recreational Fishing 

• Environmental Education (Cathlapotle Plankhouse)

• Crop Production 

• Haying and Mowing 

• Grazing 

• Research

• Mosquito Management 

Refuge Location

Location: Clark County, Washington 

Date Established: 1965

Establishing and Acquisition Authorities

• Migratory Bird Conservation Act of 1929, as amended (16 U.S.C. 715-715s) 

• Migratory Bird Hunting and Conservation Stamp Act of 1934 (16 U.S.C. 718-718j) [Funding 

for primary acquisition] 

• Fish and Wildlife Act of 1956 (16 U.S.C. 742a-742j, not including 742d-l) (Ridgeport Dairy 

Unit)
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-4 Appendix B. Compatibility Determinations

Refuge Purpose(s)

• “... for use as an inviolate sanctuary, or for any other management purpose, for migratory 

birds.” 16 U.S.C. § 715d (Migratory Bird Conservation Act) 

• “... to provide wintering habitat for dusky Canada goose and other waterfowl. Will also 

provide breeding and migration use and substantial public shooting in area. Estimated peak 

population: 125,000 ducks and 3,000 geese.” (Migratory Bird Conservation Commission 

Memorandum Number 1, May 18, 1965.)

• “...for the development, advancement, management, conservation, and protection of fish and 

wildlife resources...” 16 U.S.C. 742f(a)(4) (Fish and Wildlife Act of 1956) (Ridgeport Dairy 

Unit)

B.2 References 

Defenders of Wildlife v. Andrus (Ruby Lake Refuge I). 11 Envtl. Rptr. Case 2098 (D.D.C. 1978), p. 

873. 

House of Representatives Report 105-106 (on NWRSIA) - 

http://refuges.fws.gov/policyMakers/mandates/HR1420/part1.html 

Compatibility regulations, adopted by the Service in October, 2000: 

(http://Refuges.fws.gov/policymakers/nwrpolicies.html) 

U.S. Fish and Wildlife Service. 2010. Ridgefield National Wildlife Refuge, Draft Comprehensive 

Conservation Plan and Environmental Assessment. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-5 

B1. Compatibility Determination for Wildlife Observation, Photography, 

Interpretation, and Environmental Education on the River ‘S’ Unit, 

Ridgefield National Wildlife Refuge

Uses: Wildlife Observation, Photography, Interpretation, and Environmental Education. 

 

Station Name: Ridgefield National Wildlife Refuge

Date Established: 1965 

Establishing and Acquisition Authority(ies):

Migratory Bird Conservation Act of 1929, as amended (16 U.S.C. 715-715s) 

Migratory Bird Hunting and Conservation Stamp Act of 1934 (16 U.S.C. 718-718j) [Funding for 

primary acquisition] 

Refuge Purpose(s):

“... for use as an inviolate sanctuary, or for any other management purpose, for migratory birds.” 

16 U.S.C. § 715d (Migratory Bird Conservation Act) 

"... to provide wintering habitat for dusky Canada goose and other waterfowl. Will also provide 

breeding and migration use and substantial public shooting in area. Estimated peak population: 

125,000 ducks and 3,000 geese." (Migratory Bird Conservation Commission Memorandum 

Number 1, May 18, 1965.) 

National Wildlife Refuge System Mission: 

The mission of the System is to administer a national network of lands and waters for the 

conservation, management, and where appropriate, restoration of the fish, wildlife, and plant 

resources and their habitats within the United States for the benefit of present and future 

generations of Americans. 

Description of Uses: 

Non-consumptive wildlife dependent recreation (defined here as wildlife observation, photography, 

and interpretation) are defined as priority public uses under the Refuge Improvement Act and can 

enhance the users’ appreciation of the Refuge, the National Wildlife Refuge System, wildlife, their 

habitats, and the human environment. The Refuge would provide opportunities for these activities on 

a 4.0-mile Auto Tour Route. The Auto Tour Route would be open to non-consumptive wildlife 

dependent recreational activities year-round. From October 1 to March 31 visitors would be required 

remain in their vehicle along the Auto Tour Route to reduce disturbance to wintering wildlife. The 

exception to this seasonal restriction is the observation blind, restroom facilities, visitor contact 

station, entrance kiosk, and associated walkways. The remaining months of the year users are not 

restricted to their vehicles but would be required to stay on the road surface of the Auto Tour Route. 

From May 1 to September 30 non-consumptive wildlife dependent recreation would also be 

facilitated along the 1.1-mile walking only Kiwa Trail. In addition planned future non-consumptive 

wildlife dependent recreation would be developed along a new out and back walking trail segment 

(~1.5 miles) that follows the dike-top along the north end of the River ‘S’. In conjunction with this 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-6 Appendix B. Compatibility Determinations

trail would be an elevated viewing platform near the trail’s terminus. Similar to the Kiwa Trail, this 

new trail segment would only be open between the May 1 and September 30 timeframe. 

Non-consumptive wildlife dependent recreation would be largely self-guided and would be restricted 

to the Auto Tour Route, designated trails, and developed parking areas. Off-trail activities would 

require a Special Use Permit from the Refuge. At times, users engaged in these activities would be 

accompanied by Refuge staff and/or trained volunteers (i.e. tours conducted during BirdFest). 

Interpretive materials are also available to visitors through interpretive panels, stations along the Oak 

to Wetlands Trail, the Refuge Office/Visitor Contact Station, and brochures. 

Collection of plant material and the removal of wildlife or their parts (except fish captured while 

engaged in recreational fishing; see Compatibility Determination – Fishing) would be prohibited 

unless the Refuge issues a Special Use Permit to the user(s). Special conditions are put in place to 

reduce impacts of these activities. 

Availability of Resources: 

The River ‘S’ Unit of the Refuge is open for wildlife photography, fishing, interpretation, hunting, 

and wildlife observation. Facilities to separate consumptive and non-consumptive users have been 

developed, although access trails, parking lots, signage and other facilities are often used for multiple 

purposes. The Service has two employees dedicated to the Visitor Service program (i.e. Visitor 

Services). Additional Refuge staff also assist in trail and parking area maintenance, facility and road 

maintenance, sign posting, construction projects, talking to and answering questions from the public, 

developing and implementing Refuge management programs. The Refuge is a Recreation Fee site, 

as authorized by the Federal Lands Recreation Enhancement Act, with fees supporting visitor 

services, habitat restoration, and maintenance related to the visitor’s experience. These funds help 

offset the expenses related to maintaining and operating a visitor services program. 

Costs to Administer and Manage the River ‘S’ Unit Public Use Programs at the Refuge 

under the Preferred Alternative (Alternative 2)

Activity or Project 

One Time 

Expenses ($)

Recurring 

Expenses ($/year)

Provide facilities for self-guided wildlife observation and 

photography opportunities on the Refuge’s River ‘S’ and Carty 

Units, while limiting the impacts of noise and human activity to 

sensitive species.

$17k 

Provide 6.6 miles of seasonal pedestrian access on Refuge trails 

and roads and 2 miles of year-round pedestrian access on 

Refuge trails.

$53k 

Conduct up to 25 volunteer-guided wildlife tours annually to 

provide visitors with access to areas of the Refuge that are 

otherwise closed.

$31K 

Maintain and improve visitor contact and orientation facilities, 

signage, and interpretation $50K 

Maintain and improve public facilities: Improve visitor 

infrastructure so as to enhance safety, sanitation, comfort, and 

access for the visiting public, including visitors with 

disabilities.

$82K 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-7 

Activity or Project 

One Time 

Expenses ($)

Recurring 

Expenses ($/year)

Maintain a 4.0-mile year-round auto tour route that provides 

visitors opportunities to view and photograph wildlife, and 

supports a maximum of 200 vehicles on peak use days. 

Reroute .3 Miles $310k

Provide 6.6 miles of seasonal pedestrian access on Refuge trails 

and roads and 2 miles of year-round pedestrian access on 

Refuge trails.

 1.5 Mile Dike-top Trail 

Construct Elevated Observation Deck 

TOTAL 

$276k 

$55k 

$331k 

Totals 972k 233k

Anticipated Impacts of Uses:

Impacts resulting from the proposed uses include both direct and indirect impacts to wildlife 

resources and the associated habitat. Direct impacts have an immediate effect on wildlife and 

generally result from the public’s interaction with wildlife. Indirect impacts would include 

actions taken by the public that would impact habitat or reduce access to habitat. 

Direct Impacts 

We expect these impacts to include the presence of humans disturbing wildlife, which typically 

results in a temporary displacement of individuals. Some species such as sandhill cranes will 

avoid the areas people frequent, such as the developed trails and the Auto Tour Route during 

periods of moderate to heavy traffic, while others such as raccoons seem unaffected by or even 

drawn to the presence of humans. 

Negative impacts to wildlife have been documented when migratory birds and humans are 

present in the same areas (Boyle and Samson 1985). Responses of wildlife to human activities 

include: departure from site, use of suboptimal habitat, altered behavior (Burger 1981, Morton et 

al. 1989, Klein 1993), and increase in energy expenditure (Morton et al. 1989, Belanger and 

Bedard 1990). 

McNeil et al. (1992) found that many waterfowl species avoid disturbance by feeding at night 

instead of during the day. The location of recreational activities impacts species in different 

ways. Miller et al. (1998) found that nesting success was lower near recreational trails, where 

human activity was common, than at greater distances from the trails. A number of species have 

shown greater reactions when pedestrian use occurred off trail (Miller, 1998). In addition, 

Burger (1981) found that wading birds were extremely sensitive to disturbance in the 

northeastern US. Klein (1989) found migratory dabbling ducks to be the most sensitive to 

disturbance and migrant ducks to be more sensitive when they first arrived, in the late fall, than 

later in winter. She also found gulls and sandpipers to be apparently insensitive to human 

disturbance, with Burger (1981) finding the same to be true for various gull species. 

Gutzwiller et al. (1997) found that singing behavior of some songbirds was altered by low levels 

of human intrusion. Pedestrian travel can impact normal behavioral activities, including feeding, 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-8 Appendix B. Compatibility Determinations

reproductive, and social behavior. Studies have shown that ducks and shorebirds are sensitive to 

pedestrian activity (Burger 1981, 1986). Resident waterbirds that are regularly exposed to human 

disturbance tend to be less sensitive than migrants, especially when migrants first arrive at a site 

(Klein 1993). In areas where human activity is common, birds tolerated closer approaches than in 

areas receiving less activity. 

To help mitigate this impacts, the Refuge closes the 1.5-mile hiking trail (Kiwa Trail) and 

prohibits visitors from leaving their vehicle (except to access the observation blind) from October 

1 to April 30, which is the time when wintering waterfowl and sandhill cranes are present on the 

Refuge in the greatest numbers. Research has indicated that waterfowl are less likely to be 

flushed or swim away from slow moving vehicles than from pedestrians (Klein 1993, Pease et al. 

2005). 

Indirect Impacts

People can be vectors for invasive plants by moving seeds or other propagules from one area to 

another. Once established, invasive plants can out-compete native plants, thereby altering 

habitats and indirectly impacting wildlife. The threat of invasive plant establishment will always 

be an issue requiring annual monitoring and treatment when necessary. Refuge staff will work at 

eradicating invasive plants and educating the visiting public. 

Providing and maintaining access points indirectly impacts wildlife by creating barriers to 

movement, through vegetation removal and management, and abrupt edge creation which may 

lead to increased predation (Ratti and Reese 1988). Trail edges may concentrate prey species and 

may be used by predators as travel corridors. 

Other indirect impacts may include the deposition of litter and erosion caused by the damage to 

vegetation from trampling. These have not been a significant problem at the current level of use. 

Public Review and Comment: 

This determination was issued for public review and comment as part of the Ridgefield NWR 

Draft Comprehensive Conservation Plan and Environmental Assessment (DCCP/EA). The plan 

and associated compatibility determinations were also provided as CDs to a mailing list of 432 

recipients, and were made available on the FWS Region 1 Planning website. Printed copies of the 

DCCP/EA were available upon request. The 30-day review occurred from June 16 through July 

16, 2010. We did not receive specific comments regarding the compatibility determinations; 

however, several commenters suggested that the Auto Tour Route be shortened during the 

waterfowl hunting season. No changes have been made at this time, since data showing a link 

between the auto tour route and reduced wildlife use of the area is lacking. However the Refuge 

staff will consider seasonal closures of the auto tour route if monitoring shows unacceptable 

levels of disturbance to sensitive wildlife species. 

Determination (check one below):

_____ Uses are Not Compatible

__x__ Uses are Compatible with Following Stipulations
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-9 

Stipulations Necessary to Ensure Compatibility: 

• Activities associated with these proposed uses are restricted to portions of the River ‘S’ Unit 

that are open to the general public during daylight hours. 

• Adherence to seasonal use restrictions to reduce disturbance to wintering waterfowl and other 

wildlife.

• Camping, overnight use, and fires are prohibited. 

• Littering is prohibited. 

• Collection of plants and animals is prohibited unless a Special Use Permit is obtained from 

the Refuge (except fish captured while engaged in recreational fishing). 

• The Refuge will require advance reservations for groups over 20 to avoid conflicts with other 

groups and management activities. 

• The Refuge will provide signs, pamphlets, and verbal instructions from Refuge staff and 

volunteers will promote appropriate use of trails, blinds, and platforms to minimize wildlife 

and habitat disturbance. These materials will clearly state pertinent Refuge-specific 

regulations. 

• The Refuge will periodically monitor and evaluate sites and programs to determine if 

objectives are being met and the resource is not being degraded. 

• Where feasible, native trees and shrubs will be planted to create screening along trails and at 

observation points to reduce disturbance. 

Justification: 

Wildlife Photography, Observation, Interpretation and Environmental Education, when 

compatible, are wildlife-dependent recreational activities, and when compatible, considered 

priority public uses for the National Wildlife Refuge System. Although these activities can result 

in disturbance to wildlife, disturbance will be intermittent and short-term. There is a sufficient 

amount of undisturbed habitat available to refuge wildlife for escape and cover. In consideration 

of the limited areas open to public in the context of the amount of refuge which serves as 

sanctuary, effects associated with allowing public uses on the refuge would not be significant. 

It is anticipated that wildlife populations will find sufficient food resources and resting places 

such that their abundance and use of the Refuge will not be measurably lessened from allowing 

these activities to occur. The relatively limited number of individual animals and plants expected 

to be adversely affected will not cause wildlife populations to materially decline, the 

physiological condition and production of refuge species will not be impaired, their behavior and 

normal activity patterns will not be altered dramatically, and their overall welfare will not be 

negatively impacted. Thus, allowing wildlife photography, observation, interpretation and 

environmental education to occur under the stipulations described above will not materially 

detract or interfere with the purposes for which the refuge was established or the refuge mission. 

Mandatory 10- or 15-year Reevaluation Date: (provide month and year for “allowed” uses): 

9/2025___Mandatory 15-year re-evaluation date (for wildlife-dependent public uses)

___ ____Mandatory 10-year reevaluation date (for all uses other than wildlife-dependent public 

uses)

References:
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-10 Appendix B. Compatibility Determinations

Belanger, L., and J. Bedard. 1990. Energetic cost of man-induced disturbance to staging snow geese. 

Journal of Wildlife Management. 54:36. 

Boyle, S.A., and F.B. Samson. 1985. Effects of nonconsumptive recreation on wildlife: A review. 

Wildlife Society Bulletin 13:110.

Burger, J. 1981. The effect of human activity on birds at a coastal bay. Biological Conservation. 

21:231-241. 

Burger, J. 1986. The effect of human activity on shorebirds in two coastal bays in northeastern 

United States. Environmental Conservation. 13:123-130. 

Gutzwiller, K.J., R.T. Wiedenmann, K.L. Clements. 1997. Does human intrusion alter the seasonal 

timing of avian song during breeding periods? Auk. 114:55-65. 

Havera, S.P., L.R. Boens, M.M. Georgi, and R. T. Shealy. 1992. Human disturbance of waterfowl on 

Keokuk Pool, Mississippi River. Wildlife Society Bulletin. 20:290-298. 

Klein, M.L. 1993. Waterbird behavioral responses to human disturbances. Wildlife Society Bulletin. 

21:31-39. 

McNeil, Raymond; Pierre Drapeau; John D. Goss-Custard. 1992. The occurrence and adaptive 

significance of nocturnal habitats in waterfowl. Biological Review. 67: 381-419. 

Miller, S.G., R.L. Knight, and C.K. Miller. 1998. Influence of recreational trails on breeding bird 

communities. Ecological Applications. 8(1) 162-169. 

Morton, J.M., A.C. Fowler, and R.L. Kirkpatrick. 1989. Time and energy budgets of American black 

ducks in winter. Journal of Wildlife Management. 53:401-410. 

Pease, M.L., R.K. Rose, and M.J. Butler. 2005. Effects of human disturbances on the behavior of 

wintering ducks. Wildlife Soc. Bulletin. 33:103-112

Ratti. J.T. and K.P. Reese. 1988. Preliminary test of the ecological trap hypothesis. J. of Wildlife 

Management, 52:484-491. 

Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-12 Appendix B. Compatibility Determinations

B2. Compatibility Determination for Wildlife Observation, Photography, 

Interpretation, and Environmental Education on the Carty Unit, Ridgefield 

National Wildlife Refuge

Uses: Wildlife Observation, Photography, Interpretation, and Environmental Education 

 

Station Name: Ridgefield National Wildlife Refuge – Carty Unit 

Date Established: 1965 

Establishing and Acquisition Authority(ies):

Migratory Bird Conservation Act of 1929, as amended (16 U.S.C. 715-715s) 

Migratory Bird Hunting and Conservation Stamp Act of 1934 (16 U.S.C. 718-718j) [Funding for 

primary acquisition] 

Refuge Purpose(s):

“... for use as an inviolate sanctuary, or for any other management purpose, for migratory birds.” 

16 U.S.C. § 715d (Migratory Bird Conservation Act) 

"... to provide wintering habitat for dusky Canada goose and other waterfowl. Will also provide 

breeding and migration use and substantial public shooting in area. Estimated peak population: 

125,000 ducks and 3,000 geese." (Migratory Bird Conservation Commission Memorandum 

Number 1, May 18, 1965.) 

National Wildlife Refuge System Mission: 

The mission of the System is to administer a national network of lands and waters for the 

conservation, management, and where appropriate, restoration of the fish, wildlife, and plant 

resources and their habitats within the United States for the benefit of present and future 

generations of Americans. 

Description of Uses: 

Non-consumptive wildlife dependent recreation (defined here as wildlife observation, 

photography, and interpretation) when compatible with refuge purposes are defined in the 

National Wildlife Refuge System Administration Act, as amended, as priority uses to be 

encouraged on national wildlife refuges. These activities can enhance the users’ appreciation of 

the Refuge, the National Wildlife Refuge System, wildlife and wildlife habitat, and the human 

environment. These activities would be allowed year-round in the Refuge’s Carty Unit where 

these activities would be largely self-guided. Non-consumptive wildlife dependent recreation 

would be encouraged along the Oaks to Wetland Trail but not restricted to the trail system. The 

Carty Unit would continue to provide unstructured year-round free-roam walking opportunities. 

Improvements to the surface of the Oaks to Wetland Trail would connect the parking area, 

Plankhouse, and the first loop (~2500 feet) of the Oaks to Wetland Trial. Connecting trails over 

Gee Creek and over the north tip of Carty Lake would link the City of Ridgefield, Port of 

Ridgefield, and Refuge for non-consumptive wildlife dependent recreation. Pending a separate 

Environmental Assessment, an office/Nature Center would be constructed near the current 

office’s location and the Carty Unit footbridge would be replaced. Cumulatively, these 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-13

improvements could increase visitation to the Carty Unit and heighten the need for resource 

impact monitoring related to public use. 

Pre-arranged interpretative and educational visits (i.e. school groups, scouts) and periodic 

outreach activities (i.e. tours conducted during BirdFest) involving the Plankhouse would 

continue to be guided by Staff and/or trained volunteers. Interpretation would also be available 

to visitors through interpretive panels, websites, stations along the Oak to Wetlands Trail, the 

Refuge Office/Visitor Contact Station, and brochures. 

Collection of plant material and the removal of wildlife or their parts (except fish captured while 

engaged in recreational fishing; see Compatibility Determination – Fishing) would prohibited 

unless the Refuge issues a Special Use Permit to the user(s). Special conditions would be put in 

place to reduce impacts of these activities. 

Availability of Resources: 

The Carty Unit of the Refuge is open for environmental education, interpretation, wildlife 

photography, fishing, and wildlife observation. Access trails, parking lots, signage and other 

facilities are often used for multiple purposes. The Service has two employees dedicated to the 

Visitor Service program. Other Refuge staff assist in trail and parking area maintenance, facility 

and road maintenance, sign posting, construction projects, talking to and answering questions 

posed by the public, and developing and implementing Refuge management programs. The 

Refuge is Recreation Fee site, as authorized by the Federal Lands Recreation Enhancement Act, 

with fees supporting visitor services, habitat restoration, law enforcement, and maintenance 

related to the visitor’s experience. These funds help offset the expenses related to maintaining 

and operating a visitor services program. The Refuge has sufficient funds for managing current 

levels of these uses.

Costs to Administer and Manage Carty Unit Public Use Programs at the Refuge under the 

Preferred Alternative (Alternative 2)

Activity or Project 

One Time 

Expenses ($)

Recurring 

Expenses ($/year)

Provide 2 miles of year-round pedestrian access on Refuge trails. 15,000

Law Enforcement - Reduce illegal activities 52,500

Integrate the Plankhouse into the Refuge’s interpretation and 

environmental education programs. 47,000 

Continue recruiting, training, retaining, and utilizing volunteers 

for support of Refuge programs and activities 31,000 

Provide quality environmental education opportunities (staff) 58,000

Effectively utilize volunteers, Friends Groups, and partnerships to 

create a high quality and self-sustaining Refuge environmental 

education program.

39,000 

Totals 242,500
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-14 Appendix B. Compatibility Determinations

Anticipated Impacts of Uses:

Impacts resulting from the proposed uses include both direct and indirect impacts to wildlife 

resources and the associated habitat. Direct impacts have an immediate effect on wildlife and 

generally result from the public’s interaction with wildlife. Indirect impacts would include 

actions taken by the public that would impact habitat or reduce access to habitat. 

Direct Impacts 

We expect these impacts to include the presence of humans disturbing wildlife, which typically 

results in a temporary displacement of individuals. Some species such as sandhill cranes will 

avoid the areas people frequent, such as the developed trails and the buildings, while others such 

as raccoons seem unaffected by or even drawn to the presence of humans. 

Negative impacts have been shown to arise when migratory birds and humans are present in the 

same areas (Boyle and Samson 1985). Response of wildlife to human activities includes: 

departure from site, use of suboptimal habitat, altered behavior (Burger 1981, Morton et al. 1989, 

Klein 1993), and increase in energy expenditure (Morton et al. 1989, Belanger and Bedard 1990). 

McNeil et al. (1992) found that many waterfowl species avoid disturbance by feeding at night 

instead of during the day. The location of recreational activities impacts species in different 

ways. Miller et al. (1998) found that nesting success was lower near recreational trails, where 

human activity was common, than at greater distances from the trails. A number of species have 

shown greater reactions when pedestrian use occurred off trail (Miller, 1998). In addition, 

Burger (1981) found that wading birds were extremely sensitive to disturbance in the 

northeastern US. Klein (1989) found migratory dabbling ducks to be the most sensitive to 

disturbance and migrant ducks to be more sensitive when they first arrived, in the late fall, than 

later in winter. She also found gulls and sandpipers to be apparently insensitive to human 

disturbance, with Burger (1981) finding the same to be true for various gull species. 

Gutzwiller et al. (1997) found that singing behavior of some songbirds was altered by low levels 

of human intrusion. Pedestrian travel can impact normal behavioral activities, including feeding, 

reproductive, and social behavior. Studies have shown that ducks and shorebirds are sensitive to 

pedestrian activity (Burger 1981, 1986). 

Some studies have indicated that individuals may become acclimated to the presence of humans. 

Resident waterbirds that are regularly exposed to human disturbance tend to be less sensitive than 

migrants, especially when migrants first arrive at a site (Klein 1993). In areas where human 

activity is common, birds tolerated closer approaches than in areas receiving less activity. 

Indirect Impacts

People can be vectors for invasive plants by moving seeds or other propagules from one area to 

another. Once established, invasive plants can out-compete native plants, thereby altering 

habitats and indirectly impacting wildlife. The threat of invasive plant establishment will always 

be an issue requiring annual monitoring and treatment when necessary. Our staff will continue 

work at eradicating invasive plants and educating the visiting public about the impacts these 

species have on the Refuge.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-15

Providing and maintaining access points indirectly impacts wildlife by creating barriers to 

movement, through vegetation removal and management, and abrupt edge creation that may lead 

to increased predation (Ratti and Reese 1988). Trail edges may concentrate prey species and 

may be used by predators as travel corridors. 

Other indirect impacts may include the deposition of litter and erosion caused by the damage to 

vegetation from trampling. These have not been a significant problem at the current level of use. 

Threatened and Endangered Species

Within the Blackwater Island Research Natural Area (located in the Carty Unit), there are three 

sites where the federally-listed threatened plant water howellia (Howellia aquatilis) is known to 

occur. The Refuge will perform an intra-service consultation pursuant to the Section 7 of the 

Endangered Species Act (87 Stat. 884, as amended; 16 U.S.C. 1531 et seq.) regarding the 

proposed uses and water howellia. 

Public Review and Comment: 

This determination was issued for public review and comment as part of the Ridgefield NWR 

Draft Comprehensive Conservation Plan and Environmental Assessment (DCCP/EA). The plan 

and associated compatibility determinations were also provided as CDs to a mailing list of 432 

recipients, and were made available on the FWS Region 1 Planning website. Printed copies of the 

DCCP/EA were available upon request. The 30-day review occurred from June 16 through July 

16, 2010. We did not receive specific comments regarding the compatibility determinations, and 

no changes have been made at this time. 

Determination (check one below):

_____ Uses are Not Compatible

__x__ Uses are Compatible with Following Stipulations

Stipulations Necessary to Ensure Compatibility: 

• Activities associated with these proposed uses are restricted to portions of the Carty Unit that 

are open to the general public during daylight hours. 

• Camping, overnight use, and fires are prohibited. 

• Littering is prohibited. 

• Collection of plants and animals is prohibited unless a Special Use Permit is obtained from 

the Refuge (except fish captured while engaged in recreational fishing). 

• The Refuge will require advance reservations for groups in need of staff and volunteer 

participation to avoid conflicts with other groups and management activities. 

• The Refuge will provide signs, pamphlets, and verbal instructions from Refuge staff and 

volunteers will promote appropriate use of trails, blinds, and platforms to minimize wildlife 

and habitat disturbance. These materials will clearly state pertinent Refuge-specific 

regulations. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-16 Appendix B. Compatibility Determinations

• The Refuge will periodically monitor and evaluate sites and programs to determine if 

objectives are being met and the resource is not being degraded. 

• Where it is determined necessary, native trees and shrubs will be planted to create visual 

screening along trails and at observation points to reduce disturbance to wildlife. 

• Most of the refuge is closed to public entry affording wildlife ample amounts of sanctuary 

habitat. 

Justification: 

Wildlife Photography, Observation, Interpretation and Environmental Education, when 

compatible, are wildlife-dependent recreational activities, and when compatible, considered 

priority public uses for the National Wildlife Refuge System. Although these activities can result 

in disturbance to wildlife, disturbance will be intermittent and short-term. There is a sufficient 

amount of undisturbed habitat available to refuge wildlife for escape and cover. In consideration 

of the limited areas open to public in the context of the amount of refuge which serves as 

sanctuary, effects associated with allowing public uses on the refuge would not be significant. 

It is anticipated that wildlife populations will find sufficient food resources and resting places 

such that their abundance and use of the Refuge will not be measurably lessened from allowing 

these activities to occur. The relatively limited number of individual animals and plants expected 

to be adversely affected will not cause wildlife populations to materially decline, the 

physiological condition and production of refuge species will not be impaired, their behavior and 

normal activity patterns will not be altered dramatically, and their overall welfare will not be 

negatively impacted. Thus, allowing wildlife photography, observation, interpretation and 

environmental education to occur under the stipulations described above will not materially 

detract or interfere with the purposes for which the refuge was established or the refuge mission. 

Mandatory 10- or 15-year Reevaluation Date: (provide month and year for “allowed” uses): 

9/2025 Mandatory 15-year re-evaluation date (for wildlife-dependent public uses)

_______Mandatory 10-year reevaluation date (for all uses other than wildlife-dependent public uses) 

References:

Belanger, L., and J. Bedard. 1990. Energetic cost of man-induced disturbance to staging snow 

geese. Journal of Wildlife Management. 54:36. 

Boyle, S.A., F.B. Samson. 1985. Effects of nonconsumptive recreation on wildlife: A review. 

Wildlife Society Bulletin 13:110.

Burger, J. 1981. The effect of human activity on birds at a coastal bay. Biological Conservation. 

21:231-241. 

Burger, J. 1986. The effect of human activity on shorebirds in two coastal bays in northeastern 

United States. Environmental Conservation. 13:123-130. 

Gutzwiller, K.J., R.T. Wiedenmann, K.L. Clements. 1997. Does human intrusion alter the seasonal 

timing of avian song during breeding periods? Auk. 114:55-65. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-17

Havera, S.P., L.R. Boens, M.M. Georgi, and R. T. Shealy. 1992. Human disturbance of waterfowl on 

Keokuk Pool, Mississippi River. Wildlife Society Bulletin. 20:290-298. 

Klein, M.L. 1993. Waterbird behavioral responses to human disturbances. Wildlife Society Bulletin. 

21:31-39. 

McNeil, Raymond; Pierre Drapeau; John D. Goss-Custard. 1992. The occurrence and adaptive 

significance of nocturnal habitats in waterfowl. Biological Review. 67: 381-419. 

Miller, S.G., R.L. Knight, and C.K. Miller. 1998. Influence of recreational trails on breeding bird 

communities. Ecological Applications. 8(1) 162-169. 

Morton, J.M., A.C. Fowler, and R.L. Kirkpatrick. 1989. Time and energy budgets of American black 

ducks in winter. Journal of Wildlife Management. 53:401-410. 

Ratti. J.T. and K.P. Reese. 1988. preliminary test of the ecological trap hypothesis. J. of Wildlife 

Management, 52:484-491. 

Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-19

B3. Compatibility Determination for Waterfowl Hunting on Ridgefield 

National Wildlife Refuge

Use: Hunting (Ducks, Geese, Coots) 

Station Name: Ridgefield National Wildlife Refuge 

Date Established: 1965 

Establishing and Acquisition Authorities:

Migratory Bird Conservation Act of 1929, as amended (16 U.S.C. 715-715s) 

Migratory Bird Hunting and Conservation Stamp Act of 1934 (16 U.S.C. 718-718j) [Funding for 

primary acquisition] 

Refuge Purposes:

“... for use as an inviolate sanctuary, or for any other management purpose, for migratory birds.” 

16 U.S.C. § 715d (Migratory Bird Conservation Act) 

"... to provide wintering habitat for dusky Canada goose and other waterfowl. Will also provide 

breeding and migration use and substantial public shooting in area. Estimated peak population: 

125,000 ducks and 3,000 geese." (Migratory Bird Conservation Commission Memorandum 

Number 1, May 18, 1965.) 

National Wildlife Refuge System Mission:

The mission of the System is to administer a national network of lands and waters for the 

conservation, management, and where appropriate, restoration of the fish, wildlife, and plant 

resources and their habitats within the United States for the benefit of present and future 

generations of Americans. 

Description of Use:

The U.S. Fish and Wildlife Service (Service) proposes to continue to allow hunting of ducks, 

geese, and coots in accordance with State and Federal regulations and Refuge-specific special 

conditions. Waterfowl and migratory bird hunting in the United States is guided by an 

established regulatory process that involves numerous sources of waterfowl population and 

harvest data. Harvest data are reported by hunters to the State and season and bag limits are 

adjusted accordingly to ensure that overall populations of game species remain healthy into the 

future. 

Interagency management plans for refuge focus species like dusky Canada goose and cackling 

goose have been developed and are also used to determine seasons and bag limits (Pacific 

Flyway Council 1999, Pacific Flyway Council 2008). Furthermore, goose hunters in Washington 

Area 2 (includes Areas 2A and 2B) must pass an identification course that will help hunters in the 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-20 Appendix B. Compatibility Determinations

field distinguish between the various goose subspecies. The State, in cooperation with the 

Service, establishes an annual quota and requires individuals hunting in Washington Area 2 to 

check all harvested geese. Hunters are currently allowed to take one dusky Canada goose each 

year. If a hunter takes a dusky Canada goose, he/she is not permitted to hunt geese in 

Washington Area 2 for the remainder of that year and must retake the identification course and 

pass the test prior to obtaining a permit for the following year. The State also assigns a dusky 

harvest quota specific to the Refuge. During the 16 seasons between the 1994/95 and 2009/10 

seasons, the quota has been met 9 times. When the quota is reached, goose hunting is no longer 

permitted at the Refuge, although hunters can still harvest ducks and coots. 

Waterfowl hunting is further regulated on Ridgefield National Wildlife Refuge with hunting 

allowed in specific areas of the Refuge and only on a limited number of days per week. Blinds 

are assigned by lottery. The refuge currently maintains 21 blinds located on approximately 760 

acres of the River ‘S’ Unit. Because of limited space and the presence of other refuge users 

(primarily on the Auto Tour Route), hunters are required to hunt from established blinds. We 

anticipate relocating some of the blinds to ensure public safety once the new access road and 

bridge are constructed, but are proposing to maintain a similar number of blinds. Although dogs 

are prohibited on the Refuge they are a vital part of the waterfowl hunting tradition and can 

reduce the loss of waterfowl to the hunter’s bag and hence can reduce the overall impact to the 

resource. Because of their role, both traditional and effect on retrieval of waterfowl shot, dogs 

used in the act of hunting are allowed on the Refuge. 

In addition to restricting hunting to established blinds and limiting the number of hunt days per 

week, the Refuge has sited hunt areas away from sensitive resources such as Federally-listed 

species habitat, bald eagle nest sites, heron rookeries, and sandhill crane roosts; limited the 

number of shells each hunter may bring afield; and requiring hunters to use established parking 

areas rather than allowing them to drive through fields. 

Why Is This Use Being Proposed

Hunting is identified as a Refuge purpose in the establishing documents for Ridgefield NWR (see 

above) and thus receives special consideration. Also, under the National Wildlife Refuge System 

Administration Act, as amended, hunting is a wildlife dependent recreational activity which is to 

be encouraged on national wildlife refuges if compatible with refuge purposes. The following 

public uses (hunting, fishing, wildlife observation, photography, environmental education, and 

interpretation), when determined to be compatible, are encouraged and receive consideration in 

planning and management on national wildlife refuges. The Service recognizes that hunting has 

given many people a deeper appreciation of wildlife and a better understanding of the importance 

of conserving their habitat, which has ultimately contributed to the Refuge System mission. 

Availability of Resources

Administering the Refuge hunt program requires substantial staff time, equipment, and funding. 

In order to provide a quality hunting experience, access trails, parking lots, signs and other 

facilities must be maintained at least annually. The Refuge must exercise its water rights and 

adjust habitat management activities to provide suitable hunt areas. The Refuge does not have a 

law enforcement officer on staff and must rely on Zone Officers or partnering law enforcement 

agencies to ensure compliance with State and Federal regulations and refuge-specific special 

conditions. A portion of the funding used to support this program is provided by monies 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-21

collected as part of the hunt lottery and by blind fees charged to participants. Funding associated 

with facilities maintenance (roads, parking areas, signs, etc.) is included in other Refuge 

programs requiring the same support. 

Costs to Administer and Manage Waterfowl Hunt Program at the Refuge under the Preferred 

Alternative (Alternative 2)

Activity or Project 

One Time 

Expenses ($)

Recurring Expenses 

($/year)

Operation of Check Station (Check Station Operator, 

staff involvement with management of the program) 40,000 

Maintain Facilities (roads, blinds, water delivery) 56,000

Totals 106,000

Anticipated Impacts of the Use

Harvest of Waterfowl

Hunting, by its nature, results in the intentional take of individual animals, as well as wounding 

and disturbance (DeLong 2002). Indirect impacts such as displacement of animals by hunters or 

disturbance from gunfire also occurs in and adjacent to, areas opened for hunting. It can also 

alter behavior (e.g., foraging time), population structure (young birds are generally more 

susceptible), and distribution patterns of wildlife (Owens 1977, Raveling 1979, White-Robinson 

1982, Thomas 1983, Bartlett 1987, Madsen 1985, and Cole and Knight 1990). Prolonged and 

extensive disturbances may cause large numbers of waterfowl to leave disturbed areas and 

migrate elsewhere (Madsen 1995, Paulus 1984). 

The Refuge seeks to reduce the magnitude of these impacts by providing sanctuary areas on 

Bachelor Island, Roth, and Ridgeport Dairy Units where hunting and visitation does not occur 

and birds can feed and rest relatively undisturbed. Portions of the Columbia River adjacent to the 

refuge and floodplain habitats on the west side of the Columbia River provide open water 

sanctuary areas that are suitable habitat for some waterfowl species and are not subject to intense 

hunting pressure. The Refuge also attempts to mitigate these impacts by restricting hunting to 

established blinds and only allowing hunting a limited number of days per week. 

In 2008/2009 season waterfowl hunters at the Refuge, harvested an estimated 2,308 ducks and 

365 geese. These harvest numbers represent 0.6 percent of the Washington duck harvest of 

410,257 birds in 2008/2009. Goose harvest at Ridgefield for the 2008/2009 season was less than 

0.7 percent of the Washington harvest of 55,692 

The most heavily harvested duck species on the refuge are northern shoveler, mallard, northern 

pintail, American widgeon, and green-winged teal. In 2009, continental populations of northern 

shoveler, green-wing teal and mallard were all above their long term averages (USFWS 2009). 

American widgeon were slightly below their long-term average. Northern pintails were 20% 

below the long-term average. Given the low harvest rates of these species relative to the State 

harvest, the refuge hunt program does not significantly contribute to the population changes of 

these species and the refuge proposes to continue to conform to State bag limits for ducks. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-22 Appendix B. Compatibility Determinations

Seven subspecies of geese are harvested on the refuge. Between 1994 and 2009, cackling geese 

were the most commonly harvested subspecies with 2,212 birds taken. Taverner’s geese are 

second with 1,512 taken during that period. Relatively small numbers of western (356), dusky 

(132), Vancouver (22), lesser (184), and Aleutian geese (3) are taken. Hunters are permitted to 

harvest coots, but while this species is common on the refuge, coots are not popular with hunters 

and fewer than 25 are harvested most years. 

Impacts to Dusky Canada Goose and Cackling Goose

Two focus species on the refuge, dusky Canada geese and cackling geese, are below their 

population targets as identified by the Pacific Flyway Council (Pacific Flyway Council 1999, 

Pacific Flyway Council 2008). Each of these species has flyway-wide management plans to 

direct efforts to help these species reach population targets. In response to substantial 

agricultural damage resulting from wintering geese depredating cropland, the Pacific Flyway 

Council has developed a depredation management plan (Pacific Flyway Council 1998) which 

provides additional recommendations. The refuge is committed to following the management 

recommendations and compatible actions specified in these plans. 

Historically, dusky Canada geese were one of the most abundant subspecies in the Lower 

Columbia River/Willamette Valley. The 1964 “Good Friday” earthquake in Alaska uplifted this 

subspecies’ breeding grounds on the Copper River Delta allowing predators such as coyote, 

eagle, and bear better access to the nesting sites, greatly decreasing gosling recruitment rates. 

Accordingly, the numbers of these birds have been below the breeding ground population target 

of 10,000 to 20,000 birds based on a three-year average since 2007 (Pacific Flyway Council 

2008). The 2008 Pacific Flyway Management Plan for the Dusky Canada Goose (Plan) specifies 

three action levels based on breeding ground population thresholds. In 2009/2010, the 

population was estimated at 6,700 birds and the three-year average dropped below 9,999 and 

triggered more restrictive harvest quota pursuant to Action Level 2 (175 birds in primary dusky 

use areas in WA, OR, and AK). The refuge quota was reduced from 10 to 5 birds. Once the 

quota is reached, goose hunting is no longer permitted on the refuge, though hunters can still 

harvest ducks. Although the number of dusky Canada geese harvested on the refuge does not 

have a significant effect on the population as a whole, hunting does cause some disturbance in 

addition to direct mortality. To further reduce impacts to dusky Canada geese, the refuge has 

also prohibited goose harvest at three blinds where approximately 45% of the dusky harvest has 

traditionally occurred. As stated in the Plan, Action Level 2 restrictions remain in place until the 

three-year average exceeds 12,500. Should the population continue to decline, Action Level 3 

would take effect when the breeding ground population is below 5,000. Pursuant to Action Level 

3 of the Plan, the refuge would minimize the harvest of dusky Canada geese. 

Cackling geese nest on the Yukon-Kuskokwim Delta in Alaska and historically wintered in the 

Central Valley of California. In the 1990s, most cackling geese have wintered in the Willamette 

and Lower Columbia River valleys in Washington and Oregon and they are currently one of the 

most abundant subspecies of geese on the refuge. The population decreased from about 400,000 

in the late 1960s to less than 20,000 in the mid-1980s. The population has increased and the 

2009 estimate was 160,600 (USFWS 2009). The current population is contributing to 

agricultural damage in the Lower Columbia River and Willamette Valley (Pacific Flyway 

Council 1998). The Pacific Flyway Management Plan for the Cackling Canada Goose (Pacific 

Flyway Council 1999) has established a three-year average population target of 250,000 birds. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-23

To help reach the population target while still providing hunting opportunities and reducing 

agricultural crop depredation as described in the Pacific Flyway Management Plan for Northwest 

Oregon - Southwest Washington Canada Goose Agricultural Depredation Control (Pacific 

Flyway Council 1998), the State, in cooperation with the Service has instituted a 2 bird bag limit 

and 4 bird possession limit for cackling geese. As stated above, the goose hunting season would 

be closed when the quota for dusky geese is reached. 

Impacts to Non-Target Species

The refuge hunt program indirectly impacts species other than those targeted by hunters. The 

presence of hunters and dogs, sounds of gunfire, and the sight of hunters traveling to and from 

hunt areas can disturb other wildlife species such as pied-billed grebe, great blue heron, sandhill 

crane, bald eagle, great egrets, northern harrier, which forage in refuge wetlands and waterbodies. 

This disturbance, especially when repeated over a period of time, may result in some wildlife 

species altering food habits or moving to other areas. Hunting would occur outside of the 

breeding season for these species and hunt areas are located away from known eagle nests, crane 

roosts, and heron rookeries to limit disturbance to these sensitive areas. Accidental shootings of 

non-game birds are believed to be negligible. No significant effects are expected for refuge fish 

populations. 

Other Impacts

The need to have sufficient water available near hunt blinds limits the management options of 

wetlands in the hunt area. In general, refuge wetlands in the diked portions of the refuge, are 

managed by alternating drawdown and flooded conditions. Drawdowns expose soil, release 

nutrients, and allow propagules of native wetland plants to germinate. Flooding stresses wetland 

plants resulting in additional seed production as well as suppressing reed canarygrass growth. 

Wetlands in hunt areas must have sufficient water depths by the start of the hunting season to 

attract waterfowl provide a reasonable opportunity for successful hunts. This precludes the 

opportunity for the refuge to use extended drawdowns as a management tool on 48% or wetland 

acres on the River ‘S’ Unit. Over time, in the absence of any management changes this may 

result in changes to the vegetation community such as a reduction in species diversity and plant 

density, which would result in a reduction of habitat quality for species such as Pacific tree frog, 

marsh wren, and northern harrier. The refuge further reduces the scope of these impacts by using 

pumps to reduce the time required to “flood-up” wetlands in the hunt area and provide some 

opportunities for seasonal drawdowns. To mitigate these impacts, the refuge will work to adjust 

blind locations and the timing of water level management to provide more flexibility in wetland 

management and enhance habitat conditions. Although water management of the hunt areas has 

some effects on species in the River ‘S’ Unit, it should be noted that majority of the refuge 

provides suitable, undisturbed habitats for the species affected by hunt area water management. 

Thus, overall effect to these species is not significant.

In addition to impacts on wildlife, the hunting program can impact other Refuge visitors using 

the Auto Tour Route in the River ‘S’ Unit. Several hunt blinds are located within sight of the 

Auto Tour Route and visitors may see ducks being harvested. The sound of shots may flush 

some birds from nearby portions of the Auto Tour Route reducing wildlife observation 

opportunities for people on the Tour Route. However, closing the Auto Tour Route during the 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-24 Appendix B. Compatibility Determinations

hunt periods would eliminate a number of visitor opportunities and based on comments received 

during the scoping process (see Appendix J), was a less desirable option. In the context of the 

limited number of hunt days when the above noted impacts occur, the adverse effects to wildlife 

observation opportunities for people on the Tour Route is considered to be minor. 

Public Review and Comment: 

This determination was issued for public review and comment as part of the Ridgefield NWR 

Draft Comprehensive Conservation Plan and Environmental Assessment (DCCP/EA). The plan 

and associated compatibility determinations were also provided as CDs to a mailing list of 432 

recipients, and were made available on the FWS Region 1 Planning website. Printed copies of the 

DCCP/EA were available upon request. The 30-day review occurred from June 16 through July 

16, 2010. We did not receive specific comments regarding the compatibility determinations; 

however, several commenters suggested that the waterfowl hunt area and number of blinds be 

expanded, specifically that the southern end of Bachelor Island be added to the existing hunt area. 

No changes have been made at this time, since the refuge has decided that maintaining the 

existing sanctuary area on Bachelor Island is necessary to meet refuge goals and objectives for 

purposes species, and to support goals and objectives in the Pacific Flyway Management Plan for 

the Dusky Canada Goose (2008), the Pacific Flyway Management Plan for the Cackling Canada 

Goose (Pacific Flyway Council 1999), and the Northwest Oregon/Southwest Washington Canada 

Goose Agricultural Depredation Control Plan (1998). 

Determination 

 The use is not compatible. 

 X The use is compatible with the following stipulations. 

Stipulations Necessary to Ensure Compatibility

The Refuge hunting programs is designed to provide a safe, quality experience with reasonable 

harvest opportunities, while avoiding significant impacts to other users and non-target wildlife 

resources. The Refuge has developed the following stipulations to reduce impacts and promote 

safety:

• The refuge will continue to support the management actions specified in the Pacific Flyway 

Management Plan for the Dusky Canada Goose (Pacific Flyway Council 2008). To protect 

dusky Canada geese, the refuge will prohibit on-refuge goose hunting once the annual quota 

has been reached. 

• To protect cackling geese, the refuge will adhere to State bag limits (currently 2 birds with a 

4 bird possession limit) and follow the recommendations of the Pacific Flyway Management 

Plan for the Cackling Canada Goose (Pacific Flyway Council 1999). 

• Hunting will only be permitted from established blinds on the River ‘S’ Unit. Bachelor 

Island, Roth, and Ridgeport Dairy Units will continue to provide wildlife with sanctuary 

areas that are relatively free of disturbance. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-25

• Only ducks, geese, and coots may be taken in accordance with Washington State bag and 

possession limits. Hunters will check all harvested waterfowl prior to leaving the Refuge. 

• Hunters will use existing open roads and parking areas to access hunting sites. Camping, 

overnight use, and fires are prohibited. 

Justification

Providing a quality hunting program contributes to achieving one of the refuge’s purposes (as 

stated in the establishing documents) and one of the Refuge’s management goals. When 

determined compatible, hunting is one of the six priority public uses of the National Wildlife 

Refuge System. Refuge hunting programs are designed to provide high-quality, safe experiences, 

with a reasonable opportunity to harvest game species. 

State and Federal regulations and refuge-specific special conditions will help reduce or eliminate 

any unwanted impacts of the use and help ensure that harvest levels of waterfowl do not harm 

long-term populations. The refuge has developed specific special conditions such as limiting the 

number of hunt days per week and siting hunt locations away from sensitive areas such as crane 

roosts, heron rookeries, and eagle nests, to protect sensitive wildlife resources, reduce impacts to 

other Refuge visitors, and allow the refuge to continue to provide high quality wintering habitat 

for dusky Canada geese and other waterfowl species. Additionally, the refuge allows hunting on 

approximately 15% of the total refuge acreage leaving an adequate amount of quality, nonhunted habitat that would serve as a sanctuary for both hunted and non-hunted wildlife species.

The harvest of waterfowl on the refuge does not significantly increase the cumulative impacts of 

hunting on the population of various waterfowl species. With the exception of northern pintail, 

the most-commonly harvested duck species are at or above their long-term averages. As 

populations rise and fall, the State, in cooperation with the Service adjust bag limits to maintain 

duck populations. 

The relatively limited number of individuals of priority species (i.e. dusky Canada goose and 

cackling goose) that are removed from wildlife populations due to hunting will not cause wildlife 

populations to materially decline, the physiological condition and production of hunted species 

will not be impaired, their behavior and normal activity patterns will not be altered dramatically, 

and their overall welfare will not be negatively impacted. The refuge is committed to following 

the recommendations contained in the management plans for dusky and cackling geese to help 

reach target population levels. In response to low dusky numbers, which fell below 9,999 and 

thus triggered Action Level 2, the refuge hunt program operated under a reduced dusky quota 

(from 10 to 5 birds) and closed three blinds where traditionally, nearly half of the duskys were 

harvested. If dusky numbers continue to decline to the point where Action Level 3 is triggered, 

the refuge will minimize the harvest of duskys. The refuge limits the harvest of cackling geese, 

while still reducing depredation of off-refuge fields (as specified in the 1998 Pacific Flyway 

Management Plan for Northwest Oregon - Southwest Washington Canada goose Agricultural 

Depredation Control) by adhering to the bag limits for Washington State 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-26 Appendix B. Compatibility Determinations

Thus, allowing waterfowl hunting to occur with the stipulations described above will not 

materially detract or interfere with the purposes for which the refuge was established or the 

refuge mission. 

Mandatory 10- or 15-year Reevaluation Date: (provide month and year for “allowed” uses): 

9/2025___Mandatory 15-year re-evaluation date (for wildlife-dependent public uses) 

____ ___Mandatory 10-year reevaluation date (for all uses other than wildlife-dependent public 

uses)

NEPA Compliance for Refuge Use Decision 

 Categorical Exclusion without Environmental Action Statement. 

 Categorical Exclusion and Environmental Action Statement. 

 X Environmental Assessment and Finding of No Significant Impact. 

 Environmental Impact Statement and Record of Decision. 

References

Bartelt, G.A. 1987. Effects of disturbance and hunting on the behavior of Canada goose family 

groups in east central Wisconsin. Journal of Wildlife Management 51:517-522. 

Cole, D.N., and R.L. Knight. 1990. Impacts of recreation on biodiversity in wilderness. Utah State 

University, Logan, Utah. 

DeLong, A.K. 2002. Managing visitor use and disturbance of waterbirds – A literature review of 

impacts and mitigation measures. Appendix L (114 pages) in Stillwater National Wildlife Refuge 

Complex Final Environmental Impact Statement for the Comprehensive Conservation Plan and 

Boundary Revision (Volume II). U.S. Fish and Wildlife Service, Portland, Oregon. Available at 

www.fws.gov/stillwater/litreview. 

Korschgen, C.E., L.S. George, and W.L. Green. 1985. Disturbance of diving ducks by boaters on a 

migrational staging area. Wildlife Society Bulletin 13:290-296. 

Liddle, M.J., and H.R.A. Scorgie. 1980. The effects of recreation on freshwater plants and animals: 

A review. Biological Conservation 17:183-206. 

Madsen, J. 1985. Impact of disturbance on field utilization of pink-footed geese in West Jutland, 

Denmark. Biological Conservation 33:53-63. 

Owens, N.W. 1977. Responses of wintering brant geese to human disturbance. Wildfowl 28:5-14. 

Raveling, D.G. 1979. The annual cycle of body composition of Canada geese with special reference 

to control of reproduction. Auk 96:234-252. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-27

Thomas, V.G. 1983. Spring migration: The prelude to goose reproduction and a review of its 

implication. Pages 73-81 in Fourth Western Hemispheric Waterfowl and Waterbird Symposium (H. 

Boyd, editor). Canadian Wildlife Service, Ottawa, Canada. 

Pacific Flyway Council. 1998. Pacific Flyway Management Plan for Northwest Oregon - Southwest 

Washington Canada Goose Agricultural Depredation Control. Canada Goose Agricultural 

Depredation Working Group, Pacific Flyway Study Committee. Portland, OR 

Pacific Flyway Council. 1999. Pacific Flyway Management Plan for the Cackling Canada Goose. 

Cackling Canada Goose Subcomm., Pacific Flyway Study Comm. [c/o USFWS], Portland, OR. 

Unpubl. Rept. 36 pp.+ appendices. 

Pacific Flyway Council. 2008. Pacific Flyway management plan for the dusky Canada goose 

(unpublished report). Dusky Canada Goose Subcomm., Pacific Flyway Study Comm. [c/o USFWS], 

Portland, OR. 

White-Robinson, R. 1982. Inland and salt marsh feeding of wintering brent geese in Essex. 

Wildfowl 33:113-118. 

Wolder, M. 1993. Disturbance of wintering northern pintails at Sacramento National Wildlife 

Refuge, California. M.S. Thesis. Humboldt State University, Arcata, CA. 62 pages. 

USFWS. 1986. Pacific bald eagle recovery plan. U.S. Fish and Wildlife Service, Portland, OR. 

160 pages. 

USFWS. 2009. Waterfowl Population Status, 2009. U.S. Department of the Interior, Fish and 

Wildlife Service. Washington, DC. 

Washington Department of Fish and Wildlife. 2001. Priority species and habitats list. Available at 

www.wa.gov/wdfw/hab/phsvert.htm#birds. 

Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-29

B4. Compatibility Determination for Recreational Fishing on Ridgefield 

National Wildlife Refuge

Use: Recreational Fishing 

Station Name: Ridgefield National Wildlife Refuge

Date Established: 1965 

Establishing and Acquisition Authority(ies):

Migratory Bird Conservation Act of 1929, as amended (16 U.S.C. 715-715s) 

Migratory Bird Hunting and Conservation Stamp Act of 1934 (16 U.S.C. 718-718j) [Funding for 

primary acquisition] 

Refuge Purpose(s):

“... for use as an inviolate sanctuary, or for any other management purpose, for migratory birds.” 

16 U.S.C. § 715d (Migratory Bird Conservation Act) 

"... to provide wintering habitat for dusky Canada goose and other waterfowl. Will also provide 

breeding and migration use and substantial public shooting in area. Estimated peak population: 

125,000 ducks and 3,000 geese." (Migratory Bird Conservation Commission Memorandum 

Number 1, May 18, 1965.) 

National Wildlife Refuge System Mission: “To administer a national network of lands and waters 

for the conservation, management, and where appropriate, restoration of the fish, wildlife, and plant 

resources and their habitats within the United States for the benefit of present and future generations 

of Americans.” (National Wildlife Refuge System Administration Act of 1966, as amended (16 

U.S.C. 668dd et seq.). 

Description of Use: The Refuge provides access for recreational fishing during daylight hours on 

the Carty Unit. Fishing opportunities are available in permanent waterbodies of the Carty Unit in 

accordance with seasons and catch limits established by State regulations. Many waterbodies within 

the unit are seasonally to semi-permanently flooded and provide limited fish habitat. Permanent 

waterbodies that provide fishing opportunities include Gee Creek, Carty Lake, and Lake River, 

which is a tributary to the Columbia River and primarily accessed on the refuge through Wapato 

Portage. 

The Refuge also proposes to provide access to state-waters in Lake River in the River ‘S’ Unit. The 

Refuge proposes to construct a fishing platform when the existing Lake River bridge is 

decommissioned. Anglers must park at the Visitor Contact Station Parking Area and walk to the 

fishing platform. Anglers must comply with all refuge-specific regulations and Washington State 

regulations. 

Availability of Resources: 

The Carty Unit and portions of the River ‘S’ Unit of the Refuge are open for environmental 

education, interpretation, wildlife photography, and wildlife observation as well as fishing. Access 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-30 Appendix B. Compatibility Determinations

trails, parking lots, signage and other facilities are often used for multiple purposes. Most of the 

costs associated with administering a recreational fishing program are part of other use programs. 

Relative to other uses, fishing is not as popular a visitor activity and does not cost a great deal of time 

and expense at current levels (approximately 260 angler-days/year). The Carty and River ‘S’ Units 

are fee areas, which helps offset program expenses. 

Costs to Administer and Manage Fishing Program at the Refuge under the Preferred Alternative

(Alternative 2)

Activity or Project 

One Time 

Expenses ($)

Recurring Expenses 

($/year)

Law Enforcement 5,000

Signage and pamphlet design to accommodate fishing. 1,000

Totals 6,000

Anticipated Impacts of Use:

Recreational fishing can impact the aquatic community by direct and indirect mortality (both of 

target and non-target species), changes in species composition and other trophic effects, and changes 

within species (stunting, changes in behavior) when fishing occurs at high levels (Blaber et al. 2000, 

Allen et al. 2005, Lewin et al. 2006). Many of the targeted species at the Refuge are introduced 

warmwater species such as carp, largemouth bass, bluegill, and black crappie that compete with 

native coldwater fish species. Removal of individuals of these non-native species may benefit native 

species by reducing competition and predation (Cornelius 2006). Given the low numbers of anglers 

using the Refuge, and the opportunity for most species to move freely into and out of the Refuge into 

the Columbia River, it is not likely that there are significant impacts (positive or negative) to the fish 

community. 

Fishing can cause disturbance to birds and other wildlife that use refuge waterbodies and adjacent 

shoreline habitat in a similar manner to the disturbance caused by visitors participating in wildlifedependent recreational activities. Species likely to experience some level of disturbance include 

foraging wading birds (great blue heron, American bittern, and great egret) foraging and nesting 

waterfowl (mallard, wood duck, cinnamon teal, gadwall, Canada goose, ring-necked duck), foraging 

and nesting passerines (red-winged blackbird, marsh wren), foraging raptors (osprey and bald eagle), 

and large mammals (black-tail deer). Very little angling activity occurs during the winter months 

when waterfowl use on the Unit is highest. 

Most research studies have focused on short-term responses to human disturbance such as flushing, 

nest abandonment, site avoidance, etc. Little information is available on long-term or large scale 

responses such as relocation of major staging areas, changes in productivity and demographics, or 

changes in prey/forage selection. Fishing has been shown to affect the reproduction, distribution, 

behavior, and abundance of bird species (Bell and Austin 1985; Cooke 1987, Korschgen and 

Dahlgren 1992). Anglers often fish in shallow, sheltered bays and creeks that birds prefer, negatively 

impacting distribution and abundance of waterfowl, grebes, and coots (Cooke 1987). 

Shoreline activities, such as human noise, would cause some birds to flush and go elsewhere. In 

addition, vegetation trampling, and deposition of litter or lost gear are likely to occur. Disturbance 

and destruction of riparian vegetation, and impacts to bank stability and water quality, have not been 

documented at current participation levels, but may occur should levels increase in the future. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-31

As stated above, the number of anglers using the refuge is relatively low because there are limited 

places available for fishing opportunities. Since the level of fishing activity is low, there is very 

limited disturbance to birds and limited impacts to vegetation through trampling. Thus, impacts to 

fish and wildlife resources associated with this activity are not significant. 

Public Review and Comment: 

This determination was issued for public review and comment as part of the Ridgefield NWR 

Draft Comprehensive Conservation Plan and Environmental Assessment (DCCP/EA). The plan 

and associated compatibility determinations were also provided as CDs to a mailing list of 432 

recipients, and were made available on the FWS Region 1 Planning website. Printed copies of the 

DCCP/EA were available upon request. The 30-day review occurred from June 16 through July 

16, 2010. We did not receive specific comments regarding the compatibility determinations, and 

no changes have been made at this time. 

Determination (check one below):

_____ Use is Not Compatible 

__x__ Use is Compatible with Following Stipulations 

Stipulations Necessary to Ensure Compatibility: 

• Fishing access is permitted only during daylight hours within the Carty Unit and a portion of 

the River ‘S’ Unit adjacent to the north side of the Lake River Bridge and on the bridge once 

it is closed to vehicle traffic and modified into a fishing pier.

• Anglers must park in designated parking areas and walk to fishing areas. 

• Camping, overnight use, and fires are prohibited. 

• Littering is prohibited. 

• All persons fishing shall be required to have a valid State license and follow applicable 

refuge and Washington State regulations. 

• Law enforcement patrols will be conducted on a regular basis to assure compliance with State 

and Refuge regulations. 

Justification: 

Fishing, when compatible with refuge purposes, is listed as a priority public use in the National 

Wildlife Refuge Administration Act and is to be encouraged as wildlife dependent recreational 

activity on national wildlife refuges. Stipulations will help reduce or eliminate any unwanted 

impacts of the use. State regulations and the ability for fish to move out of or into the Refuge from 

the Columbia River, will help ensure that harvest levels of fish do not harm long-term populations. 

Although fishing activities can result in disturbance to wildlife, disturbance will be intermittent and 

short-term. Most of the shoreline areas are densely vegetated and/or associated with a nearly vertical 

bank and not easily accessed. Of the two miles of Lake River ‘S’horeline that borders the Carty 

Unit, only about 0.5 miles (25%) is accessible. Only about 40 feet of shoreline would be accessible 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-32 Appendix B. Compatibility Determinations

from the platform at the River ‘S’ Unit. There is more than an adequate amount of undisturbed 

habitat available to the majority of waterfowl, waterbirds, and other wildlife for escape and cover. 

It is anticipated that wildlife populations will find sufficient food resources and resting places such 

that their abundance and use of the Refuge will not be measurably lessened from fishing activities. 

The relatively limited number of individuals expected to be adversely affected will not cause wildlife 

populations to materially decline, the physiological condition and production of refuge species will 

not be impaired, their behavior and normal activity patterns will not be altered dramatically, and their 

overall welfare will not be negatively impacted. Thus, allowing fishing to occur with stipulations will 

not materially detract or interfere with the purposes for which the refuge was established or the 

refuge mission. 

Mandatory 10- or 15-year Reevaluation Date: (provide month and year for “allowed” uses): 

9/2025___Mandatory 15-year re-evaluation date (for wildlife-dependent public uses) 

____ ___Mandatory 10-year reevaluation date (for all uses other than wildlife-dependent public 

uses)

References:

Allen, J.D., R. Abell, Z. Hogan, C Revenga, B.W. Taylor, R.L. Welcomme, and K. Winemiller. 

2005. Overfishing in Inland Water. Bioscience, 55:1041-1051. 

Bell, D.V. and L.W. Austin. 1985. The Game-Fishing Season and its Effects on Overwintering 

Wildfowl. Biological Conservation 33:65-80. 

Blaber, S.J.M., D. P. C. J.J. Albaret, C.V. Ching, J. W. Day, M. Elliott, M. S. Fonseca, D. E. Hoss, J. 

Orensanz, I. C. Potter, and W. Silvert. 2000. Effects of fishing on the structure and functioning of 

estuarine and nearshore ecosystems. ICES Journal of Marine Science, 57:590-602. 

Cooke, A.S. 1987. Disturbance by Anglers of Birds at Grafham Water. ITE Symposium 19:15-22. 

Cornelius, L. 2006. Gee Creek Watershed Restoration Background Report. Washington State 

University, Vancouver, WA. 73 pages. 

Korschgen, C.E. and R.L. Dahlgren. 1992. Human Disturbances of Waterfowl: Causes, Effects, and 

Management. Waterfowl Management Handbook. Fish and Wildlife Service. Washington, DC. 9 

pages.

Lewin, W.C., R. Arlinghaus, and T. Mehner. 2006. Documented and Potential Biological Impacts 

of Recreational Fishing: Insights for Management and Conservation. Reviews in Fisheries Science 

14:305-367. 

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Appendix B. Compatibility Determinations. B-49

B6. Compatibility Determination for Crop Production on Ridgefield National 

Wildlife Refuge

Use: Crop Production 

 

Station Name: Ridgefield National Wildlife Refuge

Date Established: 1965 

Establishing and Acquisition Authority(ies):

Migratory Bird Conservation Act of 1929, as amended (16 U.S.C. 715-715s) 

Migratory Bird Hunting and Conservation Stamp Act of 1934 (16 U.S.C. 718-718j) [Funding for 

primary acquisition] 

Refuge Purpose(s):

“... for use as an inviolate sanctuary, or for any other management purpose, for migratory birds.” 

16 U.S.C. § 715d (Migratory Bird Conservation Act) 

"... to provide wintering habitat for dusky Canada goose and other waterfowl. Will also provide 

breeding and migration use and substantial public shooting in area. Estimated peak population: 

125,000 ducks and 3,000 geese." (Migratory Bird Conservation Commission Memorandum 

Number 1, May 18, 1965.) 

National Wildlife Refuge System Mission: 

The mission of the System is to administer a national network of lands and waters for the 

conservation, management, and where appropriate, restoration of the fish, wildlife, and plant 

resources and their habitats within the United States for the benefit of present and future 

generations of Americans. 

Description of Use: 

The refuge manages pastures, wetlands, and agricultural fields to provide a variety of foods that 

will meet the needs of wintering and migratory waterfowl. Native vegetation provides higher 

levels of protein, fiber, and water than most agricultural crops. However, crops can provide 

wildlife with easily-accessible high energy foods, are more digestible than native plants, and can 

reduce foraging time required to meet caloric demands (Raveling 1979, Alisauskas and Ankney 

1992, Baldassare and Bolen 2006). Waterfowl are able to exploit a variety of habitats to meet 

their daily and seasonal food requirements and the refuge provides a diversity of food supplies in 

relatively close proximity to each other. 

Current refuge farming practices include grazing, haying, and planting of crops such as cereal 

grains and clover. Agricultural crops grown on the refuge (primarily winter wheat and corn) are 

selected primarily to provide waterfowl with an easily-accessible source of high-energy 

carbohydrates. The refuge proposes to increase crop production acreages from the current range 

of 155 to 185 ac (including 55 to 85 ac in corn) to 290 to 330 acres (including 60 to 145 ac of 

corn). The refuge has tried propagating millet and clover in some fields with mixed results. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-50 Appendix B. Compatibility Determinations

The Refuge will continue to work to improve crop production and availability to wildlife by: 

1) testing different crops such as spring wheat, buckwheat, and milo and 

2) implementing irrigation, where practicable. 

Soil amendments (fertilizer, lime, etc.) and weed control methods are used as necessary to 

improve the growth of desirable vegetation and reduce competition from weed species. The 

refuge will test soils in crop fields and use this information to determine the need for soil 

amendments, as well as the amount needed based on local recommendations such as those 

provided by Washington State University Extension or Oregon State University Extension 

Service. Best Management Practices (BMPs) will be used to avoid undesirable effects such as 

fertilizer leaching into groundwater or sedimentation of streams and waterbodies. Examples of 

BMPs include avoiding nitrogen fertilizer applications in the fall to help avoid waste and prevent 

fertilizer from leaching into groundwater, and leaving buffer strips of dense vegetation between 

cropland and wetlands to filter runoff and prevent sedimentation. Crop varieties adapted for local 

conditions and disease resistance will be selected for refuge use (for example Yamhill and 

Cashup are winter wheat varieties that are rust-resistant and locally adapted). 

Invasive weed species have the potential to reduce habitat quality and forage opportunity and 

have been identified as one of the most serious threats to refuge habitats. Activities such as crop 

production that disturb soils may provide opportunities for weeds to sprout and become 

established. Preventing infestations is the most effective strategy. Early detection followed by 

rapid response (ED/RR) helps prevent new invasive plant occurrences from becoming 

established. The refuge staff and volunteers conduct searches of refuge lands and waters on an 

annual basis to identify new occurrences and implement efforts to eradicate these species. 

Current examples of species being targeted for eradication through ED/RR are jimsonweed 

(Datura stramonium), purple loosestrife (Lythrum salicaria), pampas grass (Cortaderia jubata), 

and fragrant water lily (Nymphaea odorata). 

A variety of methods including mechanical and cultural treatments and herbicide applications are 

used to reach refuge goals of <20% weed cover and no new infestations in managed pastures and 

old fields. The refuge uses an integrated pest management (IPM) approach to control weeds 

(Appendix K), whereby management options are selected based on site conditions and not 

implemented until established thresholds (such as percent weed cover) are exceeded. 

For species that are or become established, mechanical, cultural, and biological control methods 

are evaluated in that order. If these methods are not expected to be effective or would have 

undesirable consequences (such as impacting nests of grassland-nesting birds), then the refuge 

may decide to use a herbicide. As described in detail in Appendix K, the refuge uses the most 

efficacious herbicide available with the least potential to degrade environment quality (soils, 

surface water, and groundwater) as well as least potential effect to native species and 

communities of fish, wildlife, plants, and their habitats. All applications of herbicides will 

conform to the specific pesticide label requirements. 

The refuge reviews pesticide use annually and submits pesticide use proposals for all applications 

conducted on refuge lands. With the exception of larvicides applied for mosquito control by the 

county mosquito management agency, herbicides are the only pesticides currently used on the 

refuge. Herbicides are not applied to each field every year. In 2009, the refuge applied 60 

gallons of glyphosate to control weeds on approximately 118 acres of cropland. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-51

The refuge has little capacity currently to irrigate croplands and in some years rainfall during the 

growing season is insufficient to produce a successful corn crop. Corn is favored by both geese 

and cranes as a high carbohydrate food and the Wildlife and Habitat Management Review 

(USFWS 2004) recommended increasing the acreage in corn. Given the high costs of producing 

a successful corn crop, the refuge proposes to evaluate the feasibility of implementing a 

cooperative farm program for crop production, whereby a private farmer (cooperator) would raise 

a Refuge-specified crop in a designated field or fields, and would be entitled to a share of the 

harvest. As an example, 75% of the crop would go to the cooperator and 25% to the Refuge, 

although this would be negotiated with the cooperator as part of the development of a 

Cooperative Farming Agreement (CFA). CFAs are typically multi-year agreements that are used 

to implement cooperative programs that help achieve refuge purposes as well as an economic 

benefit to the farmer. The CFA involves a negotiated agreement between the Refuge and private 

farmer to manage lands for both parties. To benefit wildlife, the Refuge share would be left in 

the field where it would be available to wildlife. Any fields that are double-cropped (two or 

more crops raised in a single season) would be subject to the same pre-determined 

Refuge/cooperator split for each crop. 

The Oregon/Southwest Washington Canada Goose Depredation Plan (Pacific Flyway Council 

1998) discourages establishing expansive agricultural crop fields on refuge lands and in response, 

the refuge has maintained relatively small (<50 ac) and scattered fields. This factor and the need 

to set up an irrigation system may increase the difficulty in locating a cooperating farmer who is 

able to produce sufficient forage for wildlife and provide an attractive return on their investment 

of time and money. However, given the importance of corn as a highly available, high energy, 

and easily digestible forage crop for geese and cranes, the refuge believes that a examining the 

feasibility of cooperative crop farming is worthwhile. 

Availability of Resources: 

The refuge staff currently operates the crop program. The refuge biologist plans crop production 

and evaluates the condition of the crop throughout the growing season. The refuge equipment 

operator and tractor operators prepare fields for cropping, seed the crop, and control weeds, as 

well as maintain access roads to the fields. If the refuge implements an irrigation system, the 

equipment operator and tractor operators, and biologist would work together to maintain and 

operate the system(s). In the event that using a cooperator was determined to be feasible, the 

cooperator would be responsible for field preparation (including the application of any soil 

amendments), weed control, seeding, irrigation, and harvesting. 

Costs to Administer and Manage Farming Programs at the Refuge under the Preferred Alternative 

(Alternative 2)

Activity or Project 

One Time 

Expenses ($)

Recurring 

Expenses ($/year)

Enhance/Maintain Improved Pasture for Dusky Canada 

Geese 89,500 

Enhance/Maintain Improved Pasture for Other Canada Geese 

and Waterfowl 179,000 

Maintain Old Fields and Old Field/Wetland Borders 25,400

Provide Crops for Waterfowl and Sandhill Cranes 76,500 – 104,500
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-52 Appendix B. Compatibility Determinations

Activity or Project 

One Time 

Expenses ($)

Recurring 

Expenses ($/year)

Enhance/Maintain Improved Pasture for Waterfowl. 3yr 

Upland Restoration Project 208,000 

Develop Irrigated Farming to Provide Crops for Waterfowl 

and Sandhill Cranes. 204,600 

Totals 412,600 370,400 – 398,400

Anticipated Impacts of Use:

The Refuge was established in part to provide habitat for wintering geese, especially the dusky 

Canada goose subspecies. As cropland in the lower Columbia River is converted to residential 

and commercial land cover types, agricultural lands suitable for wintering waterfowl and crane 

use are declining. Invasive pasture weeds such as Italian thistle and tansy ragwort further 

degrade the ability of existing pasture to support wintering geese. Producing high quality forage 

on Refuge lands is becoming increasingly important and the Refuge’s farming program is 

designed to provide areas of high-energy grain crops and green forage grasses to meet the food 

energy needs of wintering waterfowl and cranes and reduce crop depredation in nearby 

agricultural lands. In periods of severe weather, having a readily available source of high-energy 

foods can sustain wintering waterfowl and cranes during critical periods of nutritional and 

physical stress when other food sources generally are unavailable. 

The Refuge’s farming program does impact various grassland birds, small mammals, reptiles and 

amphibians. Not only are these species subject to mortality from farm machinery, but the 

conversion of unmowed grasslands/old fields to cropland causes habitat loss. The Refuge will 

reduce impacts of cropland by restricting the amount of cropland, protecting waterbodies and 

groundwater using BMPs and controlling weeds using the refuge’s IPM program (Appendix K) 

Invasive species may be spread by moving equipment from site to site. These species may also 

become established where soils and existing plant cover is disturbed. The refuge equipment 

operators are required to clean equipment before moving between fields to reduce the spread of 

seeds and plant parts. Cooperators will also be responsible for cleaning their equipment prior to 

moving between fields. The refuge will continue to monitor farming sites for invasive weeds and 

will maintain an aggressive approach to invasive plant control and restoring sites to vegetation 

with high wildlife value. In addition, the refuge will continue to work with the County Weed 

Board to prevent, identify, and eradicate new infestations. 

Threatened and Endangered Species

Within the River ‘S’ and Bachelor Island Units, the Service has established populations of the 

Federally-listed threatened Nelson’s checkermallow by planting individual seedlings in three 

separate pasture sites. Areas where this plant has been established will not be cropped to avoid 

impacts to these planted populations. The Refuge has completed an intra-service consultation 

pursuant to the Section 7 of the Endangered Species Act (87 Stat. 884, as amended; 16 U.S.C. 

1531 et seq.) regarding the proposed use and Nelson’s checkermallow. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-53

Public Review and Comment: 

This determination was issued for public review and comment as part of the Ridgefield NWR 

Draft Comprehensive Conservation Plan and Environmental Assessment (DCCP/EA). The plan 

and associated compatibility determinations were also provided as CDs to a mailing list of 432 

recipients, and were made available on the FWS Region 1 Planning website. Printed copies of the 

DCCP/EA were available upon request. The 30-day review occurred from June 16 through July 

16, 2010. We did not receive specific comments regarding the compatibility determinations, and 

no changes have been made at this time. 

Determination (check one below):

_____ Use is Not Compatible 

__x__ Use is Compatible with Following Stipulations 

Stipulations Necessary to Ensure Compatibility: 

The following stipulations ensure that the proposed use is compatible: 

• Crops will not occupy more than 10% of the refuge acreage. 

• In portions of fields where Nelson’s checkermallow was planted, no crops will be established 

• Weeds will be controlled in accordance with the refuge’s IPM program using methods such as 

crop rotation, mechanical treatment, biological controls, and low toxicity approved pesticides 

(Appendix K). 

• Pesticide use must be in compliance with the Service policy requirements for completing an 

approved Pesticide Use Proposal, and it must meet other State and Federal requirements. 

• Cooperators will only apply herbicides and fertilizers with prior refuge approval. 

• In the event that the refuge develops a CFA for crop production, the cooperator will provide an 

annual record of planting efforts, fertilizers and herbicide applications, and plant products 

removed from the Refuge. 

• The refuge will work to prevent the spread of weeds by cleaning equipment between fields and 

will continue to cooperate with the County Weed Board to control county-listed invasive weeds.

• Monitoring of the cropland farming program will be performed by qualified Refuge staff. 

Justification: 

Crop production has been shown to provide a cost-effective means of providing high quality food 

source for target wildlife species at the Refuge. Specifically, crop production provides high 

energy grain and forage crops, as well as green forage crops that are highly digestible and easily 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-54 Appendix B. Compatibility Determinations

accessible. Wintering and migrating geese and cranes readily use agricultural crop fields to help 

meet their energetic needs. The use of a cooperator to produce grain crops, primarily corn, 

would increase the likelihood of a successful crop and providing irrigation capability that is not 

currently available. In addition, the food support crop production provides for target wildlife 

species indirectly supports several wildlife dependent recreational activities such as wildlife 

observation and photography. 

 

By conducting the crop production program under the practices and stipulations described above, 

it is anticipated that wildlife species which could be adversely affected would find sufficient food 

resources and resting places so their abundance and use will not be measurably lessened on the 

refuge. Additionally, it is anticipated that monitoring, as needed, will prevent unacceptable or 

irreversible impacts to fish, wildlife, plants, and their habitats. 

The combination of management practices and stipulations identified above will ensure that crop 

production contributes to the enhancement, protection, conservation, and management of native 

wildlife populations and their habitats on the refuge. As a result, crop production contributes to 

achieving refuge purpose(s); contributes to the Mission of the NWRS; and helps maintain the 

biological integrity, diversity, and environmental health of the refuge. 

Mandatory 10- or 15-year Reevaluation Date: (provide month and year for “allowed” 

uses): 

_________ Mandatory 15-year re-evaluation date (for wildlife-dependent public uses) 

9/2020____Mandatory 10-year reevaluation date (for all uses other than wildlife-dependent 

public uses)

References:

Alisauskas, R.T. and C.D. Ankney. 1992. The cost of egg laying and its relationship to nutritional 

reserves in waterfowl. Pages 30-61 in B.D.J. Batt, A.D. Afton, M.G. Anderson, C.D. Ankney, D.H. 

Johnson, J.A. Kadlec, and G.L. Krapu, eds. Ecology and management of breeding waterfowl. Univ. 

of Minnesota Press, Minneapolis. 

Baldassare, G.A, and E.G. Bolen. 2006. Waterfowl ecology and management, 2nd edition. Krieger 

Publishing Company, Malabar, FL 

Raveling, D.G. 1979. The annual energy cycle of the Cackling Canada Goose. pages 81-93 in R.I. 

Jarvis and J.C. Bartonek, eds. Management and biology of Pacific Flyway geese. Oregon State 

University, Corvallis. 

USFWS. 1998. Recover Plan for the Threatened Nelson’s Checkermallow (Sidalcea nelsoniana). 

Dept. of Interior, Fish and Wildlife Service. Portland, Oregon. 38 pages. 

Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-56 Appendix B. Compatibility Determinations

B7. Compatibility Determination for Haying and Mowing on Ridgefield 

National Wildlife Refuge

Uses: Haying and Mowing 

 

Station Name: Ridgefield National Wildlife Refuge

Date Established: 1965 

Establishing and Acquisition Authority(ies): 

Migratory Bird Conservation Act of 1929, as amended (16 U.S.C. 715-715s) 

Migratory Bird Hunting and Conservation Stamp Act of 1934 (16 U.S.C. 718-718j) [Funding for 

primary acquisition] 

Refuge Purpose(s):

“... for use as an inviolate sanctuary, or for any other management purpose, for migratory birds.” 

16 U.S.C. § 715d (Migratory Bird Conservation Act) 

"... to provide wintering habitat for dusky Canada goose and other waterfowl. Will also provide 

breeding and migration use and substantial public shooting in area. Estimated peak population: 

125,000 ducks and 3,000 geese." (Migratory Bird Conservation Commission Memorandum 

Number 1, May 18, 1965.) 

National Wildlife Refuge System Mission: 

The mission of the System is to administer a national network of lands and waters for the 

conservation, management, and where appropriate, restoration of the fish, wildlife, and plant 

resources and their habitats within the United States for the benefit of present and future 

generations of Americans.

Description of Uses: 

The refuge manages pastures, wetlands, and agricultural fields to provide a variety of foods that 

will meet the needs of wintering and migratory waterfowl and cranes. Geese in particular, use 

refuge pastures for most of their foraging activity, preferring young shoots that are higher in 

protein and lower in fiber than mature stems (McLandis and Raveling 1981). Pasture grasses 

serve as an important source of amino acids and carbohydrates to meet the energy and nutrient 

requirements of geese (Baldassare and Bolen 2006). To provide high quality forage for wintering 

and migrating geese and cranes, the refuge uses mowing and haying to ensure that young shoots 

less than 6 inches tall are available by October 15 each year. We also use these methods to help 

reach our goal of <20% coverage of weed species and to remove thatch, which can reduce the 

number of available shoots. 

The refuge provides approximately 1,450 ac of pasture in 55 fields that are managed by haying 

(approximately 215 ac) and/or mowing (1,235 ac); the difference being that in haying, cut grass 

stems are removed from the pasture, whereas the stems are left behind as thatch in mowed fields. 

Grazing is also used to manage some pasture lands and is described in a separate compatibility 

determination. To reduce impacts to grassland nesting birds, mowing and haying are conducted 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-57

after July 15, by which time most nesting has been completed. In most dry pastures, a single 

mowing or haying is adequate, but if the late summer precipitation is heavier than typical, a 

second cutting may need to be done. In wetter pastures two or three cuttings or a combination of 

haying and grazing (see separate compatibility determination for grazing) is used to meet the 

habitat objectives for the pastures. By early October, pastures should contain dense (>90% areal 

coverage) of short (<6 inches tall) grasses and clovers, with <20% coverage of invasive weeds 

(Himalayan blackberry, Canada thistle, tansy ragwort, etc.) to provide suitable wintering and 

migratory goose habitat. 

Invasive weed species have the potential to reduce habitat quality and forage and have been 

identified as one of the most serious threats to refuge habitats. Preventing infestations is the most 

effective strategy. Early detection followed by rapid response (ED/RR) helps prevent new 

invasive plant occurrences from becoming established. 

A variety of methods including mechanical and cultural treatments and herbicide applications are 

used to reach the refuge objective of <20% weed cover and no new infestations in managed 

pastures and old fields. The refuge uses an integrated pest management (IPM) approach to 

control weeds (Appendix K), whereby management options are selected based on site conditions 

and not implemented until established thresholds (such as percent cover) are exceeded. 

For species that are or become established, mechanical, cultural, and biological controls methods 

are evaluated in that order. If these methods are not expected to be effective or would have 

undesirable consequences (such as impacting nests of grassland-nesting birds), then the refuge 

may decide to use a herbicide. The refuge may only use the most efficacious herbicide available 

with the least potential to degrade environment quality (soils, surface water, and groundwater) as 

well as least potential effect to native species and communities of fish, wildlife, plants, and their 

habitats. All applications of herbicides conform to the specific pesticide label requirements. 

The refuge reviews pesticide use annually and submits pesticide use proposals for all applications 

conducted on refuge lands. With the exception of larvicides applied for mosquito control by the 

county mosquito management agency, herbicides are the only pesticides used on the refuge. 

Herbicides are not applied to each field every year. In 2009, the refuge applied 266 gallons of 2, 

4-D butoxyethyl ester and 52 gallons of triclopyr triethylamine to control weeds on 

approximately 850 acres of pasture. 

Pastures are periodically interseeded (seeds are drilled into the soil without removing all the 

existing vegetation, or preparing the seedbed through plowing or disking) with plants such as 

barley or clover to maintain a mix of vegetation species and quickly restore vegetation cover after 

broadleaf weeds are controlled to prevent weeds from re-establishing. Interseeding occurs 

approximately every three to four years in pastures. 

Cooperative Land Management Agreements (CLMA) are used to implement cooperative 

farming, grazing, and haying programs that help achieve refuge purposes. The CLMA, signed in 

2009, described the negotiated agreement between the Refuge and private farmer to manage 

lands for both parties. The cooperator is responsible for pasture management, and installing and 

maintaining fencing. The refuge installs the underground water delivery system, maintains 

pumps, supplies fencing materials, and constructs and maintains access roads. The cooperator is 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-58 Appendix B. Compatibility Determinations

allowed to harvest hay and raise stock animals for personal use. The amount of hay and stock 

grazed on the Refuge varies, but approximately 200 to 400 tons of hay are removed and 120 to 

250 cows and horses (combined) are allowed to graze on approximately 1,200 acres. 

Availability of Resources: 

Refuge staff and equipment are required to manage pasture land and support the CLMA program. 

The Refuge Manager and Wildlife Biologist would be required to design the mowing and haying 

program each year. The Refuge Manager also negotiates an agreement with the cooperator. The 

Refuge Equipment Operator and Tractor Operators would be required to mow some fields, 

control weeds, and maintain access roads and water delivery systems pursuant to any cooperative 

agreements. If the Refuge implements irrigation systems, the Equipment Operator, Tractor 

Operators, and Wildlife Biologist would work together to maintain and operate the system(s). 

The use of cooperators’ facilitates the management of pastures by reducing the amount of 

mowing and thatch removal that would otherwise require additional staff time and equipment not 

currently available. Options for thatch removal are limited by the slow rates of thatch 

decomposition relative to growth rates, high water table in many wetlands that precludes disking 

for much of the year, and the complexity of using prescribed fire in a region with air quality 

concerns. The removal of the thatch in the form of hay, results in improved availability of young 

shoots that provide high quality forage for wintering geese. The use of cooperators has proven to 

be a cost-effective means of managing specific pastures for wintering geese and cranes and 

helping the Refuge provide high quality habitat. 

Costs to Administer and Manage Farming Programs at the Refuge under the Preferred 

Alternative (Alternative 2)

Activity or Project 

One Time 

Expenses ($)

Recurring 

Expenses ($/year)

Enhance/Maintain Improved Pasture for Dusky Canada Geese 89,500

Enhance/Maintain Improved Pasture for Other Canada Geese 

and Waterfowl 179,000 

Maintain Old Fields and Old Field/Wetland Borders 25,400

Provide Crops for Waterfowl and Sandhill Cranes 76,500 – 104,500

Enhance/Maintain Improved Pasture for Waterfowl. 3yr 

Upland Restoration Project 208,000 

Develop Irrigated Farming to Provide Crops for Waterfowl and 

Sandhill Cranes. 204,600 

Totals 412,600 370,400 – 398,400

Anticipated Impacts of Uses:

The Refuge was established in part to provide habitat for wintering geese, especially the dusky 

Canada goose subspecies. As cropland and grassland in the lower Columbia River region is 

converted to residential and commercial land cover types, lands suitable for wintering waterfowl 

and crane use are declining. Invasive pasture weeds such as Italian thistle and tansy ragwort 

further degrade the ability of existing pasture to support wintering geese. Managing existing 

pastures on Refuge lands to provide high quality forage is becoming increasingly important and 

the Refuge’s pasture management program is designed to provide areas of green forage grasses to 

meet the needs of wintering waterfowl and cranes and reduce crop depredation in nearby 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-59

agricultural lands. Managed pastures also provide wintering habitat for a variety of migratory 

bird species including western meadowlark, rough-legged hawk, and short-eared owl.

In the absence of disturbance, refuge grasslands would revert to shrublands or woodlands that do 

not supply appropriate habitat for wintering and migratory geese. Historically, grasslands would 

have been maintained through disturbances such as grazing, wildfire, and scouring (in areas 

where rivers flooded with sufficient energy to remove thatch and plant litter). Haying and 

mowing simulate some of the effects of natural disturbances by removing woody vegetation, 

reducing thatch, and encouraging the production of young shoots which are preferred forage for 

Canada and cackling geese (Raveling 1979). 

The refuge pasture management program does impact various grassland birds, small mammals, 

reptiles and amphibians. Not only are these species subject to mortality from machinery, but the 

conversion of tall pasture grasses to mowed grasses results in habitat loss. The Refuge reduces 

impacts of pasture management by delaying haying/mowing operations until after most grassland 

bird species have completed nesting (approximately July 15) and using approved low toxicity 

chemical agents and only when needed, as specified in the refuge IPM program description 

(Appendix K). 

Invasive species may be spread by moving animals and equipment from site to site. These 

species may also become established where soils and existing plant cover is disturbed. The 

refuge equipment operators are required to clean equipment before moving between fields to 

reduce the spread of seeds and plant parts. The refuge will continue to monitor farming sites for 

invasive weeds and will maintain an aggressive approach to invasive plant control and restoring 

sites to vegetation with high wildlife value. In addition, the refuge will continue to work with the 

County Weed Board to prevent, identify, and eradicate new infestations. 

Threatened and Endangered Species

Within the River ‘S’ and Bachelor Island Units, the Service has established populations of the 

Federally-listed threatened Nelson’s checkermallow by planting individual seedlings in managed 

pastures. Areas where this plant has been planted will not be grazed and will only be mowed 

after the checkermallow plants have entered senescence to prevent the encroachment of 

competing weeds and woody vegetation pursuant to the Recovery Plan (USFWS 1998). If 

necessary, weed control will be accomplished by hand-pulling (preferred, if practicable) or spottreatment with pursuant herbicides, as specified in the refuge’s IPM program description 

(Appendix K). The Refuge has performed an intra-service consultation pursuant to the Section 7 

of the Endangered Species Act (87 Stat. 884, as amended; 16 U.S.C. 1531 et seq.) regarding the 

proposed uses and Nelson’s checkermallow. 

Public Review and Comment: 

This determination was issued for public review and comment as part of the Ridgefield NWR 

Draft Comprehensive Conservation Plan and Environmental Assessment (DCCP/EA). The plan 

and associated compatibility determinations were also provided as CDs to a mailing list of 432 

recipients, and were made available on the FWS Region 1 Planning website. Printed copies of the 

DCCP/EA were available upon request. The 30-day review occurred from June 16 through July 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-60 Appendix B. Compatibility Determinations

16, 2010. We did not receive specific comments regarding the compatibility determinations, and 

no changes have been made at this time. 

Determination (check one below):

_____ Uses are Not Compatible

__x__ Uses are Compatible with Following Stipulations

Stipulations Necessary to Ensure Compatibility: 

The following stipulations ensure that the proposed uses are compatible:

• Mowing and haying will only occur after July 15, unless surveys indicate that the specific pasture 

is not being used by nesting grassland birds. 

• In portions of fields where Nelson’s checkermallow was planted, mowing will only occur after 

checkermallow plants have entered senescence.

• Weeds will be controlled in accordance with the refuge’s IPM program using methods such as 

crop rotation, mechanical treatment, biological controls, and low toxicity approved pesticides 

(Appendix K). 

• Pesticide use must be in compliance with the Service policy requirements for completing an 

approved Pesticide Use Proposal, and it must meet other State and Federal requirements. 

• Cooperators will only apply herbicides with prior refuge approval and will provide a record of 

herbicides used including chemical name, amount used, date, location, and how applied. 

• Pursuant to the refuge’s CLMA, Cooperators will provide an annual record of animals grazed on, 

and plant products removed from, the Refuge. 

• The refuge will continue to cooperate with the County Weed Board to control county-listed 

invasive weeds.

Justification: 

Mowing and haying are two important tools for providing high quality pasture habitat for 

wintering geese and cranes. These species prefer young shoots that are higher in protein and 

carbohydrates to meet their energy and nutrient requirements. They also prefer to forage and rest 

in areas with good visibility to better detect predators such as coyotes. Haying and mowing 

remove tall vegetation that would restrict visibility. These methods also remove encroaching 

woody vegetation and help control weeds. Haying also provides the benefit of thatch removal. 

The refuge establishes seasonal restrictions on mowing and haying to protect nesting grassland 

birds. In pastures where mechanical, cultural, and biological methods of weed management are 

not effective that the refuge may use approved herbicides. The refuge also restricts the use of 

herbicides to low-toxicity compounds that have the least potential to degrade environment quality 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-61

and the least potential effect to native species and communities of fish, wildlife, plants, and their 

habitats. 

The use of a cooperator to assist with pasture management by haying and providing weed 

control, allows the refuge to manage more pasture acreage than could be done by existing staff 

and equipment. The cooperator also removes 200 to 400 tons of hay, which reduces the amount 

of thatch present, and increases the amount of preferred forage by encouraging the growth of 

young shoots. 

By conducting the haying and mowing program under the practices and stipulations described 

above, it is anticipated that wildlife species which could be adversely affected would find 

sufficient food resources and resting places so their abundance and use will not be measurably 

lessened on the refuge. Additionally, it is anticipated that monitoring, as needed, will prevent 

unacceptable or irreversible impacts to fish, wildlife, plants, and their habitats. 

The combination of management practices and stipulations identified above will ensure that 

haying and mowing contributes to the enhancement, protection, conservation, and management 

of native wildlife populations and their habitats on the refuge. As a result, haying and mowing 

contributes to achieving refuge purpose(s); contributes to the Mission of the NWRS; and helps 

maintain the biological integrity, diversity, and environmental health of the refuge. 

Mandatory 10- or 15-year Reevaluation Date: (provide month and year for “allowed” uses): 

_______ Mandatory 15-year re-evaluation date (for wildlife-dependent public uses)

__9/2020 Mandatory 10-year reevaluation date (for all uses other than wildlife-dependent public 

uses)

References:

Alisauskas, R.T. and C.D. Ankney. 1992. The cost of egg laying and its relationship to nutritional 

reserves in waterfowl. Pages 30-61 in B.D.J. Batt, A.D. Afton, M.G. Anderson, C.D. Ankney, D.H. 

Johnson, J.A. Kadlec, and G.L. Krapu, eds. Ecology and management of breeding waterfowl. Univ. 

of Minnesota Press, Minneapolis. 

Baldassare, G.A, and E.G. Bolen. 2006. Waterfowl ecology and management, 2nd edition. Krieger 

Publishing Company, Malabar, FL. 

Raveling, D.G. 1979. The annual energy cycle of the Cackling Canada Goose. pages 81-93 in R.I. 

Jarvis and J.C. Bartonek, eds. Management and biology of Pacific Flyway geese. Oregon State 

University, Corvallis, OR. 

USFWS. 1998. Recover Plan for the Threatened Nelson’s Checkermallow (Sidalcea nelsoniana). 

Fish and Wildlife Service. Portland, OR. 38 pages.

Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-63

B8. Compatibility Determination for Grazing on Ridgefield National 

Wildlife Refuge

Use: Grazing 

 

Station Name: Ridgefield National Wildlife Refuge

Date Established: 1965 

Establishing and Acquisition Authority(ies):

Migratory Bird Conservation Act of 1929, as amended (16 U.S.C. 715-715s) 

Migratory Bird Hunting and Conservation Stamp Act of 1934 (16 U.S.C. 718-718j) [Funding for 

primary acquisition] 

Refuge Purpose(s):

“... for use as an inviolate sanctuary, or for any other management purpose, for migratory birds.” 

16 U.S.C. § 715d (Migratory Bird Conservation Act) 

"... to provide wintering habitat for dusky Canada goose and other waterfowl. Will also provide 

breeding and migration use and substantial public shooting in area. Estimated peak population: 

125,000 ducks and 3,000 geese." (Migratory Bird Conservation Commission Memorandum 

Number 1, May 18, 1965.) 

National Wildlife Refuge System Mission:

The mission of the System is to administer a national network of lands and waters for the 

conservation, management, and where appropriate, restoration of the fish, wildlife, and plant 

resources and their habitats within the United States for the benefit of present and future 

generations of Americans. 

Description of Use: 

The refuge manages pastures, wetlands, and agricultural fields to provide a variety of foods that 

will meet the needs of wintering and migratory waterfowl and cranes. Geese in particular, use 

refuge pastures for most of their foraging activity, preferring young shoots that are higher in 

protein and lower in fiber than mature stems (McLandis and Raveling 1981). Pasture grasses 

serve as an important source of amino acids and carbohydrates to meet the energy and nutrient 

requirements of geese (Baldassare and Bolen 2006). To provide high quality forage for wintering 

and migrating geese and cranes, the refuge uses grazing to ensure that young shoots less than 6 

inches tall are available by early October each year and to reduce the accumulation of thatch 

(thatch can reduce the number of available shoots). Other tools used by the refuge include 

mowing and haying, which are discussed in detail in a separate compatibility determination. 

The refuge provides approximately 1,450 acres of pasture in 55 fields. Of these, approximately 

490 ac (193 cattle and horses, combined) were grazed in 2009 to help achieve refuge goals. 

Grazing by cattle and/or horses is allowed in fields between May 1 and October 1, subject to 

approval by the refuge biologist and manager, and only after surveys conducted by refuge staff 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-64 Appendix B. Compatibility Determinations

indicate that introducing livestock to an area will not significantly affect grassland nesting birds. 

Stock is removed when the vegetation height is <6 inches over 90% of the pasture. Depending 

on rainfall and vegetation growth, grazing may occur more than once in a pasture as necessary to 

achieve habitat goals. By early October, pastures should contain dense (>90% areal coverage) of 

short (<6 inches tall) grasses and clovers, with <20% coverage of invasive weeds (Himalayan 

blackberry, Canada thistle, tansy ragwort, etc.) to provide suitable wintering and migratory goose 

habitat. 

Cooperative Land Management Agreements (CLMAs) are used to implement cooperative 

farming, grazing, and haying programs that help achieve refuge purposes. The CLMA, signed in 

2009, described the negotiated agreement between the Refuge and a private farmer to manage 

lands for both parties. The cooperator is responsible for pasture management, weed control, and 

installing and maintaining fencing. The refuge installs the underground water delivery system, 

maintains pumps, supplies fencing materials, and constructs and maintains access roads. The 

cooperator is allowed to harvest hay and raise stock animals for personal use. The amount of 

stock grazed on the Refuge varies, but 120 to 250 cows and horses (combined) are allowed to 

graze on approximately 740 acres, but not all acres will be grazed each year. 

Availability of Resources: 

Refuge staff and equipment are required to manage pasture land and support the CLMA program. 

The refuge manager and wildlife biologist would be required to design the grazing program each 

year. The refuge manager also negotiates an agreement with the cooperator. The refuge 

equipment operator and tractor operators would be required maintain access roads and water 

delivery systems pursuant to any cooperative agreements. As stated above, the cooperator 

would manage pasture lands, install and maintain fences, and ensure that the pasture meets the 

refuge habitat goals for migrating and wintering geese and cranes (dense young grasses, <6 

inches tall and <20% weed cover) by October 1 each year. 

The use of cooperators facilitates the management of pastures by reducing the amount of mowing 

and thatch removal that would otherwise require additional staff time and equipment not 

currently available. Thatch reduction by mowing alone, is limited by the slow rates of thatch 

decomposition relative to growth rates, high water table in many wetlands that precludes mowing 

and discing for much of the year, and the complexity of using prescribed fire in a region with air 

quality concerns. The removal of vegetation by grazing, results in thatch reduction and in 

improved availability of young shoots that provide high quality forage for wintering geese. The 

use of cooperators has proven to be a cost-effective means of managing specific pastures for 

wintering geese and cranes and helping the Refuge provide high quality habitat. 

Costs to Administer and Manage Farming Programs at the Refuge under the Preferred Alternative 

(Alternative 2)

Activity or Project 

One Time 

Expenses ($)

Recurring 

Expenses ($/year)

Enhance/Maintain Improved Pasture for Dusky Canada Geese 89,500

Enhance/Maintain Improved Pasture for Other Canada Geese 

and Waterfowl 179,000 

Maintain Old Fields and Old Field/Wetland Borders 25,400

Provide Crops for Waterfowl and Sandhill Cranes 76,500 – 104,500

Enhance/Maintain Improved Pasture for Waterfowl. 3yr 208,000
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-65

Activity or Project 

One Time 

Expenses ($)

Recurring 

Expenses ($/year)

Upland Restoration Project

Develop Irrigated Farming to Provide Crops for Waterfowl 

and Sandhill Cranes. 204,600 

Totals 412,600 370,400 – 398,400

Anticipated Impacts of Use:

The Refuge was established in part to provide habitat for wintering geese, especially the dusky 

Canada goose subspecies. As cropland in the lower Columbia River is converted to residential 

and commercial land cover types, agricultural lands suitable for wintering waterfowl and crane 

use are declining. Invasive pasture weeds such as Italian thistle and tansy ragwort further 

degrade the ability of existing pasture to support wintering geese. Managing existing pastures on 

Refuge lands to provide high quality forage is becoming increasingly important and the Refuge’s 

farming program is designed to provide areas of high-energy grain crops and green forage 

grasses to meet the needs of wintering waterfowl and cranes and reduce crop depredation in 

nearby agricultural lands. Managed pastures also provide wintering habitat for a variety of 

migratory bird species including western meadowlark, rough-legged hawk, and short-eared owl. 

In the absence of disturbance, refuge grasslands would revert to shrublands or woodlands that do 

not supply appropriate habitat for wintering and migratory geese. Historically, grasslands would 

have been maintained through disturbances such as grazing, wildfire, and scouring (in areas 

where rivers flooded with sufficient energy to remove thatch and plant litter). Grazing by 

livestock simulates some of the effects of natural disturbances by removing woody vegetation, 

reducing thatch, and encouraging the production of young shoots which are preferred forage for 

Canada and cackling geese (Raveling 1979). 

Grazing has been demonstrated to impact various grassland birds, nesting waterfowl, and small 

mammals (Fleischner 1994). Not only are these species subject to injury and mortality from 

trampling, but the conversion of tall pasture grasses to short-cropped grasses results in habitat 

loss for some species. The Refuge reduces impacts of pasture management by limiting grazing 

operations to <10% of available lands and restricting the introduction of cattle during the 

breeding season in areas where significant impacts to grassland nesting birds would occur. 

Invasive species may be spread by moving animals and equipment from site to site. These 

species may also become established where soils and existing plant cover is disturbed. The 

refuge equipment operators are required to clean equipment before moving between fields to 

reduce the spread of seeds and plant parts. Weed control measures are conducted prior to 

introducing livestock into pastures to reduce the likelihood of spreading invasive plant seeds. 

The refuge will continue to monitor pasture lands for invasive weeds and will maintain an 

aggressive approach to invasive plant control and restoring sites to vegetation with high wildlife 

value. In addition, the refuge will continue to work with the County Weed Board to prevent, 

identify, and eradicate new infestations. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-66 Appendix B. Compatibility Determinations

Threatened and Endangered Species

Within the River ‘S’ and Bachelor Island Units, the Service has established populations of the 

Federally-listed threatened Nelson’s checkermallow by planting individual seedlings in managed 

pastures. Areas where this plant has been planted will not be grazed and will only be mowed 

after the checkermallow plants have entered senescence to prevent the encroachment of 

competing weeds and woody vegetation pursuant to the Recovery Plan (USFWS 1998). If 

necessary, weed control will be accomplished by hand-pulling (preferred, if practicable) or spottreatment with pursuant herbicides, as specified in the refuge’s IPM program description 

(Appendix K). The Refuge has performed an intra-service consultation pursuant to the Section 7 

of the Endangered Species Act (87 Stat. 884, as amended; 16 U.S.C. 1531 et seq.) regarding the 

proposed use and Nelson’s checkermallow. 

Public Review and Comment: 

This determination was issued for public review and comment as part of the Ridgefield NWR 

Draft Comprehensive Conservation Plan and Environmental Assessment (DCCP/EA). The plan 

and associated compatibility determinations were also provided as CDs to a mailing list of 432 

recipients, and were made available on the FWS Region 1 Planning website. Printed copies of the 

DCCP/EA were available upon request. The 30-day review occurred from June 16 through July 

16, 2010. We did not receive specific comments regarding the compatibility determinations, and 

no changes have been made at this time. 

Determination (check one below):

_____ Use is Not Compatible 

__x__ Use is Compatible with Following Stipulations 

Stipulations Necessary to Ensure Compatibility: 

The following stipulations ensure that the proposed use is compatible: 

• Grazing will only occur between May 1 and October 1 and only in areas where refuge staff have 

determined that significant impacts to grassland nesting birds will not occur. 

• In portions of fields where Nelson’s checkermallow was planted, grazing will not be permitted. 

• Weeds will be controlled in accordance with the refuge’s IPM program using methods such as 

crop rotation, mechanical treatment, biological controls, and low toxicity approved pesticides 

(Appendix K). 

• Pesticide use must be in compliance with the Service policy requirements for completing an 

approved Pesticide Use Proposal, and it must meet other State and Federal requirements. 

• Cooperators will only apply herbicides with prior refuge approval and will provide a record of 

herbicides used including chemical name, amount used, date, location, and how applied. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-67

• Pursuant to the refuge’s CLMA, Cooperators will provide an annual record of animals grazed on, 

and plant products removed from, the Refuge. 

• The refuge will continue to cooperate with the County Weed Board to control county-listed 

invasive weeds.

Justification: 

The refuge uses grazing as a tool to achieve specific habitat objectives for wintering and 

migrating waterfowl (specifically Canada and cackling geese) and cranes. These species prefer 

young shoots that are higher in protein and carbohydrates to meet their energy and nutrient 

requirements. They also prefer to forage and rest in areas with good visibility to better detect 

predators, such as coyotes. Grazing reduces residual thatch, and tall vegetation thus enhancing 

visibility. This method also removes encroaching woody vegetation and helps control weeds by 

preventing seed production in species such as reed canarygrass. The refuge establishes 

restrictions on grazing to protect nesting grassland birds by only allowing grazing to occur in 

areas where impacts to nesting grassland birds are not significant. 

In pastures where mechanical, cultural, and biological methods of weed management are not 

effective that the refuge may use approved herbicides. The refuge also restricts the use of 

herbicides to low-toxicity compounds that have the least potential to degrade environment quality 

and the least potential effect to native species and communities of fish, wildlife, plants, and their 

habitats. 

The use of a cooperator to assist with pasture management by grazing, haying, and providing 

weed control, allows the refuge to manage more pasture acreage than could be done by existing 

staff and equipment. Also, because grazing results in thatch removal and stimulates shoot growth 

more than mowing, the refuge (and migratory and wintering geese and cranes) benefits from the 

increased habitat quality. 

By conducting the grazing program under the practices and stipulations described above, it is 

anticipated that wildlife species which could be adversely affected would find sufficient food 

resources and resting places so their abundance and use will not be measurably lessened on the 

refuge. Additionally, it is anticipated that monitoring, as needed, will prevent unacceptable or 

irreversible impacts to fish, wildlife, plants, and their habitats. 

The combination of management practices and stipulations identified above will ensure that 

grazing contributes to the enhancement, protection, conservation, and management of native 

wildlife populations and their habitats on the refuge. As a result, grazing contributes to achieving 

refuge purpose(s); contributes to the Mission of the NWRS; and helps maintain the biological 

integrity, diversity, and environmental health of the refuge. 

Mandatory 10- or 15-year Reevaluation Date: (provide month and year for “allowed” uses): 

_____ Mandatory 15-year re-evaluation date (for wildlife-dependent public uses) 

9/2020 Mandatory 10-year reevaluation date (for all uses other than wildlife-dependent public uses) 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-68 Appendix B. Compatibility Determinations

References:

Alisauskas, R.T. and C.D. Ankney. 1992. The cost of egg laying and its relationship to nutritional 

reserves in waterfowl. Pages 30-61 in B.D.J. Batt, A.D. Afton, M.G. Anderson, C.D. Ankney, D.H. 

Johnson, J.A. Kadlec, and G.L. Krapu, eds. Ecology and management of breeding waterfowl. Univ. 

of Minnesota Press, Minneapolis. 

Baldassare, G.A, and E.G. Bolen. 2006. Waterfowl ecology and management, 2nd edition. Krieger 

Publishing Company, Malabar, Florida. 

Fleischner, T.L. 1994. Ecological costs of livestock grazing in western North America. 

Conservation Biology 8(3): 629-644 

Raveling, D.G. 1979. The annual energy cycle of the Cackling Canada Goose. pages 81-93 in R.I. 

Jarvis and J.C. Bartonek, eds. Management and biology of Pacific Flyway geese. Oregon State 

University, Corvallis. 

USFWS. 1998. Recover Plan for the Threatened Nelson’s Checkermallow (Sidalcea nelsoniana). 

Dept. of Interior, Fish and Wildlife Service. Portland, Oregon. 38 pages. 

Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-70 Appendix B. Compatibility Determinations

B9. Compatibility Determination for Research on Ridgefield National 

Wildlife Refuge

Use: Research

Refuge Name: Ridgefield National Wildlife Refuge 

Establishing and Acquisition Authorities:

• Migratory Bird Conservation Act of 1929, as amended (16 U.S.C. 715-715s) 

• Migratory Bird Hunting and Conservation Stamp Act of 1934 (16 U.S.C. 718-718j) [Funding 

for primary acquisition] 

Refuge Purposes:

“... for use as an inviolate sanctuary, or for any other management purpose, for migratory birds.” 16 

U.S.C. § 715d (Migratory Bird Conservation Act) 

"... to provide wintering habitat for dusky Canada goose and other waterfowl. Will also provide 

breeding and migration use and substantial public shooting in area. Estimated peak population: 

125,000 ducks and 3,000 geese." (Migratory Bird Conservation Commission Memorandum Number 

1, May 18, 1965.) 

National Wildlife Refuge System Mission

The mission of the System is to administer a national network of lands and waters for the 

conservation, management, and where appropriate, restoration of the fish, wildlife, and plant 

resources and their habitats within the United States for the benefit of present and future generations 

of Americans. 

Description of Use

The Refuge receives periodic requests (less than six per year) to conduct scientific research. Priority 

would be given to studies that support refuge purposes, goals and objectives. This would include, for 

example, studies that contribute to the enhancement, protection, use, preservation, and management 

of native Refuge wildlife populations and their habitats. The refuge receives an annual request to 

monitor and collect mosquito larvae from Clark County. This action is discussed in a separate 

compatibility determination. Research applicants must submit a proposal that would outline: 1) 

objectives of the study; 2) justification for the study; 3) detailed methodology and schedule; 4) 

potential impacts on Refuge wildlife and/or habitat, including disturbance (short and long term), 

injury, or mortality; 5) personnel required; 6) costs to Refuge, if any; and 7) end products (i.e. 

reports, publications). Research proposals would be reviewed by Refuge staff, Regional Office 

Branch of Refuge Biology, and others as appropriate. Evaluation criteria will include, but not be 

limited to, the following: 1) Research that will contribute to management will have higher priority 

than other requests. 2) Research that will conflict with higher priority research, monitoring or 

management programs may not be granted. 3) Research projects that can be done elsewhere offRefuge, and outside wilderness, are less likely to be approved. 4) Research which causes undue 

disturbance or is intrusive, will likely not be granted. Level and type of disturbance will be carefully 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-71

weighed when evaluating a request. 5) Research evaluation will determine if any effort has been 

made to minimize disturbance through study design, including considering adjusting location, timing, 

scope, number of permittees, study methods, number of study sites, etc. 6) If staffing or logistics 

make it impossible for the Refuge to monitor researcher activity in a sensitive area, this may be 

reason to deny the request. 7) The length of the project will be considered and agreed upon before 

approval. Projects will not be open-ended, and at a minimum, will be reviewed annually. 

Availability of resources: Direct costs to administer research activities are primarily in the form of 

staff time, transportation, and equipment acquisition and maintenance. It is estimated that the 

following level of involvement by Refuge staff will be required annually to adequately manage and 

monitor research activities over the long term. 

Costs to Administer and Manage Research Program at the Refuge.

Activity or Project 

One Time 

Expenses ($)

Recurring Expenses 

($/year)

Staff assistance to Researcher (i.e. permit initiation, 

review and administrative support and compliance)

10,000

Totals 10,000

Anticipated Impacts of the Use

Impacts would be project- and site-specific, where they will vary depending upon nature and scope 

of the field work. Data collection techniques will generally have minimal animal mortality or 

disturbance, habitat destruction, no introduction of contaminants, or no introduction of nonindigenous species. In contrast, projects involving the collection of biotic samples (plants or 

animals) or requiring intensive ground-based data or sample collection will have short-term impacts. 

To reduce impacts, the minimum number of samples (e.g., water, soils, vegetative litter, plants, 

macroinvertebrates, and vertebrates) will be collected for identification and/or experimentation and 

statistical analysis. Where possible, researchers would coordinate and share collections to reduce 

sampling needed for multiple projects. 

There also could be localized and temporary effects from vegetation trampling, collecting of soil and 

plant samples, or trapping and handling of wildlife. Impacts may also occur from infrastructure 

necessary to support a projects (e.g., permanent transects or plot markers, exclosure devices, 

monitoring equipment, solar panels to power unattended monitoring equipment). Some level of 

disturbance is expected with these projects, especially if investigator(s) enter areas closed to the 

public and collect samples or handle wildlife. However, wildlife disturbance (including altered 

behavior) will usually be localized and temporary in nature. Where long-term or cumulative 

unacceptable effects cannot be avoidable, the project will be found not compatible. Project proposals 

will be reviewed by refuge staff and others, as needed, to assess the potential impacts (short, longterm, and cumulative) relative to benefits of the investigation to refuge management issues and 

understanding of natural systems. 

Spread of invasive plants and/or pathogens is possible from ground disturbance and/or transportation 

of project equipment and personnel, but it will be minimized or eliminated by requiring proper 

cleaning of investigator equipment and clothing as well as quarantine methods, where necessary. If 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-72 Appendix B. Compatibility Determinations

after all practical measures are taken and unacceptable spread of invasive species is anticipated to 

occur, then the project will be found not compatible without a restoration or mitigation plan. 

Public Review and Comment: 

This determination was issued for public review and comment as part of the Ridgefield NWR 

Draft Comprehensive Conservation Plan and Environmental Assessment (DCCP/EA). The plan 

and associated compatibility determinations were also provided as CDs to a mailing list of 432 

recipients, and were made available on the FWS Region 1 Planning website. Printed copies of the 

DCCP/EA were available upon request. The 30-day review occurred from June 16 through July 

16, 2010. We did not receive specific comments regarding the compatibility determinations, and 

no changes have been made at this time. 

Determination 

 The use is not compatible.

 X The use is compatible with the following stipulations. 

Stipulations Necessary to Ensure Compatibility

If the proposed research methods would impact or potentially impact refuge resources (habitat or 

wildlife), it must be demonstrated that the research is and the researcher must identify the issues in 

advance of the impact. Highly intrusive or manipulative research is generally not permitted in order 

to protect native plant and wildlife populations. Potential researchers must submit a written study 

proposal with their request. In addition the following must be met: 

• Researchers are responsible for acquiring and/or renewing any necessary State and Federal 

permits prior to beginning or continuing their project.

• Research will adhere to current species protocols for data collection. 

• Approved research projects will be conducted under a refuge-issued special use permit which 

will have additional project-specific stipulations.

• Special use permits will be valid for one year only. Renewals will be subject to refuge 

manager review of research data, status reports, and compliance with compatibility 

determination and permit stipulations, and permits.

• Refuge Manager can suspend/modify conditions/terminate on-refuge research that is already 

permitted and in progress, should unacceptable impacts or issues arise or be noted. 

• Investigator(s) obtaining required State, and/or Federal collecting permits will also ensure 

minimal impacts to fish, wildlife, plants, and their habitats. If after incorporating the above 

strategies, projects will not be compatible if they will result in long-term or cumulative 

effects. A Section 7 consultation under the Endangered Species Act (16 U.S.C. 1531-1544, 

87 Stat. 884, as amended Public Law 93-205) will be required for activities that may affect a 

federally listed species and/or critical habitat. Only projects which have no effect or will 

result in not likely to adversely affect determinations will be considered compatible. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-73

• At least 6 months before initiation of field work (unless an exception is made by prior 

approval of the Refuge Manager), project investigator(s) must submit a detailed proposal 

using an approved format. Project proposals will be reviewed by refuge staff and others, as 

needed, to assess the potential impacts (short, long-term, and cumulative) relative to benefits 

of the investigation to refuge management issues and understanding of natural systems. This 

assessment will form the primary basis for allowing or denying a specific project. Projects 

which result in unacceptable refuge impacts will not be found compatible. If allowed and 

found compatible after approval, all projects also will be assessed during implementation to 

ensure impacts and conflicts remain within acceptable levels. 

• If the proposal is approved, then the Refuge Manager will issue a SUP(s) with required 

stipulations (terms and conditions) of the project to avoid and/or minimize potential impacts 

to refuge resources as well as conflicts with other public-use activities and refuge field 

management operations. After approval, projects also are monitored during implementation 

to ensure impacts and conflicts remain within acceptable levels based upon documented 

stipulations. 

Justification

Use of the refuge to conduct research, scientific collecting, and surveys will generally provide 

information that would benefit fish, wildlife, plants, and their habitats. Scientific findings gained 

through these projects provide important information regarding life-history needs of species and 

species groups as well as identify or refine management actions to achieve resource management 

objectives in refuge management plans (especially CCPs). Reducing uncertainty regarding wildlife 

and habitat responses to refuge management actions in order to achieve desired outcomes reflected in 

resource management objectives is essential for adaptive management in accordance with 522 DM 1. 

Research, scientific collecting, and surveys on refuge lands are inherently valuable to the Service 

because they will expand scientific information available for resource management decisions. In 

addition, only projects which directly or indirectly contribute to the enhancement, protection, use, 

preservation, and management of refuge wildlife populations and their habitats generally will be 

authorized on refuge lands. In many cases, if it were not for the refuge staff providing access to 

refuge lands and waters along with some support, the project would never occur and less scientific 

information would be available to the Service to aid in managing and conserving the refuge 

resources. By allowing the use to occur under the stipulations described above, it is anticipated that 

wildlife species which could be disturbed during the use would find sufficient food resources and 

resting places so their abundance and use will not be measurably lessened on the refuge. 

Additionally, it is anticipated that monitoring, as needed, will prevent unacceptable or irreversible 

impacts to fish, wildlife, plants, and their habitats. 

The combination of stipulations identified above and conditions included in any SUP(s) will ensure 

that proposed projects contribute to the enhancement, protection, conservation, and management of 

native wildlife populations and their habitats on the refuge. As a result, these projects will help fulfill 

refuge purpose(s); contribute to the Mission of the NWRS; and maintain the biological integrity, 

diversity, and environmental health of the refuge. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-74 Appendix B. Compatibility Determinations

Mandatory 10- or 15-year Reevaluation Date: (provide month and year for “allowed” uses): 

______ _ Mandatory 15-year re-evaluation date (for wildlife-dependent public uses) 

 9/2020 Mandatory 10-year reevaluation date (for all uses other than wildlife-dependent public 

uses)

Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-76 Appendix B. Compatibility Determinations

B10. Compatibility Determination for Mosquito and Disease Vector 

Management on Ridgefield National Wildlife Refuge

Use: Mosquito and Disease Vector Management 

Station Name: Ridgefield National Wildlife Refuge

Date Established: 1965 

Establishing and Acquisition Authority(ies):

Migratory Bird Conservation Act of 1929, as amended (16 U.S.C. 715-715s) 

Migratory Bird Hunting and Conservation Stamp Act of 1934 (16 U.S.C. 718-718j) [Funding for 

primary acquisition] 

Refuge Purpose(s):

“... for use as an inviolate sanctuary, or for any other management purpose, for migratory birds.” 

16 U.S.C. § 715d (Migratory Bird Conservation Act) 

"... to provide wintering habitat for dusky Canada goose and other waterfowl. Will also provide 

breeding and migration use and substantial public shooting in area. Estimated peak population: 

125,000 ducks and 3,000 geese." (Migratory Bird Conservation Commission Memorandum 

Number 1, May 18, 1965.) 

National Wildlife Refuge System Mission: 

The mission of the System is to administer a national network of lands and waters for the 

conservation, management, and where appropriate, restoration of the fish, wildlife, and plant 

resources and their habitats within the United States for the benefit of present and future 

generations of Americans. 

Description of Use: 

With the spread of mosquito-borne diseases across the country, National Wildlife Refuges have 

come under increasing pressure to manage mosquito populations that are bred or harbored within 

refuge boundaries. The Director of the Service has produced Interim Guidance for refuges 

(USFWS 2005) until the Service policy document is finalized. The refuge will adhere to the 

Director’s interim guidance and our mosquito management program will follow the response 

matrix presented in Table 1. 

The refuge in cooperation with Clark County Mosquito Control District (District) proposes to 

monitor and control larval mosquito species that have the potential to serve as disease vectors 

that may affect public health, adjacent to portions of the refuge. Monitoring generally takes place 

between early April and late September, by which time most of the seasonally-flooded wetland 

areas are too dry to support large numbers of mosquito larvae. 

The District staff proposes to monitor and control mosquito larvae with Bacillus thuringiensis 

var. israelensis, which is frequently referred to as B.t.i. [EPA Registration No. 73049-10]) when 

established thresholds are exceeded as indicated through monitoring. Monitoring and larval 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-77

treatments will be restricted to shallowly flooded (<8 inches) vegetation that represent mosquito 

breeding habitat. In 2004 through 2009, the following specific areas (956 acres) on the refuge 

were monitored for potential treatment: portions of the Carty Unit, the southern portion of the 

Ridgefield Dairy Unit near Post Office Lake, and a small area at the north edge of the River ‘S’ 

Unit (Figure 1). Approximately 18% of the refuge area was monitored for potential mosquito 

treatment. However, only a small portion of the monitoring area would be treated in a given year 

(see below). An additional 2,970 acres are currently monitored but are not treated because of high 

water levels or sensitive waterbodies. These areas are subject to change depending on monitoring 

results or new information on the occurrence of sensitive resources. To protect sensitive wildlife 

resources such as eagle nests and heron rookeries and reduce the spread of invasive plant species, 

sampling periods and frequency as well as type of access (4wd vehicle, ATV, foot traffic only) 

will be determined by the refuge in late winter/early spring. Because the locations of sensitive 

resources (e.g., bald eagle nests, heron rookeries, and listed species occurrences) may change 

over time, the refuge will establish sampling and treatment stipulations on an annual basis 

through the Special Use Permit (SUP) process described in 5 RM 17. 

The District also monitors adult mosquito populations from May to September using dry ice 

traps, one each in the Carty and Roth Units, as part of the county-wide surveillance for the 

presence of mosquito borne-diseases. Common species collected include Aedes vexans, 

Amopheles punctipennis, Anopheles freeborni, Culex pipiens, Culex incidens, Culex tarsalis, and 

Ochlerotatus sticticus. 

The current protocol for southwest Washington mosquito control districts when monitoring 

wetlands for mosquito larvae is to treat with the larvicide B.t.i. when the larvae reach established 

threshold levels. The current treatment threshold used by the District is five mosquito larvae per 

dip net sample. On other national wildlife refuges, threshold levels used by mosquito control 

districts range from 1 to 15 larvae per dip, with an average of five (M. Higgins 2002, Pers. 

Comm.). 

Mosquito larvae numbers within the refuge are affected by a number of factors such as weather 

conditions, precipitation, and time of year. The primary factor contributing to the production of 

the mosquitoes, however, is the water level fluctuation along shorelines, where mosquitoes lay 

their eggs and subsequently hatch. Water fluctuations are primarily due to precipitation, tidal 

influences, and refuge water management activities. Due to the uncertainty of the water levels 

resulting from the above factors, and subsequent mosquito hatches, the total amount of larvicide 

to be used, and the times, dates, and exact locations of application (magnitude and frequency) 

cannot be predicted. In some cases, certain areas may need repeated treatments. 

The refuge and the District established larval abundance thresholds through the Special Use 

Permit process to protect public health and reduce impacts to fish and wildlife populations. If 

mosquito larvae dip numbers reach threshold levels (currently, 5 larvae/dip), District staff request 

approval from the Refuge Manager to apply B.t.i, at a rate of 2.5 to 5 lbs/ac. District staff 

estimates that B.t.i. treatment of areas described above would generally take 2 to 6 hours, and it 

would be done as soon as possible after threshold levels are exceeded. 

B.t.i. is a selective microbial insecticide targeting mosquito larvae; however, studies during the 

mid-1990s in the Midwest (Hershey el al. 1998) had found that other Dipteran species (flies) can 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-78 Appendix B. Compatibility Determinations

also be impacted, including chironomids, an important fish and wildlife food source. B.t.i. has 

practically no acute or chronic toxicity to mammals, fish, birds, or vegetation (USEPA 1998). 

B.t.i. produces protein endo-toxins that, when ingested by the susceptible insect, cause paralysis 

of cells in the gut, interfering with normal digestion and feeding. As proposed, B.t.i may be 

applied (2.5 to 5 lbs pounds/acre) as often as once every two to three weeks depending on larval 

mosquito populations. The bacteria are grown on high-protein bases (fishmeal, soy flour), which 

are then formulated onto corncob pellets enabling it to be broadcast over the treatment area by a 

hand-held or all terrain vehicle-mounted spreader. 

All applications are required to be reported to the refuge and included in an annual report 

submitted to the refuge from the District. The areal extent of treatments and frequency of 

treatments is likely to vary annually in response to water levels, weather conditions, and larvae 

distribution. In 2007, for example, the District treated a 9.25 ac of wetlands and no site was 

treated more than 3 times during the season. In 2008, the Columbia River reached an elevation 

of 15 feet (approximately 1 foot below flood stage) and 58 acres were treated with larvicide. 

In accordance with the 2005 Interim Mosquito Management Policy and the response matrix 

(Table 1), the Service may also permit the use of approved adulticides and/or pupacides on 

refuge lands in response to a declaration of a human health threat or emergency by a Federal, 

State or local public health agency (see Table 1). A health emergency indicates an imminent risk 

of serious human disease or death, or an imminent risk to populations of wildlife or domestic 

animals. A health emergency represents the highest level of mosquito-associated health threats. 

Health emergencies will be determined by Federal, State, or local public health authorities and 

documented with local and current mosquito population and disease monitoring data. With the 

exception of vaccines to protect horses against West Nile virus and western equine 

encephalomyelitis, there are no vaccines that provide specific protection against these diseases. 

Mosquito control is the only practicable method currently available to protect the public from 

these diseases. 

To date, the refuge staff has not needed to permit the application of pupacides or adulticides, and 

all adult sampling tests for West Nile Virus were negative. Clark County does not currently use 

pupacides (such as methoprene), although, adulticides have been applied in Clark County to 

control nuisance mosquitoes. As per the Director’s guidance, the refuge does not permit the 

treatment of nuisance mosquitoes on refuge lands. In 2007, the District applied 1,390 gallons of 

Anvil 2+2 (a synthetic pyrethroid) using a fogger system. 

The refuge will continue to evaluate measures to control mosquitoes that pose a threat to human 

health while limiting the risk associated with the use of chemical control. Most of the mosquitoproducing areas on the refuge are outside the levee system, and the refuge cannot manipulate 

water levels to effectively reduce larvae production in these areas. Water level manipulation is 

possible in portions of the River ‘S’ Unit where mosquito larvae have been found. In the event 

that a human health emergency is declared, and the use of adulticides is authorized, the refuge 

will work with the District to identify which portions of the refuge are supporting species of 

mosquitoes that may serve as disease vectors and reduce the treatment area to the extent 

practicable. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-79

Why this Use is being Proposed: 

On wetland habitats of the refuge, annual precipitation and Columbia River high water flows 

flood much of the bottomlands on the refuge. This water permeates the ground cover vegetation 

that provides vegetative debris as egg-laying sites for two major species of floodwater 

mosquitoes, Aedes vexans and Ochlerotatus sticticus. When high-water levels recede, the eggs 

hatch, larvae grow rapidly, and adults feed for two weeks or more until they breed, lay eggs, and 

then die. Under certain conditions the Refuge may provide suitable habitat for multiple hatches 

of mosquitoes in a single summer. 

Arboviral (arthropod-borne viral) diseases are a potential concern. These include West Nile virus, 

western equine encephalitis and St. Louis encephalitis. The last reported human infection western 

equine encephalitis acquired in the state was in 1988. St. Louis encephalitis has been documented 

in the past, primarily east of the Cascade Mountains (Washington State Department of Health 

2009). 

Although West Nile virus was first documented in the eastern states, it has been moving west 

since that time. In the state of Washington, birds and horses have been confirmed with West Nile 

Virus (Duffy 2006, pers. comm.). During 2002, a common raven from Pend Oreille County tested 

positive for the virus, as well as one American crow from Thurston, Snohomish, and Pierce 

Counties, and two horses, one from Island County and one from Whatcom County. During 2005, 

a magpie and two horses were reported from Yakima County. In 2009, there were 36 human 

cases state-wide of West Nile virus. None of these reported cases were in Clark or Skamania 

Counties. The only known case of West Nile virus in Clark County was a single case in 2006 

(Washington State Department of Health 2009). Moreover, less than 1 percent of humans who are 

exposed and infected with West Nile virus become seriously ill. The fatality rate of those who do 

develop serious illness is 3 to 15 percent. Most human infections of West Nile virus are 

asymptomatic or characterized by mild flu-like symptoms. The elderly and persons with 

compromised immune systems are more likely to develop severe illness (Ashe 2002). 

Availability of Resources: 

The District is responsible for staffing and expenditures for sampling and pesticide applications 

(mainly B.t.i.). Refuge staff resources are needed to review annual proposals, prepare SUPs, and 

monitor District personnel to ensure compliance. 

Costs to Administer and Manage Vector Control Programs at the Refuge under the Preferred 

Alternative (Alternative 2)

Activity or Project 

One Time 

Expenses ($)

Recurring Expenses 

($/year)

Development and issuance of SUP $500.00

Totals $500.00

Anticipated Impacts of Use:

This use has three principle, potential impacts on refuge lands, waters or interests: the 

disturbance of wildlife caused by the monitoring efforts and application of pesticides, the impacts 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-80 Appendix B. Compatibility Determinations

on wildlife from the periodic elimination of mosquito larvae from the wetland community, and 

the impacts of pesticides on non-target organisms. 

Impacts associated with disturbance of wildlife caused by the monitoring efforts

The disturbance of wildlife by District staff is minimized to the extent practicable by restricting 

access to sensitive areas and by controlling the type of access (4wd vehicle, ATV, or foot traffic). 

The impacts anticipated from the logistical activities resulting from the proposed monitoring and 

treatment actions on wildlife are minimal. One or two Control Board employees using an allterrain vehicle (ATV) would conduct these activities and would be restricted to refuge service 

roads and a minimum of trails. By using an all-terrain vehicle to access the area, the District 

reduces the number of trips needed on foot for monitoring and treatment, thereby, reducing 

disturbance to wildlife. The speed limit for the District staff using ATVs is restricted to 5 miles 

per hour. Monitoring activities would occur once a week, and take approximately 2-6 hours. 

Subsequent treatments, if necessary, would occur as soon as possible after monitoring activities 

and take an estimated 4 hours (Williams 2006). These activities cause short-term and temporary 

disturbance to wildlife. In the event of an identified public health threat or emergency (e.g., West 

Nile Virus) by the Washington State Public Health Agency, the data from these monitoring 

efforts would be used by the refuge for determining an appropriate course of action. 

Impacts associated with application of pesticides

Where necessary and in accordance with the response matrix (Table 1), pesticides (larvicides, 

pupacides, and adulticides) would only be used on refuge lands for mosquito control after 

approval of a pesticide use propose (PUP). The Service’s Pest Control policy (7 RM 14) requires 

preparation and approval of a PUP before pesticides can be applied on refuge lands. In general, 

proposed pesticide uses on refuge lands would only be approved where there would likely be 

minor, temporary, or localized effects to fish and wildlife species as well as minimal potential to 

degrade environmental quality. Potential effects to listed and non-listed species would be 

evaluated with quantitative ecological risk assessments and other screening measures. Potential 

effects to environmental quality would be based upon pesticide characteristics of environmental 

fate (water solubility, soil mobility, soil persistence, and volatilization) and other quantitative 

screening tools. Ecological risk assessments as well as characteristics of environmental fate and 

potential to degrade environmental quality for pesticides would be documented in Chemical 

Profiles (see Appendix K). These profiles would include threshold values for quantitative 

measures of ecological risk assessments and screening tools for environmental fate that represent 

minimal potential effects to species and environmental quality. In general, only pesticide uses 

with appropriate BMPs on refuge lands that would potentially have minor, temporary, or 

localized effects on refuge biological and environmental quality (threshold values not exceeded) 

would be approved. However, pesticides may be used on refuge lands where substantial effects to 

species and the environment are possible (exceed threshold values) in order to protect human 

health and safety (e.g., mosquito-borne disease). 

 

The Service does not anticipate any short-term effects of the proposed use directly on non-target 

invertebrates or indirectly to fish. Tamayo et al. (2005) did not observe significant negative 

effects of B.t.i. applications on the invertebrate community at the south shoreline of Franz Lake 

National Wildlife Refuge (a nearby refuge within the Ridgefield National Wildlife Refuge 

Complex). Application of B.t.i for the study followed protocols identified by the Control Board 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-81

for the proposed use and was conducted at the same location during periods of water elevations 

lower than 20 feet MSL. 

Adulticides and pupacides have not been used for mosquito control on the refuge. The refuge 

will develop an IPM plan to manage mosquito populations. Based on adult mosquito control 

conducted in Clark County, pyrethroids such as Anvil are the most likely adulticides to be used 

to address a human health emergency. Pyrethroids are synthetic molecules that mimic natural 

pyrethrins that are extracted from plants in the chrysanthemum family. Pyrethroids are generally 

less toxic to terrestrial wildlife than other families of adulticides such as organophosphates. 

However, they are toxic to fish and aquatic invertebrates. The County has not used pupacides in 

recent years. Methoprene, a commonly-used pupacide, is an insect growth regulator that 

prevents pupae from metamorphosizing into adults. Methoprene has been found to be practically 

non-toxic to people and terrestrial vertebrates and minimal chronic and acute risk to fish, 

freshwater invertebrates (other than mosquitoes and closely-related chironomids), and estuarine 

species at the doses tested (USEPA 2001). Detailed mapping of areas where disease-carrying 

mosquitoes are present and the use of an ultra-low volume fogger will reduce the impacts to nontarget organisms. Other practices to reduce impacts to non-target wildlife include application in 

the evening hours (when many insect pollinators are less active) and conducting applications 

when winds speeds are steady and low, and temperatures lower. 

Impacts on wildlife from the periodic elimination of mosquito larvae from the wetland community.

The Service does not anticipate long-term impacts to result from the proposed use. Hershey et al. 

(1998) conducted a six-year study on 27 wetlands in Wright County, Minnesota, consisting of 

three years of pre-treatment sampling of aquatic invertebrates and other parameters, followed by 

three years of treatment with B.t.i.. Insect densities and diversity were reduced by 57 to 83 

percent in the second and third years of treatment. During this study, 179 genera of aquatic 

insects were examined, with chironomids (primarily midges) representing about half of the insect 

genera present at the beginning of the study. By the end of the study, however, only one to six 

genera dominated the treatment sites. Adverse impacts were primarily observed in the 

invertebrate tribes Chironomini and Tantarsini. These tribes are ubiquitous and are represented 

in almost every wetland with chironomids. Although Hershey et al. (1998) found negative 

effects of B.t.i. on non-target invertebrates; this study is not applicable in the case of Ridgefield 

NWR for the following reasons: 

1. Entire wetlands were treated with B.t.i. multiple times within and over several consecutive 

years in the Minnesota study. In contrast, the proposed maximum number of acres to be 

treated at Ridgefield 925 acres, which represents 18% of the total acres of the refuge. In 

practice, only about 15% of the maximum treatment area is impacted in a given year. 

2. Because of fluctuating water levels changing the location of the shallow flooded shoreline, 

it is unlikely B.t.i. applications would occur in the same areas more than three times in a 

single year and most areas would receive a single application. Stipulations in the SUP will 

limit the number of applications in a specific location during one season. 

The recently completed invertebrate and salmonid research along the south Franz Lake shoreline 

(Franz Lake NWR) has provided valuable information regarding the cumulative impacts of 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-82 Appendix B. Compatibility Determinations

mosquito treatment and control measures that are applicable to the program at the refuge. The 

invertebrate study was conducted during the latter part of the application period (July–

September) when lower Columbia River elevations eliminate the flows from the river through 

Arthur Lake to Franz Lake, representing minimal opportunity for an influx of new invertebrate 

communities. Furthermore, during the single treatment season of this study, stable water levels 

during July-September resulted in three applications of B.t.i. to the same locations. 

Consequently, it is unlikely there will be negative cumulative direct impact on the invertebrate 

community or indirectly on fish and wildlife. 

During the two years of monitoring fish resources at Franz Lake NWR, 2,357 individuals were 

collected in six sampling locations. Of those, 121 salmon were collected, with one Chinook 

salmon and one coho salmon collected in the proposed treatment area during the treatment period 

(April through September). Because there were no impacts to non-target invertebrates from B.t.i.

treatment, it is unlikely that other native fish would be impacted from applications. 

Although mosquito larva were reduced from B.t.i. treatments, there were no significant 

differences in the over 40 taxa of invertebrates, with 50 percent of the taxa represented by other 

insects, which had been represented at shallow water sites where treatments would occur prior to 

treatment. Based on the results of the invertebrate survey, it would be expected that alternative 

prey would be available for native fishes (including salmonids), as well as other wildlife, that 

depend on larval or adult mosquitoes as forage. Consequently, the Service believes that the 

proposed monitoring and subsequent applications of B.t.i. would not have substantial short-term, 

long-term or cumulative impacts on refuge fish and wildlife resources. 

Impacts to Biological Integrity, Diversity, and Environmental Health

Biological integrity, diversity, and environmental health can be simply defined as native fish, 

wildlife, plants, and their habitats as well as natural processes that support them. As described 

above, the impacts from larvicide application to most fish, wildlife, and plants will be temporary 

and localized. Mosquito populations which are part of the biological integrity, diversity, and 

environmental health of the refuge, will be impacted from control actions. However, these 

impacts will only occur on a maximum of 18% percent of the entire refuge in any given year. 

Although numbers of mosquitoes will be temporarily and locally reduced, there will likely be no 

long-term or cumulative effects to mosquitoes and the species that feed upon them at the refuge. 

As part of the refuge’s mosquito management plan the refuge will assess the impacts of 

adulticide applications on biological integrity, diversity, an environmental health. 

Public Review and Comment: 

This determination was issued for public review and comment as part of the Ridgefield NWR 

Draft Comprehensive Conservation Plan and Environmental Assessment (DCCP/EA). The plan 

and associated compatibility determinations were also provided as CDs to a mailing list of 432 

recipients, and were made available on the FWS Region 1 Planning website. Printed copies of the 

DCCP/EA were available upon request. The 30-day review occurred from June 16 through July 

16, 2010. We did not receive specific comments regarding the compatibility determinations, and 

no changes have been made at this time. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-83

Determination (check one below):

_____ Use is Not Compatible 

 x Use is Compatible with Following Stipulations

Stipulations Necessary to Ensure Compatibility: 

• The District must apply for and receive a SUP annually from the Refuge Manager. The 

permit will specify conditions including, but not limited to access restrictions, timing of 

applications, measures that will be required to limit the spread of invasive plants. 

• Mosquito management will follow an IPM approach and any compatible cultural and/or 

mechanical control methods will be identified and implemented before chemical control is 

permitted. 

• Larvae control is to be conducted only when the District determined that breeding in specific 

units is widespread. 

• Only Service-approved pesticides may be applied on refuge wetlands and only after Pesticide 

Use Proposals have been approved. 

• The District will contact the Refuge Manager at least one day in advance of each application. 

The Refuge Manager has final approval over all pesticide treatments.

• The District will notify the Refuge Manager in the event that virus activity is detected within 

or near the refuge and will work with the refuge to determine whether additional surveillance 

or control actions are necessary. 

• The District must provide the Refuge Manager with a monthly report of all control activities 

on the refuge. 

• The refuge may rescind this compatibility determination (CD) at any time based on future 

Service policy determinations or scientific studies of the effects of pesticides on the 

environment or non-target organisms. 

• This CD will be reviewed when the Service finalizes its pending policy on mosquito 

management, and a new CD will be issued if this CD is not in full compliance with the new 

policy. 

Justification: 

Several suburban communities occur near the refuge within the flight range of adult mosquitoes 

(5-10 miles). Several species capable of transmitting diseases to people are present on the refuge, 

though the risk of transmission is generally low. The refuge’s mosquito control program is 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-84 Appendix B. Compatibility Determinations

consistent with the Service’s 2005 Interim Mosquito Management Policy and will help manage 

nuisance mosquito population. 

The Refuge will ensure that its mosquito management program is consistent with national 

policies for disease control. We will prepare a mosquito management plan that includes an IPM 

approach to adult mosquito control. We will work with the District to continue to identify new 

ways to use compatible mechanical and cultural control methods, reduce larvicide applications, 

and avoid impacts to sensitive resources. 

In the event that compatible mechanical and cultural control methods are not effective or 

practicable, the use of the larvicide B.t.i. will help avoid ecologically significant impacts to nontarget organisms and help the District avoid the need to apply adulticides which are generally 

more toxic to non-target organisms. For the following reasons, mosquito monitoring and B.t.i.

treatments for control of mosquitoes on the Refuge will not materially interfere with or detract 

from fulfilling the NWRS mission or achieving Refuge purposes: 

• Under the worst-case scenario a maximum of 18 % of the total Refuge acreage would be 

impacted by mosquito monitoring and treatment activities annually from April 1 through 

September 30. 

• Results of the invertebrate B.t.i. study indicate that no impacts to non-target invertebrates 

were associated with three B.t.i. treatments for control of mosquito larva on the shallowly 

flooded south shoreline of Franz Lake NWR. 

• Although mosquito larvae will be reduced from B.t.i. treatments, over 40 taxa of 

invertebrates, with 50 percent of the taxa represented by other insects, were found at shallow 

water sites (where treatments would occur) after treatment. Therefore, alternative prey is likely 

available for fish as well as other wildlife species. 

• Monitoring and treatment activities will likely result in only temporary and localized 

disturbance to fish and wildlife. 

• The localized and temporary impacts of the mosquito monitoring and treatments will be 

conducted in areas closed to public use and thus will likely not conflict with any wildlifedependent public uses in the future. Wildlife-dependent uses include hunting, fishing, wildlife 

observation, wildlife photography, environmental education, and interpretation. 

Mandatory 10- or 15-year Reevaluation Date: (provide month and year for “allowed” uses): 

____ ____ Mandatory 15-year re-evaluation date (for wildlife-dependent public uses) 

__9/2020__ Mandatory 10-year reevaluation date (for all uses other than wildlife-dependent public 

uses)
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-85

Table 1. Example of Mosquito-Borne Disease Health Threat and Response Matrix

Current Conditions Threat

Level

Refuge Response

Health Threat

Category1

Refuge Mosquito

Populations2

No documented 

existing or historical 

health threat/

emergency

No action 

threshold 

1 Remove/manage artificial mosquito breeding 

sites such as tires, tanks, or similar 

debris/containers. Allow compatible 

monitoring.

Documented historical 

health 

threat/emergency

Below action 

threshold 

2 Response as in threat level 1, plus: evaluate 

compatible nonpesticide management 

options such as water level management and 

vegetation removal to reduce mosquito 

production.

Above action 

threshold 

3 Response as in threat level 2, plus: allow 

compatible site-specific larviciding of 

infested areas as determined by monitoring.

Documented existing 

health threat (specify 

multiple levels, if 

necessary; e.g., 

disease found in 

wildlife, disease found 

in mosquitoes, etc.)

Below action 

threshold

4 Response as in threat level 2, plus: increase 

monitoring and disease surveillance.

Above action 

threshold 

5 Response as in threat levels 3 and 4, plus: 

allow compatible site-specific larviciding, 

pupaciding, or adulticiding of infested areas 

as determined by monitoring data. Identify 

ways to minimize treatment area to avoid 

non-target effects

Officially determined 

existing health 

emergency

Below action 

threshold

6 Maximize monitoring and disease 

surveillance.

Above action 

threshold 

7 Response as in threat level 6, plus: allow 

site-specific larviciding, pupaciding, and 

adulticiding of infested areas as determined 

by monitoring. 1 Health threat/emergency as determined by Federal and/or State/local public health or wildlife management 

authorities with jurisdiction inclusive of refuge boundaries and/or neighboring public health authorities.

2 Action thresholds represent mosquito population levels that may require intervention measures. Thresholds will be 

developed in collaboration with Federal and/or State/local public health or wildlife management authorities and 

vector control districts. They must be species and life stage specific (see text).
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

B-86 Appendix B. Compatibility Determinations
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix B. Compatibility Determinations. B-87

References:

Fortin, C., A. Marie, and R. Leclair. 1987. The residual effect of Abate on nontarget communities. J. 

Am. Mosquito Control Assoication. 3:282-288. 

Hershey, A.E., L. Shannon, R. Axler, C. Ernst, P. Mickelson. 1995. Effects of methoprene and Bti 

(Bacillus thuringiensis var.israelensis) on non-target insects. Hydrobiologia. 308-219-227. 

Higgins, M. 2002. U.S. Fish and Wildlife Service, National Mosquito Control Coordinator. 

Personal communication with Jim Clapp. March 2002. 

Jackson, J.K., R.J. Horwitz, and B.W. Sweeney. 2002. Effects of Bacillus thuringiensis israelensis

on black flies and nontarget macroinvertebrates and fish in a large river. Transactions of the 

American Fisheries Society. 131:910-930. 

Lee, B.M., and G.I. Scott. 1989. Acute Toxicity of Temephos, Fenoxycarb, Diflubenzuron, and 

Methoprene and Bacillus thuringiensis var. israelensis to the Mummichog. Bull. Environ. 

Contamination and Toxicology 43:827-832. 

Marten, G.G., W. Che, and E.S. Bordes. 1993. Compatibility of cyclopoid copepods with mosquito 

insecticides. J. Am. Mosquito Control Association 9:150-154. 

Mittal, P.K., T. Adak, and V.P. Sharma. 1991. Acute toxicity of certain organochlorine, 

organophosphorus, synthetic pyrethroid and microbial insecticides to the mosquito fish. Indian J. of 

Malariology 28:167-170. 

Parsons, J.T., and G.A. Surgeoner. 1991. Acute toxicities of permethrin, fenitrothion, carbaryl and 

carbofuran to mosquito larvae during sing pulse or multiple pulse exposures. Environ. Toxicology 

and Chemistry 10:1229-1233. 

Purcell, B.H. 1981. Effects of Bacillus thuringiensis on Aedes taeniorhynchus and some nontarget 

organisms in the salt marsh. Mosquito News 41:476-484). 

Tamayo , M. 2005. West Nile Virus, Mosquito Control and Aquatic Invertebrates: Implications for 

Wetlands in Western Washington (Presentation April 20, 2005). Pullman, WA. 

USEPA. 1998. Re-registration eligibility document. Bacillus thuringiensis. Washington, DC. 

USEPA. 2001. EPA Pesticide fact Sheet–Methorpene. Washington, DC. 9 pages. 

USFWS. 2005. Interim Guidance for Mosquito Management on National Wildlife Refuges. 

FWS/ANRS-NR-WR/020301. Washington DC. 20 pages. 

Washington Department of Health. 2009. Arboviral Disease. URL: www.doh.wa.gov. 

Washington Department of Health. 2009. West Nile Virus Surveillance Updates. URL: 

www.doh.wa.gov/ehp/ts/Zoo/WNV/Surveillance09.html#Statistics accessed 12/09/09. 

Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix C. Wildlife and Plant List C-1 

Appendix C. Wildlife and Plants of Ridgefield National Wildlife 

Refuge 

Birds

Common Name Scientific Name Subspecies

Greater White-fronted Goose Anser albifrons

Emperor Goose Chen canagica

Snow Goose Chen caerulescens caerulescens

Ross's Goose Chen rossii

Brant Branta bernicla nigricans

Cackling Goose Branta hutchinsii taverneri, minima, leucopareia

Canada Goose Branta canadensis moffitti, parvipes, occidentalis, fulva

Trumpeter Swan Cygnus buccinator

Tundra Swan Cygnus columbianus

Wood Duck Aix sponsa

Gadwall Anas strepera

Eurasian Wigeon Anas penelope

American Wigeon Anas americana

Mallard Anas platyrhynchos

Blue-winged Teal Anas discors

Cinnamon Teal Anas cyanoptera

Northern Shoveler Anas clypeata

Northern Pintail Anas acuta

Green-winged Teal Anas crecca

Canvasback Aythya valisineria

Redhead Aythya americana

Ring-necked Duck Aythya collaris

Tufted Duck Aythya fuligula

Greater Scaup Aythya marila

Lesser Scaup Aythya affinis

Surf Scoter Melanitta perspicillata

Bufflehead Bucephala albeola

Common Goldeneye Bucephala clangula

Barrow’s Goldeneye Bucephala islandica

Hooded Merganser Lophodytes cucullatus

Common Merganser Mergus merganser

Red-breasted Merganser Mergus serrator

Ruddy Duck Oxyura jamaicensis

Ring-necked Pheasant Phasianus colchicus

Ruffed Grouse Bonasa umbellus sabini

California Quail Callipepla californica

Red-throated Loon Gavia stellata

Pacific Loon Gavia pacifica

Common Loon Gavia immer

Pied-billed Grebe Podilymbus podiceps

Horned Grebe Podiceps auritus
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

C-2 Appendix C. Wildlife and Plant List

Common Name Scientific Name Subspecies

Red-necked Grebe Podiceps grisegena

Eared Grebe Podiceps nigricollis

Western Grebe Aechmophorus occidentalis

American White Pelican Pelecanus erythrorhynchos

Double-crested Cormorant Phalacrocorax auritus

American Bittern Botaurus lentiginosus

Great Blue Heron Ardea herodias

Great Egret Ardea alba

Snowy Egret Egretta thula

Cattle Egret Bubulcus ibis

Green Heron Butorides virescens

Black-crowned Night-Heron Nycticorax nycticorax

White-faced Ibis Plegadis chihi

Turkey Vulture Cathartes aura

Osprey Pandion haliaetus carolinensis

White-tailed Kite Elanus leucurus majusculus

Bald Eagle Haliaeetus leucocephalus

Northern Harrier Circus cyaneus

Sharp-shinned Hawk Accipiter striatus

Cooper’s Hawk Accipiter cooperii

Northern Goshawk Accipiter gentilis

Red-shouldered Hawk Buteo lineatus elegans

Red-tailed Hawk Buteo jamaicensis harlani, calurus

Rough-legged Hawk Buteo lagopus

Golden Eagle Aquila chrysaetos

American Kestrel Falco sparverius sparverius

Merlin Falco columbarius suckleyi, columbarius

Peregrine Falcon Falco peregrinus tundrius, pealei, anatum

Prairie Falcon Falco mexicanus

Virginia Rail Rallus limicola

Sora Porzana carolina

American Coot Fulica americana

Sandhill Crane Grus canadensis canadensis, tabida, rowani

Black-bellied Plover Pluvialis squatarola

American Golden-Plover Pluvialis dominica

Pacific Golden-Plover Pluvialis fulva

Semipalmated Plover Charadrius semipalmatus

Killdeer Charadrius vociferus

Black-necked Stilt Himantopus mexicanus

American Avocet Recurvirostra americana

Greater Yellowlegs Tringa melanoleuca

Lesser Yellowlegs Tringa flavipes

Solitary Sandpiper Tringa solitaria

Spotted Sandpiper Actitis macularius

Whimbrel Numenius phaeopus

Long-billed Curlew Numenius americanus

Marbled Godwit Limosa fedoa
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix C. Wildlife and Plant List C-3 

Common Name Scientific Name Subspecies

Red Knot Calidris canutus

Sanderling Calidris alba

Semipalmated Sandpiper Calidris pusilla

Western Sandpiper Calidris mauri

Least Sandpiper Calidris minutilla

Baird’s Sandpiper Calidris bairdii

Pectoral Sandpiper Calidris melanotos

Sharp-tailed Sandpiper Calidris acuminata

Dunlin Calidris alpina

Stilt Sandpiper Micropalama himantopus

Buff-breasted Sandpiper Tryngites subruficollis

Ruff Philomachus pugnax

Short-billed Dowitcher Limnodromus griseus

Long-billed Dowitcher Limnodromus scolopaceus

Wilson’s Snipe Gallinago delicata

Wilson’s Phalarope Steganopus tricolor

Red-necked Phalarope Phalaropus lobatus

Red Phalarope Phalaropus fulicarius

Bonaparte's Gull Larus philadelphia

Mew Gull Larus canus

Ring-billed Gull Larus delawarensis

California Gull Larus californicus

Herring Gull Larus argentatus

Thayer’s Gull Larus thayeri

Western Gull Larus occidentalis

Glaucous-winged Gull Larus glaucescens

Glaucous Gull Larus hyperboreus

Caspian Tern Sterna caspia

Forster’s Tern Sterna forsteri

Black Tern Chlidonias niger

Rock Pigeon Columba livia

Band-tailed Pigeon Patagioenas fasciata monilis

Mourning Dove Zenaida macroura

Barn Owl Tyto alba

Western Screech-Owl Megascops kennicottii

Great Horned Owl Bubo virginianus

Northern Pygmy-Owl Glaucidium gnoma

Barred Owl Strix varia

Long-eared Owl Asio otus

Short-eared Owl Asio flammeus

Northern Saw-whet Owl Aegolius acadicus

Common Nighthawk Chordeiles minor hesperis

Black Swift Cypseloides niger

Vaux’s Swift Chaetura vauxi

Black-chinned Hummingbird Archilochus alexandri

Anna’s Hummingbird Calypte anna

Rufous Hummingbird Selasphorus rufus
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

C-4 Appendix C. Wildlife and Plant List

Common Name Scientific Name Subspecies

Belted Kingfisher Ceryle alcyon

Lewis’s Woodpecker Melanerpes lewis

Acorn Woodpecker Melanerpes formicivorus

Red-naped Sapsucker Sphyrapicus nuchalis

Red-breasted Sapsucker Sphyrapicus ruber ruber

Downy Woodpecker Picoides pubescens gairdnerii

Hairy Woodpecker Picoides villosus harrisi

Northern Flicker Colaptes auratus cafer, auratus, hybrid

Pileated Woodpecker Dryocopus pileatus picinus

Olive-sided Flycatcher Contopus cooperi

Western Wood-Pewee Contopus sordidulus

Willow Flycatcher Empidonax traillii brewsteri

Least Flycatcher Empidonax minimus

Hammond’s Flycatcher Empidonax hammondii

Dusky Flycatcher Empidonax oberholseri

Pacific-slope Flycatcher Empidonax difficilis difficilis

Black Phoebe Sayornis nigricans

Say’s Phoebe Sayornis saya

Vermilion Flycatcher Pyrocephalus rubinus

Western Kingbird Tyrannus verticalis

Loggerhead Shrike Lanius ludovicianus

Northern Shrike Lanius excubitor

Cassin’s Vireo Vireo cassinii

Hutton’s Vireo Vireo huttoni

Warbling Vireo Vireo gilvus

Red-eyed Vireo Vireo olivaceus

Steller’s Jay Cyanocitta stelleri stelleri

Western Scrub-Jay Aphelocoma californica immanis

Black-billed Magpie Pica hudsonia

American Crow Corvus brachyrhynchos

Common Raven Corvus corax

Horned Lark Eremophila alpestris

Purple Martin Progne subis arboricola

Tree Swallow Tachycineta bicolor

Violet-green Swallow Tachycineta thalassina

N. Rough-winged Swallow Stelgidopteryx serripennis

Bank Swallow Riparia riparia

Cliff Swallow Petrochelidon pyrrhonota

Barn Swallow Hirundo rustica

Black-capped Chickadee Poecile atricapilla

Chestnut-backed Chickadee Poecile rufescens

Bushtit Psaltriparus minimus

Red-breasted Nuthatch Sitta canadensis

White-breasted Nuthatch Sitta carolinensis aculeata

Brown Creeper Certhia americana

Bewick’s Wren Thryomanes bewickii

House Wren Troglodytes aedon
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix C. Wildlife and Plant List C-5 

Common Name Scientific Name Subspecies

Winter Wren Troglodytes troglodytes

Marsh Wren Cistothorus palustris

Golden-crowned Kinglet Regulus satrapa

Ruby-crowned Kinglet Regulus calendula

Blue-gray Gnatcatcher Polioptila caerulea

Western Bluebird Sialia mexicana

Mountain Bluebird Sialia currucoides

Swainson’s Thrush Catharus ustulatus ustulatus (breeding)

Hermit Thrush Catharus guttatus

American Robin Turdus migratorius

Varied Thrush Ixoreus naevius

European Starling Sturnus vulgaris

American Pipit Anthus rubescens

Cedar Waxwing Bombycilla cedrorum

Orange-crowned Warbler Vermivora celata

Nashville Warbler Vermivora ruficapilla

Yellow Warbler Dendroica petechia

Chestnut-sided Warbler Dendroica pensylvanica

Yellow-rumped Warbler Dendroica coronata

Black-throated Gray Warbler Dendroica nigrescens

Townsend’s Warbler Dendroica townsendi

Palm Warbler Dendroica palmarum

Blackpoll Warbler Dendroica striata

Black-and-white Warbler Mniotilta varia

American Redstart Setophaga ruticilla

Northern Waterthrush Seiurus noveboracensis

MacGillivray’s Warbler Oporornis tolmiei

Common Yellowthroat Geothlypis trichas

Wilson’s Warbler Wilsonia pusilla

Yellow-breasted Chat Icteria virens

Western Tanager Piranga ludoviciana

Spotted Towhee Pipilo maculatus

American Tree Sparrow Spizella arborea

Clay-colored Sparrow Spizella pallida

Chipping Sparrow Spizella passerina

Vesper Sparrow Pooecetes gramineus

Savannah Sparrow Passerculus sandwichensis brooksi (breeding); sandwichensis, 

anthinus

Fox Sparrow Passerella iliaca

Song Sparrow Melospiza melodia morphna (breeding)

Lincoln’s Sparrow Melospiza lincolnii

Swamp Sparrow Melospiza georgiana

White-throated Sparrow Zonotrichia albicollis

Harris’s Sparrow Zonotrichia querula

White-crowned Sparrow Zonotrichia leucophrys

Golden-crowned Sparrow Zonotrichia atricapilla

Dark-eyed Junco Junco hyemalis
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

C-6 Appendix C. Wildlife and Plant List

Common Name Scientific Name Subspecies

Lapland Longspur Calcarius lapponicus

Black-headed Grosbeak Pheucticus melanocephalus

Lazuli Bunting Passerina amoena

Red-winged Blackbird Agelaius phoeniceus

Western Meadowlark Sturnella neglecta

Yellow-headed Blackbird Xanthocephalus xanthocephalus

Rusty Blackbird Euphagus carolinus

Brewer's Blackbird Euphagus cyanocephalus

Brown-headed Cowbird Molothrus ater

Bullock's Oriole Icterus bullockii

Purple Finch Carpodacus purpureus

House Finch Carpodacus mexicanus

Red Crossbill Loxia curvirostra

Common Redpoll Carduelis flammea

Pine Siskin Carduelis pinus

Lesser Goldfinch Carduelis psaltria

American Goldfinch Carduelis tristis

Evening Grosbeak Coccothraustes vespertinus

House Sparrow Passer domesticus

Mammals

Common opossum* Didelphis virginiana

Vagrant shrew Sorex vagrans

Townsend’s mole Scapanus townsendii

Coyote Canis latrans

Red fox Vulpes vulpes

Mountain lion Puma concolor

Striped skunk Mephitis mephitis

River otter Lontra canadensis

Long-tailed weasel Mustela frenata

Mink Mustela vison

Raccoon Procyon lotor

Roosevelt elk Cervus elaphus

Black-tailed deer Odocoileus hemionus

Eastern gray squirrel* Sciurus carolinensis

Beechey ground squirrel Spermophilus beecheyi

Townsend’s chipmunk Tamias townsendii

Beaver Castor canadensis

Pacific jumping mouse Zapus trinotatus

Townsend’s vole Microtus townsendii

Muskrat Ondatra zibethicus

House mouse* Mus musculus

Deer mouse Peromyscus maniculatus

Nutria* Myocastor coypus

Eastern cottontail* Sylvilagus floridanus

*=Introduced species
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix C. Wildlife and Plant List C-7 

Reptiles and Amphibians

Long-toed salamander Ambystoma macrodactylum

Northwestern salamander Ambystoma gracile

Rough-skinned newt Taricha granulosa

Ensatina Ensatina eschscholtzii

Western red-backed salamander Plethodon vehiculum

Pacific treefrog Pseudacris regilla

Bullfrog* Rana catesbeiana (non-native)

Northern red-legged frog Rana aurora

Western painted turtle Chrysemys picta

Western pond turtle Actinemys marmorata

Western skink Eumeces skiltonianus

Northern alligator lizard Elgaria coerulea

Common (red-spotted) garter snake Thamnophis sirtalis concinnus

Northwestern garter snake Thamnophis ordinoides

Rubber boa Charina bottae

*=Introduced species

Fish

Common Name Scientific Name Verified Occurrence

Western brook lamprey Lampetra richardsoni G, C

Pacific lamprey Lampetra tridentata C, L

White sturgeon Acipenser transmontanus G, C

Green sturgeon Acipenser medirostris C

American shad* Alosa sapidissima C, R (CS)

Mountain whitefish Prosopium williamsoni C, L

Brown trout* Salmo trutta C, L

Coastal cutthroat trout Oncorhynchus clarkii clarkii G, C

Steelhead Oncorhynchus mykiss G, C

Coho salmon Oncorhynchus kisutsch G, C

Chinook salmon Oncorhynchus tshawytscha G, C, R (CS)

Sockeye salmon Oncorhynchus nerka C

Chum salmon Oncorhynchus keta C

Pacific smelt (Eulachon) Thaleichthys pacificus G, C

Common carp* Cyprinus carpio G,C, R

Goldfish* Carassius auratus G, R

Chiselmouth Acrocheilus alutaceus C, L

Redside shiner Richardsonius balteatus G

Northern pikeminnow Ptychocheilus oregonensis G, C

Peamouth Mylocheilus caurinus G

Speckled dace Rhinichthys osculus G

Longnose dace Rhinichthys cataractae G, R

Longnose sucker Catostomus catostomus C, L

Bridgelip sucker Catostomus columbianus C

Largescale sucker Catostomus macrocheilus G,C, R

Channel catfish* Ictalurus punctatus C, L

Brown bullhead* Ameiurus nebulosus G,C, R
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

C-8 Appendix C. Wildlife and Plant List

Common Name Scientific Name Verified Occurrence

Black bullhead* Ameiurus melas G

Western Mosquitofish* Gambusia affinis G, R

Banded killifish* Fundulus diaphanus R (CS)

Threespine stickleback Gasterosteus aculeatus G, R

Sand Roller Percopsis transmontana C, L

Largemouth bass* Micropterus salmoides G, R (CS)

Smallmouth bass* Micropterus dolomieu G, C

Black crappie* Pomoxis nigromaculatus G,C, R (CS)

White crappie* Pomoxis annularis G, R

Bluegill* Lepomis macrochirus G, R (CS)

Pumpkinseed* Lepomis gibbosus G, C

Warmouth* Lepomis gulosus G

Walleye* Sander vitreus G, C

Yellow perch* Perca flavescens G,C, R (CS)

Prickly sculpin Cottus asper G

Riffle sculpin Cottus gulosus G

Reticulate sculpin Cottus perplexus G

Starry flounder Platichthys stellatus C

*=Introduced species

G= Gee Creek (Refuge waters) L= Lake River (outside Refuge)

R= Other Refuge waters CS=Campbell Slough

C= Columbia River (outside 

Refuge)

Odonata (Damselflies and Dragonflies)

Common Name Scientific Name Notes

Spotted Spreadwing Lestes congener X

Lyre-tipped Spreadwing Lestes unguiculatus X

Common Spreadwing Lestes disjunctus X

Western Forktail Ischnura perparva X

Pacific Forktail Ischnura cervula X

Tule Bluet Enallagma carunculatum X

Olive Clubtail Stylurus olivaceus X

Common Green Darner Anax junius X

Blue-eyed Darner Rhionaeschna multicolor V

Paddle-tailed Darner Aeshna palmata X

Shadow Darner Aeshna umbrosa X

California Darner Rhionaeschna californica X

Common Whitetail Libellula lydia X

Twelve-spotted Skimmer Libellula pulchella X

Widow Skimmer Libellula luctuosa X

Eight-spotted Skimmmer Libellula forensis X

Western Pondhawk Erythemis collocata X

Red-veined Meadowhawk Sympetrum madidum X

Striped Meadowhawk Sympetrum pallipes X

Variegated Meadowhawk Sympetrum corruptum V
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix C. Wildlife and Plant List C-9 

Common Name Scientific Name Notes

Yellow-legged 

Meadowhawk Sympetrum vicinum X

Cardinal Meadowhawk Sympetrum illotum X

Blue Dasher Pachydiplax longipennis X

X = specimen collected

V= sight record

Plants

Vascular Plants

Aquatic Plants

Common Name Scientific Name

American waterplantain Alisma plantago-aquatica

Mexican mosquitofern Azolla mexicana

Nodding beggartick Bidens cernua

Devil’s (leafy) beggartick Bidens frondosa

Big devils beggartick (tall bur marigold) Bidens vulgata

Twoheaded water-starwort Callitriche heterophylla

Columbia sedge Carex aperta

Greensheath sedge Carex feta

Greenfruit sedge Carex interrrupta

Slough sedge Carex obnupta

Blister sedge Carex vesicaria

Coon’s tail Ceratophyllum demersum

Needle spikerush Eleocharis acicularis

Ovate spikerush Eleocharis ovata

Common spikerush Eleocharis palustris

Canadian waterweed Elodea canadensis

Common mare’s-tail Hippuris vulgaris

Howellia Howellia aquatilis

Toad rush Juncus bufonius (N/weedy)

Common (soft) rush Juncus effusus

Jointleaf rush Juncus articulatus

Poverty (slender) rush Juncus tenuis

Common duckweed Lemna minor

Eurasian watermilfoil Myriophyllum spicatum* NOX

Knotgrass Paspalum distichum

water smartweed Polygonum amphibium (Syn: P. coccineum)

Japanese knotweed Polygonum cuspidatum* NOX

Marshpepper knotweed Polygonum hydropiper

Swamp smartweed Polygonum hydropiperoides

Spotted ladysthumb Polygonum persicaria*

Dotted smartweed Polygonum punctatum

Curly pondweed Potamogeton crispus* NOX

Wapato, arrowhead Sagittaria latifolia

Woolgrass Scirpus cyperinus

Cosmopolitan (seacoast) bulrush Schoenoplectus (Scirpus) maritimus

Common threesquare (American bulrush) Schoenoplectus pungens (Syn:Scirpus americanus)
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

C-10 Appendix C. Wildlife and Plant List

Common Name Scientific Name

Panicled bulrush Scirpus microcarpus

Ricefield bulrush, bog bulrush, pointed 

bulrush Schoenoplectus mucronatus*

Softstem bulrush Scirpus tabernaemontani (Syn: S.validus)

Bur-reed Sparganium spp.

Common duckmeat Spirodela polyrrhiza

Sago pondweed Stuckenia (Potamogeton) pectinatus

Broadleaf cattail Typha latifolia (N/weedy)

Columbian watermeal Wolffia columbiana

Grasses

Spike bentgrass Agrostis exarata*

Colonial bentgrass Agrostis capillaris (Syn: A. tenuis)*

Seashore (thin) bentgrass Agrostis pallens (Syn: A.diegoensis)

Rough (winter) bentgrass Agrostis scabra

Shortawn foxtail Alopecurus aequalis

Sweet vernalgrass Anthoxanthum odoratum*

Wild oat Avena fatua**

Common oat Avena sativa*

Soft brome Bromus hordeaceus (Syn: B.mollis)**

Poverty brome Bromus sterilis*

Orchardgrass Dactylis glomerata*

Barnyardgrass Echinochloa crus-galli**

Elymus spp.

Bearded wheatgrass Elymus caninus* (Syn: Agropyron caninum)

Teal lovegrass Eragrostis hypnoides

Red fescue Festuca rubra

Small floating mannagrass Glyceria borealis

Common velvetgrass Holcus lanatus**

Meadow barley Hordeum brachyantherum

Rice cutgrass Leersia oryzoides

Italian ryegrass Lolium perenne ssp. multiflorum**

Perennial ryegrass Lolium perenne ssp. perenne*

Witchgrass Panicum capillare**

Reed canarygrass Phalaris arundinacea** NOX

Timothy Phleum pratense

Canada bluegrass Poa compressa

Fowl bluegrass Poa palustris

Kentucky bluegrass Poa pratensis

Tall fescue Schedonorus phoenix** (Syn: Festuca arundinacea)

Brome fescue Vulpia (Festuca) bromoides*

Trees and Shrubs

Vine maple Acer circinatum

Bigleaf maple Acer macrophyllum

Red alder Alnus rubra

Saskatoon serviceberry Amelanchier alnifolia

False indigo (indigobush) Amorpha fruticosa** NOX

Tall Oregongrape Berberis aquifolium

Cascade Oregongrape Berberis nervosa

Pacific dogwood Cornus nuttallii
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix C. Wildlife and Plant List C-11

Common Name Scientific Name

Red-osier dogwood Cornus stolonifera

California hazelnut Corylus cornuta var. californica

Black hawthorn Crataegus douglasii

English hawthorn Crataegus monogyna*

Scotch broom Cytisus scoparius**

Oregon ash Fraxinus latifolia

Salal Gaultheria shallon

Oceanspray Holodiscus discolor

American holly Ilex opaca

Indian plum Oemleria cerasiformus

Lewis’s mock-orange Philadelphus lewisii

Pacific ninebark Physocarpus capitatus

Black cottonwood Populus trichocarpa

Bitter cherry Prunus emarginata

Douglas-fir Pseudotsuga menziesii

Crabapple Pyrus fusca

Apple Pyrus malus*

Oregon white oak Quercus garryana

Cascara Rhamnus purshiana

Poison oak Rhus diversiloba

Prickly currant, Swamp gooseberry Ribes lacustre

Redflower currant Ribes sanguineum

Sweetbrier Rosa eglanteria*

Nootka rose Rosa nutkana

Cluster rose Rosa pisocarpa

Himalayan blackberry Rubus armeniacus* (Syn: R.discolor)

Cutleaf (Evergreen) blackberry Rubus laciniatus*

Whitebark raspberry Rubus leucodermis

Largeleaf blackberry Rubus macrophyllus*

Thimbleberry Rubus parviflorus

Salmonberry Rubus spectabilis

California (trailing) blackberry Rubus ursinus

Pacific willow Salix lasiandra ssp. lucida

Northwest sandbar willow Salix sessilifolia

Blue elderberry Sambucus nigra ssp. cerulea

Red elderberry Sambucus racemosa

Rose spiraea (Douglas’ spiraea) Spiraea douglasii

Common snowberry Symphoricarpos albus

Western redcedar Thuja plicata

Western hemlock Tsuga heterophylla

Red huckleberry Vaccinium parvifolium

Common (oval leaf) viburnum Viburnum ellipticum

Herbaceous Plants, Wildflowers

Common yarrow Achillea millefolium (N/weedy)

Vanilla leaf Achlys triphylla

Nodding onion Allium cernuum

Pearly everlasting Anaphalis margaritacea

Stinking chamomile (mayweed) Anthemis cotula**

Western columbine Aquilegia formosa
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

C-12 Appendix C. Wildlife and Plant List

Common Name Scientific Name

Lesser (common) burdock Arctium minus**

Silverweed cinquefoil Argentina (Potentilla) anserina

Pacific silverweed Argentina edegii (Syn: Potentilla pacifica)

Clasping arnica Arnica amplexicaulis

Bride’s feathers (goatsbeard) Aruncus dioicus (Syn: A. sylvester)

British Columbia wildginger Asarum caudatum

American yellowrocket (wintercress) Barbarea orthoceras

Lawndaisy (English daisy) Bellis perennis**

Crown brodiaea Brodiaea coronaria

Small (common) camas Camassia quamash

Pale (Scouler's) bellflower Campanula scouleri

Giant mountain aster Canadanthus (Aster) modestus

Shepherd’s purse Capsella bursa-pastoris**

Palmate toothwort Cardamine nuttallii var. nuttallii

Slenderflower thistle Carduus tenuiflorus* NOX

Doubtful chickweed Cerastium dubium**

Sticky chickweed Cerastium glomeratum

Fireweed Chamerion angustifolium

Pigweed Chenopodium album**

Western water hemlock Cicuta douglasii

Chicory Cichorium intybus**

Canada thistle Cirsium arvense** NOX

Bull thistle Cirsium vulgare** NOX

Farewell-to-spring Clarkia amoena

Miner's lettuce Claytonia (Montia) perfoliata

Siberian springbeauty (candyflower) Claytonia (Montia) sibirica

Giant blue eyed Mary Collinsia grandiflora

Maiden (small-flowered) blue eyed Mary Collinsia parviflora

Spinster’s (few-flowered) blue eyed Mary Collinsia sparsiflora

Poison hemlock Conium maculatum** NOX

Field bindweed (morning-glory) Convolvulus arvensis** NOX

False bindweed (lady’s nightcap) Convolvulus sepium**

Atkinson’s tickseed (Columbia coreopsis) Coreopsis tinctoria var. atkinsoniana

bunchberry dogwood Cornus canadensis

Water pygmyweed Crassula (Tillaea) aquatica

Bristly hawksbeard Crepis setosa**

Common spring-gold (goldstar) Crocidium multicaule

Pacific hound’s tongue Cynoglossum grande

Queen Anne's lace Daucus carota** NOX

Upland (Nuttall's) larkspur Delphinium nuttallii

Pacific bleeding heart Dicentra formosa

Forktooth ookow Dichelostemma (Brodiaea) congesta

Purple foxglove Digitalis purpurea**

Fuller’s teasel Dipsacus fullonum** (Syn: D. sylvestris)

Cascade calicoflower Downingia yina

Spring draba (whitlow-grass) Draba verna

Fringed (common) willowherb Epilobium ciliatum ssp. glandulosum

Small-flowered willowherb Epilobium minutum

Watson's willowherb Epilobium ciliatum ssp. watsonii
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix C. Wildlife and Plant List C-13

Common Name Scientific Name

Philadelphia fleabane Erigeron philadelphicus

Common wooly sunflower (Oregon 

sunshine) Eriophyllum lanatum

Redstem stork’s-bill (filaree) Erodium cicutarium**

Giant white fawnlily Erythronium oregonum

California poppy Eschscholzia californica

Woodland strawberry Fragaria vesca

Virginia strawberry Fragaria virginiana

Checker lily Fritillaria affinis (Syn: F.lanceolata)

Cleavers Galium aparine**

Northern bedstraw Galium boreale

Oregon bedstraw Galium oreganum

Threepetal (small) bedstraw Galium trifidum

Fragrant bedstraw Galium triflorum

Rainier pleated gentian (explorer’s 

gentian) Gentiana calycosa

Longstalk cranesbill Geranium columbinum*

Cutleaf geranium Geranium dissectum*

Dovefoot geranium Geranium molle*

Small geranium Geranium pusillum*

Largeleaf avens Geum macrophyllum

Bluehead (globe) gilia Gilia capitata

Ground ivy (creeping Charlie) Glechoma hederacea*

Western marsh cudweed Gnaphalium palustre (N/weedy)

Marsh cudweed Gnaphalium uliginosum*

Western rattlesnake plantain Goodyera oblongifolia

Clammy hedgehyssop Gratiola neglecta

English ivy Hedera helix* NOX

Common sneezeweed Helenium autumnale

Common cowparsnip Heracleum lanatum

Pacific waterleaf Hydrophyllum tenuipes

Common St. Johnswort Hypericum perforatum** NOX

Hairy cat’s ear Hypochaeris radicata** NOX

Jewelweed Impatiens capensis

Paleyellow iris (yellow flag) Iris pseudacorus* NOX

Purple deadnettle Lamium purpureum**

Common nipplewort Lapsana communis**

Perennial pea Lathyrus latifolius**

Leafy pea Lathyrus polyphyllus

Oxeye daisy

Leucanthemum vulgare** NOX (Syn:

Chrysanthemum leucanthemum)*

Columbia lily (tiger lily) Lilium columbianum

Water mudwort Limosella aquatica

Dalmatian toadflax Linaria dalmatica** NOX

Butter and eggs, yellow toadflax Linaria vulgaris** NOX

Yellowseed false pimpernel Lindernia dubia

Twinflower Linnaea borealis

Smallflower woodland-star Lithophragma parviflorum

Orange honeysuckle Lonicera ciliosa
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

C-14 Appendix C. Wildlife and Plant List

Common Name Scientific Name

Bird’s-foot trefoil Lotus corniculatus*

Desert deervetch (miniature lotus) Lotus micranthus

American bird’s-foot trefoil Lotus unifoliolatus (Syn: L.purshianus)

Marsh seedbox (false loosestrife) Ludwigia palustris

Broadleaf lupine Lupinus latifolius

American skunkcabbage Lysichiton americanus

Creeping jenny (moneywort) Lysimachia nummularia*

Spatulaleaf loosestrife (water purslane) Lythrum portula*

Feathery false lily of the valley 

(Solomon's seal) Maianthemum racemosum

Disc mayweed (pineapple weed) Matricaria discoidea** (Syn: M.matricarioides)

Black medick Medicago lupulina**

Alfalfa Medicago sativa*

Wild mint Mentha arvensis

Pennyroyal Mentha pulegium*

Peppermint Mentha x piperita

Coastal (tooth-leaved) monkey-flower Mimulus dentatus

Seep (common) monkey-flower Mimulus guttatus

Largeleaf sandwort Moehringia (Arenaria) macrophylla

Narrowleaf minerslettuce Montia linearis

Changing forget-me-not Myosotis discolor*

Bay forget-me-not Myosotis laxa

Skunkbush Navarretia squarrosa

Smallflower nemophila Nemophila parviflora

Catnip Nepeta cataria*

Rocky Mountain (yellow) pond-lily Nuphar lutea ssp. polysepala

Fragrant water lily Nymphaea odorata ssp. tuberosa*NOX

Water parsley Oenanthe sarmentosa

Hooker’s evening-primrose Oenothera elata (Syn: O.hookeri)

Oneflowered broomrape Orobanche uniflora

Dwarf owl’s-clover Orthocarpus pusillus

Sweetcicely Osmorhiza berteroi (Syn: O.chilensis)

Redwood-sorrel Oxalis oregana

Oriental poppy Papaver orientale*

Yellow glandweed Parentucellia viscosa*

Common (Gairdner’s) yampah Perideridia gairdneri

Shade phacelia Phacelia nemoralis

Western false dragonhead Physostegia parviflora

Narrowleaf plantain Plantago lanceolata**

Common plantain Plantago major**

Shortspur seablush Plectritis congesta

Sticky cinquefoil Potentilla glandulosa

Hooker’s drops of gold (fairy-bell) Prosartes (Disporum) hookeri

Common selfheal Prunella vulgaris

Crowfoot Ranunculus aquatilis

Greater creeping spearwort Ranunculus flammula

Western buttercup Ranunculus occidentalis

Straightbeak buttercup Ranunculus orthorhynchus

Creeping buttercup Ranunculus repens**
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix C. Wildlife and Plant List C-15

Common Name Scientific Name

Hairy buttercup Ranunculus sardous

Woodland buttercup Ranunculus uncinatus

Curvepod yellowcress Rorippa curvilisqua

Northern marsh yellowcress Rorippa islandica

Clustered dock Rumex conglomeratus*

Curly dock Rumex crispus**

Bitter dock Rumex obtusifolius*

Western dock

Rumex aquaticus var. fenestratus (Syn:

R.occidentalis)

Bouncingbet Saponaria officinalis**

Wholeleaf saxifrage Saxifraga integrifolia

Alberta (redwood) saxifrage Saxifraga occidentalis

Leiberg stonecrop Sedum leibergii

Stinking willie (tansy ragwort) Senecio jacobaea** NOX

Woodland ragwort Senecio sylvaticus

Blue fieldmadder Sherardia arvensis*

Bladder (white) campion Silene latifolia** NOX (Syn: Lychnis alba)

Blessed milkthistle Silybum marianum** NOX

Hedgemustard Sisymbrium officinale*

Starry false lily of the valley Smilacina stellatum

Climbing nightshade Solanum dulcamara**

American black nightshade Solanum americanum (Syn: S.nigrum) (N/weedy)

Canada goldenrod Solidago canadensis (N/weedy)

Western goldentop Solidago occidentalis

Common sowthistle Sonchus oleraceus**

Red sandspurry Spergularia rubra*

Cooley's hedgenettle Stachys chamissonis var. cooleyae

Common chickweed Stellaria media**

Hall's aster Symphiotrichum (Aster) hallii

Douglas’ aster

Symphiotrichum (Aster) subspicatum var. 

subspicatum

Common tansy Tanacetum vulgare** NOX

Common dandelion Taraxacum officinale**

Bigflower tellima (fringecup) Tellima grandiflora

Western meadow-rue Thalictrum occidentale

Youth on age Tolmiea menziesii

Lesser baby innocence Tonella tenella

Broadleaf starflower Trientalis borealis ssp. latifolia

Rabbitfoot clover Trifolium arvense*

Golden clover Trifolium aureum* (Syn: T. agrarium)

Alsike clover Trifolium hybridum*

Field clover Trifolium campstre*(Syn: T. procumbens)

White clover Trifolium repens*

Subterranean clover Trifolium subterraneum*

Pacific trillium Trillium ovatum

Smallflower wakerobin Trillium parviflorum

White brodiaea Tritelia (Brodiaea) hyacinthina

Stinging nettle Urtica dioica (N/weedy)

Lewiston cornsalad Valerianella locusta*
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

C-16 Appendix C. Wildlife and Plant List

Common Name Scientific Name

White insideout flower Vancouveria hexandra

Moth mullein Verbascum blattaria**

Common mullien Verbascum thapsus**

American speedwell Veronica americana

Threadstalk speedwell Veronica filiformis*

Skullcap (Marsh) speedwell Veronica scutellata

American vetch Vicia americana

Tiny vetch Vicia hirsuta*

Garden vetch Vicia sativa*

Pioneer (stream) violet Viola glabella

Aleutian violet Viola langsdorffii

Northern woodland violet Viola septentrionalis

Rough cocklebur Xanthium strumarium**

Ferns

Northern maidenhair fern Adiantum pedatum

Ladyfern Athyrium filix-femina

Coastal woodfern Dryopteris arguta

Licorice fern Polypodium glycyrrhiza

Western swordfern Polystichum munitum

Western brackenfern Pteridium aquilinum (N/weedy)

Cryptograms

California antitrichia moss Antitrichia californica

Dendroalsia moss Dendroalsia abientina

Rough goose neck moss Rhytidiadelphus triquetris

Beard lichen Usnea barbata

Bryophytes

Tree climacium moss Climacium dendroides

Dichelyma moss Dichelyma sp.

Drepanocladus moss Drepanocladus

Antifever fontinalis moss Fontinalis antipyretica

Leucolepis umbrella moss Leucolepis acanthoneuron

Rough goose neck moss Rhytidiadelphus triquetrus

A liverwort Ricciocarpos natans

Wallace's spikemoss Selaginella wallacei

Notes:

*Introduced species 

**Introduced and listed in Whitson T.D. (ed) et al. 2000 

NOX=Listed as noxious weed in state of Washington 

N/weedy=Native but listed in Whitson T.D. (ed) et al. 2000 

References

Christy, John and J. Putera. 1993. Lower Columbia River Natural Area Inventory 1992. Oregon 

Natural Heritage Program. Report to the Nature Conservancy, Washington Field Office, Seattle. 89 

pp. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix C. Wildlife and Plant List C-17

Morrison, Elizabeth. 1973. The Blackwater Island Research Natural Area. A description of the 

vegetation and environment. 45 pp., illus, plus maps. On file at Ridgefield NWR Office, Ridgefield, 

WA.

Sondegaard, Craig A. Species List for the Ridgefield National Wildlife Refuge (exclusive of birds), 

14th revision, January 1994 

. 

USDA Plants Database. URL: plants.usda.gov 

Washington Administrative Code. 2005. Noxious weed control, Chapter 16-752 (24 May 2006). 

State of Washington. 

Washington Administrative Code. 2005. State noxious weed list and schedule of monetary penalties, 

Chapter 16-750 (24 May 2006). State of Washington. 

Washington Native Plant Society. 2004. Vascular plant list, Clark County, Washington. List prepared 

by Don Knoke, 2004. 

Whitson, T.D. (ed.) et al. 2000. Weeds of the West (9th edition). Western Society of Weed Science 

in cooperation with Cooperative Extension Services, University of Wyoming, Laramie, Wyoming. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

C-18 Appendix C. Wildlife and Plant List
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix D. Implementation D-1 

Appendix D. Implementation 

D.1 Overview

Implementation of the CCP will require increased funding, which will be sought from a variety of 

sources. This plan will depend on additional Congressional allocations, partnerships and grants. 

There are no guarantees that additional federal funds will be made available to implement any of 

these projects. Other sources of funds will need to be obtained (both public and private). Activities 

and projects identified will be implemented as funds become available. 

Many of the infrastructure and facility projects will be eligible for funding through construction or 

Federal Lands Highway Program funds (i.e. Refuge Roads). 

The Comprehensive Conservation Plan proposes several projects to be implemented over the next 15 

years. All of these projects are included in the Refuge Management Information System (RONSRefuge Operational Needs System or MMS- Maintenance Management System) which are used to 

request funding from Congress. Currently, a large backlog of maintenance needs exists on the 

Refuge. An attempt at reducing this backlog needs to be addressed and is included here in the 

analysis of funding needs. The Refuge Operational Needs System (RONS) documents proposed new 

projects to implement the CCP to meet Refuge goals and objectives and legal mandates. 

Annual revenue sharing payments to Clark County will continue. If the Refuge expands through the 

purchase of inholdings (privately owned lands within the current approved boundary) or through an 

expanded refuge boundary, additional in lieu of tax payments will be made to the county.

Monitoring activities will be conducted on a percentage of all new and existing projects and activities 

to document wildlife populations and changes across time, habitat conditions and responses to 

management practices. Actual monitoring and evaluation procedures will be detailed in step-down 

management plans.

D.2 Step-Down Plans

The Comprehensive Conservation Plan is one of several plans necessary for Refuge management. 

The CCP provides guidance in the form of goals, objectives, and strategies for several Refuge 

program areas but may lack some of the specifics needed for implementation. Step-down 

management plans will be developed for individual program areas within approximately 5 years after 

CCP completion. All step-down plans require appropriate NEPA compliance; implementation may 

require additional permits. Step-down plans for the Refuge follow. Project-specific plans, with 

appropriate NEPA compliance, may be prepared outside of these step-down plans. 

Step Down Management Plan Status (Date Completed and/or Date to be 

Prepared/Updated)

Habitat Management Plan 2010 (CCP meets requirements for HMP) 

Fish and Wildlife Monitoring Plan 2015 

Waterfowl Hunt Plan 

Fishing Plan

Visitor Services Plan
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

D-2 Appendix D. Implementation.

Environmental Education Plan?

IPM Plan 2010 (prepared concurrently with CCP, Appendix K) 

Occupational Safety and Health Plan

Fire Management Plan 2011 (in progress) 

Cultural Resources Management Plan

Step Down Plans Identified in CCP Strategies:

Contingency plan for dike breach 

Tidal wetlands restoration plan (includes feasibility study, wetland basin assessment and topographic 

survey of aquatic habitats) 2016 (dependent on ACOE feasibility study to be completed in 2011) 

Land Protection Plan to analyze alternatives for expansion of refuge boundary to the south Initiate 

by 2012 

Feasibility study for reintroduction of Columbian white-tailed deer Initiate by 2015 

Feasibility study for reintroduction of western pond turtle 2013 

Feasibility study for native wet meadow restoration Within 15 years 

Interior interpretive plan for Cathlapotle Plankhouse 

D.3 Costs to Implement CCP

The following sections detail both one time and recurring costs for various projects. One time costs 

reflect the initial costs associated with a project, such as the purchase of equipment, contracting 

services, construction, purchase of land, etc. Recurring costs reflect the future operational and 

maintenance costs associated with the project.

D.3.1 One-Time Costs

One time costs are project costs that have a start up cost associated with them, such as purchasing a 

new vehicle for wildlife and habitat monitoring or designing and installing an interpretive sign. 

Some are full project costs for those projects that can be completed in 3 years or less. One time costs 

can include the cost of temporary or term salary associated with a short term project. Salary for new 

positions and operational costs are reflected in operational or recurring costs. 

Funds for one time costs will be sought through increases in Refuge base funding, special project 

funds, grants, etc. Some projects also might require land acquisition funds, or other special 

appropriations or grants. 

Projects listed below in Table D-1 show one time costs, such as those associated with building and 

facility needs such as offices, public use facilities, road improvements, and new signs. One time 

costs are also associated with habitat restoration and protection projects such as specific forestry and 

wetland projects, research and land acquisition. New research projects, because of their short term 

nature, are considered one time projects, and include costs of contracting services or hiring a 

temporary for the short term project. Some project costs are displayed as ranges since there are many 

factors that will influence the number of acres managed per year. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix D. Implementation D-3 

Table D-1. Estimates of one time costs under current management, and under the CCP (future 

management). This data is separated into two tables, Wildlife and Habitat and Public Use, and each 

is organized by goals and objectives.

Goal 1. Grasslands Provide and manage a mixture of secure, diverse, productive grassland 

habitats for foraging migratory waterfowl and grassland-dependent wildlife

Current 

Management

Future 

Management

Priority Funding

1.1 & 1.2 Enhance/Maintain Improved Pasture for Waterfowl

Total Number of Acres 1426 1450

Number of Acres 

Treated

1426 1450

3yr Upland Restoration 

Project

$0 $208,000 H 1260 RONS

Total One-time Cost $0 $208,000

1.3 Rehabilitate Old Fields and Wetland Borders

Number of Acres 400 140

Number of Acres 

Rehabilitated

0 260 H 1260

Total One-time Cost $0 $12,550

1.4 Enhance Native Grassland Habitat

Number of Acres 15 15

Number of Acres 

Enhanced

0 15 M 1260

Total One-time Cost $0 $21,500 
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

D-4 Appendix D. Implementation.

Goal 2. Crops Provide agricultural crops as forage for migratory waterfowl and 

sandhill cranes

Current 

Management

Future 

Management

Priority Funding

2.1 Provide Crops for Waterfowl and Sandhill Cranes

Number of Acres 185 330

Number of Corn Acres 85 145

Number of new 

Pasture to Corn Acres

0 60 M 1260

Total One-Time Cost $100,000 $204,600 

Goal 3. Wetlands Provide and manage a mixture of secure, diverse, productive grassland 

habitats for foraging migratory waterfowl and grassland-dependent 

wildlife. 

Current 

Management

Future 

Management

Priority Funding

3.1 - 3.3 Enhance and Maintain Managed Seasonal and Semipermanent Wetlands, and Seasonal 

Wetlands

Number of Acres 790 800

Monitor/Treat Plant 

and Animal Invasives

$125,000 $185,000 H 1260

Reconfigure Water 

Delivery

$200,000 M 1260

Disk 5 Wetlands 

Annually for 3 years

$198,373 H RONS

Total One-time Cost $125,000 $583,373

3.4 Howellia Wetlands

Number of Ponds 4 4

Maintain high water $8,000 $8,000 M 1260

Total One-time Cost $0 $8,000

3.5 Permanent, non-tidal wetlands

Number of Acres 150 70

Monitor for Carp $0 $50,000 M 1260

Total One-time Cost $0 $50,000

3.6 Maintain Wet Meadow Habitat

Number of Acres 300 400

Number of new acres 

restored

0 100

Graze $3,000 $3,000 M 6860

Restore Wet Meadow $0 $75,000 H 1261

Increase Native Wet 

Meadow Vegetation

$0 $3,000 H 1261

Total One-time Cost $3,000 $81,000

Goal 4. Floodplain 

Forests

Protect, manage, and restore a natural diversity of native floodplain 

forests representative of the historic lower Columbia River ecosystem. 

Current 

Management

Future 

Management

Priority Funding

4.1 Protect/Maintain Early Successional Floodplain Forest

Number of Acres 0 165

Restore Gee Creek 

Watershed 

$0 $123,477 H RONS

Plant Trees/

Understory, Protect 

from Beaver, etc

$0 $1,740,750 H RONS
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix D. Implementation D-5 

Total One-time Cost $0 $1,864,227

Goal 5. Upland Forest Protect, manage, and restore a natural diversity of native upland 

forests representative of the historic Lower Columbia River ecosystem. 

Current 

Management

Future 

Management

Priority Funding

5.1 & 5.1a Protect/Maintain/Restore Oak Woodland

Number of Acres 0 10-20

Remove Encroaching 

Trees

$0 $20,000 M 1261

Plant Trees/Understory $0 $156,000 H 1261

Total One-time Cost $0 $176,000

Goal 6. Riverine 

Habitat/Tidal Wetlands

Protect, enhance and, where feasible, restore riverine habitat and tidal 

wetlands representative of the historic lower Columbia River 

ecosystem to benefit salmonids and other native aquatic species. 

Current 

Management

Future 

Management

Priority Funding

6.1 Enhance/Improve Instream/Riverine Habitat

Number of Stream 

Miles

0.8 0.8

Implement Restoration 

for fish passage

0 $200,000 M 1261

Gee Creek 

Assessment (1.5 yr 

Project)

0 $73,000 M RONS

Improve Rearing 

Habitat

0 $20,000 M 1261

Total One-time Cost $0 $293,000

6.2 Enhance/Maintain Tidal Wetlands

Number of Acres 490 497

Acquisition $0 $50,000 H MBTA

Reduce carp w/o neg. 

effect on salmonids

$100,000 $100,000 M 1261

Total One-time Cost $100,000 $150,000

Goal 7. Research Collect Scientific Information for Adaptive Management

Current 

Management

Future 

Management

Priority Funding

7.1 Inventory and Monitoring Activities

Monitor water quality 

and temp of Gee Creek 

and Campbell Slough

$0 $5,000 M 1261

Conduct banding $0 $2,000 M 1261

Total One-Time Cost $0 $7,000

7.2 Conduct Surveys 

Participate in regional 

waterfowl surveys and 

banding studies (midwinter, dusky, others)

$1,500 $1,500 M 1261

Total One-time Cost $1,500 $1,500

Total One-Time Cost $329,500 $3,660,750
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

D-6 Appendix D. Implementation.

Table D-1. Public Use Alternatives - One-Time Costs

Goal 1. Waterfowl 

Hunting

Waterfowl hunters of all abilities will enjoy a quality, safe hunting program 

that provides a variety of waterfowl hunting experiences, promotes youth 

hunting, balances hunt program needs with other public use program 

needs, and reduces impacts to non-target species. As a result of 

participating in the waterfowl hunting program, hunters will gain a better 

appreciation of the refuge’s mission and its resource management.

1.1a. Provide a quality, safe waterfowl hunt program on the Refuge, capable of supporting 

approximately 2000 hunter visits per season, including master, youth, and disabled hunters, and 

reduces conflicts between hunters, adjacent landowners, and other user groups.

1.1b. Increase opportunities for duck hunters to hunt desirable waterfowl species, for example, 

mallard, wigeon, and pintail.

1.1c. Provide goose hunting opportunities on 790 acres of the Refuge while reducing the 

disturbance to, and rate of take of, dusky Canada geese. 

Current 

Management 

Future 

Management 

Priority Funding

1.1a. Number of 

Acres—duck 

hunting

790 790

1.1c. Number of 

Acres—goose 

hunting

790 790

Open Waterfowl 

Hunt on Bachelor 

Island.

1261, 1263, 8081

Co-Locate Check 

Station and VCS

$329,000 M 1261, 1263, 8081

Move Blind 15 

North

1261, 1263, 8081

Add 2nd Blinds 

for Gradual Floodup

$35,000 M 1261, 1263, 8081

Evaluate/upgrade 

ADA Blinds Biannually

$95,450 M 1261, 1263, 8081

Total Cost $0 $459,450

Goal 2. Wildlife 

Dependent 

Recreation

Visitors of all abilities will have the opportunity to participate in safe, quality 

wildlife-dependent recreation programs, including wildlife observation, 

photography, interpretation, and fishing, consistent with the needs of other 

public use programs and which limit wildlife disturbance in the face of 

increasing Refuge visitation. These programs will focus on enhancing 

public understanding and appreciation of wildlife, and building support for 

the Ridgefield National Wildlife Refuge. 

2.2 Maintain a 4.0-mile year-round auto tour route that provides visitors opportunities to view and 

photograph wildlife, and supports a maximum of 200 vehicles on peak use days. 

Current 

Management

Future 

Management

Priority Funding

Year-round Miles 4.3 4

Reroute .3 Miles $310,000 M Refuge Roads

Reroute South 

End Oct 1-March 

15

Refuge Roads
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix D. Implementation D-7 

2.2 Auto Tour 

Route (cont.)

Current 

Management

Future 

Management

Priority Funding

Pullouts every 

.5mi

$16,000 H Refuge Roads

Pave ATR $1,280,000 M Refuge Roads

Roth Maintenance 

Lane

$450,000 M Refuge Roads

Total Cost $0 $2,056,000

2.3 Provide 6.9 miles of seasonal pedestrian access on Refuge trails and roads and 2 miles of 

year-round pedestrian access on Refuge trails. 

1.5 Mile Dike-top 

Trail, River ‘S’ 

Unit

$275,880 M Refuge Roads, 

Special Project 

Funding

Construct 

Elevated 

Observation 

Deck, River ‘S’

$55,000 M Refuge Roads, 

Special Project 

Funding

Trail Through 

Time on Carty

$200,000 H Refuge Roads

Maintain/Improve 

Carty Road

$10,450,000 M Refuge Roads

Total Cost $10,980,880

2.5 Improve visitor contact and orientation facilities, signage, and interpretation 

Construct Visitor 

Center (pending 

separate 

EA/funding)

$8,623,833 $8,623,833 H 1261, MMS

Update Kiosk $15,000 M 1261, 1263, 8081

Interpretive 

Exhibits at 

Visitor Contact 

Station/Kiosks

$20,000 M 1261, 1263, 8081

Total Cost $8,623,833 $8,658,833

2.6 Improve public facilities: Improve visitor infrastructure so as to enhance safety, sanitation, 

comfort, and access for the visiting public, including visitors with disabilities.

New Entrance 

Road/Bridge 

from Port of 

Ridgefield, elim 

in grade 

crossing

$17,420,000 H Refuge Roads, 

Special Project 

Funding

Repair/Replace 

Existing Bridge

$6,000,000 H Refuge Roads

New Carty Unit 

Footbridge

$1,700,000 H Refuge Roads

ADA Oaks to 

Wetlands Trail 

(2500ft)

$90,000 M 1261, 1263, 8081

Bike Parking $2,700 M 1261, 1263, 8081

Pave Refuge 

Parking Lots

$248,000 M Refuge Roads
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

D-8 Appendix D. Implementation.

2.6 Visitor 

Infrastructure 

(cont)

Current 

Management

Future 

Management

Priority Funding

Kiwa Bathroom 

Trail

$16,533 M 1261, 1263, 8081

Benches every 

1000 ft of trail

$8,800 M 1261, 1263, 8081

Total Cost $6,000,000 $19,486,033

Goal 4. Outreach Through Refuge outreach efforts local residents will have the opportunity to 

gain an appreciation and understanding of the Ridgefield National Wildlife 

Refuge and National Wildlife Refuge System missions

Current 

Management

Future 

Management

Priority Funding

Portable 

Outreach 

Presentation Kit

0 $10,000 M 1261

Welcome 

Package for New 

Residents

0 $1,000 M 1261

Total Cost $0 $11,000

Goal 5. 

Environmental 

Education

Students from southwest Washington schools will participate in quality onrefuge environmental education programs that meet State educational 

requirements and provide safe and memorable experiences that foster a 

connection with nature and the Refuge. 

Current 

Management

Future 

Management

Priority Funding

5.1 Provide Quality Environmental Education Opportunities

3yr EE/Cultural 

Education 

Project

0 $245,828 H RONS

Total Cost $0 $245,828

5.2 Expand environmental education facilities

EE Shelter 

(groups of 40)

0 $210,000 H 1261, 1263, 8081

Total Cost $0 $210,000

Total One-Time 

Costs

$14,623,833 $42,119,024

D.3.2. Operational (Recurring) Costs

Operational costs reflect Refuge spending of base funds allocated each year. These are also known as 

recurring costs and are usually associated with day to day operations and projects that last longer 

than three years. 

Table D-2 displays projected operating costs under the CCP. The CCP reflects increased funding 

needs for proposed increases in public uses and facilities, new land acquisitions, increased habitat 

restoration and conservation activities, and new monitoring needs. This table includes such things as 

salary, operational expenditures such as travel, training, supplies, utilities and annual maintenance 

costs. 

Table D-2 includes costs for permanent and seasonal staff needed year after year. It does not include 

staff costs associated with special projects; these are summarized in Table D-1. Table D-2 is also 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix D. Implementation D-9 

related to the Refuge Comprehensive Accomplishment Report. The table does not project costs other 

than operational. This data is separated into three tables, Wildlife and Habitat, Cultural Resources, 

and Public Use, and each is organized by goals. 

Table D2. Wildlife and Habitat Recurring Costs

Goal 1. 

Grasslands

Provide and manage a mixture of secure, diverse, productive grassland 

habitats for foraging migratory waterfowl and grassland-dependent wildlife. 

Current 

Management

Future 

Management

New Staff Priority Funding

1.1 Enhance/Maintain Improved Pasture for Dusky Canada Geese

Number of Acres 186 340

Number of Acres 

Enhanced

186 340 Supv Bio H 1260, 6860

Total Cost $50,700 $89,500

1.2 Enhance/Maintain Improved Pasture for Other Canada Geese and Waterfowl

Number of Acres 1240 1110

Number of Acres 

Enhanced

1240 1110 H 1260, 6860

Total Cost $209,000 $179,000

1.3 Maintain Old Fields and Old Field/Wetland Borders

Number of Acres 400 140

Number of Acres 

Maintained

400 140 Supv Bio H 1260

Total Cost $30,300 $25,395

1.4 Maintain and Enhance Native Grassland Habitat

Number of Acres 15 15

Number of Acres 

Enhanced

15 15 M 1260

Total Cost $13,800 $13,800

Goal 2. Crops Provide agricultural crops as forage for migratory waterfowl and sandhill 

cranes

Current 

Management

Future

Management

New Staff Priority Funding

2.1 Provide Crops for Waterfowl and Sandhill Cranes

Total Acres of 

Crops

155-185 290-330 Supv. Bio H 1260

Acres Planted in 

Corn

55-85 60-145 Supv. Bio H 1260

Total Cost $49,000-

$56,500

$76,500-

$104,500
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

D-10 Appendix D. Implementation.

Goal 3. Wetlands Provide and manage a mixture of secure, diverse, productive grassland 

habitats for foraging migratory waterfowl and grassland-dependent wildlife. 

Current 

Management

Future 

Management

New Staff Priority Funding

3.1 - 3.2 Enhance and Maintain Managed Seasonal and Semipermanent Wetlands

Total Acres 

Managed 

Seasonal 

Wetlands

445 445

Total Acres 

Managed 

Semipermanent 

Wetlands

190 230 Supv. Bio H 1260

Total Acres 

Seasonal Wetland 

in SeasonalSemipermanent 

Rotation

0 365 Supv. Bio H 1260

Total Cost $99,700 $128,800

3.3 Enhance and Annually Maintain Seasonal Wetlands

Total Acres of 

Enhanced/Maintai

ned Seasonal 

Wetlands

155 125 M 1260

Total Cost $13,800 $15,800 

3.4 Howellia Wetlands

Total Number of 

Ponds

4 4

Number of Ponds 

Managed

0 4 Supv. Bio M 1260

Total Cost $5,000 $11,600

3.5 Permanent, non-tidal wetlands

Total Acres 

Permanent Nontidal wetlands

150 70

Mechanically 

open areas that 

have become 

vegetated 

w/emergent veg

0 20 M 1260

Total Cost $15,100 $16,100

3.6 Maintain Wet Meadow Habitat

Total Acres of 

Wet Meadow 

Habitat

300 400 Supv. Bio, 

Biotech

H 1260

Total Cost $35,600 $42,600
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix D. Implementation D-11

Goal 4. 

Floodplain 

Forests

Protect, manage, and restore a natural diversity of native floodplain forests 

representative of the historic lower Columbia River ecosystem. 

Current 

Management

Future 

Management

New Staff Priority Funding

4.1 Protect/Maintain Early Successional Floodplain Forest

% Acres 

Monitored and 

Treated Annually 

for Invasives

5% 10%

Acres Monitored 

and Treated 

Annually for 

Invasives

16 31 Supv. Bio, 

Biotech

M 1260

Total Cost $15,100 $24,300

4.1a Restore Early Successional Floodplain Forest

Total Acres 

Restored 

0 160 Supv. Bio, 

Biotech

M 1260

Total Cost $0 $24,300

4.2 Protect/Maintain Mid to Late Successional Floodplain Forest

Total Acres of 

Mid-Late 

Successional 

Riparian Forest

400 400

% Acres 

Monitored and 

Treated Annually 

for Invasives

5% 10%

Acres Monitored 

and Treated 

Annually for 

Invasives

20 40 Supv. Bio, 

Biotech

Partners Bio

M 1260, Partners

Total Cost $13,400 $55,000

4.3 Protect/Maintain Oregon Ash Floodplain Forest

Total Acres 

Oregon Ash

330 335

Acres Monitored 

and Treated 

Annually for 

Invasives 

33 34 Biotec Partner,

Bio

M 1260, Partners

Total Cost $15,750.00 $55,800.00

4.3a Restore Oregon Ash Floodplain Forest

Total Acres of 

Ash Forest 

Planted

0 5 Biotech M 1260

Total Cost $0 $16,000
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

D-12 Appendix D. Implementation.

Goal 5. Upland 

Forest

Protect, manage, and restore a natural diversity of native upland forests 

representative of the historic Lower Columbia River ecosystem. 

Current 

Management

Future 

Management

New Staff Priority Funding

5.1 Protect/Maintain Oak Woodland

Total Oak 

Woodland

70 90

% Acres 

Monitored and 

Treated Annually 

for Invasives

5% 10%

Total Acres 

Monitored and 

Treated Annually 

for Invasives

3 9 Supv. Bio, 

Biotech

H 1260

Total Cost $14,120 $23,360

5.1a Restore Oak Woodland

Total Acres of 

Oak Woodland 

Planted

0 10-20 Supv. Bio, 

Biotech

M 1260

Total Cost $0 $18,500

Goal 6. Riverine 

Habitat/Tidal 

Wetlands

Protect, enhance and, where feasible, restore riverine habitat and tidal 

wetlands representative of the historic lower Columbia River ecosystem to 

benefit salmonids and other native aquatic species. 

Current 

Management

Future 

Management

New Staff Priority Funding

6.1 Enhance/Improve Instream Riverine Habitat

Improve instream 

habitat by 

planting riparian 

trees and shrubs. 

0.8 (stream 

miles)

0.8 (stream 

miles)

Supv. Bio

Partners Biotech

M 1260, Partners

Total Cost $16,100 $56,700

6.2 Enhance/Maintain Tidal Wetlands

Total Acres of 

Tidal Wetlands

490 490

Mechanically 

remove 

encroaching 

vegetation and 

maintain open 

areas

100 100 H 1260

Total Cost $18,600 $18,600

Goal 7. Research Collect Scientific Information for Adaptive Management

Current 

Management

Future 

Management

New Staff Priority Funding

7.1 Inventory and Monitoring Activities

Total Cost $0 $24,000 Supv. Bio, 

Biotech,

Planner

M 1260

7.2 Conduct Surveys 

Total Cost $11,500 $24,500 Supv. Bio, 

Biotech,

Planner

M 1260
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix D. Implementation D-13

Current 

Management

Future 

Management

New Staff Priority Funding

7.3 Invasive species monitoring and control and studies of techniques

Total Cost $87,200 $138,500 Supv. Bio, 

Biotech, 

Planner, GIS 

Con-tractor

M 1260, Grants

Total Recurring 

Costs 

$702,270 $1,082,855

Table D.2. Cultural Resources Program — Recurring Costs

Goal 1. 

Cultural 

Resources

The Refuge will protect and manage its cultural resources for their educational, 

scientific, and cultural values for the benefit of present and future generations of 

Refuge users and communities. 

Current 

Management

Future 

Management

Priority New Staff Funding

1.1 Inventory, evaluate, monitor, and protect the Refuge’s cultural resources.

Total Cost $20,000 $88,000 H Supv. PR, 1/2 

FTE Planner, 

GIS

1260

1.2 Coordinate and Consult with Tribes on Cultural Resources Protection 

Total Cost $20,000 $39,000 H LE Officer 1260

Total

Recurring 

Costs 

$40,000 $127,000
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

D-14 Appendix D. Implementation.

Table D2. Public Use Programs - Recurring Costs

Goal 1. 

Waterfowl 

Hunting

Waterfowl hunters of all abilities will enjoy a quality, safe hunting program that 

provides a variety of waterfowl hunting experiences, promotes youth hunting, 

balances hunt program needs with other public use program needs, and reduces 

impacts to non-target species. As a result of participating in the waterfowl hunting 

program, hunters will gain a better appreciation of the refuge’s mission and its 

resource management.

1.1a Provide a quality, safe waterfowl hunt program on the Refuge, capable of supporting 

approximately 2000 hunter visits per season, including master, youth, and disabled hunters, and 

reduces conflicts between hunters, adjacent landowners, and other user groups.

1.1b Increase opportunities for duck hunters to hunt desirable waterfowl species, for example, 

mallard, wigeon, and pintail.

1.1c Provide goose hunting opportunities on 790 acres of the Refuge while reducing the 

disturbance to, and rate of take of dusky Canada geese. 

Current 

Management

Future 

Management

Priority New Staff Funding

1.1a. 

Number of 

Acres--

Duck 

Hunting

790 790

1.1c. 

Number of 

Acres—

Goose 

Hunting

790 790

Total Cost $53,200 $76,200 H Supv. PR, 

Maintenance 

Worker, LE 

Officer, 1/2 FTE 

Planner

1260, 8081

Goal 2. 

Wildlife 

Dependent 

Recreation

Visitors of all abilities will have the opportunity to participate in safe, quality 

wildlife-dependent recreation programs, including wildlife observation, 

photography, interpretation, and fishing, consistent with the needs of other public 

use programs and which limit wildlife disturbance in the face of increasing Refuge 

visitation. These programs will focus on enhancing public understanding and 

appreciation of wildlife, and building support for the Ridgefield National Wildlife 

Refuge. 

2.1 Provide facilities for self-guided wildlife observation and photography opportunities on the 

Refuge’s River ‘S’ and Carty Units, while limiting the impacts of noise and human activity to 

sensitive species.

Current 

Management

Future 

Management

Priority New Staff Funding

Total 

Cost

$17,000 M Supv. PR, 

Maintenance 

Worker, 1/2 

FTE Planner

1260, 8081

2.2 Maintain a 4.0-mile year-round auto tour route that supports a maximum of 200 vehicles on 

peak use days. 

Total 

Cost

$21,100 $65,100 H Supv. PR, 

Maintenance 

Worker, 1/2 

FTE Planner

1260, 8081
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix D. Implementation D-15

2.3 Provide 6.9 miles of seasonal pedestrian access on Refuge trails and roads and 2 miles of 

year-round pedestrian access on Refuge trails. 

Current 

Management

Future 

Management

Priority New Staff Funding

Total 

Cost

$12,000 $53,000 H Supv. PR, 

Maintenance 

Worker, 1/2 

FTE Planner, 

Fee Collection, 

LE Officer

1260, 8081

2.4 Conduct up to 25 volunteer-guided wildlife tours annually to provide visitors with access to 

areas of the Refuge that are otherwise closed.

Total 

Cost

$22,000 $31,000 M Supv. PR 1260, 8081

2.5 Improve visitor contact and orientation facilities, signage, and interpretation. 

Total 

Cost

$18,500 $50,000 H Supv. PR, 

Maintenance 

Worker, 1/2 

FTE Planner

1260, MMS, 

8081

2.6 Improve public facilities: Improve visitor infrastructure so as to enhance safety, sanitation, 

comfort, and access for the visiting public, including visitors with disabilities.

Total 

Cost

$23,000 $82,000 H Fee Collector, 

Supv. Park 

Ranger, 

Maintenance 

Worker, LE 

Officer, 1/2 FTE 

Planner

1260, 8081

2.7 Maintain access to fishing opportunities at Ridgefield National Wildlife Refuge.

Total 

Cost

$6,000 $18,500 M Supv. PR, LE 

Officer, 1/2 FTE 

Planner

1260, 8081

2.8 Reduce illegal activities 

Total 

Cost

$14,500 $52,500 H LE Officer, 

Supv. PR, 

Maintenance 

Worker

1260, 8081

Goal 3. 

Cultural 

Resources

Preserve, evaluate, and interpret its cultural resources and heritage. Cultural 

resources and the Cathlapotle Plankhouse will be interpreted to enlighten visitors 

about the Refuge’s unique natural and cultural history. Through accurate interpretive 

and educational opportunities, visitors will gain an understanding and appreciation of 

the Refuge’s natural and cultural heritage.

Current 

Management

Future 

Management

Priority New Staff Funding

3.1 Increase public awareness and appreciation of the Refuge’s historic, archaeological and 

cultural resources.

Total 

Cost

$59,000 $86,000 H Supv. PR, 

Maintenance 

Worker

1260, 8081

3.2 Partner with Tribes, friends groups, and volunteers to provide cultural resources interpretation 

and education programs and exhibits for both Tribal members and the general public.

Total 

Cost

$26,000 $112,000 H Supv. PR, Ed 

Specialist, 1/2 

FTE Planner

1260, 8081, 

Grants
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

D-16 Appendix D. Implementation.

3.3 Integrate the Plankhouse into the Refuge’s interpretation and environmental education 

programs. 

Total 

Cost

$19,000 $47,000 H Ed Specialist 1260, 8081, 

Grants

Goal 4. 

Outreach

Through Refuge outreach efforts local residents will have the opportunity to gain an 

appreciation and understanding of the Ridgefield National Wildlife Refuge and 

National Wildlife Refuge System missions

Current 

Management

Future 

Management

Priority New Staff Funding

4.1 Conduct Public Outreach

Total 

Cost

$29,100 $47,100 M Ed Specialist, 

Supv. PR, .5 

FTE Planner

1260

4.2 Continue recruiting, training, retaining, and utilizing volunteers for support of Refuge 

programs and activities. 

Total 

Cost 

$30,000 $39,000 H 1260

4.3 Establish and Maintain Partnerships 

Total 

Cost

$21,000 $31,000 H 1260

Goal 5. 

Environmental 

Education

Students from southwest Washington schools will participate in quality onrefuge environmental education programs that meet State educational 

requirements and provide safe and memorable experiences that foster a 

connection with nature and the Refuge. 

Current 

Management

Future 

Management

Priority New Staff Funding

5.1 Provide quality environmental education opportunities 

# Student 

Visits 

Annually

2000-3000 4500

Total Cost $28,000 $58,000 H Ed Specialist, 

Supv. PR, .5 

FTE Planner

1260, 8081, 

Grants

5.2 Effectively utilize volunteers, Friends Groups, and partnerships to create a high quality and 

self-sustaining Refuge environmental education program. 

Total Cost $38,000 $39,000 H 1260, 8081, 

Grants

5.3: Expand environmental education facilities 

Total Cost $15,000 $34,000 H Supv. PR, 

Maintenance 

Worker 

1260, 8081, 

Grants

Total 

Recurring 

Costs

$435,400 $938,400
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix D. Implementation D-17

D.3.3 Staffing 

Staff is needed to conserve and enhance the quality and diversity of indigenous wildlife habitats on 

the Ridgefield NWR. With the proper staffing to implement this plan, habitat management practices 

can be implemented and monitoring of flora and fauna responses to management can be applied, 

which will allow us to apply adaptive management strategies that are crucial for long term success in 

meeting the mission, goals and objectives of the Refuge. 

Staff will interact with the public for education purposes and to provide for public safety. 

Maintenance staff will maintain facilities and equipment. Training of staff and coordination among 

staff, volunteers and partners will ensure the mission and guiding principles of the National Wildlife 

Refuge System endure. 

The following proposed full development level staffing plan would achieve CCP goals within 15 

years. The rate at which this station achieves its full potential to fulfill the objectives and strategies 

contained in the plan is totally dependent upon receiving adequate funding and staffing. 

Table D-3 below shows the staffing levels needed to fully implement the CCP, and associated 

staffing costs. Note that these costs are already included (project by project) in the recurring 

costs. The table simply provides a picture of how the staff structure would look and provides an 

indication of what percent of the total recurring costs would be allocated towards staff. 

Table D3. Staffing to Implement the CCP, Ridgefield NWR

Project Leader PFT GS-0485-13 $134,000

Visitor Services Manager PFT GS-0025-11/12 $108,000

Wildlife Biologist PFT GS-0486-12 $108,000

LE Officer PFT GS-0025-7/9 $102,000

Deputy Project Leader PFT GS-0485-12 $97,000

Wildlife Biologist PFT GS-0486-11 $94,000

Education Specialist PFT GS-1001-7/9/11 $94,000

Geographic Information Specialist PFT GS-9/11 $94,000

Private Lands Biologist PFT GS-0401-7/9 $81,000

Administrative Officer PFT GS-0341-09 $81,000

Engineering Equipment Operator PFT WG-5716-10 $81,000

Instructional Systems Specialist PFT GS-1750-11 $75,000

Tractor Operator PFT WG-5716-7 $75,000

Maintenance Worker PFT WG-4749-6/7/8 $75,000

Volunteer Coordinator PFT GS-0024-5/7 $61,000

Bio Tech PFT GS-0404-5/7 $61,000

Fee Collections Officer PFT GS-5/6/7 $61,000

Planner .5 PFT GS-11/12 $54,000

Office Automation Clerk FTE GS-4/5 $50,000

YCC Crew Seasonal GS-4/5 $21,500

Hunter Check Station Seasonal GS-0404-4/5 $15,000

Tractor Operator Seasonal WG-5716-5 $15,000

Totals $1,637,500
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

D-18 Appendix D. Implementation.

D.3.4. Partnership Opportunities

The Refuge’s location next to a large metropolitan area facilitates many opportunities for 

partnerships with other agencies, interest groups and schools. Coordinated partnership efforts will 

focus on habitat restoration, land protection, environmental education, fish and wildlife monitoring, 

outreach, and quality wildlife-dependent recreation. Current and past partners include local schools, 

and non-profit groups (such as The Audubon Society, Friends of Ridgefield NWR, Lower Columbia 

River Estuary Partnership, Washington State University, and many others). Future partners will 

include these groups as well as state and tribal agencies. Partnerships like these will increase our 

effectiveness, knowledge, and community support, as well as reduce Refuge operating costs. 

In order for the Service to be effective in the Stewardship area around the Refuge we will strive to 

exchange information and provide technical assistance to neighboring landowners to promote 

protection of valuable wildlife habitat on neighboring properties. Volunteers will continue to assist 

with various Refuge programs, as detailed in Chapter 5 of the CCP. 

D.3.5. Budget Summary 

Table D-4 summarizes the data from the above tables and displays the total funding need, over the 15 

year lifetime of the CCP, for Ridgefield National Wildlife Refuge to implement the CCP in full, as 

described in Chapter 2. 

Table D4. Budget Summary: Funding Needed to Implement the CCP

Budget Category Current Management Future Management

One Time Expenditures

Wildlife & Habitat $329,500 $3,660,750

Public Use $14,623,833 $42,119,024

Subtotal $14,953,333 $45,779,774

Recurring Costs (Annual costs totaled over 15 year lifetime of CCP)

Wildlife & Habitat $10,534,050 $16,239,825

Public Use $7,131,000 $15,981,000

Subtotal $17,665,050 $32,220,825

Total CCP Cost $32,618,383 $78,000,599
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix E. Wilderness Review E-1 

Appendix E. Wilderness Review for Ridgefield National Wildlife 

Refuge 

E.1 Introduction 

The Ridgefield National Wildlife Refuge (Refuge) is located in southwest Washington at an 

elevation ranging from 0 - 60 feet. It is situated at the northern end of the Willamette Valley, 

approximately 15 miles north of Portland, Oregon. The majority of the refuge lies within the 

floodplain of the Columbia River. The Refuge’s acquisition boundary encompasses 6,170 acres, of 

which 5,218 acres has been acquired through fee title, agreement, or lease. The Refuge consists of 

three primary management units that are separated by water or private lands. These units include the 

768-acre Carty Unit, the 1,610-acre Bachelor Island Unit, and the 1,739-acre River S Unit, the 511- 

acre Roth Unit, and the 590-acre Ridgeport Dairy Unit. (The River S, Roth, and Ridgeport Dairy 

units are contiguous and are hereafter called the River Unit.) 

 

The Carty Unit is situated at the northern end of the refuge. It is comprised of riparian forests, 

flooded meadows, ponds, and meandering sloughs; all components of the Gee Creek watershed. The 

north end of the unit is comprised of unique basaltic upliftings and is managed as the Blackwater 

Island Research Natural Area (RNA). 

The Bachelor Island Unit is situated west of the mainland refuge and as its name implies, is an island 

within the Columbia River. The island is approximately 1-1/3 miles wide at its widest point, by 3 

miles long. This unit is comprised primarily of upland pastures and croplands with some sloughs and 

wetland impoundments. The northwest quarter of the island lies within the acquisition boundary but 

is privately owned. 

The River Unit is the primary mainland portion of the refuge and consists mostly of meandering 

sloughs, riparian corridors, man-made impoundments, croplands, and managed pastures. It also 

contains two relatively large lake systems.

E.1.1 Policy and Direction for Wilderness Reviews

U.S. Fish and Wildlife Service policy (Part 602 FW 3.4 C.(1) (c)) requires that wilderness reviews be 

completed as part of the Comprehensive Conservation Planning process. This review includes the reevaluation of refuge lands existing during the initial 10-year review period of The Wilderness Act of 

1964, as amended (16 U.S.C. 1131-1136) as well as new lands and waters added to the NWRS since 

1974. A preliminary inventory of the wilderness resources is to be conducted during pre-acquisition 

planning for new or expanded refuges (341 FW 2.4 B., “Land Acquisition Planning”). NWRS policy 

on Wilderness Stewardship (610 FW 1-5) includes guidance for conducting wilderness reviews (610 

FW 4 – Wilderness Review and Evaluation). 

A wilderness review is the process of determining whether the Service should recommend NWRS 

lands and waters to Congress for wilderness designation. The wilderness review process consists of 

three phases: wilderness inventory, wilderness study, and wilderness recommendation. 
Ridgefield National Wildlife Refuge Comprehensive Conservation 

E-2 Appendix E. Wilderness Review

The inventory is a broad look at a refuge to identify lands and waters that meet the minimum criteria 

for wilderness - size, naturalness, and outstanding opportunities for solitude or primitive and 

unconfined type of recreation. All areas meeting the criteria are preliminarily classified as 

Wilderness Study Areas (WSAs). If WSAs are identified, the review proceeds to the study phase. 

Wilderness Inventory

During the study phase, WSAs are further analyzed: 

Wilderness Study

1) for all values of ecological, recreational, cultural, economic, symbolic 

2) for all resources, including wildlife, vegetation, water, minerals, soils 

3) for existing and proposed public uses 

4) for existing and proposed refuge management activities within the area, 

5) to assess the Refuge’s ability to manage and maintain the wilderness character in 

perpetuity, given the current and proposed management activities. Factors for evaluation 

may include, but are not limited to staffing and funding capabilities, increasing 

development and urbanization, public uses, and safety. 

We evaluate at least an “All Wilderness Alternative” and a “No Wilderness Alternative” for each 

WSA to compare the benefits and impacts of managing the area as wilderness as opposed to 

managing the area under an alternate set of goals, objectives, and strategies that do not involve 

wilderness designation. We may also develop “Partial Wilderness Alternatives” that evaluate the 

benefits and impacts of managing portions of a WSA as wilderness. 

In the alternatives, we evaluate:

1) the benefits and impacts to wilderness values and other resources 

2) how each alternative will achieve the purposes of the Wilderness Act and the NWPS

3) how each alternative will affect achievement of refuge purpose(s) and the refuge’s 

contribution toward achieving the Refuge System mission

4) how each alternative will affect maintaining and, where appropriate, restoring biological 

integrity, diversity, and environmental health at various landscape scales 

5) other legal and policy mandates 

6) whether a WSA can be effectively managed as wilderness by considering the effects of 

existing private rights, land status and service jurisdiction, refuge management activities and 

refuge uses and the need for or possibility of eliminating Sec 4 (c) prohibited uses 

If the wilderness study demonstrates that a WSA meets the requirements for inclusion in the National 

Wilderness Preservation System, a wilderness study report should be written that presents the results 

of the wilderness review, accompanied by a Legislative Environmental Impact Statement (LEIS). 

The wilderness study report and LEIS that support wilderness designation are then transmitted 

through the Secretary of Interior to the President of United States, and ultimately to the United States 

Congress for action. Refuge lands recommended for wilderness consideration by the wilderness 

study report will retain their WSA status and be managed as “... wilderness according to the 

management direction in the final CCP until Congress makes a decision on the area or we amended 

the CCP to modify or remove the wilderness recommendation” (610 FW 4.22B). When a WSA is 

revised or eliminated, or when there is a revision in “wilderness stewardship direction, we include 

appropriate interagency and tribal coordination, public involvement, and documentation of 

compliance with NEPA” (610 FW 3.13). 

Wilderness Recommendation 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix E. Wilderness Review E-3 

The following constitutes the inventory phase of the wilderness review for the Ridgefield National 

Wildlife Refuge.

E.1.2 Previous Wilderness Reviews 

There have been no previous wilderness reviews conducted for the refuge. 

E.1.3 Lands Considered Under This Wilderness Review

All Service-owned lands and waters (in fee title) within the Ridgefield National Wildlife Refuge 

acquired boundary were considered during this wilderness review. 

E.2 Wilderness Inventory

E.2.1 Criteria for Evaluating Lands for Possible Inclusion in the National Wilderness 

Preservation System

The Wilderness Act of 1964, as amended (16 U.S.C. 1131-1136) provides the following description 

of wilderness: 

“A wilderness, in contrast with those areas where man and his own works dominate the landscape, is 

hereby recognized as an area where the earth and its community of life are untrammeled by man, 

where man himself is a visitor who does not remain. An area of wilderness is further defined to 

mean in this Act as an area of undeveloped Federal land retaining its primeval character and 

influence, without permanent improvements or human habitation, which is protected and managed so 

as to preserve its natural conditions...” 

The following criteria for identifying areas as wilderness are outlined in Section 2(c) of the Act and 

are further expanded upon in NWRS policy (610 FW 4). The first three criteria are evaluated during 

the inventory phase; the fourth criterion is evaluated during the study phase. 

1. generally appears to have been affected primarily by the forces of nature, with the imprint of 

man's work substantially unnoticeable; 

2. has outstanding opportunities for solitude or a primitive and unconfined type of recreation; 

3. has at least five thousand acres of land or is of a sufficient size as to make practicable its 

preservation and use in an unimpaired condition; and 

4. may also contain ecological, geological, or other features of scientific, educational, scenic, or 

historic value. 

 

Criterion 3 is further defined in Section 3(c) of the Act as 1) a roadless area of 5,000 contiguous 

acres or more, or 2) a roadless island. Roadless is defined as the absence of improved roads suitable 

and maintained for public travel by means of 4-wheeled, motorized vehicles that are intended for 

highway use. 
Ridgefield National Wildlife Refuge Comprehensive Conservation 

E-4 Appendix E. Wilderness Review

E.2.2. Process of Analysis

The following evaluation process was used in identifying the suitability of refuge units for wilderness 

designation: 

• Determination of Refuge unit sizes. 

• Assessment of the units’ capacity to provide opportunities for solitude or primitive and 

unconfined recreation. 

• Assessment of “naturalness” of Refuge units. 

More detail on the actual factors considered and used for each assessment step follows.

E.2.2.1 Unit Size: Roadless areas meet the size criteria if any one of the following 

standards apply: 

• An area with over 5,000 contiguous acres solely in FWS ownership. 

• A roadless island of any size. A roadless island is defined as an area surrounded by 

permanent waters or an area that is markedly distinguished from the surrounding lands by 

topographical or ecological features. 

 

• An area of less than 5,000 contiguous Federal acres that is of sufficient size as to make 

practicable its preservation and use in an unimpaired condition, and of a size suitable for 

wilderness management.

• An area of less than 5,000 contiguous Federal acres that is contiguous with a designated 

wilderness, recommended wilderness, or area under wilderness review by another Federal 

wilderness managing agency such as the Forest Service, National Park Service, or Bureau 

of Land Management. 

The 768-acre Carty Unit does not meet the minimum size requirements for a wilderness area. 

The 1,610-acre Bachelor Island Unit does not meet the minimum size requirements for a wilderness 

area.

The 2,840-acre River Unit does not meet the minimum size requirement for a wilderness area. 

E. 2.2.2 Outstanding Solitude or Primitive or Unconfined Recreation: 

A designated wilderness area must provide outstanding opportunities for solitude, or a primitive and 

unconfined type of recreation. Possession of only one of these outstanding opportunities is sufficient 

for an area to qualify as wilderness, and it is not necessary for one of these outstanding opportunities 

to be available on every acre. Furthermore, an area does not have to be open to public use and access 

to qualify under these criteria. 

Opportunities for solitude refer to the ability of a visitor to be alone and secluded from other visitors 

in the area. Primitive and unconfined recreation means non-motorized, dispersed outdoor recreation 

activities that are compatible and do not require developed facilities or mechanical transport. 

Primitive recreation activities may provide opportunities to experience challenge and risk, self 

reliance, and adventure.

 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix E. Wilderness Review E-5 

All but the Bachelor Island Unit is open to public use. Current public use exceeds 93,000 visits per 

year. Hunting and other wildlife-dependent recreational activities are allowed. The River and Carty 

units have extensive public use facilities, including an auto tour route, walking trails, information 

kiosks, hunting blinds, and a wildlife observation/photography blind. Walking and hiking is allowed 

on designated roads and trails; camping is not allowed. The individual units are small in size, the 

refuge sits adjacent to an urban area (including an active port area), and the two mainland units are 

adjacent to an active railroad line. In addition, auto touring is allowed on the River Unit and is a 

popular activity, with visits exceeding 55,000 annually. These units would not provide any 

significant amount of solitude, and their recreational values above the current uses are limited. None 

of these units provide outstanding opportunities for solitude, and do not provide opportunities for a 

primitive or unconfined type of recreation. 

E. 2.2.3 Naturalness and Wildness: the area generally appears to have been affected 

primarily by the forces of nature, with the imprint of man’s work substantially 

unnoticeable.

This criterion must be evaluated in the context of current natural conditions and societal values and 

expectations without compromising the original intent of the Wilderness Act. It is well recognized 

that there are few areas remaining on the planet that could be truly classified as primeval or pristine, 

with even fewer, if any, existing in the conterminous United States. Likewise, few areas exist that do 

not exhibit some impact from anthropogenic influences, be it noise, light, or air pollution; water 

quality or hydrological manipulations; past and current land management practices; road or trails, 

suppression of wildfires; invasions by non-native species of plants and animals; or public uses. 

While allowing for the near-complete pervasiveness of modern society on the landscape, the spirit of 

the Wilderness Act is to protect lands that still retain the wilderness qualities of: 1) natural, 2) 

untrammeled, 3) undeveloped. These three qualities are cornerstones of wilderness character. For 

areas proposed or designated as wilderness, wilderness character must be monitored to determine 

baseline conditions and thereafter be periodically monitored to assess the condition of these 

wilderness qualities. Proposed and designated wilderness areas by law and policy are required to 

maintain wilderness character through management and/or restoration in perpetuity. 

 

Defining the first two qualities (natural and untrammeled) requires a knowledge and understanding of 

the ecological systems which are being evaluated as potential wilderness. Ecological systems are 

comprised of three primary attributes – composition, structure, function. Composition is the 

components that make up an ecosystem, such as the habitat types, native species of plants and 

animals, and abiotic (physical and chemical) features. These contribute to the diversity of the area. 

Structure is the spatial arrangement of the components that contribute to the complexity of the area. 

Composition and structure are evaluated to determine the naturalness of the area. Function is the 

processes that result from the interaction of the various components both temporally and spatially, 

and the disturbance processes that shape the landscape. These processes include but are not limited 

to predator-prey relationships, insect and disease outbreaks, nutrient and water cycles, 

decomposition, fire, windstorms, flooding, and both general and cyclic weather patterns. Ecological 

functions are evaluated to determine the wildness or untrammeled quality of the area. 

The third quality assessment is whether an area is undeveloped. Undeveloped refers to the absence 

of permanent structures such as roads, buildings, dams, fences, and other man-made alterations to the 

landscape. Exceptions can be made for historic structures or structures required for safety or health 
Ridgefield National Wildlife Refuge Comprehensive Conservation 

E-6 Appendix E. Wilderness Review

considerations, providing they are made of natural materials and relatively unobtrusive on the 

landscape. 

General guidelines used for evaluating areas for wilderness potential during this wilderness inventory 

process include: 

1. The area should provide a variety of habitat types and associated abiotic features, as well as a 

nearly complete complement of native plants and wildlife indicative of those habitat types. 

Non-native and invasive species should comprise a negligible portion of the landscape. 

2. The area should be spatially complex (vertically and/or horizontally) and exhibit all levels of 

vegetation structure typical of the habitat type, have an interspersion of these habitats, and 

provide avenues for plant and wildlife dispersal. 

3. The area should retain the basic natural functions that define and shape the associated 

habitats including but not limited to flooding regimes, fire cycles, unaltered hydrology and 

flowage regimes, basic predator-prey relationships including herbivory patterns. 

4. Due to their size, islands may not meet the habitat guidelines in 1. and 2. above. Islands 

should, however, exhibit the natural cover type with which it evolved and continue to be 

shaped and modified by natural processes. Islands should be further analyzed during the 

study portion of the review, if they provide habitat for a significant portion of a population, or 

key life cycle requirements for any resources of concern, or listed species. 

5. Potential wilderness areas should be relatively free of permanent structures or man-made 

alterations. Areas may be elevated to the study phase if existing structures or alterations can 

be removed or remediated within a reasonable timeframe, and prior to wilderness 

recommendation to the Secretary of the Interior. 

The Carty Unit is comprised predominately of riparian forest, one relatively large pond, and 

meandering tidal sloughs and wetlands typical of the Columbia River floodplain. The overstory 

canopy is primarily native trees, however much of the understory is comprised of both native and 

invasive plants such as Himalayan blackberry. The ground component is dominated by invasive reed 

canarygrass, though some native grasses and forbs persist at the higher, drier elevations of the RNA. 

The unit retains significant portions of remnant fences. The primary lake on this unit has significant 

contamination from toxic chemicals once utilized in the adjacent lumber processing facility. The 

refuge’s headquarters and visitor facilities also exist on this unit. The unit contains a hardpacked 

gravel road that bisects length-wise much of the unit. The Carty Unit does not meet the ‘naturalness 

and wildness’ standards for wilderness designation. 

The Bachelor Island Unit is comprised almost wholly of intensively managed cattle pastures, hay 

lands, and croplands. All of the wetland entities are man-made or have been significantly altered; 

they are intensively managed through the use of water control structures. The riparian conditions 

have a natural component to the overstory, however the understory and shorelines are dominated by 

invasive plants such as Himalayan blackberry and false indigo-bush. The ground component is 

almost wholly introduced pasture grasses and non-native plants. This island also contains adjacent 

private and state lands. The unit contains several miles of permanent roads and high dike systems. 

This unit does not meet the ‘naturalness and wildness’ standards for wilderness designation. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix E. Wilderness Review E-7 

The River Unit consists of a combination of natural and man-made wetlands; all are intensively 

managed through water control structures. As with the other two units, the overstory is primarily 

native trees, however the shrub, grass and forb component is mostly non-native plants and introduced 

forage grasses. The upland portion of this unit is intensively managed through mowing, haying, and 

cattle grazing. Fences are still utilized for the cattle operation and an old barn is still utilized on the 

site. Portions of this unit receive extremely intensive public use and include a 4-mile long auto tour 

route and 2 miles of trails. Much of this unit contains permanent roads and high dikes that prohibit 

natural flooding of the wetlands. This unit does not meet the ‘naturalness and wildness’ standards for 

wilderness designation. 

E.2.2.4 Inventory Summary and Conclusion: 

Based on this inventory, the Refuge Unit does not meet the basic criteria for inclusion into the 

National Wilderness Preservation System. The overall refuge is approximately 5,218 acres and is 

divided into three separate tracts of land, none of which meet the minimum size for wilderness. The 

refuge lands are actively managed for wetland and upland habitat characteristics using a variety of 

techniques, including grazing, haying, croplands, herbicide use for invasive plants, prescribed fire, 

and mechanical manipulations. Much of the refuge lands have undergone significant degradation 

due to nearly a century of livestock grazing, hydrologic alterations, and invasions by non-native plant 

species. These lands do not fulfill the criteria for naturalness and wildness, and therefore do not 

possess outstanding wilderness character. The refuge provides wildlife-dependent recreational 

opportunities, as well as opportunities to walk or hike on trails; however, these opportunities are not 

considered to be outstanding in terms of solitude, and do not provide a primitive and unconfined type 

of recreation. 

 

Table E1. Results of Wilderness Inventory for Ridgefield National Wildlife Refuge

Refuge 

Unit

(1) Unit Size: 

has at least 

5,000 acres of 

land or is of 

sufficient size 

to make 

practicable its 

preservation 

and use in an 

unconfined 

condition, or 

is a roadless 

island

(2) Naturalness 

and wildness: 

generally 

appears to 

have been 

affected 

primarily by 

the forces of 

nature, with 

the imprint of 

man’s work 

substantially 

unnoticeable 

(3a) 

Outstanding 

opportunities

for solitude

(3b) 

Outstanding 

opportunities 

for primitive 

and 

unconfined 

recreation

(4) contains 

ecological, 

geological or 

other 

features of 

scientific, 

educational, 

scenic, or 

historical 

value

Area 

qualifies as a 

wilderness 

study area 

(meets 

criteria 1,2, 

and 3a or 3b)

Carty Unit No No No No Yes No

Bachelor 

Island

No No No No No No

River Unit No No No No No No
Ridgefield National Wildlife Refuge Comprehensive Conservation 

E-8 Appendix E. Wilderness Review
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix F. Biological Resources of Concern. F-1

Appendix F. Biological Resources of Concern 

F.1 Introduction 

Early in the planning process, the team cooperatively identified species, species groups, and 

communities of concern for the Refuge. A comprehensive list of these resources was compiled based 

upon review of numerous plans (see Section 1.7 of the Draft CCP/EA), many of which highlight 

priority species or habitats for conservation. The Comprehensive Resources of Concern list is 

contained in Table F.3. In addition, a table of species and species groups specifically identified in 

establishing documents for the Refuge was compiled (Table F.1). 

The Comprehensive Resources of Concern table was further culled in developing a more targeted 

assemblage of Priority Resources of Concern. Most of the biological emphasis of the CCP is focused 

on maintaining and restoring these priority resources. Table F.4 contains the Priority Resources of 

Concern identified for the Ridgefield National Wildlife Refuge. 

Definitions for the column headings in Table F.4 are as follows: 

Focal Species: Species selected as representatives or indicators for the overall condition of the 

conservation target. In situations where the conservation target may include a broad variety of 

habitat structures and plant associations, several different conservation focal species may be listed. 

In addition, species with specific “niche” ecological requirements may be listed as a focal species. 

Management will be focused on attaining conditions required by the focal species. Other species 

utilizing the conservation target will generally be expected to benefit as a result of management for 

the focal species. 

Habitat Type: The general habitat description utilized by the focal species. 

Habitat Structure: The specific and measurable habitat attributes considered necessary to support the 

focal species. 

Life History Requirement: The general season of use for the focal species. 

Other Benefiting Species: Other species that are expected to benefit from management for the 

selected focal species. The list is not comprehensive; see the Table of Potential Resources of 

Concern for the Refuge for a more complete list. 
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

F-2 Appendix F. Biological Resources of Concern

Table 1. Identification of Refuge Purpose Resources of Concern 

Conservation Target 

(Species/Species 

Group or Habitat) 

Supporting Habitat Type Life History 

Requirement 

Supporting 

Documentation* 

Wintering: 125000 

Ducks, 3000 Geese 

Old Fields, Bottomland Prairie, emergent 

wetlands, agricultural pastures Wintering habitat MBCC 1 

Breeding, Migration, 

Resting, Wintering 

Waterfowl 

Old Fields, Bottomland Prairie, emergent 

wetlands, agricultural pastures, croplands 

Migration and 

wintering Habitat 

MBCC 1 

Dusky Canada Goose - 

wintering 

Old Fields, Bottomland Prairie, emergent 

wetlands, agricultural pastures 

Migration and 

wintering Habitat 

MBCC 1, MBCC 

8, RPD PPP/ Cat 

Ex. 

Other Canada Geese – 

resting and wintering 

Old Fields, Bottomland Prairie, emergent 

wetlands, agricultural pastures, croplands 

Migration and 

wintering Habitat 

MBCC 4 

BI/RPD EA 

Taverner’s, dusky, 

western, cackling, lesser 

Old Fields, Bottomland Prairie, emergent 

wetlands, agricultural pastures, croplands 

Migration and 

wintering Habitat 

RPD PPP/ Cat Ex. 

Aleutian Old Fields, Bottomland Prairie, emergent 

wetlands, agricultural pastures, croplands 

Migration and 

wintering Habitat 

RPD Cat Ex. 

Tundra Swans - roosting Emergent wetlands, tidal riverine Migration and 

wintering Habitat 

BI/RPD EA, RPD 

PPP/Cat. Ex. 

Trumpeter Swans Emergent wetlands, tidal riverine Migration and 

wintering Habitat 

RPD PPP 

Dabbling ducks – resting 

and nesting 

emergent wetlands, bottomland prairie, 

dry prairie 

Migration and 

wintering Habitat 

MBCC 1 

BI/RPD EA 

Wintering habitatmallard, pintail, bluewinged teal 

Emergent wetlands, tidal riverine Wintering habitat 

RPD PPP/Cat. Ex. 

Diving Ducks- wintering Emergent wetlands, tidal riverine Migration and 

wintering Habitat 

BI/RPD EA 

Wigeon – Native Pasture Dry prairie, bottomland prairie Wintering habitat MBCC 1 

Sandhill Crane Emergent wetlands Nesting MBCC 8, BI EIS 

Sandhill Cranes

resting/roosting 

Tidal riverine, bottomland prairie, 

croplands, agricultural pastures 

Migration and 

wintering Habitat 

MBCC 8, 10, BI 

EIS, BI/RPD EA, 

RPD PPP/Cat. Ex 

Bald Eagles - nesting Bottomland forest Nesting 

Great Blue Herons– 

nesting 

Bottomland forest Nesting MBCC 8 

Resting, feeding, 

wintering waterfowl 

Old Fields, Bottomland Prairie, emergent 

wetlands, agricultural pastures 

Resting, feeding, 

wintering 

MBCC 4, 6, 8, 10, 

unnumbered 

MBCC memo circa 

1972 

Bald Eagle Bottomland forest Roosting, nesting MBCC 8, BI EIS, 

BI/RPD EA, RPD 

PPP/Cat. Ex 

Great blue heron Bottomland forest Nesting MBCC 8, BI EIS 

Preserve Major 

Wintering Area for 

Waterfowl 

Old Fields, Bottomland Prairie, emergent 

wetlands, agricultural pastures, croplands 

wintering MBCC 10 

Feeding and Resting 

dusky and cackling 

geese 

Old Fields, Bottomland Prairie, emergent 

wetlands, agricultural pastures, croplands 

Migration and 

wintering 

MBCC 10 

Preserve Wintering 

grounds 

Old Fields, Bottomland Prairie, emergent 

wetlands, agricultural pastures, croplands 

wintering BI EIS 
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix F. Biological Resources of Concern. F-3

Conservation Target 

(Species/Species 

Group or Habitat) 

Supporting Habitat Type Life History 

Requirement 

Supporting 

Documentation* 

Resting, Feeding 

waterfowl 

Wetland, agricultural Old Fields, 

Bottomland Prairie, emergent wetlands, 

agricultural pastures, croplands 

Migration and 

wintering 

BI EIS 

Shorebird, raptors, marsh 

and waterbirds, 

mammals, riparian 

Wetland, agricultural Old Fields, 

Bottomland Prairie, emergent wetlands, 

agricultural pastures, croplands, 

bottomland forests 

 BI EIS 

BI/RPD EA 

Shorebirds, marshbirds, 

songbirds, black-tailed 

deer, coyote, fox, 

raccoon, skunk, beaver, 

otter, brush rabbit 

Wetland, agricultural Old Fields, 

Bottomland Prairie, emergent wetlands, 

agricultural pastures, croplands, 

bottomland forests 

Spring and fall 

migrations and 

resident 

populations 

RPD PPP 

Shorebirds, marshbirds, 

songbirds 

Wetland, agricultural Old Fields, 

Bottomland Prairie, emergent wetlands, 

agricultural pastures, croplands, 

bottomland forests 

Spring and fall 

migrations 

RPD Cat. Ex. 

Provide and protect 

wintering habitat 

 winteri ng BI/RPD EA 

Peregrine falcon wintering BI/RPD EA 

RPD PPP/ Cat. Ex. 

Common loon wintering RPD PPP 

Water howellia

(Howellia aquatilis) 

 RPD PPP 

Smallflower wakerobin

(Trillium parviflorum) 

 RPD PPP 

Giant white fawnlily

(Erythronium oregonum) 

 RPD PPP 

Upland (Nuttall’s) 

larkspur (Delphinium 

nuttallii) 

 PRD PPP 

Olive-sided flycatcher RPD PPP 

*Documents establishing purposes of the Refuge and/or Refuge units: 

MBCC 1: Migratory Bird Conservation Commission Memorandum 1, May 18, 1965 

MBCC 4: Migratory Bird Conservation Commission Memorandum 4, August 5, 1965 

MBCC 6: Migratory Bird Conservation Commission Memorandum 6, January 22, 1974 

MBCC 8: Migratory Bird Conservation Commission Memorandum 8, February 5, 1985 

MBCC 10: Migratory Bird Conservation Commission Memorandum 10, March 21, 1995

BI EIS: Environmental Impact Statement (EIS), Land Acquisition—Zimmerly Tract for Addition to Ridgefield 

National Wildlife Refuge, Washington, March 1980 

BI/RPD EA: Environmental Assessment (EA), Acquisition of Remaining Tracts, Ridgefield National Wildlife 

Refuge, Clark County, Washington, December 1983 

RPD PPP/Cat Ex.: Preliminary Project Proposal (May 1989) and the Decision Document (Categorical Exclusion), 

Acquisition of Port of Vancouver Tract, Ridgefield National Wildlife Refuge, Clark County, Washington (October 

12, 1989) 
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

F-4 Appendix F. Biological Resources of Concern

Table 2. Biological Diversity, Integrity and Environmental Health 

Habitats (plant 

communities that 

Represent Existing 

BIDEH) 

Population/Habitat Attributes 

(Age class, structure, serial 

stage, species composition) 

 

Natural processes 

responsible for these 

conditions 

Limiting Factors 

Bottomland Forest Subtypes: 

 Black cottonwood with 

appropriate native shrub 

understory 

 Pacific willow pure stand 

(wet sites) 

 Ash/nettle/sedge 

community; Ash with 

dense herbaceous and 

shrub understory, 

overstory >12” DBH with 

>40% canopy coverage 

General Attributes of Bottomland 

Forest: Native shrub layer 

dominants include willow, 

snowberry, cascara, Nootka rose, 

red-osier dogwood, red alder, 

spirea, and red elderberry and 

saplings of native canopy trees. 

Native sub-canopy trees include 

black hawthorn, vine maple, big 

leaf maple, willow, ninebark, 

hazelnut, and young canopy trees. 

Native canopy trees include 

Oregon ash and black 

cottonwood.2

Potential Conservation Species: 

song sparrow (all stages), 

Swainson’s thrush (dense shrub), 

willow flycatcher (shrub/young 

seral), purple martin (snag/low 

competition by non-native birds, 

nearby water) , Columbian whitetailed deer 

Functioning 

floodplain major 

flood events, scour of 

trees/herbaceous 

layers, deposition of 

silts 

Frequency of 

flooding: 

Historically, 

overbank flooding 

annually (spring) 

Flooding is the 

primary natural 

disturbance regime in 

Columbia River 

bottomland forest.6

 

Non-Functioning 

Floodplain 

Dike construction 

and dams 

reduce/alter flood 

events 

Past grazing, 

agriculture, 

invasive species 

(competition and 

soil binding), lack 

of silt deposition 

Bottomland (wet) 

Prairie 

(Deschampsia 

caespitosa prairie) 

Native herbaceous species, (e.g. 

Columbia sedge, tufted hairgrass, 

rushes). Unique: Willamette daisy, 

Bradshaw’s lomatium, Nelson’s 

checkermallow 

Potential Conservation Species: 

rails, northern harrier 

Periodic fire and 

poorly drained soils; 

seasonal flooding. 

Transition zone 

above mean high 

gauge, throughout 

refuge 

Invasive species 

(especially reed 

canarygrass) 

displace/out 

compete native 

communities; lack 

of periodic fire 

Upland (Dry) 

Prairie 

Agropyron caninum, Bromus 

sterilis, Holcus, Hordeum 

Periodic fire, shallow 

well drained soils 

Invasive species 

encroachment, lack 
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix F. Biological Resources of Concern. F-5

Habitats (plant 

communities that 

Represent Existing 

BIDEH) 

Population/Habitat Attributes 

(Age class, structure, serial 

stage, species composition) 

 

Natural processes 

responsible for these 

conditions 

Limiting Factors 

brachyantherum, Poa palustris. 

Unique: basalt outcrops, northern 

alligator lizard, Camassia spp, 

Nuttall’s larkspur 

Potential Conservation Species: 

Mazama pocket gopher, graytailed vole 

of fire, grazing/soil 

disturbance 

Western Hemlock 

Forest 

Mixed forest, Douglas-fir, 

Western red cedar, Indian plum, 

Oregon white oak. Unique: 

smallflower wakerobin, giant 

white fawnlily 

Infrequent fire, light 

grazing/browsing by 

large ungulates 

Blackberry 

encroachment; 

canopy closure 

Oak Woodlands 

(unique habitat based 

on basalt outcrops 

and transitional 

floodplain habitat) 

Understory of Symphoricarpos 

albus, Holodiscus discolor, Rhus 

diversiloba, Rosa spp., Festuca 

rubra, Danthonia californica, 

Agropyron caninum, Bromus 

sterilis. Unique: Wheeler’s 

bluegrass, slender-billed whitebreasted nuthatch 

Potential Conservation Species: 

slender-billed white-breasted 

nuthatch, western gray squirrel 

Frequent low 

intensity fire (approx 

every 5 years); 

absence of ground 

disturbance; presence 

of acorn dispersing 

animals (squirrels, 

jays, acorn 

woodpeckers); light 

grazing/browsing by 

native ungulates 

Oak habitats were 

formerly maintained 

by fires of various 

frequencies. Areas of 

infrequent fire 

supported shrub 

cover. Fire reduced 

encroachment by 

conifers and other 

competing species. 

Post-fire 

establishment and 

survival of oak 

saplings is increased. 

Invasive species 

(e.g. blackberry) 

displace/out 

compete native 

communities; lack 

of fire; conifer 

encroachment; 

competition by 

native trees/canopy 

closure; lack of 

light 

grazing/browsing 

pressure by large 

ungulates; 

overgrazing during 

summer (oak 

seedlings eaten); 

oak diseases 

(sudden oak death 

fungus, anthracnose 

disease) 

Emergent Wetlands Subtypes: Seasonal, Semipermanent, Permanent 

Potential Conservation Species: 

waterfowl, Canada geese, dusky 

Canada goose, cackling goose, 

tundra swan, Canadian sandhill 

Periodic flooding/ 

scouring; seasonal 

fluctuations/drying 

but more permanent 

water situation than 

typical seasonal 

wetlands 

Invasive plants, 

(e.g. reed 

canarygrass); 

nutria; dams on 

river change 

hydrological 

regime; lack of 
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

F-6 Appendix F. Biological Resources of Concern

Habitats (plant 

communities that 

Represent Existing 

BIDEH) 

Population/Habitat Attributes 

(Age class, structure, serial 

stage, species composition) 

 

Natural processes 

responsible for these 

conditions 

Limiting Factors 

crane, great blue heron, and other 

species identified in Purpose 

document (rails, shorebirds) 

spring 

flooding/scouring; 

diking; reduced 

tidal connection to 

Columbia River; 

flood depth and 

duration 

Tidal Riverine Open, generally flowing water; 

potentially supporting rearing 

anadromous fish; affording fish 

passage throughout watershed 

Potential Conservation Species: 

coastal cutthroat trout, Chinook 

salmon (Lower Columbia ESU), 

coho salmon (Lower Columbia 

ESU) 

Tidal and periodic 

flooding, open water, 

submergent 

vegetation, perennial 

water flows 

Residental/commer

cial development, 

lack of major 

flooding, siltation, 

invasive species 

encroachment (e.g. 

reed canarygrass); 

contaminants; 

water 

quality/temperature 

Ephemeral Ponds Small (<1 acre) perched wetlands 

located on RNA/Carty Unit 

providing habitat for Howellia 

aquatilis 

Potential Conservation Species: 

Howellia aquatilis 

Generally open water 

(< 1’ depth) from 

November through 

June (rainfall) with 

sparse emergent and 

submergent 

vegetation 

Reed canarygrass 

encroachment ; 

canopy closure 

Croplands Row crops (grain, legumes) for 

waterfowl and cranes 

Potential Conservation Species: 

Dusky Canada goose, cackling 

goose, Canadian sandhill crane; 

most species identified in Purpose 

documents 

NA Invasive plant 

species, cost and 

labor intensive 

Agricultural 

Pastures 

Mixed non-native/native upland 

grasses w/ legume/forbs; 

restoration every 5-10 years 

Potential Conservation Species: 

Dusky Canada goose, cackling 

goose, Canadian sandhill crane; 

most species identified in Purpose 

documents

NA Invasive plant 

species; lack of 

fertilization, fire, 

lack of coop 

farmers (grazing 

and haying), thatch 

accumulation 

Large flocks of 

migrating/wintering 

waterfowl 

Native prairie, expansive 

emergent wetlands and wooded 

wetlands within the lower 

Columbia River 

Predominant, 

historical Canada 

goose subspecies 

(dusky) adapted to 

small fields and wet 

Diking, draining 

and leveling of 

ridges/swales 

resulting in reduced 

wetland area; 
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix F. Biological Resources of Concern F-7 

Habitats (plant 

communities that 

Represent Existing 

BIDEH) 

Population/Habitat Attributes 

(Age class, structure, serial 

stage, species composition) 

 

Natural processes 

responsible for these 

conditions 

Limiting Factors 

meadows 

interspersed with 

riparian communities. 

Anthropogenic fire 

maintained native 

prairie. Emergent 

wetlands and wet 

meadows abundant in 

LCR. Dynamic 

flooding regime of 

lowland areas. 

Historical accounts 

describe area as the 

Wapato Valley. 

damming; 

manipulated river 

hydrology; lack of 

periodic fire; 

development within 

floodplain 
 Table 3. Ridgefield National Wildlife Refuge Potential Resources of Concern

Species / Species Groups / Communities

uf e R P eg opr u ses

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H N A W

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ana C Gad soo e

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snoC

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dexi M

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ser o t

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Wintering waterfowl X X xxxxx

Dusky Canada Goose

X X X GBBDC x x x x

Aleutian Cackling Goose X FCo ST SNA X X xx x

Cackling Goose

X X X GBBDC I x x x x

Western Canada Goose

X X X I x x x

Taverner's Cackling Goose

X X X I x x x

Lesser Canada Goose

X X X I x x x

Pacific White-fronted Goose GBBDC x x x

Snow Goose x x

Trumpeter Swan X S3 X Xx x

Tundra Swan X S4 X x x

Dabbling ducks X X X x x x

Wood Duck S3 GBBDC xx x

Mallard X X GBBDC x xx x

Northern Pintail X S5 X D GBBDC X x x

American Wigeon X S4 GBBDC

X x x x

Blue-winged Teal

X x

Diving ducks X X X x x x

Ring-necked Duck S4 GBBDC X x x x x

Lesser Scaup S4 D GBBDC X x x

Canvasback GBBDC x x

Canadian Sandhill Crane X SE xxxxx

Common Loon X SS X x x

Raptors

X X x x x x x x x

Bald Eagle, Bald Eagle Roosts X X FCo SS T X X x x x x x

Northern Harrier X1

X x xx

American Kestrel S4 X1 xx

American Peregrine Falcon X FCo SS BCC/BCR

X X2c

X

X x xx

Red-shouldered Hawk X2 x x

Cooper's Hawk X2 x x

Short-eared Owl S3

X

X

X x x

Western Screech-owl S4 X2 xx x

Pileated Woodpecker SC S4

X X1 xx x

GBBDC (Wrangel Is.)

GBBDC (Interior, 

Rocky Mts)

S1B,S3N S2B,S4N 

ST S4B,S4N 

SE S1B,S3N 

5/18/2010 page 1

____________________________________________________________________ Ridgefield National Wildlife Refuge Comprehensive Conservation Plan ___________________________

______________________________________________________________________________________________ 

F-8 Appendix F. Biological Resources of Concern
 Table 3. Ridgefield National Wildlife Refuge Potential Resources of Concern

Species / Species Groups / Communities

uf e R P eg opr u ses

. l oi B

evi D i sr , yt et In yit r g

dna vn E H ir hlt ae

deF l ar e t at S su

in hsa W

not g ut at S s

ger O S no ut at s

H N A W

a R P kn

wyl F Wya

r et a wof Pl sn la

m A. N

cir e MWna

02 ( P ) 40

ana C Gad soo e

r pe D ade n iot

n la P

sdri B Cf o sno avr e noit

cnoC nr e 002 SU ( 2 S WF )

moC her p sne We iv ldi ef li

snoC

avr e n iot D W( ) WF

CPN i ge R l ano

r ohS ir be d

nal P 002 0

naL ir bd oC d S sn art 02-t 00

sar G nal s i B d sdr W/ V. 99 1 9

CNT V W- TP/ B /G

r ocE

oi ge Al an ess mss t ne

CCB

oit a N ( l an baT 4 le ) 8

cepS sei

ucc O nerr in ec

of wlol H g in it ba : st a

ana M deg sar G n la s sd

nalt e W N- sd it no l ad

nalt e W - sd a id T l

cir gA

utl u Hl ar ti ba t a

Mt e W

odae

r P, w ie ir a

 Wka O doo dnal

ool F al pd ni R/ api n iar r o F t se

dexi M

i noC Fr ef

ser o t

r evi R t S/ s maer s

Downy Woodpecker X2 xx x

Shorebirds--concentrations

X X x x

Common Snipe S4 4 x xx

Black-bellied Plover S4 4 x x

Dunlin S4 4 x x

Greater Yellowlegs S4 4 x x

Lesser Yellowlegs 2 x x

Killdeer S4 4 x x

Western Sandpiper S4 4 x x

Least Sandpiper S4 4 x x x

Wilson's Phalarope S3 3 X x

Semi-palmated Plover 3 x

Spotted Sandpiper S3 3 x x

Long-billed Dowitcher S4 3 x x

Black-necked Stilt M S3B X 1 x

Great Blue Heron, GBH nesting X MS4

X

X x x xx x x

Olive-sided flycatcher X FCo SV S4 BCC/BCR X1 X

X x

Pacific-slope flycatcher S4 X2a X x x x

Willow flycatcher FCo SU S4B X1 X x

Western Wood Peewee S5 X1 X x x x

Purple Finch X2a xx x

Bullock's Oriole X2 X x x x

Swainson's Thrush S5 X1 xx x

House Wren X2 xx x

Bewick's Wren X1 

X x x

Oregon Vesper Sparrow FCo SC SC S1B BCR X X1 X x

Spotted Towhee X2a xx x

Streaked Horned Lark(ssp. 

Strigata )

FC SE SC S1

BCC/BCR X

X1 X

X xx

Western Meadowlark

X X1 (D) X X x x

Lazuli Bunting S4 X2a x

Black-headed Grosbeak X2b x

Yellow Warbler S4 X1 x

SC S4N,S4S5B 

5/18/2010 page 2

______________________________________________________________________________________________ Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix F. Biological Resources of Concern

_____________________________________________________________________________________________

F-9
 Table 3. Ridgefield National Wildlife Refuge Potential Resources of Concern

Species / Species Groups / Communities

uf e R P eg opr u ses

. l oi B

evi D i sr , yt et In yit r g

dna vn E H ir hlt ae

deF l ar e t at S su

in hsa W

not g ut at S s

ger O S no ut at s

H N A W

a R P kn

wyl F Wya

r et a wof Pl sn la

m A. N

cir e MWna

02 ( P ) 40

ana C Gad soo e

r pe D ade n iot

n la P

sdri B Cf o sno avr e noit

cnoC nr e 002 SU ( 2 S WF )

moC her p sne We iv ldi ef li

snoC

avr e n iot D W( ) WF

CPN i ge R l ano

r ohS ir be d

nal P 002 0

naL ir bd oC d S sn art 02-t 00

sar G nal s i B d sdr W/ V. 99 1 9

CNT V W- TP/ B /G

r ocE

oi ge Al an ess mss t ne

CCB

oit a N ( l an baT 4 le ) 8

cepS sei

ucc O nerr in ec

of wlol H g in it ba : st a

ana M deg sar G n la s sd

nalt e W N- sd it no l ad

nalt e W - sd a id T l

cir gA

utl u Hl ar ti ba t a

Mt e W

odae

r P, w ie ir a

 Wka O doo dnal

ool F al pd ni R/ api n iar r o F t se

dexi M

i noC Fr ef

ser o t

r evi R t S/ s maer s

Red-eyed Vireo X1 x

Western Purple Martin FCo SC SC S3B

X X1 Xx x

Band-tailed Pigeon FCo GBBDC X X1 X x x

Mourning Dove S5 GBBDC xx

Vaux's Swift SC S3

X X2b X xx x x

Tree Swallow X2 (D) x xx x

Rufous Hummingbird S4 BCC/BCR X1

X

X xxx x

S-Billed White-breasted 

Nuthatch

FCo SC S1

X

X1

X x

Common Bushtit X1 xx x

Western gray squirrel FCo ST SU S2 xx

Columbian white-tailed deer FE SE SV S1

X

Townsend's big-eared bat FCo SC SC S2S3 

X X x

Yuma myotis FCo S5 X x x

Western pocket gopher FC ST S2

X

Gray-tailed vole SC S2

X

X

Northwestern pond turtle FCo SE SC S1

X

X x x x

Northern red-legged frog FCo SV S4

X X xx x

Pacific lamprey FCo SV S3S X x

Steelhead (LCR ESU)-winter FT SC SC SNR x

Steelhead (LCR ESU)-summer FT SC SC SNR x

Coho (LCR ESU) FC SE SNR x

Chinook (LCR ESU)-fall FT SC SC SNR xx

Coastal cutthroat trout (SW 

WA/Columbia River ESU)

FCo SE SNR

 x

Pacific smelt FT SC S4

Golden paintbrush (Castilleja 

levisecta)

FT SE SE S1

X X x

Nelson’s checkermallow 

(Sidalcea nelsoniana)

FT SE ST S1

X X xx x

S3S4B,S4N 

5/18/2010 page 3

______________________________________________________________________________________________ Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

______________________________________________________________________________________________ 

F-10 Appendix F. Biological Resources of Concern
 Table 3. Ridgefield National Wildlife Refuge Potential Resources of Concern

Species / Species Groups / Communities

uf e R P eg opr u ses

. l oi B

evi D i sr , yt et In yit r g

dna vn E H ir hlt ae

deF l ar e t at S su

in hsa W

not g ut at S s

ger O S no ut at s

H N A W

a R P kn

wyl F Wya

r et a wof Pl sn la

m A. N

cir e MWna

02 ( P ) 40

ana C Gad soo e

r pe D ade n iot

n la P

sdri B Cf o sno avr e noit

cnoC nr e 002 SU ( 2 S WF )

moC her p sne We iv ldi ef li

snoC

avr e n iot D W( ) WF

CPN i ge R l ano

r ohS ir be d

nal P 002 0

naL ir bd oC d S sn art 02-t 00

sar G nal s i B d sdr W/ V. 99 1 9

CNT V W- TP/ B /G

r ocE

oi ge Al an ess mss t ne

CCB

oit a N ( l an baT 4 le ) 8

cepS sei

ucc O nerr in ec

of wlol H g in it ba : st a

ana M deg sar G n la s sd

nalt e W N- sd it no l ad

nalt e W - sd a id T l

cir gA

utl u Hl ar ti ba t a

Mt e W

odae

r P, w ie ir a

 Wka O doo dnal

ool F al pd ni R/ api n iar r o F t se

dexi M

i noC Fr ef

ser o t

r evi R t S/ s maer s

Bradshaw's desert parsley 

(Lomatium bradshawii)

FE SE SE S1

X X xx

Water Howellia (Howellia 

aquatilis)

X FT ST ST S2S

3 X X x

Trillium parviflorum

X SS S2S

3 x x

Erythronium oregonum

X x x

Delphinium nuttallii

X S1 (OR) x x

Wheeler's bluegrass (Poa 

nervosa ) SS S2

X 

X S2 X 

Bottomland (Wet) prairie

X X 

Upland (Dry) prairie

X X 

Riparian forest/shrubland

X X X S2

Depressional wetland 

X X 

Freshwater marshes

X X X X 

Freshwater aquatic beds

X X 

Mudflats, autumnal freshwater

X X 

Vernal pools

X X 

Freshwater wetlands, tidally 

influenced

Oregon white oak-(Oregon 

ash)

Oregon white oak/oval leaf 

viburnum woodland

Definition of Resources of Concern table: From approx 16 wildlife conservation plans, assessments, and/or lists: Species, species groups, or plant communities/habitats that were ranked highly within those documents for conservation concern or management action, and currently or historically occurred on the Refuge.

Oregon ash/Carex 

deweyana/Urtica dioica assoc

5/18/2010 page 4

______________________________________________________________________________________________ Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix F. Biological Resources of Concern

_____________________________________________________________________________________________

F-11
Table 3. Category Codes:

Federal Status: FE-Endangered; FT-Threatened; FC-Candidate; FCo-Species of Concern 

Washington Status: SE-State Endangered; ST-State Threatened; SC-State Candidate; 

SS-State Sensitive; M-Monitor 

Oregon Status: SC-Critical; SV-Vulnerable; SP: Peripheral/naturally rare; SUUndetermined Status 

Washington Natural Heritage Program: 

S1: Critically imperiled because of extreme rarity or because it is somehow especially 

vulnerable to extinction or extirpation, typically with 5 or fewer occurrences. 

S2: Imperiled because of rarity or because other factors demonstrably make it very 

vulnerable to extinction (extirpation), typically with 6-20 occurrences. 

S3: Rare, uncommon or threatened, but not immediately imperiled, typically with 21-100 

occurrences. 

S4:Not rare and apparently secure, but with cause for long-term concern, usually with more 

than 100 occurrences. 

S5:Demonstrably widespread, abundant, and secure. 

SNR = Not yet ranked; B= breeding; N= nonbreeding 

NPC Reg. Shorebird Plan: 4: High concern; 3: Mod concern; 2: Low concern; 1-no risk 

Landbird Conservation Plan: I: Increasing; D: Declining 

Birds of Management Concern, Region 1 USFWS: 

BCC/BCR: BCC/Birds of Conservation Concern/Regional 

BCC/N: BCC/National 

BCC: Birds of Conservation Concern 

GBBDC: Gamebirds below desired condition 

N. American Waterfowl Management Plan: D-decreasing long-term trend 

Willamette Valley/Puget Trough/Georgia Basin Ecoregional Assessment (TNC): 

Number indicated Refuge contribution (as percent) of total known occurrence (EO) score. 

Species for which the Refuge contributes <10% for either measure are not indicated on this 

sheet. 

Other Plans: X- Addressed in Plan, no specific category 

Table 3. Sources/Criteria for Potential Resources of Concern Table:

North American Waterfowl Management Plan, 2004 Strategic Guidance. Long term 

trends in breeding populations (1970-2003). All species occurring on RNWR with a 

decreasing long-term trend.

______________________________________________________________________________________________ Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

______________________________________________________________________________________________ 

F-12

Appendix F. Biological Resources of Concern
USFWS Birds of Conservation Concern 2002 . Table 41, Region 1 (Pacific Region) BCC 

2002 List; Table 8. Bird Conservation Region (BCR) 5 (Northern Pacific Forest-U.S. only) 

BCC 2002 List; USFWS Division of Migratory Bird Management 2007 (Draft), Gamebirds 

Below Desired Condition (GBBDC). All species occurring on RNWR.

Conservation Strategy For Landbirds in Lowlands and Valleys of Western Oregon 

and Washington. March 2000. Bob Altman, American Bird Conservancy. Prepared for 

Oregon-Washington Partners in Flight. All species occurring on RNWR with significantly 

declining trends.

North Pacific Coast Regional Shorebird Management Plan. 2000. Martin Drut and 

Joseph Buchanan. All species occurring on RNWR with a regional score above 1 (no risk).

Washington Natural Heritage Plan. 2007, revised 2009. All species and community types 

occurring on RNWR. 

Pacific Flyway Management Plan for the Cackling Canada Goose. Pacific Flyway 

Council, USFWS. 1999.

Pacific Flyway Management Plan for the Dusky Canada Goose. Pacific Flyway Council, 

USFWS. 2008.

Pacific Flyway Management Plan for the Aleutian Canada Goose. Pacific Flyway 

Council, USFWS. 1999.

Washington Comprehensive Wildlife Conservation Strategy. Washington Dept. of Fish 

and Wildlife, Olympia, WA. 2005. All species ocurring on RNWR.

Willamette Valley- Puget Trough- Georgia Basin Ecoregional Assessment. The Nature 

Conservancy, Portland, OR. 2004. 

Species with >10% occurrences of each analysis area on RNWR. 

Northwest Oregon-Southwest Washington Canada Goose Agricultural Depredation 

Control Plan. Pacific Flyway Council, USFWS/USDA. Portland, OR 1998.

Rare, Threatened and Endangered Species of Oregon. Oregon Natural Heritage 

Program, March 2007.

______________________________________________________________________________________________ Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

______________________________________________________________________________________________ 

Appendix F. Biological Resources of Concern F-13 
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

F-14 Appendix F. Biological Resources of Concern 

Table 4. Priority Resources of Concern 

Focal 

Species Habitat Type Habitat Structure Life History Requirement Other Benefiting Species 

Riparian 

Swainson’s 

thrush 

Bottomland Forest 

-mid to late 

successional with 

intact understory 

(Fraxinus 

latifolia/Populus 

trichocarpa/ 

Cornus stolonifera/ 

Urtica dioica) 

Shrub layer cover >50% 

with >60% of native 

shrubs; canopy cover >50% 

(Ref: PIF 2000 p. 81) 

Breeding 

song sparrow, Bewick’s 

wren, house wren, pileated 

woodpecker, downy 

woodpecker, black-headed 

grosbeak, red-eyed vireo, 

Pacific-slope flycatcher, 

tree swallow, great blue 

heron (nesting), bald eagle 

(nesting, roosting) 

Willow 

flycatcher 

Bottomland Forest 

- 

early successional, 

willow 

(Salix 

lasiandra/Urtica 

dioica) 

Patchy shrub layer, 1-4 m 

tall, with 30-80% cover and 

scattered herbaceous 

openings; canopy trees >4 

m covering <20% of 

landscape (Ref: PIF 2000 

pp 75) 

Breeding yellow warbler, song 

sparrow 

Bewick’s 

wren 

Bottomland Forest 

- 

Ash Forest with 

little shrub layer 

(Fraxinus 

latifolia/Carex 

deweyana/Urtica 

dioica) 

Canopy cover >50% ash 

dominated, Shrub layer 

<20% consisting of native 

floodplain species 

(snowberry, rose, spirea), 

herb layer >50 native 

species consisting of nettle 

and Carex (based on 

Christy 2004) 

Breeding, 

year-round 

for 

benefiting 

species 

s.-b. white-breasted 

nuthatch, western woodpeewee, house wren, tree 

swallow, song sparrow, 

downy woodpecker, 

pileated woodpecker 

Grassland/Pasture/Old Field/Wet Meadow 

Savannah 

sparrow 

(western 

ssp) 

Dry (Native) 

Prairie – moderate 

to tall 

Manage fallow fields, 

pastures, and/or native 

prairies in variable heights 

of 6-24 inch, >90% grass 

forb cover, <5% shrub 

cover, patches of >50 acres 

(PIF 2000 pp 44) 

Breeding 

savannah sparrow, northern 

harrier, short-eared owl, 

western meadowlark, graytailed vole, streaked horned 

lark, Oregon vesper 

sparrow, western pond 

turtle, lazuli bunting, 

nesting waterfowl 

Dusky 

Canada 

goose 

Agricultural 

pastures – small 

adjoining water 

Short grass (<6”); pastures 

<100 acres adjacent to 

wetlands, (legumes?) 

(refine with Dusky meeting) 

Foraging 

other Canada geese, 

American wigeon, great 

blue heron, American pipit, 

streaked horned lark (pipits 

and larks prefer grazed 

pasture), short-eared owl, 

raptors, coyote, great 

egrets, sandhill crane (feed 

on voles), black-bellied 

plover, semipalmated 

plover, Wilson’s 

phalarope 
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix F. Biological Resources of Concern F-15 

Focal 

Species Habitat Type Habitat Structure Life History Requirement Other Benefiting Species 

Northern 

Harrier 

Bottomland (wet) 

Prairie 

Short-medium height native 

emergent wetland plant 

species 

Buffer >122 m radius for 

harrier nests, residual duff 

preferred for nesting 

habitat, but no mowing 

before July 15 

(see pg 45 PIF 2000) 

Breeding, 

wintering 

Common yellowthroat, 

American bittern, nesting 

waterfowl, dusky Canada 

goose (feeding), rare plant 

species (lomatium, 

checkermallow), shorteared owl, savannah 

sparrow, common snipe, 

song sparrow, western 

meadowlark 

Cackling 

goose 

Agricultural 

Pastures 

Short grass (<6”); pastures 

>100 acres, (legumes?) Foraging 

other Canada and cackling 

geese, great blue heron, 

American pipit, streaked 

horned lark (pipits and 

larks prefer grazed 

pasture), short-eared owl, 

raptors, coyote, great egret, 

sandhill crane (feed on 

voles), black-bellied 

plover, semipalmated 

plover, Wilson’s 

phalarope 

Forest Types 

Orangecrowned 

warbler 

Mixed Coniferous/ 

Deciduous Forest 

In early successional 

forests provide an average 

of >30% cover of 

deciduous shrubs and small 

trees (<15 feet tall) 

All, 

breeding 

Rufous hummingbird, 

Wilson’s warbler, 

MacGillivray’s warbler, 

willow flycatcher, 

Bewick’s wren, song 

sparrow, spotted towhee 

Slenderbilled 

whitebreasted 

nuthatch 

Oak Savannah/ 

Woodland 

Maintain and provide: 

Contiguous minimum stand 

size 100 acre. 

Canopy 40 to 80% with 

non-oak cover less than 

10%. Mean DBH of oak 

should exceed 21 inches 

with 20% greater than 28 

inches. (RNA 129 ac) 

(Ref: PIF 2000, pp 55) 

Breeding, 

year-round 

western pond turtle, 

Bewick’s wren, western 

skink, northern alligator 

lizard, western gray 

squirrel, house wren 

Wetland Types 

Mallard 

Emergent wetlands 

– winter water 

depth 4-18 inches 

Shallow water depths 

averaging 4-18” over 75% 

of the wetland; largely 

native emergent vegetative 

community Dabbling ducks 

use 4-9 inches with most 

species using lower end of 

range (Ref: Frederickson in

wintering 

Other ducks, tundra swans, 

western painted turtle, 

yellow-headed blackbird 

(could be focal species), 

common snipe, long-billed 

dowitcher, black-necked 

stilt, rails 
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

F-16 Appendix F. Biological Resources of Concern 

Focal 

Species Habitat Type Habitat Structure Life History Requirement Other Benefiting Species 

Bookout), low/no velocity; 

(flood strategy could 

include incremental floodup to allow dabblers staged 

access to appropriate 

depths), >40% cover of >10 

genera of native (or 

desirable non-native) short 

and tall emergent plants 

Dusky 

Canada 

goose 

Wet meadow 

(Emergent 

wetlands - <4 

inches of water) 

Potential plants species 

include Carex obnupta, 

Juncus effusus, reed 

canarygrass (mowed), 

Juncus bufonus. 

Mowed (preseason) to <6 

inch, flooding of critical 

dusky areas to <4 inch of 

water, minimal hydroperiod 

early Dec. to mid March, 

willow management may 

be necessary with 

encroachment. 

American wigeon, mallard, 

rail, heron, snipe, stilt, 

shorebirds 

Lesser 

Scaup 

Permanent 

wetlands (Post 

Office Lake, Carty 

Lake) 

Water depths 3-10 feet, 

mixed open water and 

submergent vegetation, 

water present in summer 

months, winter depths 

variable with precipitation 

 Ring-necked duck 

Mallard - 

Swans 

Emergent wetlands 

– Semi-permanent 

(Rest Lake, 

Mantrap Lake) 

Summer depths may be 

several inches, winter 

depths 18-36 inches, 

vegetation includes tall 

emergents, wapato, 

submergent vegetation 

Mallard – 

brood water 

(summer) 

Mallard, tundra swan, 

trumpeter swan, wapato, 

amphibians, turtles, 

yellow-headed blackbird 

Water 

Howellia 

– (Federal 

Threatene

d) 

Ephemeral Vernal 

ponds 

Seasonal pools 

<20% reed canary grass, 

water depth dry in late 

summer, depths <36 inches 

spring, >30% canopy cover 

predominately ash, fish 

absent 

all Amphibians 

Sandhill 

crane 

Tidally influenced 

wetlands 

(Campbell Lake, 

Fowler Lake, Boot 

Lake) 

Hydroperiod and depth 

variable with river. Water 

body has open water, 

submergent, and emergent 

wetland types. Tall 

emergents <40% of 

wetland 

Wintering 

Anadromous fish, geese, 

herons, shorebirds, all 

dabbling ducks, swans 
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix F. Biological Resources of Concern F-17 

Focal 

Species Habitat Type Habitat Structure Life History Requirement Other Benefiting Species 

Agricultural 

Sandhill 

cranes Croplands Corn and other grain crops Foraging Canada geese, American wigeon, mallard 

Riverine Habitat 

Coastal 

cutthroat 

trout 

(tidally connected) 

Riverine habitats 

(Gee Creek, 

Campbell Slough) 

Barrier free, water 

quality/chemistry/ 

Temperature, intact riparian 

corridor, Seven day 

minimum intragravel DO 

6.5 mg oxygen/liter, 

Temperature <73 

Fahrenheit 

Anadromous 

fish rearing, 

lamprey 

spawning, 

connectivity 

between 

spawning 

habitat/river 

Coho (Lower Columbia 

ESU), Chinook salmon 

(Lower Columbia ESU), 

Pacific lamprey, western 

brook lamprey, steelhead, 

bald eagle (foraging) 

 
 Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

F-18 Appendix F. Biological Resources of Concern 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix G. Compliance Statement G-1 

Appendix G. Statement of Compliance 

STATEMENT OF COMPLIANCE

for Implementation of the 

Ridgefield National Wildlife Refuge, Clark County, Washington 

Comprehensive Conservation Plan 

The following executive orders and legislative acts have been reviewed as they apply to 

implementation of the Comprehensive Conservation Plan for the Ridgefield National Wildlife 

Refuge, located in Washington state. 

1. National Environmental Policy Act (1969). (42 U.S.C. 4321 et seq.). The planning process has 

been conducted in accordance with National Environmental Policy Act Implementing Procedures, 

Department of the Interior and Service procedures, and has been performed in coordination with the 

affected public. The requirements of the National Environmental Policy Act (NEPA)(42 U.S.C. 

4321 et seq.) and its implementing regulations in 40 CFR Parts 1500-1508 have been satisfied in the 

procedures used to reach this decision. These procedures included: the development of a range of 

alternatives for the CCP; analysis of the likely effects of each alternative; and public involvement 

throughout the planning process. An environmental assessment (EA) was prepared for the project 

that integrated the Draft CCP management objectives and alternatives into the EA and NEPA 

process. The Draft CCP and EA was released for a 30-day public comment period, which ended on 

July 16, 2010. The affected public was notified of the availability of these documents through a 

Federal Register notice, news releases to local newspapers, the Service’s refuge planning website, 

and a planning update. Copies of the Draft CCP/EA and planning updates were distributed to an 

extensive mailing list. The CCP was revised based on public comment received on the draft 

documents. 

2. National Historic Preservation Act (1966). (16 U.S. C.470 et seq.). The management of 

archaeological and cultural resources of the refuge will comply with the regulations of Sections 106 

and 110 of the National Historic Preservation Act. The Refuge contains a number of prehistoric and 

historic sites, one site included in the National Register of Historic Places (NRHP), and one site 

eligible for inclusion in the NRHP. No historic properties are known to be affected by the proposed 

action, based on the criteria of an effect or adverse effect as an undertaking defined in 36 CFR 800.9 

and Service Manual 614 FW2. However, determining whether a particular action has the potential to 

affect cultural resources is an ongoing process that occurs as step-down and site-specific project 

plans are developed. The Service will comply with the National Historic Preservation Act if any 

management actions have the potential to affect any historic properties which may be present. 

3. Executive Order 12372. Intergovernmental Review. Coordination and consultation with 

affected Tribal, local and State governments, other Federal agencies, and local interested persons has 

been completed through personal contact by the Project Leader and Refuge Manager. 

4. Executive Order 13175. Consultation and Coordination with Indian Tribal Governments. 

As required under Secretary of the Interior Order 3206 American Indian Tribal Rights, FederalTribal Responsibilities, and the Endangered Species Act, the Project Leader consulted and 

coordinated with Chinook and Cowlitz Tribes regarding the proposed action. Specifically, the 

Service coordinated with the Chinook and Cowlitz Tribes throughout the Service's planning process 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

G-2 Appendix G. Compliance Statement

over the past 4 years in developing the Refuge's Comprehensive Conservation Plan. The Tribes had 

the opportunity to review and provide input to the CCP Alternatives. 

5. Executive Order 12898. Federal Actions to Address Environmental Justice in Minority and 

Low-Income Populations. All Federal actions must address and identify, as appropriate, 

disproportionally high and adverse human health or environmental effects of its programs, policies, 

and activities on minority populations, low-income populations, and Indian Tribes in the United 

States. The CCP was evaluated and no adverse human health or environmental effects were 

identified for minority or low-income populations, Indian Tribes, or anyone else. 

6. Wilderness Act. The Service has evaluated the suitability of the Refuge for wilderness 

designation and concluded that the Refuge does not meet the basic criteria for inclusion into the 

National Wilderness Preservation System (see Appendix E, Wilderness Review). 

7. National Wildlife Administration Act of 1966, as amended by The National Wildlife Refuge 

System Improvement Act of 1997 (16 U.S.C. 668dd-668ee). The National Wildlife Refuge System 

Improvement Act (Public Law 105-57, Improvement Act) requires the Service to develop and 

implement a CCP for each refuge. The CCP identifies and describes refuge purposes; refuge vision 

and goals; fish, wildlife, and plant populations and related habitats; archaeological and cultural 

values of the refuge; issues that may affect populations and habitats of fish, wildlife, and plants; 

actions necessary to restore and improve biological diversity on the refuge; and opportunities for 

wildlife-dependent recreation, as required by the Act. 

During the CCP process the Project Leader and Refuge Manager evaluated all existing and proposed 

refuge uses. Priority wildlife-dependent uses (hunting, fishing, wildlife observation and 

photography, environmental education and interpretation) are considered automatically appropriate 

under Service policy and thus exempt from appropriate uses review. Uses that were found Not 

Appropriate include: allowing dogs on refuge (other than dogs used in waterfowl hunting); jogging; 

bicycle use; horseback riding; berry picking; and providing a kayak launching facility (Appendix A). 

Compatibility Determinations have been prepared for the following uses: waterfowl hunting, fishing, 

nonconsumptive uses (wildlife observation and photography, interpretation, and environmental 

education), mosquito and disease vector management, grazing, haying, crop production, research, 

and environmental interpretation at the Cathlapotle Plankhouse. All of these were found to be 

compatible with refuge purposes and the System mission with stipulations specified in each of the 

compatibility determinations (Appendix B). 

8. EO 13186. Responsibilities of Federal Agencies to Protect Migratory Birds. This order directs 

departments and agencies to take certain actions to further implement the Migratory Bird Treaty Act. 

A provision of the order directs Federal agencies to consider the impacts of their activities, especially 

in reference to birds on the Fish and Wildlife Service’s list of Birds of Conservation (Management) 

Concern (BCC). It also directs agencies to incorporate conservation recommendations and objectives 

in the North American Waterbird Conservation Plan and bird conservation plans developed by 

Partners in Flight into agency planning. The effects of all alternatives to refuge habitats used by 

migratory birds were assessed within the Draft CCP and EA. 

9. Endangered Species Act. (16 U.S.C. 1531-1544). This Act provides for the conservation of 

threatened and endangered species of fish, wildlife, and plants by Federal action and by encouraging 

the establishment of state programs. Section 7 of the Act requires consultation before initiating 

Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

G-4 Appendix G. Compliance Statement
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix H. Glossary H-1 

Appendix H. Glossary

Abbreviations

Act National Wildlife Refuge System Improvement Act of 1997 

 (also Improvement Act or NWRSIA) 

ABC American Bird Conservancy 

ADA Americans with Disabilities Act

AHPA Archaeological and Historic Preservation Act 

ARPA Archaeological Resources Protection Act 

ATV All Terrain Vehicles

AUD Appropriate Use Determination 

BCC Birds of Conservation Concern 

BIDEH Biological Diversity, Integrity and Environmental Health

BP Before Present 

CCP Comprehensive Conservation Plan 

CD Compatibility Determination

CFR Code of Federal Regulations 

CRFPO Columbia River Fisheries Program Office 

COE U. S. Army Corps of Engineers 

CWCS Comprehensive Wildlife Conservation Strategy 

CWTD Columbian white-tailed deer

DO Dissolved oxygen

DPS Distinct Population Segment 

EA Environmental Assessment

EE Environmental Education

EPA U.S. Environmental Protection Agency 

ESU Evolutionarily Significant Unit

FCRPS Federal Columbia River Power System 

FWS U.S. Fish and Wildlife Service (also, Service, USFWS) 

GAP Gap Analysis Program 

GIS Geographic Information System 

IAC Interagency Committee for Outdoor Recreation (Washington State) 

IBA Important Bird Area 

Improvement Act National Wildlife Refuge System Improvement Act of 1997 

(also Act, NWRSIA) 

IPM Integrated Pest Management

LE Law Enforcement

MAPS Monitoring Avian Productivity System 

MBCC Migratory Bird Conservation Commission 

MMS Maintenance Management System

MOA Memorandum of Agreement 

MOU Memorandum of Understanding 

NAGPRA Native American Graves Repatriation Act

NAS National Audubon Society 

NEPA National Environmental Policy Act

NHPA National Historic Preservation Act

NRHP National Register of Historic Places
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

H-2 Appendix H. Glossary

NTU Nephelometric turbidity unit, a measure of water turbidity 

NWR National Wildlife Refuge

NWRS National Wildlife Refuge System

NWRSIA National Wildlife Refuge System Improvement Act of 1997 

ODFW State of Oregon Department of Fish and Wildlife 

PCJV Pacific Coast Joint Venture

PIF Partners in Flight 

R1 Region 1 of the FWS (WA, OR, CA, HI, NV, ID) 

RNA Research Natural Area

ROC Resource of Concern 

RONS Refuge Operating Needs System

ROS Recreational Opportunity Spectrum 

SCORP Statewide Comprehensive Outdoor Recreation Plan 

Service U.S. Fish and Wildlife Service (also FWS, USFWS) 

TES Threatened and Endangered Species 

TNC The Nature Conservancy 

USFWS U.S. Fish and Wildlife Service 

WDFW State of Washington Department of Fish and Wildlife 

WNHP Washington Natural Heritage Program 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix H. Glossary H-3 

Glossary 

Accessible wetland. Wetland without fences or vegetative barriers (tall, dense vegetation) at its 

margins. 

Alluvium. Sediment transported and deposited in a delta or riverbed by flowing water. 

Adaptive Management. The rigorous application of management, research, and monitoring to gain 

information and experience necessary to assess and modify management activities. A process that 

uses feedback from refuge research and monitoring and evaluation of management actions to support 

or modify objectives and strategies at all planning levels. (Service Manual 602 FW 1.4) 

Alternative. Different sets of objectives and strategies or means of achieving refuge purposes and 

goals, helping fulfill the Refuge System mission, and resolving issues. (Service Manual 602 FW 1.6). 

The “no action” alternative is current refuge management, while the “action” alternatives are all other 

alternatives.

Appropriate Use. A proposed or existing use on a refuge that meets at least one of the following 

four conditions: 

(1) The use is a wildlife-dependent recreational use as identified in the Improvement Act. 

(2) The use contributes to fulfilling the refuge purpose(s), the Refuge System mission, or goals or 

objectives described in a refuge management plan approved after October 9, 1997, the date the 

Improvement Act was signed into law. 

(3) The use involves the take of fish and wildlife under State regulations. 

(4) The use has been found to be appropriate as specified in section 1.11 of the USFWS Appropriate 

Use Policy (603FW1). 

Approved Refuge Boundary. A National Wildlife Refuge boundary approved by the National or 

Regional Fish and Wildlife Service Director. Within this boundary, the Service may negotiate with 

landowners to acquire lands not already owned by the Service. (Modified from Region 1 Landowner 

Guide, USFWS Division of Refuge Planning.) 

Archaeology. The scientific study of material evidence remaining from past human life and culture. 

(Webster’s II) 

Basalt. A dark dense volcanic rock. (Webster’s II) 

B.P. (Before Present). Used as a designation following radiocarbon dates to express the point from 

which radiocarbon years are measured. This measuring point is arbitrarily taken to be 1950. A date of 

5,200±200 B.P. means that it dates to 5,200 (plus or minus 200) years before 1950. 

Benefiting resources. Those species, species groups, or resources expected to benefit from actions 

taken for a Resource of Concern. 

Birds of Conservation Concern. A category assembled by the U.S. Fish and Wildlife Service 

Division of Migratory Birds identifying the migratory and non-migratory species (beyond those 

already designated as Federally threatened or endangered) that represent the Division’s highest 

conservation priorities. (FWS, Division of Migratory Birds) 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

H-4 Appendix H. Glossary

Biological Diversity (also Biodiversity). The variety of life and its processes, including the variety 

of living organisms, the genetic differences among them, and communities and ecosystems in which 

they occur (FWS Manual 601FW3). The System’s focus is on indigenous species, biotic 

communities, and ecological processes. 

Biological Integrity. Biotic composition, structure, and functioning at genetic, organism, and 

community levels comparable with historic conditions, including the natural biological processes that 

shape genomes, organisms, and communities. (FWS Manual 601FW3) 

Candidate species. Plant or animal species for which FWS or NOAA Fisheries has on file sufficient 

information on biological vulnerability and threats to support a proposal to list as endangered or 

threatened. (FWS, Endangered Species Glossary, http://www.fws.gov/endangered/glossary.html) 

Categorical Exclusion. A category of actions that do not individually or cumulatively have a 

significant effect on the human environment and have been found to have no such effect in 

procedures adopted by a Federal agency pursuant to the National Environmental Policy Act (40 CFR 

1508.4). 

Chinookan. The speakers of several closely related languages who historically occupied the 

Columbia River from the upstream end of the Columbia Gorge (near the present town of The Dalles, 

Oregon), to the river's mouth, and adjacent portions of the coasts of Washington and Oregon. Lower 

Chinook was spoken by peoples living on both sides of the river's mouth, and Upper Chinook spoken 

along both sides from the river's estuary upriver through the Gorge. (Silverstein 1990) 

Colonial nesting birds. Birds that nest in groups. At Ridgefield, colonial nesting birds are 

waterbirds (great blue herons and great egrets). 

Columbia Basin. The region drained by the Columbia River system. 

Compatible Use. A wildlife-dependent recreational use or any other use of a refuge that, in the 

sound professional judgment of the Director, will not materially interfere with or detract from the 

fulfillment of the Mission of the System or the purposes of the refuge (Service Manual 603 FW 3.6). 

A compatibility determination supports the selection of compatible uses and identifies stipulations or 

limits necessary to ensure compatibility.

Composition (plant). The inventory of plant species found in any particular area. 

Comprehensive Conservation Plan. A document that describes the desired future conditions of a 

refuge or planning unit and provides long-range guidance and management direction to achieve the 

purpose(s) of the refuge; helps fulfill the mission of the System; maintains and, where appropriate, 

restores the biological integrity, diversity, and environmental health of each refuge and the System; 

helps achieve the goals of the National Wilderness Preservation System, if appropriate; and meets 

other mandates. (FWS Habitat Management Planning policy, 602 FW 1.4) 

Connectivity. The arrangement of habitats that allows organisms and ecological processes to move 

across the landscape; patches of similar habitats are either close together or linked by corridors of 

appropriate vegetation. The opposite of fragmentation.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix H. Glossary H-5 

Conservation Targets (also see Resources of Concern; Priority Species, Species Groups, and 

Communities). Term used by land management agencies and conservation organizations to describe 

the resources (ecological systems, ecological communities, species, species groups, or other natural 

resources) selected as the focus of conservation actions. (Adapted from Low, Functional Landscapes, 

2003.) 

Consumptive use. Recreational activities, such as hunting and fishing that involve harvest or 

removal of wildlife or fish, generally to be used as food by humans. 

Contaminants or Environmental contaminants. Chemicals present at levels greater than those 

naturally occurring in the environment resulting from anthropogenic or natural processes that 

potentially result in changes to biota at any ecological level. (USGS, assessing EC threats to lands 

managed by USFWS.) Pollutants that degrade other resources upon contact or mixing. (Adapted 

from Webster’s II.) 

Cooperative Agreement. An official agreement between two parties. 

Cover. The estimated percent of an area, projected onto a horizontal surface, occupied by a 

particular plant species.

Cultural Resources. The physical remains, objects, historic records, and traditional lifeways that 

connect us to our nation’s past. (USFWS, Considering Cultural Resources) 

Cultural Resource Inventory. A professionally conducted study designed to locate and evaluate 

evidence of cultural resources present within a defined geographic area. Inventories may involve 

various levels, including background literature search, comprehensive field examination to identify 

all exposed physical manifestations of cultural resources, or sample inventory to project site 

distribution and density over a larger area. Evaluation of identified cultural resources to determine 

eligibility for the National Register follows the criteria found in 36 CFR 60.4. (Service Manual 614 

FW 1.7) 

Decadence. Marked by decay or decline. For plants, showing little or no new growth. (Adapted 

from Merriam-Webster online dictionary.) 

Deciduous. Describes trees and shrubs which shed all of their leaves each year. 

Distinct population segment (DPS). A subdivision of a vertebrate species that is treated as a species 

for purposes of listing under the Endangered Species Act. To be so recognized, a potential distinct 

population segment must satisfy standards specified in a FWS or NOAA Fisheries policy statement 

(See the February 7, 1996, Federal Register, pages 4722-4725). The standards require it to be 

separable from the remainder of and significant to the species to which it belongs. (FWS, Endangered 

Species Glossary, http://www.fws.gov/endangered/glossary.html) 

Disturbance. Significant alteration of habitat structure or composition, or of the behavior or 

wildlife. May be natural (e.g., fire) or human-caused events (e.g., aircraft overflight). 

Drawdown. A lowering of the ground-water surface caused by pumping. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

H-6 Appendix H. Glossary

Ecosystem. A dynamic and interrelating complex of plant and animal communities and their 

associated non-living environment.

Ecosystem Management. Management of natural resources using system-wide concepts to ensure 

that all plants and animals in ecosystems are maintained at viable levels in native habitats and basic 

ecosystem processes are perpetuated indefinitely.

Environmental Assessment. A concise public document, prepared in compliance with the National 

Environmental Policy Act, that briefly discusses the purpose and need for an action, alternatives to 

such action, and provides sufficient evidence and analysis of impacts to determine whether to prepare 

an environmental impact statement or finding of no significant impact (40 CFR 1508.9). 

Endangered Species (Federal). An animal or plant species in danger of extinction throughout all or 

a significant portion of its range. (FWS, Endangered Species Glossary)

Endangered Species (State). A plant or animal species in danger of becoming extinct or extirpated 

in a state within the near future if factors contributing to its decline continue. Populations of these 

species are at critically low levels or their habitats have been degraded or depleted to a significant 

degree.

Environmental Education Study Sites. Outdoor locations where groups of students engage in 

hands-on activities within an environmental education curriculum. 

Environmental Health. Composition, structure, and functioning of soil, water, air, and other abiotic 

features comparable with historic conditions, including the natural abiotic processes that shape the 

environment. (FWS Manual 601FW3) 

Enhance. To improve the condition of an area or habitat, usually for the benefit of certain native 

species.

Evolutionarily significant unit (ESU). A Pacific salmonid stock that is substantially reproductively 

isolated from other stocks of the same species and which represents an important part of the 

evolutionary legacy of the species. Life history, ecological, genetic, and other information can be 

used to determine whether a stock meets these two criteria. NOAA Fisheries uses this designation. 

(FWS, Endangered Species Glossary) 

Experimental population. A population (including its offspring) of a listed species designated by 

rule published in the Federal Register that is wholly separate geographically from other populations 

of the same species. An experimental population may be subject to less stringent prohibitions than 

are applied to the remainder of the species to which it belongs. (FWS, Endangered Species Glossary) 

Extirpated species. A species that no longer survives in regions that were once part of its range, but 

that still exists elsewhere in the wild or in captivity. (FWS, Endangered Species Glossary) 

Finding of No Significant Impact (FONSI). A document prepared in compliance with the National 

Environmental Policy Act, supported by an environmental assessment, that briefly presents why a 

Federal action will have no significant effect on the human environment and for which an 

environmental impact statement, therefore, will not be prepared (40 CFR 1508.13). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix H. Glossary H-7 

Fee hunt (also reservation hunt; regulated hunt). Areas containing designated blinds for 

waterfowl hunting, which are allocated via a lottery system and available for a fee. 

Floodplain. Mostly level land along rivers and streams that may be submerged by floodwater. A 

100-year floodplain is an area which can be expected to flood once in every 100 years. 

Fluvial processes. Referring to the physical interaction of flowing water and the natural channels of 

rivers and streams. (Adapted from Brittanica Online Encyclopedia 

http://www.britannica.com/memberlogin.) 

GAP analysis. Analysis done to identify and map elements of biodiversity that are not adequately 

represented in the nation’s network of reserves. It provides an overview of the distribution and 

conservation status of several components of biodiversity, with an emphasis on vegetation and 

terrestrial vertebrates. (Cassidy et al.1997) 

Goal. Descriptive, open-ended, and often broad statement of desired future conditions that conveys a 

purpose but does not define measurable units. (Service Manual 620 FW 1.6) 

Habitat. Suite of existing environmental conditions required by an organism for survival and 

reproduction. The place where an organism typically lives. 

Habitat Management Plan. A plan that provides refuge managers a decisionmaking process; 

guidance for the management of refuge habitat; and long-term vision, continuity, and consistency for 

habitat management on refuge lands. (FWS Habitat Management Planning policy 620FW1.4) 

Habitat Restoration. Management emphasis designed to move ecosystems to desired conditions 

and processes, and/or to healthy ecosystems. 

Historic Conditions. Composition, structure, and functioning of ecosystems resulting from natural 

processes that we believe, based on sound professional judgment, were present prior to substantial 

human related changes to the landscape. (FWS Manual 601FW3) 

Hydrograph. The annual flow pattern of a river. 

Hydrologic Regime. The normal pattern of rainfall and runoff occurring in an area. 

Important Bird Area (IBA). A site that provides essential habitat for one or more species of birds; 

program coordinated by The American Bird Conservancy and The National Audubon Society. 

Indicator. A measurable characteristic of a key ecological attribute that strongly correlates with the 

status of the key ecological attribute. 

Inholding. Refers to lands within an Approved Refuge Boundary that are not owned by the U.S. 

Fish and Wildlife Service. These can be private lands or lands owned by city, county, state, or other 

federal agencies. 

Integrated Pest Management (IPM). The use of pest and environmental information in conjunction 

with available pest control technologies to prevent unacceptable levels of pest damage by the most 

economical means and with the least possible hazard to persons, property and the environment. (U.S. 

EPA Pesticide Glossary) 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

H-8 Appendix H. Glossary

Interpretation. A teaching technique that combines factual information with stimulating 

explanation (yourdictionary.com). Frequently used to help people understand natural and cultural 

resources. 

Invasive. Nonnative species disrupting and replacing native species. (thebiotechdictionary.com) 

Inventory. A survey of the plants or animals inhabiting an area. 

 

Issue. Any unsettled matter that requires a management decision, e.g., an initiative, opportunity, 

resource management problem, threat to the resources of the unit, conflict in uses, public concern, or 

the presence of an undesirable resource condition. (Service Manual 620 FW 1.6) 

Key ecological attribute. Those aspects of the environment, such as ecological processes or 

patterns of biological structure and composition that are critical to sustain the long-term viability of 

the target. These key ecological attributes are further divided into measurable indicators.

Keystone species. Species who enrich ecosystem function in a unique and significant manner 

through their activities, and the effect is disproportionate to their numerical abundance. Their 

removal initiates changes in ecosystem structure and often loss of diversity. These keystones may be 

habitat modifiers (i.e. Cottonwoods or beavers), predators (ie. puma and coyote) or herbivores (i.e. 

prairie dog). (Sonoran Desert Conservation Plan) 

Lacustrine wetlands. Those areas that are generally permanently flooded and lacking trees, shrubs, 

or emergent vegetation with greater than 30% areal coverage and measuring greater than 20 acres. 

Smaller areas than this can be included if the water depth in the deepest part of the basin exceeds 6.6 

feet at low water. (National Wetlands Inventory) 

Landform. A natural feature of a land surface. (yourdictionary.com) 

Maintenance. The upkeep of constructed facilities, structure and capitalized equipment necessary to 

realize the originally anticipated useful life of a fixed asset. Maintenance includes preventative 

maintenance; cyclic maintenance; repairs; replacement of parts, components, or items of equipment, 

periodic condition assessment; periodic inspections, adjustment, lubrication and cleaning (nonjanitorial) of equipment; painting, resurfacing, rehabilitation; special safety inspections; and other 

actions to assure continuing service and to prevent breakdown. 

Maintenance Management System (MMS). A national database of refuge maintenance needs and 

deficiencies. It serves as a management tool for prioritizing, planning, and budgeting purposes. 

(RMIS descriptions) 

Managed seasonal or semipermanent wetlands. Those wetlands which have existing infrastructure 

(pumps, culverts, water control structures) to manipulate water levels on a seasonal basis, relatively 

independent of water conditions in the surrounding watershed. 

Migration. The seasonal movement from one area to another and back. 

Migratory birds. Those species of birds listed under 50 CFR section 10.13. (FWS Manual 720FW 

1, Policies and Responsibilities of the Migratory Bird Program) 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix H. Glossary H-9 

Monitoring. The process of collecting information to track changes of selected parameters over 

time.

National Environmental Policy Act of 1969. Requires all Federal agencies, including the Service, 

to examine the environmental impacts of their actions, incorporate environmental information, and 

use public participation in the planning and implementation of all actions. Federal agencies must 

integrate NEPA with other planning requirements, and prepare appropriate NEPA documents to 

facilitate better environmental decision making. (40 CFR 1500) 

Native. With respect to a particular ecosystem, a species that, other than as a result of an 

introduction, historically occurred or currently occurs in that ecosystem. (FWS Manual 601FW3) 

National Geodetic Vertical Datum (NGVD). (1) As corrected in 1929, a vertical control measure 

used as a reference for establishing varying elevations. (2) Elevation datum plane previously used by 

the Federal Emergency Management Agency (FEMA) for the determination of flood elevations. 

FEMA currently uses the North American Vertical Datum Plane. (USGS Water Science Glossary) 

National Geodetic Vertical Datum of 1929 (NGVD-29). A geodetic datum derived from a general 

adjustment of the first order level nets of the United States and Canada. It was formerly called "Sea 

Level Datum of 1929" or "mean sea level" (MSL) in the USGS series of reports. Although the datum 

was derived from the average sea level over a period of many years at 26 tide stations along the 

Atlantic, Gulf of Mexico, and Pacific Coasts, it does not necessarily represent local mean sea level at 

any particular place. (USGS Water Science Glossary) 

National Register of Historic Places. The Nation’s master inventory of known historic properties 

administered by the National Park Service. Includes buildings, structures, sites, objects, and districts 

that possess historic, architectural, engineering, archeological, or cultural significance at the national, 

state, and local levels. (USFWS, Considering Cultural Resources) 

National Wildlife Refuge. A designated area of land, water, or an interest in land or water within 

the Refuge System, excluding coordination areas. (FWS Manual 601FW1.3) 

National Wildlife Refuge System. Various categories of areas administered by the Secretary of the 

Interior for the conservation of fish and wildlife, including species threatened with extinction; all 

lands, waters, and interests therein administered by the Secretary as wildlife refuges; areas for the 

protection and conservation of fish and wildlife that are threatened with extinction; wildlife ranges; 

game ranges; wildlife management areas; or waterfowl production areas. 

National Wildlife Refuge System Improvement Act of 1997 (Public Law 105-57). A federal law 

that amended and updated the National Wildlife Refuge System Administration Act of 1966 (16 

U.S.C. 668). 

Nephelometric turbidity unit (NTU). Unit of measure for the turbidity of water. Essentially, a 

measure of the cloudiness of water as measured by a nephelometer. Turbidity is based on the amount 

of light that is reflected off particles in the water. (USGS Water Science Glossary of Terms)

Nonconsumptive recreation. Recreational activities that do not involve harvest, removal or 

consumption of fish, wildlife or other natural resources. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

H-10 Appendix H. Glossary

Noxious Weed. A plant species designated by Federal or State law as generally possessing one or 

more of the following characteristics: aggressive or difficult to manage; parasitic; a carrier or host of 

serious insect or disease; or non-native, new, or not common to the United States, according to the 

Federal Noxious Weed Act (PL 93-639), a noxious weed is one that causes disease or had adverse 

effects on man or his environment and therefore is detrimental to the agriculture and commerce of 

the United States and to the public health. 

Objective. A concise statement of what we want to achieve, how much we want to achieve, when 

and where we want to achieve it, and who is responsible for the work. Objectives derive from goals 

and provide the basis for determining strategies, monitoring refuge accomplishments, and evaluating 

the success of strategies. Make objectives attainable, time-specific, and measurable. (Service Manual 

620 FW 1.6) 

Operations. Activities related to the normal performance of the functions for which a facility or 

item of equipment is intended to be used. Costs such as utilities (electricity, water, sewage) fuel, 

janitorial services, window cleaning, rodent and pest control, upkeep of grounds, vehicle rentals, 

waste management, and personnel costs for operating staff are generally included within the scope of 

operations. 

Pacific Flyway. One of several major north-south travel corridors for migratory birds. The Pacific 

Flyway is west of the Rocky Mountains. 

Palatable grass. Short (generally less than 6 inches tall) actively growing grass preferred by Canada 

geese and certain other waterfowl (e.g., American wigeon). 

Palustrine Wetlands. Wetlands that may or may not be permanently flooded and typically 

recognized by the presence of trees, shrubs, or herbaceous emergent vegetation. May include nonvegetated areas measuring less than 20 acres in extent and with water depths shallower than 6.6 feet 

in the deepest part of the basin at low water (Cowardin et al. 1979). 

Planning Team. The primary U.S. Fish and Wildlife staff and others who played a key role in 

developing and writing the CCP. Planning teams are interdisciplinary in membership and function. 

Teams generally consist of a Planning Team Leader, Refuge Manager and staff biologists, a state 

natural resource agency representative, and other appropriate program specialists (e.g., social 

scientist, ecologist, recreation specialist). We also will ask other Federal and Tribal natural resource 

agencies to provide team members, as appropriate. The planning team prepares the CCP and 

appropriate NEPA documentation. (Service Manual 620 FW 1.6) 

Plant Association. A classification of plant communities based on the similarity in dominants of all 

layers of vascular species in a climax community (e.g., Oregon white oak/ovalleaf viburnum/poison 

oak plant association).

Plant Community. An assemblage of plant species unique in its composition; occurs in particular 

locations under particular influences; a reflection or integration of the environmental influences on 

the site such as soils, temperature, elevation, solar radiation, slope, aspect, and rainfall; denotes a 

general kind of climax plant community (e.g., Oregon white oak woodland). 

Polychlorinated biphenyls (PCBs). A group of synthetic, toxic industrial chemical compounds once 

used in making paint and electrical transformers, which are chemically inert and not biodegradable. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix H. Glossary H-11

PCBs were frequently found in industrial wastes, and subsequently found their way into surface and 

ground waters. As a result of their persistence, they tend to accumulate in the environment. In terms 

of streams and rivers, PCBs are drawn to sediment, to which they attach and can remain virtually 

indefinitely. Although virtually banned in 1979 with the passage of the Toxic Substances Control 

Act, they continue to appear in the flesh of fish and other animals (USGS Water Science Glossary). 

Portland Basin or Portland-Vancouver Basin. A 900 square mile basin generally defined as the 

area of low topography at the confluence of the Willamette and Columbia Rivers, including the 

region along the Columbia River from the Sandy River downstream to the Cowlitz River, and the 

Willamette River north (downstream) from its falls at Oregon City to its confluence with the 

Columbia River (Ames 1999). Geologically, the Portland Basin proper begins roughly at the Sandy 

River and extends downstream to the confluence of the Lewis and Columbia rivers. (Evarts et al.

2009). 

Preferred Alternative. This is the alternative determined [by the decision maker] to best achieve 

the Refuge purpose, vision, and goals; to best contribute to the Refuge System mission; to best 

address the significant issues; and to be consistent with principles of sound fish and wildlife 

management.

Priority Public Uses. Hunting, fishing, wildlife observation and photography, environmental 

education and interpretation, where compatible, are identified under the National Wildlife Refuge 

System Improvement Act of 1997 as the six priority public uses of the National Wildlife Refuge 

System. 

Public. Individuals, organizations, and groups; officials of Federal, State, and local government 

agencies; Indian tribes; and foreign nations. It may include anyone outside the planning team. It 

includes those who may or may not have indicated an interest in Service issues and those who may 

be affected by Service decisions.

Raptor. A category of carnivorous birds, most of which have heavy, sharp beaks, strong talons, and 

take live prey (e.g., peregrine falcon, bald eagle). 

Refuge Operating Needs System (RONS). A national database of unfunded refuge operating needs 

required to meet and/or implement station goals, objectives, management plans, and legal mandates. 

It is used as a planning, budgeting, and communication tool describing funding and staffing needs of 

the Refuge System. 

Refuge Purpose(s). The purposes specified in or derived from the law, proclamation, executive 

order, agreement, public land order, donation document, or administrative memorandum establishing, 

authorizing, or expanding a refuge, refuge unit, or refuge subunit. For refuges that encompass 

congressionally designated wilderness, the purposes of the Wilderness Act are additional purposes of 

the refuge. (Service Manual 620 FW 1.6). 

Research Natural Area (RNA). Special designation areas on NWRs established to: (1) Preserve 

examples of major ecosystem types or other outstanding physical or biological phenomena; (2) 

Provide research and educational opportunities; and (3) Preserve a full range of genetic and 

behavioral diversity for native plants and animals, including endangered or threatened species. 

(USFWS 1981). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

H-12 Appendix H. Glossary

Residual cover. In pastures or grasslands, tall decadent grass and/or forbs left standing through the 

fall and winter seasons. 

Resource of Concern (ROC). All plant and/or animal species, species groups, or communities 

specifically identified in refuge purpose(s), System mission, or international, national, regional, State, 

or ecosystem conservation plans or acts. For example, waterfowl and shorebirds are a resource of 

concern on a refuge whose purpose is to protect “migrating waterfowl and shorebirds.” Federal or 

State threatened and endangered species on that same refuge are also a resource of concern under 

terms of the respective endangered species acts. (FWS Habitat Management Planning policy, 620 

FW1.4). 

Restore. To bring back to a former or original condition. (Webster’s II). 

Revenue Sharing. Service payments (government lands are exempt from taxation) made to counties 

in which national wildlife refuges reside. These payments may be used by the counties for any 

governmental purpose such as, but not limited to, roads and schools. (USFWS Revenue sharing 

pamphlet.) 

Riparian. Refers to an area or habitat that is transitional from terrestrial to aquatic ecosystems; 

including streams, lakes wet areas, and adjacent plant communities and their associated soils which 

have free water at or near the surface; an area whose components are directly or indirectly attributed 

to the influence of water; of or relating to a river; specifically applied to ecology, “riparian” describes 

the land immediately adjoining and directly influenced by streams. For example, riparian vegetation 

includes any and all plant life growing on the land adjoining a stream and directly influenced by the 

stream.

Shorebirds. Sandpipers, plovers, and their close relatives of similar size and ecology, often 

associated with coastal and inland wetlands. (Sibley Guide to Birds 2000.) 

Songbirds (Also Passerines). A category of medium to small, perching landbirds. Most are 

territorial singers and migratory. 

Source. An extraneous factor that causes a stress (the most proximate cause). (TNC 2000) 

Species of concern (Federal). An informal term referring to a species that might be in need of 

conservation action. This may range from a need for periodic monitoring of populations and threats 

to the species and its habitat, to the necessity for listing as threatened or endangered. Such species 

receive no legal protection and use of the term does not necessarily imply that a species will 

eventually be proposed for listing. (FWS, Endangered Species Glossary) 

Step-down Management Plan. A plan that provides specific guidance on management subjects 

(e.g., habitat, public use, fire, safety) or groups of related subjects. It describes strategies and 

implementation schedules for meeting CCP goals and objectives. (Service Manual 620 FW 1.6) 

Strategy. A specific action, tool, technique, or combination of actions, tools, and techniques used to 

meet unit objectives. (Service Manual 620 FW 1.6) 

Stress. The impairment or degradation of a key ecological attribute for a conservation target. (TNC 

2000) 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix H. Glossary H-13

Thatch. The dense covering of cut grass that remains after mowing. Thatch inhibits growth of new 

grass and also inhibits goose foraging.

Threatened Species (Federal). An animal or plant species likely to become endangered within the 

foreseeable future throughout all or a significant portion of its range. (FWS, Endangered Species 

Glossary)

Threatened Species (State). A plant or animal species likely to become endangered in a State 

within the near future if factors contributing to population decline or habitat degradation or loss 

continue. 

Turbidity. The amount of particulate matter that is suspended in water, measured in NTUs 

(nephelometric turbidity units). Clear water generally measures less than 10 NTU. 

Vegetation Type (Also Habitat Type, Forest Cover Type). A land classification system based 

upon the concept of distinct plant associations. 

Vision Statement. A concise statement of what the planning unit should be, or what we hope to do, 

based primarily upon the Refuge System mission and specific refuge purposes, and other mandates. 

The vision statement for the refuge is tied to the mission of the Refuge System; the purpose(s) of the 

refuge; the maintenance or restoration of the ecological integrity of each refuge and the Refuge 

System; and other mandates. (Service Manual 620 FW 1.6) 

Wapato Valley. Name given by Lewis and Clark to the lowlands (floodplain) of the Portland Basin; 

an ecologically rich area characterized by annual spring flooding and a mosaic of wetlands, wet 

meadows and prairies, shrub swamps, and bottomland forest. (Ames 1999) 

Waterfowl. Resident and migratory ducks, geese, and swans. 

Water quality. A term used to describe the chemical, physical, and biological characteristics of 

water, usually in respect to its suitability for a particular purpose. 

Watershed. The land area that drains water to a particular stream, river, or lake. It is a land feature 

that can be identified by tracing a line along the highest elevations between two areas on a map, often 

a ridge. Large watersheds, like the Mississippi River basin contain thousands of smaller watersheds. 

Wetlands. Wetlands are lands transitional between terrestrial and aquatic systems where the water 

table is usually at or near the surface or the land is covered by shallow water at some time during the 

growing season of each year. (Service Manual 660 FW 2; Cowardin et al. 1979) 

Permanent wetland. A wetland basin or portion of a basin that is covered with water throughout the 

year in all years except extreme drought. At Ridgefield, these are wetlands and slough remnants 

historically connected to the Columbia River but since cut off from the river by dikes and/or 

cessation of major flooding events. 

Permanent tidal wetlands. On the Refuge, these are freshwater wetlands connected to, and having 

tidal exchange with, the Columbia River. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

H-14 Appendix H. Glossary

Semi-permanent wetland. A wetland basin or portion of a basin where surface water persists 

throughout the growing season of most years. 

Seasonal wetland. A wetland basin or portion of a basin where surface water is present in the early 

part of the growing season but is absent by the end of the season in most years. At Ridgefield, 

seasonal wetlands are typically dry in summer (June-September) and fill with rainwater in fall. 

Wet meadows. Shallowly flooded wetland edges with little to no slope. Flooding is generally of 

short duration. Historically on the lower Columbia River bottomlands, this habitat was dominated by 

Columbia sedge. Today the dominant vegetation is reed canarygrass. 

Wildlife-dependent recreational use. A use of a refuge involving hunting, fishing, wildlife 

observation and photography, or environmental education and interpretation. These are the six 

priority public uses of the Refuge System as established in the National Wildlife Refuge System 

Administration Act, as amended. Wildlife-dependent recreational uses, other than the six priority 

public uses, are those that depend on the presence of wildlife. The Service will also consider these 

other uses in the preparation of refuge CCPs; however, the six priority public uses always will take 

precedence. (Service Manual 620 FW 1.6) 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix I. CCP Team Members I-1 

Appendix I. CCP Team Members

The CCP was developed primarily by core team members. The core planning team consisted of 

persons responsible for the preparation and completion of the Comprehensive Conservation Plan and 

Environmental Assessment. They are the primary strategists, analysts, and writers, and attended all 

team meetings. To avoid scheduling and logistical conflicts, the core team had a limited number of 

participants. 

The extended team, which included professionals from several different agencies, organizations, and 

Fish and Wildlife Service programs, played a supporting role to the core team. Extended team 

members provided critical input early in the alternatives development process, and continued to 

provide review and comment as the document evolved. They attended periodic planning meetings, 

compiled information for use in the plan, and provided comment on portions of the plan within their 

areas of expertise. Extended team members’ varied responsibilities include providing technical 

expertise and assisting with development of objectives, strategies, and alternatives; analysis; writing; 

and reviewing. In addition, content specialists from other agencies, universities, or organizations 

were contacted as needed by members of the core and extended teams for specific planning needs. 

Core and extended team members are listed below.

Table I.1 Ridgefield NWR CCP/EA Core Team Members

Name

Title

(Team Role)

Address

Bob Flores Project Leader 

(May 14, 2007-present)

(Main Refuge contact/lead)

U.S. Fish and Widlife Service 

Ridgefield NWR Complex

29808 NW Main Avenue 

Ridgefield, WA, 98642

Tim Bodeen Project Leader 

(through October 1, 2006)

(Main Refuge contact/lead)

U.S. Fish and Widlife Service 

Ridgefield NWR Complex

301 N. Third

Ridgefield, WA 98642 

Jennifer Brown Refuge Manager

(through September 2009) 

(Refuge Resources and 

Operations; 

Main Refuge contact/lead, 

Oct 2, 2006-May 2007)

Same as Bob Flores

Joe Engler Complex Wildlife Biologist 

(through October 2007)

(Refuge Resources)

Same as Bob Flores

Alex Chmielewski Complex Wildlife Biologist

(March 2009-present)

(Refuge Resources)

Same as Bob Flores
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

I-2 Appendix I. CCP Team Members

Eric Anderson Outdoor Recreation Planner 

(through Feb. 2007) Instructional 

Systems Specialist (Refuge 

Resources and Visitor Services 

Programs) (March 2007-present)

Same as Bob Flores

Ken Morris Conservation Planner 

(Team Leader)

U.S. Fish and Wildlife Service

Division of Planning,Visitor Services 

and Transportation

911 NE 11th Ave

Portland, OR 97213

Table I.2 Extended Team Members

Name Title Address

Fred Paveglio Regional Biologist U.S. Fish and Wildlife Service

1211 SE Cardinal Ct., Suite 100

Vancouver, WA 98683

Kevin Kilbride Assistant Regional Biologist

(Regional IPM Coordinator)

Same as Fred Paveglio

Joe Engler Assistant Regional Biologist

(October 2007-present)

Same as Fred Paveglio

Sam Lohr Fish biologist, Columbia River 

Fisheries Program

U.S. Fish and Wildlife Service

Columbia River Fisheries Program 

Office

1211 SE Cardinal Ct., Suite 100

Vancouver, WA 98683

Mike Marxen Chief, Branch of Visitor Services U.S. Fish and Wildlife Service

Division of Planning,Visitor Services 

and Transportation

911 NE 11th Ave

Portland, OR 97213

Brad Bortner Chief, Division of Migratory 

Birds and Habitat Programs

U.S. Fish and Wildlife Service

Division of Migratory Birds and 

Habitat Programs

911 NE 11th Ave.

Portland, OR 97232-4181

Virginia Parks Cultural Resources U.S. Fish and Wildlife Service

Cultural Resources Team

20555 SW Gerda Lane

Sherwood, OR 97140
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix I. CCP Team Members I-3 

David Anderson District Wildlife Biologist

Washington Dept of Fish and 

Wildlife

Washington Dept. of Fish and Wildlife

PO Box 68

Trout Lake, WA 98650

Brian Calkins Acting Regional Wildlife 

Program Manager

Washington Dept of Fish and 

Wildlife

WDFW

2108 Grand Blvd.

Vancouver, WA 98661

Eric Holman Regional Wildlife Biologist

Washington Dept of Fish and 

Wildlife

Same as Brian Calkins

Brad Bales Migratory Game Bird 

Coordinator, Oregon Dept. of 

Fish and Wildlife

Oregon Dept. of Fish and Wildlife

3406 Cherry Ave NE

Salem, OR 97303

Mark Nebeker Manager, Sauvie Island Wildlife 

Area

Oregon Dept. of Fish and 

Wildlife

Oregon Department of Fish and 

Wildlife

18330 NW Sauvie Island Road 

Portland, OR 97231

Mike Iyall Cowlitz Indian Tribe Cowlitz Indian Tribe

P.O. Box 2547

Longview, WA 98632-8594 

Nathan Reynolds Natural Resources Specialist

Cowlitz Indian Tribe

Same as Mike Iyall

Greg Robinson

(assisted by Tony 

Johnson, Sam 

Robinson)

Chinook Indian Nation Chinook Indian Nation

P.O. Box 228

Chinook, WA 98614

Kendra Maty GIS Specialist U.S. Fish and Wildlife Service

Division of Realty and Refuge 

Information 

911 NE 11th Ave

Portland, OR 97232

Todd Welker Aquatics Region Rivers District 

Manager, Washington Dept. of 

Natural Resources

Washington Dept. of Natural 

Resources

PO Box 280

Castle Rock, WA 98611-0280

Lynn Cornelius Gee Creek Watershed 

Coordinator, WSU Clark County 

Extension (March 2006- Dec. 

2009)

Ridgefield NWR Complex

29808 NW Main Avenue 

Ridgefield, WA, 98642
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

I-4 Appendix I. CCP Team Members
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix J. Public Involvement J-1 

Appendix J. Public Involvement

Public involvement was sought throughout the development of the CCP, starting in March 2006 with 

the preparation of a Public Outreach Plan. Public involvement strategies included face to face 

meetings with key agencies, federally elected officials, Tribal representatives, and local Refuge 

users. The Refuge also held open houses, sent planning updates, and gave presentations to 

community organizations to inform the public, invite discussion and solicit feedback. 

A mailing list of approximately 450 persons and organizations is maintained at the Refuge and was 

used to distribute planning updates and public meeting announcements. Below is a brief summary of 

the events, meetings, and outreach tools that were used in our public involvement efforts.

Meetings with Congressional Representatives and/or their Aides:

• September 2006. Project Leader Tim Bodeen met with Kelly Love, aide for Congressman 

Brian Baird, WA 3rd District, to discuss the planning process, and talked with both 

Congressman Baird’s and Senator Patty Murray’s aides by phone. 

• July 2008. Project Leader Bob Flores met with Congressman Brian Baird, WA 3rd District, 

and staff from Senator Patty Murray's office. Purpose of meeting: Discuss overpass project 

for Ridgefield (Port, City, Refuge) and potential locations for Refuge bridge to cross. 

• Sept 16, 2008. Project Leader Bob Flores met with Congressman Brian Baird, WA 3rd

District, and staff, Port of Ridgefield, and Federal Highways. Purpose of meeting: Ridgefield 

NWR access and community transportation needs. 

• Oct 29, 2008. Project Leader Bob Flores and Port of Ridgefield staff met with Senator Patty 

Murray’s staff. Purpose of meeting: Ridgefield NWR access and community transportation 

needs. 

• Feb 9, 2009. Project Leader Bob Flores met with Congressman Brian Baird, WA 3rd District, 

and staff from Senator Patty Murray's office. Purpose of meeting: Transportation issues and 

general public use programs as they relate to CCP. 

Meetings with Tribal Officials:

• Sept 2006. Refuge staff briefed representatives of the Chinook Tribe on the CCP planning 

process. 

• Feb 21, 2007. Ridgefield NWR CCP Extended Team Meeting, WDFW Office, Vancouver, 

WA. Purpose: Alternatives development. Cowlitz Tribal representative attended this meeting. 

• April 9, 2007. Ridgefield NWR CCP Extended Team Meeting, Vancouver, WA. Purpose: 

Alternatives development. Cowlitz Tribal representative attended this meeting.

• May 23, 2007. Refuge Manager Jennifer Brown and USFWS Cultural Resources 

representative meet with Chinook Tribe to discuss preliminary alternatives. Location: RNWR 

Office, Ridgefield, WA. 

• April 6, 2008. Project Leader Bob Flores met with Cowlitz Tribal Chairman John Barnett 

and other members. Purpose of meeting: Discuss interpretation of cultural resources and 

Cowlitz Tribal history on and around Ridgefield NWR in our planning efforts. 

• Feb 26, 2009. Project Leader Bob Flores met with Cowlitz Tribal Chairman Bill Iyall and 

other members. Purpose of meeting: To discuss the CCP as it relates to cultural resources 

and interpretation. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

J-2 Appendix J. Public Involvement

• Feb 3, 2010. Project Leader Bob Flores met with Cowlitz Tribal Councilman/Attorney Philip 

Harju and other members. Purpose of meeting: To discuss CCP planning as it relates to 

cultural management and restoration of native plants and animal species.

• Mar 6, 2010. Project Leader Bob Flores met with Chinook Tribal Vice-Chairman Sam 

Robinson. Purpose of meeting: Overview of CCP. 

Meetings with Local Elected Officials:

• 2006. Project Leader Tim Bodeen met with the City of Ridgefield and the Port of Ridgefield 

to discuss the planning process. 

• Oct 23, 2007. Refuge and FWS Planning staff met with Port of Ridgefield and Federal 

Highways to discuss bridge proposal (affects access to River S Unit). Location: Port of 

Ridgefield Office, Ridgefield, WA.

• Feb 18, 2009. Project Leader Bob Flores, Region 1 Refuges Chief Carolyn Bohan and 

Refuge Supervisor Forrest Cameron met with Port of Ridgefield. Location: Port of Ridgefield 

Office, Ridgefield WA. 

• March 26, 2009. Public open house, CCP preliminary draft alternatives. In attendance: 

Ridgefield Mayer Ron Onslow and City Manager Justin Clary, representative from the Port 

of Ridgefield. 

• April 27, 2009. Project Leader Bob Flores attended Miller’s Landing Redevelopment 

Conference. In attendance: Port of Ridgefield Commissioners, Director Grening and other 

staff, City of Ridgefield Manager, local and county residents. Purpose of meeting: 

Discussion of Port of Ridgefield planning of proposed Miller’s Landing. Discussion of 

community trails, transportation, access to public lands, including Ridgefield NWR. 

• June 9, 2009. Project Leader Bob Flores met with Port of Ridgefield’s Commissioners, 

Director Grening and other staff. Purpose of meeting: Discuss Refuge CCP planning as it 

pertains to transportation, access to refuge and community trail development. 

• Feb 8, 2010. Project Leader Bob Flores met with County staff and Commissioner. Purpose 

of meeting: Proposed community access trail through Ridgefield NWR. Discussed CCP and 

Service/Refuge purposes and goals. 

Meetings with Local Community Organizations involving CCP Issues: 

• August 14, 2006. Lead planner gave presentation at the Friends of Ridgefield NWR Board 

Meeting to discuss the planning process. 

• October 5, 2006. Refuge staff and lead planner attend meeting hosted by the Friends of 

Ridgefield NWR to discuss hunting issues. Location: Ridgefield Community Center, 

Ridgefield, WA. 

• Nov 2006. Refuge staff and lead planner meet with representative of local birding groups to 

discuss scoping comments.

• March 6, 2009. Project Leader Bob Flores met with members of the Friends of Ridgefield 

NWR. Purpose of meeting: Discussion of future needs of the refuge and actions planned by 

the group to assist the refuge. General CCP topics were discussed. 

• March 26, 2009. Public open house, CCP preliminary draft alternatives. 

• April 30, 2009. Project Leader Bob Flores attends regular meeting of Washington Waterfowl 

Association to discuss the preliminary draft alternatives outlined in CCP Planning Update #3. 

• May 18, 2009. Project Leader Bob Flores presented draft alternatives to members of the 

Ridgefield Junction Association. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix J. Public Involvement J-3 

• May 28, 2009. Project Leader Bob Flores and staff host a meeting on refuge with 

Washington Waterfowl Association members to discuss CCP alternatives. 

• January 21, 2010. Project Leader Bob Flores attends regular meeting of Washington 

Waterfowl Association to discuss the final draft alternatives outlined in CCP Planning 

Update #4. 

• March 2, 2010. Project Leader Flores described alternatives and general CCP process to the 

City of Ridgefield Gateway Committee (downtown revitalization).

• April 4, 2010. Project Leader Bob Flores presented the draft alternatives to members of the 

Vancouver Audubon Society. 

• April 26, 2010. Project Leader Bob Flores met with and answered questions concerning the 

planned Overlook Park and connection to alternatives in the CCP. 

• June 14, 2010. Project Leader Bob Flores presented draft alternatives to board members of 

the Friends of Ridgefield NWR. 

 

Meetings with Agency Representatives:

• March 22-26, 2004. Representatives from WDFW, ODFW, and other State agencies 

participated in the Ridgefield NWR Wildlife and Habitat Review. 

• February 2005. Representatives from the R1 Regional Office and Refuge Project Leaders met 

with the Washington Department of Fish and Wildlife’s (WDFW) Regional Directors for 

Regions 1 and 3, and the Oregon Department of Fish and Wildlife (ODFW), to discuss the 

CCP process and other issues of interest. 

• January 2006. Representatives from the R1 Regional Office and Refuge Project Leaders met 

with the Oregon Department of Fish and Wildlife (ODFW) to discuss the CCP process and 

other issues of interest. 

• January 24, 2007. Ridgefield NWR CCP Extended Team Meeting, USFWS Regional Office, 

Portland, OR. Purpose: Alternatives development. WDFW and ODFW representatives at 

meeting.

• Feb 21, 2007. Ridgefield NWR CCP Extended Team Meeting, WDFW, Vancouver, WA. 

Purpose: Alternatives development. WDFW, ODFW, and Washington DNR representatives 

at meeting.

• April 9, 2007. Ridgefield NWR CCP Extended Team Meeting, WDFW, Vancouver, WA. 

Purpose: Alternatives development. WDFW, ODFW, and Washington DNR representatives 

at meeting.

• May 15, 2007. Ridgefield NWR CCP Extended Team Meeting, Columbia River Fisheries 

Resource Office, Vancouver WA. Purpose: Alternatives development. WDFW and ODFW 

representatives at meeting.

• Oct 23, 2007: Refuge and FWS Planning staff meets with Port of Ridgefield and Federal 

Highways to discuss bridge proposal (affects access to River S Unit). Location: Port of 

Ridgefield Office, Ridgefield WA. 

• Nov 1, 2007. National Wildlife Refuge System/Washington Department of Fish and Wildlife 

Comprehensive Conservation Planning Coordination Meeting. Refuge Manager Jennifer 

Brown presents progress on Ridgefield NWR CCP to date. 

• Dec 6, 2007: Core planning team meeting with Federal Highways. Location: Ridgefield 

NWR. Purpose: Discuss scope of transportation study. 

• Dec 19, 2007: Core planning team meeting with Federal Highways. Location: Ridgefield 

NWR. Purpose: Develop transportation study. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

J-4 Appendix J. Public Involvement

• Jan 24, 2008: Core planning team meeting with Federal Highways. Location: Vancouver, 

WA. Purpose: Attend presentation on Ridgefield transportation study. 

• August 12, 2008: Ridgefield Transportation alternatives meeting. 

• May 19, 2009. Project Leader Bob Flores and planning team lead meet with WDFW to 

obtain WDFW’s feedback on preliminary draft alternatives. 

• May 27, 2009. Project Leader Bob Flores attended a multi-agency goose depredation 

meeting hosted by ODFW to discuss goose depredation issues and goose management 

recommendations for CCP. 

• Sept 16, 2009. National Wildlife Refuge System/Washington Department of Fish and 

Wildlife Comprehensive Conservation Planning Coordination Meeting. Location: Nisqually 

NWR, Olympia, WA. Purpose: Update WDFW on CCP progress to date on Washington 

NWRs. Draft alternatives for Ridgefield NWR were presented. 

• July 27, 2010. Project Leader Bob Flores and refuge staff meet with WDFW and ODFW 

to discuss States’ comments to the final draft CCP and alternatives.

Public Open Houses/Scoping Sessions:

• September 14, 2006. Public scoping meeting at the Ridgefield Community Center, 210 North 

Main Avenue, Ridgefield, Washington 98642 

• September 20, 2006. Public scoping meeting at the Vancouver Community Library, 1007 

East Mill Plain Boulevard, Vancouver, Washington 98663 

Format: The public scoping meetings were in an open-house format. At the open house, 

Refuge staff and the lead planner explained the CCP process; Refuge purposes, vision, and 

management; and preliminary management issues, concerns and opportunities that had been 

identified early in the planning process. They also answered questions from attendees and 

took written comments. 

Attendance: A total of 44 private citizens and representatives from various organizations 

attended the open houses, providing comments on the issues and opportunities presented. 28 

people attended the event in Ridgefield and 16 people attended the event in Vancouver. 

Comments Received:

• March 26, 2009. Public open house at the Ridgefield Community Center, 210 North Main 

Avenue, Ridgefield, Washington 98642 

 During scoping a total of 91 responses were received from individuals 

or organizations in writing from September through November 3, 2006. Seventy of these 

were comment forms returned by mail or fax, at the public meetings, or hand delivered to the 

Refuge. Twenty-one of the responses were letters (one of which was signed by 21 

individuals) sent by e-mail or mail.

Purpose of open house: To gather public input on the draft alternatives for Ridgefield NWR. 

Format: Following introductions by the Project Leader, Bob Flores, lead planner Ken Morris 

gave a presentation on the CCP process, progress to date, how the draft alternatives were 

developed, and future opportunities for public input. The public was invited to submit 

comments either in writing or verbally. The attendees then had the opportunity to visit four 

tables staffed by Refuge staff (Bob Flores, Jennifer Brown, Alex Chmielewski, and Eric 

Anderson) and the lead planner. Each table had a scribe to record verbal comments. 

Interest Groups in Attendance: Approximately 60 people attended the meeting. Most of the 

attendees identified themselves as hunters, birdwatchers, and/or wildlife photographers. 

Members of the Washington Waterfowlers (Lower Columbia chapter) and the Vancouver 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix J. Public Involvement J-5 

Wildlife League were in attendance.

Comments Received: A total of 188 verbal comments were transcribed at the open house. 

Written comments were received until April 10, 2009. Eighty-six written comments were 

received, 76 by email and the remainder mailed or faxed to the refuge. Organizations 

submitting written comments included Washington Waterfowlers (Lower Columbia chapter), 

Vancouver Wildlife League, Vancouver Audubon, and Washington DNR. 

Other Meetings:

• January 24, 2007. Ridgefield NWR CCP Extended Team Meeting, USFWS Regional Office, 

Portland, OR. Purpose: Alternatives development. 

• Feb 21, 2007. Ridgefield NWR CCP Extended Team Meeting, WDFW, Vancouver, WA. 

Purpose: Alternatives development. 

• April 9, 2007. Ridgefield NWR CCP Extended Team Meeting, WDFW, Vancouver, WA. 

Purpose: Alternatives development. 

• May 15, 2007. Ridgefield NWR CCP Extended Team Meeting, Columbia River Fisheries 

Resource Office, Vancouver WA. Purpose: Alternatives development. 

• June 4, 2007. Alternatives briefing for Region 1 Refuges Chief and staff, USFWS Regional 

Office, Portland, OR. 

• Sept 11, 2007. Alternatives briefing for Region 1 Refuges Chief and staff, USFWS Regional 

Office, Portland, OR. 

• March 6, 2008. Briefing for Region 1 Refuges Chief on transportation access alternatives, 

USFWS Regional Office, Portland, OR. 

• April 8, 2008. Core planning team meeting with Branch of Refuge Biology to refine 

alternatives.

• April 17, 2008. Core planning team meeting with Branch of Refuge Biology to refine 

alternatives.

• April 30, 2008. Core planning team meeting with Branch of Refuge Biology to refine 

alternatives.

• Sept 25 2008. Alternatives briefing for Region 1 Refuges Chief and staff, USFWS Regional 

Office, Portland, OR. 

• Nov 6, 2008. Alternatives briefing for Region 1 Refuges Chief and staff, USFWS Regional 

Office, Portland, OR. 

• May 28, 2009. Project Leader meets with Regional Office staff to obtain approval on draft 

alternatives, in order to proceed with CCP development. 

Press Coverage: 

• September 5, 2006. News release announcing public scoping meetings sent to four daily 

newspapers (the Oregonian, the Columbian, the Longview Daily News, and the CamasWashougal Post-Record) and two weekly papers (the Reflector and the Woodland-Kalama 

Daily News). Notices of public meetings appeared in the Oregonian and the Columbian. 

• September 2006. Columbian article describing changes at the Ridgefield NWR Complex and 

the CCP process. 

• April 2, 2009. “Change is coming to Ridgefield National Wildlife Refuge” – Online article in

Natural Oregon. 

• April 16, 2009. “Groups seek more hunting at Ridgefield Refuge” – The Columbian. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

J-6 Appendix J. Public Involvement

• June 17, 2010. News release announcing the availability of the Draft CCP/EA and requesting 

public comments was sent to four daily newspapers (the Oregonian, the Columbian, the 

Longview Daily News, and the Camas-Washougal Post-Record) and two weekly papers (the 

Reflector and the Woodland-Kalama Daily News). The news release was also posted on the 

FWS Region 1 website and the national FWS Virtual News Room. 

• July 8, 2010. “Ridgefield refuge plan opts for status-quo hunting” – The Columbian. 

• July 15, 2010. “Hunters unhappy with draft Ridgefield refuge plan” – The Columbian. 

Planning Updates:

• August 30, 2006. Planning Update 1 sent to a mailing list of approximately 450 recipients, 

including private individuals, government agencies, and non-governmental organizations. 

The planning update included a comment form. In addition, the Planning Update was posted 

on the Refuge website, and copies were available at the CCP open houses, the refuge office 

and entrance, the hunter check station, and at the Refuge information table at the annual 

BirdFest event on October 14-15, 2006. 

• Jan 23, 2007. Planning Update 2, summarizing the results of public scoping, was distributed 

to a mailing list of approximately 450 recipients. In addition, the Planning Update and a 

detailed report on the results of public scoping were posted on the Refuge website. 

• March 13, 2009. Planning Update 3, summarizing preliminary draft alternatives, was 

distributed to a mailing list of approximately 400 recipients. In addition, the Planning Update 

was posted on the Refuge website. 

• June 16, 2010. Planning Update 4, summarizing the draft CCP, was distributed to a mailing 

list of 432 recipients. In addition, the Planning Update was posted on the Region 1 planning 

website (a link was posted on the Refuge website). 

Other Tools:

• Sept 2006: Letters sent from Refuge to ODFW and WDFW notifying them of the planning 

process and inviting their participation. 

• August 25, 2006: Letters sent from Refuge to the following Tribal governments notifying 

them of the planning process and inviting their participation: the Chinook Indian Tribe, 

Cowlitz Indian Tribe, Confederated Tribes of Grande Ronde, Shoalwater Bay Indian Tribe, 

Confederated Tribes of Warm Springs, and the Confederated Tribes and Bands of the 

Yakama Nation, The Chinook Indian Tribe and the Cowlitz Indian Tribe agreed to appoint 

representatives to the Extended Planning Team. 

• August 30, 2006: Comment form sent to approx 450 people in conjunction with Planning 

Update 1. Comment form was also posted on Refuge website, and distributed during public 

scoping meetings. 

• Sept 2006: Article on CCP process published in Refuge Friends Group newsletter. 

• October 14-15, 2006: Information on CCP process, Planning Updates, and comment forms at 

refuge information table at the annual BirdFest event. 

• Oct 24, 2006: Followup calls to Tribes made and original letters inviting Tribes to participate 

as planning team members resent as needed.

• Jan 4, 2007: Letter sent by acting Refuge Manager (Eric Anderson) to representatives of 

WDFW, ODFW, the Cowlitz Indian Tribe, the Chinook Indian Nation, Washington DNR, 

and other programs in the Fish and Wildlife Service requesting participation in extended 

team meetings.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix J. Public Involvement J-7 

• Jan 7, 2007: Scoping briefing statement sent to FWS Washington DC Office. 

• June 4, 2009: Alternatives status report sent to FWS Washington DC Office. 

• March 29, 2010: Information Memorandum on the Draft CCP/EA sent to FWS Washington 

DC office.

Federal Register Notices: 

• August 2, 2006: Federal Register published Notice of Intent to Prepare a Draft 

Comprehensive Conservation Plan and Associated NEPA Document; and Notice of Public 

Meetings (71 FR 43787). 

• June 16, 2010: Federal Register published Notice of Availability of the Draft Comprehensive 

Conservation Plan and Environmental Assessment; and request for comments (75 FR 34154). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

J-8 Appendix J. Public Involvement
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-1

Appendix K. Ridgefield NWR CCP Integrated Pest 

Management (IPM) Program

1.0 Background 

IPM is an interdisciplinary approach utilizing methods to prevent, eliminate, contain, and/or control pest 

species in concert with other management activities on refuge lands and waters to achieve wildlife and 

habitat management goals and objectives. IPM is also a scientifically based, adaptive management 

process where available scientific information and best professional judgment of the refuge staff as well 

as other resource experts would be used to identify and implement appropriate management strategies that 

can be modified and/or changed over time to ensure effective, site-specific management of pest species to 

achieve desired outcomes. In accordance with 43 CFR 46.145, adaptive management would be 

particularly relevant where long-term impacts may be uncertain and future monitoring would be needed to 

make adjustments in subsequent implementation decisions. After a tolerable pest population (threshold) 

is determined considering achievement of refuge resource objectives and the ecology of pest species, one 

or more methods, or combinations thereof, would be selected that are feasible, efficacious, and most 

protective of non-target resources, including native species (fish, wildlife, and plants), and Service 

personnel, Service authorized agents, volunteers, and the public. Staff time and available funding would 

be considered when determining feasibility/practicality of various treatments. 

IPM techniques to address pests are presented as CCP strategies (see Chapter 2) in an adaptive 

management context to achieve refuge resource objectives. In order to satisfy requirements for IPM 

planning as identified in the Director’s Memo (dated September 9, 2004) entitled Integrated Pest 

Management Plans and Pesticide Use Proposals: Updates, Guidance, and an Online Database, the 

following elements of an IPM program have been incorporated into this CCP: 

• Habitat and/or wildlife objectives that identify pest species and appropriate thresholds to indicate 

the need for and successful implementation of IPM techniques; and 

• Monitoring before and/or after treatment to assess progress toward achieving objectives including 

pest thresholds.

Where pesticides would be necessary to address pests, this Appendix provides a structured procedure to 

evaluate potential effects of proposed uses involving ground-based applications to refuge biological 

resources and environmental quality in accordance with effects analyses presented in Chapter 7 

(Environmental Consequences) of the Draft CCP and Environmental Assessement (USFWS 2010). Only 

pesticide uses that likely would cause minor, temporary, or localized effects to refuge biological resources 

and environmental quality with appropriate best management practices (BMPs), where necessary, would 

be allowed for use on the refuge. 

This Appendix does not describe the more detailed process to evaluate potential effects associated with 

aerial applications of pesticides. Moreover, it does not address effects of mosquito control with pesticides 

(larvicides, pupacides, or adulticides) based upon identified human health threats and presence of diseasecarrying mosquitoes in sufficient numbers from monitoring conducted on a refuge. However, the basic 

framework to assess potential effects to refuge biological resources and environmental quality from aerial 

application of pesticides or use of insecticides for mosquito management would be similar to the process 

described in this Appendix for ground-based treatments of other pesticides. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-2 Appendix K. Integrated Pest Management

2.0 Pest Management Laws and Policies 

 

In accordance with Service policy 7 RM 14 (Pest Control), wildlife and plant pests on units of the 

National Wildlife Refuge System can be controlled to assure balanced wildlife and fish populations in 

support of refuge-specific wildlife and habitat management objectives. Pest control on federal (refuge) 

lands and waters also is authorized under the following legal mandates: 

• National Wildlife Refuge System Administration Act of 1966, as amended (16 USC 668dd668ee); 

• Plant Protection Act of 2000 (7 USC 7701 et seq

• Noxious Weed Control and Eradication Act of 2004 (7 USC 7781-7786, Subtitle E); 

.); 

• Federal Insecticide, Fungicide, and Rodenticide Act of 1996 (7 USC 136-136y); 

• National Invasive Species Act of 1996 (16 USC 4701); 

• Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 (16 USC 4701); 

• Food Quality Protection Act of 1996 (7 USC 136); 

• Executive Order 13148, Section 601(a); 

• Executive Order 13112; and 

• Animal Damage Control Act of 1931 (7 USC 426-426c, 46 Stat. 1468). 

Pests are defined as “...living organisms that may interfere with the site-specific purposes, operations, or 

management objectives or that jeopardize human health or safety” from Department policy 517 DM 1 

(Integrated Pest Management Policy). Similarly, 7 RM 14 defines pests as “Any terrestrial or aquatic 

plant or animal which interferes, or threatens to interfere, at an unacceptable level, with the attainment of 

refuge objectives or which poses a threat to human health.” 517 DM 1 also defines an invasive species as 

“a species that is non-native to the ecosystem under consideration and whose introduction causes or is 

likely to cause economic or environmental harm or harm to human health.” Throughout the remainder of 

this CCP, the terms pest and invasive species are used interchangeably because both can prevent/impede 

achievement of refuge wildlife and habitat objectives and/or degrade environmental quality. 

In general, control of pests (vertebrate or invertebrate) on the refuge would conserve and protect the 

nation’s fish, wildlife, and plant resources as well as maintain environmental quality. From 

7 RM 14, animal or plant species, which are considered pests, may be managed if the following criteria 

are met:

• Threat to human health and well being or private property, the acceptable level of damage by the 

pest has been exceeded, or State or local government has designated the pest as noxious;

• Detrimental to resource objectives as specified in a refuge resource management plan (e.g., 

comprehensive conservation plan, habitat management plan), if available; and 

• Control would not conflict with attainment of resource objectives or the purposes for which the 

refuge was established.

From 7 RM 14, the specific justifications for pest management activities on the refuge are the following:

• Protect human health and well being; 

• Prevent substantial damage to important to refuge resources; 

• Protect newly introduced or re-establish native species;

• Control non-native (exotic) species in order to support existence for populations of native species;

• Prevent damage to private property; and 

• Provide the public with quality, compatible wildlife-dependent recreational opportunities. 

In accordance with Service policy 620 FW 1 (Habitat Management Plans), there are additional 

management directives regarding invasive species found on the refuge:
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-3

• “We are prohibited by Executive Order, law, and policy from authorizing, funding, or carrying 

out actions that are likely to cause or promote the introduction or spread of invasive species in the 

United States or elsewhere.” 

• “Manage invasive species to improve or stabilize biotic communities to minimize unacceptable 

change to ecosystem structure and function and prevent new and expanded infestations of 

invasive species. Conduct refuge habitat management activities to prevent, control, or eradicate 

invasive species...”

Animal species damaging/destroying federal property and/or detrimental to the management program of a 

refuge may be controlled as described in 50 CFR 31.14 (Official Animal Control Operations). Based 

upon 7 RM 14.7E, a pest control proposal is required, in some cases, to initiate a control program on 

refuge lands. The required elements of a pest control proposal are described in 7 RM 14.7A-E. However, 

a pest control proposal is not required under the following scenarios: 

• Routine protection of refuge buildings, structures (e.g., dikes, levees, water control structures), 

and facilities not involving prohibited chemicals. 

• Incidental control of exotics (e.g., non-native rats, non-native rabbits) or feral animals on refuge 

lands that are not protected by either federal or state laws, except where chemicals may he used. 

• The use of routine habitat management techniques, selective trapping, on-refuge transfer, and 

physical and mechanical protection such as barriers and fences (including electric fences).

For example, the incidental removal of beaver damaging refuge infrastructure (e.g., clogging with 

subsequent damaging of water control structures) and/or negatively affecting habitats (e.g., removing 

woody species from existing or restored riparian) managed on refuge lands may be conducted without a 

pest control proposal. We recognize beavers are native species and most of their activities or refuge lands 

represent a natural process beneficial for maintaining wetland habitats. Exotic nutria, whose denning and 

burrowing activities in wetland dikes causes cave-ins and breaches, can be controlled using the most 

effective techniques considering site-specific factors without a pest control proposal. Along with the loss 

of quality wetland habitats associated with breaching of impoundments, the safety of refuge staffs and 

public (e.g. auto tour routes) driving on structurally compromised levees and dikes can be threaten by 

sudden and unexpected cave-ins. 

Trespass and feral animals also may be controlled on refuge lands. In accordance with 7 RM 14.9B(1), 

animals trespassing on refuge lands may be captured and returned to their owners or transferred to 

humane societies or local animal shelters, where feasible. Based upon 50 CFR 28.43 (Destruction of 

Dogs and Cats), dogs and cats running at large on a national wildlife refuge and observed in the act of 

killing, injuring, harassing or molesting humans or wildlife may be disposed of in the interest of public 

safety and protection of the wildlife. In accordance with 7 RM 14.9B(2), feral animals should be 

disposed by the most humane method(s) available and in accordance with relevant Service directives 

(including Executive Order 11643). 

Disposed wildlife specimens may be donated or loaned to public institutions. Donation or loans of 

resident wildlife species will only be made after securing State approval (50 CFR 30.11 [Donation and 

Loan of Wildlife Specimens]). Surplus wildlife specimens may be sold alive or butchered, dressed and 

processed subject to Federal and State laws and regulations (50 CFR 30.12 [Sale of Wildlife Specimens]). 

As previously stated for controlling animals damaging/destroying federal property and/or detrimental to 

the management program of a refuge, incidentally removing such animals from refuge lands does not 

require a pest control proposal. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-4 Appendix K. Integrated Pest Management

3.0 Strategies 

To fully embrace IPM, the following strategies, where applicable, would be carefully considered on the 

refuge for each pest species:

Prevention. This would be the most effective and least expensive long-term management option for 

pests. It encompasses methods to prevent new introductions or the spread of the established pests to uninfested areas. It requires identifying potential routes of invasion to reduce the likelihood of infestation. 

Hazard Analysis and Critical Control Points (HACCP) planning can be used determine if current 

management activities on a refuge may introduce and/or spread invasive species in order to identify 

appropriate BMPs for prevention. See http://www.haccp-nrm.org/ for more information about HACCP 

planning. 

Prevention may include source reduction, using pathogen-free or weed-free seeds or fill; exclusion 

methods (e.g., barriers) and/or sanitation methods (e.g., wash stations) to prevent re-introductions by 

various mechanisms including vehicles, personnel, livestock, and horses. Because invasive species are 

frequently the first to establish newly disturbed sites, prevention would require a reporting mechanism for 

early detection of new pest occurrences with quick response to eliminate any new satellite pest 

populations. Prevention would require consideration of the scale and scope of land management activities 

that may promote pest establishment within un-infested areas or promote reproduction and spread of 

existing populations. Along with preventing initial introduction, prevention would involve halting the 

spread of existing infestations to new sites (Mullin et al. 2000). The primary reason of prevention would 

be to keep pest-free lands or waters from becoming infested. Executive Order 11312 emphasizes the 

priority for prevention with respect to managing pests. The following methods would prevent the 

introduction and/or spread of pests on refuge lands: 

• Before beginning ground-disturbing activities (e.g., disking, scraping), inventory and prioritize 

pest infestations in project operating areas and along access routes. Refuge staff would identify 

pest species on site or within reasonably expected potential invasion vicinity. Where possible, the 

refuge staff would begin project activities in un-infested areas before working in pest-infested 

areas.

• The refuge staff would locate and use pest-free project staging areas. They would avoid or 

minimize travel through pest-infested areas, or restrict to those periods when spread of seed or 

propagules of invasive plants would be least likely. 

• The refuge staff would determine the need for, and when appropriate, identify sanitation sites 

where equipment can be cleaned of pests. Where possible, the refuge staff would clean 

equipment before entering lands at on-refuge approved cleaning site(s). This practice does not 

pertain to vehicles traveling frequently in and out of the project area that will remain on 

roadways. Seeds and plant parts of pest plants would need to be collected, where practical. The 

refuge staff would remove mud, dirt, and plant parts from project equipment before moving it 

into a project area. 

• The refuge staff would clean all equipment, before leaving the project site, if operating in areas 

infested with pests. The refuge staff would determine the need for, and when appropriate, 

identify sanitation sites where equipment can be cleaned.

• Refuge staffs, their authorized agents, and refuge volunteers would, where possible, inspect, 

remove, and properly dispose of seed and parts of invasive plants found on their clothing and 

equipment. Proper disposal means bagging the seeds and plant parts and then properly discarding 

of them (e.g., incinerating). 

• The refuge staff would evaluate options, including closure, to restrict the traffic on sites with ongoing restoration of desired vegetation. The refuge staff would revegetate disturbed soil (except 

travel ways on surfaced projects) to optimize plant establishment for each specific site. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-5

Revegetation may include topsoil replacement, planting, seeding, fertilization, liming, and weedfree mulching as necessary. The refuge staff would use native material, where appropriate and 

feasible. The refuge staff would use certified weed-free or weed-seed-free hay or straw where 

certified materials are are reasonably available. 

• The refuge staff would provide information, training and appropriate pest identification materials 

to refuge staffs, permit holders, and recreational visitors. The refuge staff would educate them 

about pest identification, biology, impacts, and effective prevention measures. 

• The refuge staff would require grazing permittees to utilize preventative measures for their 

livestock while on refuge lands. 

• The refuge staff would inspect borrow material for invasive plants prior to use and transport onto 

and/or within refuge lands. 

• The refuge staff would consider invasive plants in planning for road maintenance activities.

• The refuge staff would restrict off road travel to designated routes. 

The following methods would prevent the introduction and/or spread of pests into refuge waters: 

• The refuge staff would inspect boats (including air boats), trailers, and other boating equipment. 

Where possible, the refuge staff would remove any visible plants, animals, or mud before leaving 

any waters or boat launching facilities. Where possible, the refuge staff would drain water from 

motor, live well, bilge, and transom wells while on land before leaving the site. If possible, the 

refuge staff would wash and dry boats, downriggers, anchors, nets, floors of boats, propellers, 

axles, trailers, and other boating equipment to kill pests not visible at the boat launch. 

• Where feasible, the refuge staff would maintain a l00-foot buffer of aquatic pest-free clearance 

around boat launches and docks or quarantine areas when cleaning around culverts, canals, or 

irrigation sites. Where possible, the refuge staff would inspect and clean equipment before 

moving to new sites or one project area to another.

These prevention methods to minimize/eliminate the introduction and/or spread of pests were taken 

verbatim or slightly modified from Appendix E of US Forest Service (2005). 

Mechanical/Physical Methods. These methods would remove and destroy, disrupt the growth of, or 

interfere with the reproduction of pest species. For plant species, these treatments can be accomplished 

by hand, hand tool (manual), or power tools (mechanical) and include pulling, grubbing, digging, 

tilling/disking, cutting, swathing, grinding, sheering, girdling, mowing, and mulching of the pest plants. 

Thermal techniques such as heating, steaming, super-heated water, and hot foam may also be viable 

treatments. 

For animal species, Service employees or their authorized agents could use mechanical/physical methods 

(including trapping) to control pests as a refuge management activity. Based upon 50 CFR 31.2, trapping 

can be used on a refuge reduce surplus wildlife populations for a “balanced conservation program” in 

accordance with federal or state laws and regulations. In some cases, non-lethally trapped animals would 

be relocated to off-refuge sites with prior approval from the state. A pest control proposal (see 7 RM 

14.7A-D for required elements) is needed before initiation of trapping activities, except those operations 

identified in 7 RM 14.7E. In addition, a separate pest control proposal is not necessary if the required 

information can be incorporated into an EA (or other appropriate NEPA document). 

Each of these tools would be efficacious to some degree and applicable to specific situations. In general, 

mechanical controls can effectively control annual and biennial pest plants. However, to control 

perennial plants, the root system has to be destroyed or it would resprout and continue to grow and 

develop. Mechanical controls are typically not capable of destroying a perennial plants root system. 

Although some mechanical tools (e.g., disking, plowing) may damage root systems, they may stimulate 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-6 Appendix K. Integrated Pest Management

regrowth producing a denser plant population that may aid in the spread depending upon the target 

species (e.g., Canada thistle). In addition, steep terrain and soil conditions would be major factors that 

can limit the use of many mechanical control methods.

Some mechanical control methods (e.g., mowing), which would be used in combination with cultural 

methods and/or herbicides, can be a very effective technique to control some perennial species. For 

example, mowing perennial plants followed sequentially by treating the plant regrowth with a systemic 

herbicide often would improve the efficacy of the herbicide compared to herbicide treatment only.

Cultural Methods. These methods would involve manipulating habitat to increase pest mortality by 

reducing its suitability to the pest. Cultural methods would include water-level manipulation, mulching, 

winter cover crops, changing planting dates to minimize pest impact, prescribed burning (facilitate 

revegetation, increase herbicide efficacy, and remove litter to assist in emergence of desirable species), 

flaming with propane torches, trap crops, crop rotations that would include non-susceptible crops, 

moisture management, addition of beneficial insect habitat, reducing clutter, proper trash disposal, 

planting or seeding desirable species to shade or out-compete invasive plants, applying fertilizer to 

enhance desirable vegetation, prescriptive grazing, and other habitat alterations. 

Biological Control Agents. Classical biological control would involve the deliberate introduction and 

management of natural enemies (parasites, predators, or pathogens) to reduce pest populations. Many of 

the most ecologically or economically damaging pest species in the United States originated in foreign 

countries. These newly introduced pests, which are free from natural enemies found in their country or 

region of origin, may have a competitive advantage over cultivated and native species. This competitive 

advantage often allows introduced species to flourish, and they may cause widespread economic damage 

to crops or out compete and displace native vegetation. Once the introduced pest species population 

reaches a certain level, traditional methods of pest management may be cost prohibitive or impractical. 

Biological controls typically are used when these pest populations have become so widespread that 

eradication or effective control would be difficult or no longer practical.

Biological control has advantages as well as disadvantages. Benefits would include reducing pesticide 

usage, host specificity for target pests, long-term self-perpetuating control, low cost/acre, capacity for 

searching and locating hosts, synchronizing biological control agents to hosts’ life cycles, and the 

unlikelihood that hosts will develop resistance to agents. Disadvantages would include the following: 

limited availability of agents from their native lands, the dependence of control on target species density, 

slow rate at which control occurs, biotype matching, the difficulty and expense of conflicts over control of 

the target pest, and host specificity when host populations are low. 

A reduction in target species populations from biological controls is typically a slow process, and efficacy 

can be highly variable. It may not work well in a particular area although it does work well in other areas. 

Biological control agents would require specific environmental conditions to survive over time. Some of 

these conditions are understood; whereas, others are only partially understood or not at all. 

Biological control agents would not eradicate a target pest. When using biological control agents, 

residual levels of the target pest typically are expected; the agent population level or survival would be 

dependent upon the density of its host. After the pest population decreases, the population of the 

biological control agent would decrease correspondingly. This is a natural cycle. Some pest populations 

(e.g., invasive plants) would tend to persist for several years after a biological control agent becomes 

established due to seed reserves in the soil, inefficiencies in the agents search behavior, and the natural 

lag in population buildup of the agent.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-7

The full range of pest groups potentially found on refuge lands and waters would include diseases, 

invertebrates (insects, mollusks), vertebrates and invasive plants (most common group). Often it is 

assumed that biological control would address many if not most of these pest problems. There are several 

well-documented success stories of biological control of invasive weed species in the Pacific Northwest 

including Mediterranean sage, St. Johnswort (Klamath weed) and tansy ragwort. Emerging success 

stories include Dalmatian toadflax, diffuse knapweed, leafy spurge, purple loosestrife and yellow star 

thistle. However, historically, each new introduction of a biological control agent in the United States has 

only about a 30% success rate (Coombs et al 2006). Refer to Coombs et al (2006) for the status of 

biological control agents for invasive plants in the Pacific Northwest.

Introduced species without desirable close relatives in the United States would generally be selected as 

biological controls. Natural enemies that are restricted to one or a few closely related plants in their 

country of origin are targeted as biological controls (Center et al. 1997, Hasan and Ayres 1990). 

The refuge staff would ensure introduced agents are approved by the applicable authorities. Except for a 

small number of formulated biological control products registered by USEPA under FIFRA, most 

biological control agents are regulated by the US Department of Agriculture (USDA)-Animal Plant 

Health Inspection Service, Plant Protection and Quarantine (APHIS-PPQ). State departments of 

agriculture and, in some cases, county agricultural commissioners or weed districts, have additional 

approval authority.

Federal permits (USDA-APHIS-PPQ Form 526) are required to import biocontrols agents from another 

state. Form 526 may be obtained by writing: 

USDA-APHIS-PPQ

 Biological Assessment and Taxonomic Support 

 4700 River Road, Unit 113 

 Riverdale, MD 20737 

Or through the internet at URL address: http://www.aphis.usda.gov/ppq/permits/bioligical/weedbio.html.

The Service strongly supports the development, and legal and responsible use of appropriate, safe, and 

effective biological control agents for nuisance and non-indigenous or pest species. 

State and county agriculture departments may also be sources for biological control agents or they may 

have information about where biological control agents may be obtained. Commercial sources should 

have an Application and Permit to Move Live Plant Pests and Noxious Weeds (USDA-PPQ Form 226 

USDA-APHIS-PPQ, Biological Assessment and Taxonomic Support, 4700 River Road, Unit 113, 

Riverdale, MD 20737) to release specific biological control agents in a state and/or county. Furthermore, 

certification regarding the biological control agent’s identity (genus, specific epithet, sub-species and 

variety) and purity (e.g., parasite free, pathogen free, and biotic and abiotic contaminants) should be 

specified in purchase orders. 

Biological control agents are subject to 7 RM 8 (Exotic Species Introduction and Management). In 

addition, the refuge staff would follow the International Code of Best Practice for Classical Biological 

Control of Weeds (http://sric.ucdavis.edu/exotic /exotic.htm) as ratified by delegates to the X 

International Symposium on Biological Control of Weeds, Bozeman, MT, July 9, 1999. This code 

identifies the following:

• Release only approved biological control agents,

• Use the most effective agents,
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K-8 Appendix K. Integrated Pest Management

• Document releases, and

• Monitor for impact to the target pest, nontarget species and the environment. 

Biological control agents formulated as pesticide products and registered by the USEPA (e.g., Bti) are 

also subject to PUP review and approval (see below). 

A record of all releases would be maintained with date(s), location(s), and environmental conditions of 

the release site(s); the identity, quantity, and condition of the biological control agents released; and other 

relevant data and comments such as weather conditions. Systematic monitoring to determine the 

establishment and effectiveness of the release is also recommended. 

NEPA documents regarding biological and other environmental effects of biological control agents 

prepared by another federal agency, where the scope is relevant to evaluation of releases on refuge lands, 

would be reviewed. Possible source agencies for such NEPA documents include the Bureau of Land 

Management, US Forest Service, National Park Service, US Department of Agriculture-Animal and Plant 

Health Inspection Service, and the military services. It might be appropriate to incorporate by reference 

parts or all of existing document(s) from the review. Incorporating by reference (43 CFR 46.135) is a 

technique used to avoid redundancies in analysis. It also can reduce the bulk of a Service NEPA 

document, which only must identify the documents that are incorporated by reference. In addition, 

relevant portions must be summarized in the Service NEPA document to the extent necessary to provide 

the decision maker and public with an understanding of relevance of the referenced material to the current 

analysis. 

Pesticides. The selective use of pesticides would be based upon pest ecology (including mode of 

reproduction), the size and distribution of its populations, site-specific conditions (e.g., soils, topography), 

known efficacy under similar site conditions, and the capability to utilize best management practices 

(BMPs) to reduce/eliminate potential effects to non-target species, sensitive habitats, and potential to 

contaminate surface and groundwater. All pesticide usage (pesticide, target species, application rate, and 

method of application) would comply with the applicable federal (FIFRA) and state regulations pertaining 

to pesticide use, safety, storage, disposal, and reporting. Before pesticides can be used to eradicate, 

control, or contain pests on refuge lands and waters, pesticide use proposals (PUPs) would be prepared 

and approved in accordance with 7 RM 14. PUP records would provide a detailed, time-, site-, and 

target-specific description of the proposed use of pesticides on the refuge. All PUPs would be created, 

approved or disapproved, and stored in the Pesticide Use Proposal System (PUPS), which is a centralized 

database only accessible on the Service’s intranet (https://systems.fws.gov/pups). Only Service 

employees would be authorized to access PUP records for a refuge in this database.

Application equipment would be selected to provide site-specific delivery to target pests while 

minimizing/eliminating direct or indirect (e.g., drift) exposure to non-target areas and degradation of 

surface and groundwater quality. Where practicable, target-specific equipment (e.g., backpack sprayer, 

wiper) would be used to treat target pests. Other target-specific equipment to apply pesticides would 

include soaked wicks or paint brushes for wiping vegetation and lances, hatchets, or syringes for direct 

injection into stems. Granular pesticides may be applied using seeders or other specialized dispensers. In 

contrast, aerial spraying (e.g., fixed wing or helicopter) would only be used where access is difficult 

(remoteness) and/or the size/distribution of infestations precludes practical use of ground-based methods. 

Because repeated use of one pesticide may allow resistant organisms to survive and reproduce, multiple 

pesticides with variable modes of action would be considered for treatments on refuge lands and waters. 

This is especially important if multiple applications within years and/or over a growing season likely 

would be necessary for habitat maintenance and restoration activities to achieve resource objectives. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-9

Integrated chemical and non-chemical controls also are highly effective, where practical, because 

pesticide resistant organisms can be removed from the site.

Cost may not be the primary factor in selecting a pesticide for use on a refuge. If the least expensive 

pesticide would potentially harm natural resources or people, then a different product would be selected, 

if available. The most efficacious pesticide available with the least potential to degrade environment 

quality (soils, surface water, and groundwater) as well as least potential effect to native species and 

communities of fish, wildlife, plants, and their habitats would be acceptable for use on refuge lands in the 

context of an IPM approach. 

Habitat restoration/maintenance. Restoration and/or proper maintenance of refuge habitats associated 

with achieving wildlife and habitat objectives would be essential for long-term prevention, eradication, or 

control (at or below threshold levels) of pests. Promoting desirable plant communities through the 

manipulation of species composition, plant density, and growth rate is an essential component of invasive 

plant management (Masters et al. 1996, Masters and Shelly 2001, Brooks et al. 2004). The following 

three components of succession could be manipulated through habitat maintenance and restoration: site 

availability, species availability, and species performance (Cox and Anderson 2004). Although a single 

method (e.g., herbicide treatment) may eliminate or suppress pest species in the short term, the resulting 

gaps and bare soil create niches that are conducive to further invasion by the species and/or other invasive 

plants. On degraded sites where desirable species are absent or in low abundance, revegetation with 

native/desirable grasses, forbs, and legumes may be necessary to direct and accelerate plant community 

recovery, and achieve site-specific objectives in a reasonable time frame. The selection of appropriate 

species for revegetation would be dependent on a number of factors including resource objectives and 

site-specific, abiotic factors (e.g., soil texture, precipitation/temperature regimes, and shade conditions). 

Seed availability and cost, ease of establishment, seed production, and competitive ability also would be 

important considerations. 

4.0 Priorities for Treatments

For many refuges, the magnitude (number, distribution, and sizes of infestations) of pest problems is too 

extensive and beyond the available capital resources to effectively address during any single field season. 

To manage pests in the refuge, it would be essential to prioritize treatment of infestations. Highest 

priority treatments would be focused on early detection and rapid response to eliminate infestations of 

new pests, if possible. This would be especially important for aggressive pests potentially impacting 

species, species groups, communities, and/or habitats associated refuge purpose(s), NWRS resources of 

concern (federally listed species, migratory birds, selected marine mammals, and interjurisdictional fish), 

and native species for maintaining/restoring biological integrity, diversity, and environmental health. 

The next priority would be treating established pests that appear in one or more previously un-infested 

areas. Moody and Mack (1988) demonstrated through modeling that small, new outbreaks of invasive 

plants eventually would infest an area larger than the established, source population. They also found that 

control efforts focusing on the large, main infestation rather than the new, small satellites reduced the 

chances of overall success. The lowest priority would be treating large infestations (sometimes 

monotypic stands) of well established pests. In this case, initial efforts would focus upon containment of 

the perimeter followed by work to control/eradicate the established infested area. If containment and/or 

control of a large infestation is not effective, then efforts would focus upon halting pest reproduction or 

managing source populations. Maxwell et al. (2009) found treating fewer populations that are sources 

represents an effective long-term strategy to reduce of total number of invasive populations and 

decreasing meta population growth rates. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-10 Appendix K. Integrated Pest Management

Although state listed noxious weeds would always of high priority for management, other pest species 

known to cause substantial ecological impact would also be considered. For example, cheatgrass may not 

be listed by a state as noxious, but it can greatly alter fire regimes in shrub steppe habitats resulting in 

large monotypic stands that displace native bunch grasses, forbs, and shrubs. Propagules of many 

invasive plant species can remain viable in the seedbank for years or decades. Therefore, pest control 

would likely require a multi-year commitment from the refuge staff. Essential to the long-term success of 

pest management would be pre- and post-treatment monitoring, assessment of the successes and failures 

of treatments, and development of new approaches when proposed methods do not achieve desired 

outcomes. 

5.0 Best Management Practices (BMPs)

BMPs can minimize or eliminate possible effects associated with pesticide usage to non-target species 

and/or sensitive habitats as well as degradation of water quality from drift, surface runoff, or leaching. 

Based upon the Department of Interior Pesticide Use Policy (517 DM 1), Pesticide Users Safety Policy 

(242 FW 7), and the Service Pest Management Policy and Responsibilities (30 AM 12), the use of 

applicable BMPs (where feasible) also would likely ensure that pesticide uses may not adversely affect 

federally listed species and/or their critical habitats through determinations made using the process 

described in 50 CFR part 402. 

The following are BMPs pertaining to mixing/handling and applying pesticides for all ground-based 

treatments of pesticides, which would be considered and utilized, where feasible, based upon target- and 

site-specific factors and time-specific environmental conditions. Although not listed below, the most 

important BMP to eliminate/reduce potential impacts to non-target resources would be an IPM approach 

to prevent, control, eradicate, and contain pests. 

5.1 Pesticide Handling and Mixing 

• As a precaution against spilling, spray tanks would not be left unattended during filling. 

• All pesticide containers would be triple rinsed and the rinsate would be used as water in the sprayer 

tank and applied to treatment areas.

• All pesticide spray equipment would be properly cleaned. Where possible, rinsate would be used as 

part of the make up water in the sprayer tank and applied to treatment areas.

• The refuge staff would follow label recommendations when disposing of empty, triple rinsed 

pesticide containers. 

• All unused pesticides would be properly discarded at a local “safe send” collection. 

• Pesticides and pesticide containers would be lawfully stored, handled, and disposed of in accordance 

with the label and in a manner safeguarding human health, fish, and wildlife and prevent soil and 

water contaminant. 

• The refuge staff would consider the water quality parameters (e.g., pH, hardness) that are important to 

ensure greatest efficacy where specified on the pesticide label.

• All pesticide spills would be addressed immediately using procedures identified in the refuge spill 

respond plan. 

5.2 Applying Pesticides 

• Pesticide treatments would only be conducted by or under the supervision of Service personnel and 

non-Service applicators with the appropriate state or BLM certification to safely and effectively 

conduct these activities on refuge lands and waters. 

• The refuge staff would comply with all applicable pesticide use laws and regulations as well as 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-11

Departmental, Service, and NWRS pesticide-related policies. For example, the refuge staff would use 

application equipment and apply rates for the specific pest(s) identified on the pesticide label as 

required under FIFRA. 

• Before each treatment season and prior to mixing or applying any product for the first time each 

season, all applicators would review the labels, MSDSs, and Pesticide Use Proposal (PUPs) for each 

pesticide, determining the target pest, appropriate mix rate(s), PPE, and other requirements listed on 

the pesticide label.

• Use no-spray buffers as specified on product labels. 

• Use low impact herbicide application techniques (e.g., spot treatment, cut stump, oil basal, Thinvert 

system applications) rather than broadcast foliar applications (e.g., boom sprayer, other larger tank 

wand applications), where practical. 

• Use low volume rather than high volume foliar applications where low impact methods above are not 

feasible or practical, to maximize herbicide effectiveness and ensure correct and uniform application 

rates.

• Applicators would use the largest droplet size that results in uniform coverage while minimizing drift 

and runoff. 

• Applicators would use drift reduction technologies such as low-drift nozzles, where practicable. 

• Per label recommendations, spraying would occur during low (average<7mph and preferably 3 to 5 

mph) and consistent direction wind conditions with moderate temperatures (typically <85 oF). 

• Where possible, applicators would avoid spraying during inversion conditions (often associated with 

calm and very low wind conditions) that can cause large-scale herbicide drift to non-target areas.

• Equipment would be calibrated regularly to ensure that the proper rate of pesticide is applied to the 

target area or species.

• Spray applications would be made at the lowest height for uniform coverage of target pests to 

minimize/eliminate potential drift.

• Spray applications would not be conducted on days with >30% forecast for rain within 6 hours, 

except for pesticides that are rapidly rain fast (e.g., glyphosate in 1 hour) to minimize/eliminate 

potential runoff. 

• Where practicable, applicators would use drift retardant adjuvants during spray applications, 

especially adjacent to sensitive areas. 

• Where practicable, applicators would use a non-toxic dye to aid in identifying target area treated as 

well as potential over spray or drift. A dye can also aid in detecting equipment leaks. If a leak is 

discovered, the application would be stopped until repairs can be made to the sprayer. 

• For pesticide uses associated with cropland and facilities management, buffers, as appropriate, would 

be used to protect sensitive habitats, especially wetlands and other aquatic habitats as required by the 

pesticide label. 

• When drift cannot be sufficiently reduced through altering equipment set up and application 

techniques, buffer zones may be identified to protect sensitive areas downwind of applications. 

• Applicators would utilize scouting for early detection of pests to eliminate unnecessary pesticide 

applications. 

• The refuge staff would consider timing of application so native plants are protected to the extent 

practicable, while effectively treating invasive plants. 

• Where practicable, rinsate from cleaning spray equipment after application would be recaptured and 

reused or applied to an appropriate pest plant infestation. 

• Application equipment (e.g., sprayer, ATV, tractor) would be thoroughly cleaned and PPE would be 

removed/disposed of on-site by applicators after treatments to eliminate the potential spread of pests. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-12 Appendix K. Integrated Pest Management

6.0 Safety 

6.1 Personal Protective Equipment 

All applicators would wear the specific personal protective equipment (PPE) identified on the pesticide 

label. The appropriate PPE will be worn at all times during handling, mixing, and applying. Because 

exposure to concentrated product is usually greatest during mixing, extra care should be taken while 

preparing pesticide solutions. 

Protective clothing used during an application would be laundered separately from other laundry items. 

Transporting, storing, handling, mixing and disposing of pesticide containers will be consistent with label 

requirements, USEPA and OSHA requirements, and Service policy. 

If a respirator is necessary, then the following requirements would be met in accordance with Service 

safety policy: a written Respirator Program, fit testing, physical examination (including pulmonary 

function and blood work for contaminants), and proper storage of the respirator. 

6.2 Notification 

The restricted entry interval (REI) is the time period required after the application at which point someone 

may safely enter a treated area without PPE. Refuge staff, authorized management agents of the Service, 

volunteers, and members of the public who could be in or near a pesticide treated area within the stated 

re-entry time period on the label would be notified about treatment areas. Posting would occur at any site 

where individuals might inadvertently become exposed to a pesticide during other activities on the refuge 

within the stated re-entry period. Where required by the label and/or state-specific regulations, sites 

would also be posted on its perimeter and at other likely locations of entry. The refuge staff would also 

notify appropriate private property owners of an intended application, including any private individuals 

who have requested notification. Special efforts would be made to contact nearby individuals who are 

beekeepers or who have expressed chemical sensitivities.

6.3 Medical Surveillance 

Medical surveillance may be required for Service personnel and approved volunteers who mix, apply, 

and/or monitor use of pesticides (see 242 FW 7 [Pesticide Users] and 242 FW 4 [Medical Surveillance]). 

In accordance with 242 FW 7.12A, Service personnel would be medically monitoring if 1 or more of the 

following criteria is met: exposed or may be exposed to concentrations at or above the published 

permissible exposure limits or threshold limit values (see 242 FW 4); use pesticides in a manner 

considered “frequent pesticide use”; or use pesticides in a manner that requires a respirator (see 242 FW 

14 for respirator use requirements). In 242 FW7.7A, “Frequent Pesticide Use means when a person 

applying pesticide handles, mixes, or applies pesticides, with a Health Hazard rating of 3 or higher, for 8 

or more hours in any week or 16 or more hours in any 30-day period.” Under some circumstances, 

individuals may be medically monitored who use pesticides infrequently (see section 7.7), experience an 

acute exposure (sudden, short term), or use pesticides with a health hazard ranking of 1 or 2. This 

decision would consider the individual’s health and fitness level, the pesticide’s specific health risks, and 

the potential risks from other pesticide-related activities. Refuge cooperators (e.g., cooperative farmers) 

and other authorized agents (e.g., state and county employees) would be responsible for their own medical 

monitoring needs and costs. 

Standard examinations (at refuge expense) of appropriate refuge staff would be provided by the nearest 

certified occupational health and safety physician as determined by Federal Occupational Health. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-13

6.4 Certification and Supervision of Pesticide Applicators 

Refuge staff or approved volunteers handling, mixing, and/or applying or directly supervising others 

engaged in pesticide use activities would be trained and state or federally (BLM) licensed to apply 

pesticides to refuge lands or waters. In accordance with 242 FW7.18A, certification is required to apply 

restricted use pesticides based upon USEPA regulations. For safety reasons, all individuals participating 

in pest management activities with general use pesticides also are encouraged to attend appropriate 

training or acquire pesticide applicator certification. The certification requirement would be for a 

commercial or private applicator depending upon the state. Documentation of training would be kept in 

the files at the refuge office. 

6.5 Record Keeping 

6.5.1 Labels and material safety data sheets 

Pesticide labels and material safety data sheets (MSDSs) would be maintained at the refuge shop and 

laminated copies in the mixing area. These documents also would be carried by field applicators, where 

practicable. A written reference (e.g., note pad, chalk board, dry erase board) for each tank to be mixed 

would be kept in the mixing area for quick reference while mixing is in progress. In addition, approved 

PUPs stored in the PUPS database typically contain website links (URLs) to pesticide labels and MSDSs.

6.5.2 Pesticide use proposals (PUPs) 

A PUP would be prepared for each proposed pesticide use associated with annual pest management on 

refuge lands and waters. A PUP would include specific information about the proposed pesticide use 

including the common and chemical names of the pesticide(s), target pest species, size and location of 

treatment site(s), application rate(s) and method(s), and federally listed species determinations, where 

applicable.

In accordance with 30 AM 12 and 7 RM 14, PUPs would be required for the following: 

• Uses of pesticides on lands and facilities owned or managed by the Service, including properties 

managed by Service personnel as a result of the Food Security Act of 1985;

• Service projects by non-Service personnel on Service owned or controlled lands and facilities and 

other pest management activities that would be conducted by Service personnel; and 

• Where the Service would be responsible or provides funds for pest management identified in 

protective covenants, easements, contracts, or agreements off Service lands. 

In accordance with Service guidelines (Director’s memo [December 12, 2007]), a refuge staff may 

receive up to 5-year approvals for Washington Office and field reviewed proposed pesticide uses based 

upon meeting identified criteria including an approved IPM plan, where necessary (see 

http://www.fws.gov/contaminants/Issues/IPM.cfm). For a refuge, an IPM plan (requirements described 

herein) can be completed independently or in association with a CCP or HMP if IPM strategies and 

potential environmental effects are adequately addressed within appropriate NEPA documentation. 

PUPs would be created, approved or disapproved, and stored as records in the Pesticide Use Proposal 

System (PUPS), which is a centralized database on the Service’s intranet (https://systems.fws.gov/pups). 

Only Service employees can access PUP records in this database.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-14 Appendix K. Integrated Pest Management

6.5.3 Pesticide usage 

In accordance with 30 AM 12 and 7 RM 14, the refuge Project Leader would be required to maintain 

records of all pesticides annually applied on lands or waters under refuge jurisdiction. This would 

encompass pesticides applied by other federal agencies, state and county governments, non-government 

applicators including cooperators and their pest management service providers with Service permission. 

For clarification, pesticide means all insecticides, insect and plant growth regulators, dessicants, 

herbicides, fungicides, rodenticides, acaricides, nematicides, fumigants, avicides, and piscicides. 

The following usage information can be reported for approved PUPs in the PUPS database: 

• Pesticide trade name(s) 

• Active ingredient(s) 

• Total acres treated

• Total amount of pesticides used (lbs or gallons)

• Total amount of active ingredient(s) used (lbs)

• Target pest(s) 

• Efficacy (% control) 

To determine whether treatments are efficacious (eradicating, controlling, or containing the target pest) 

and achieving resource objectives, habitat and/or wildlife response would be monitored both pre- and 

post-treatment, where possible. Considering available annual funding and staffing, appropriate 

monitoring data regarding characteristics (attributes) of pest infestations (e.g., area, perimeter, degree of 

infestation-density, % cover, density) as well as habitat and/or wildlife response to treatments may be 

collected and stored in a relational database (e.g., Refuge Habitat Management Database), preferably a 

geo-referenced data management system (e.g., Refuge Lands GIS [RLGIS]) to facilitate data analyses and 

subsequent reporting. In accordance with adaptive management, data analysis and interpretation would 

allow treatments to be modified or changed over time, as necessary, to achieve resource objectives 

considering site-specific conditions in conjunction with habitat and/or wildlife responses. Monitoring 

could also identify short- and long-term impacts to natural resources and environmental quality associated 

with IPM treatments in accordance with adaptive management principles identified in 43 CFR 46.145. 

7.0 Evaluating Pesticide Use Proposals

Pesticides would only be used on refuge lands for habitat management as well as croplands/facilities 

maintenance after approval of a PUP. In general, proposed pesticide uses on refuge lands would only be 

approved where there would likely be minor, temporary, or localized effects to fish and wildlife species as 

well as minimal potential to degrade environmental quality. Potential effects to listed and non-listed 

species would be evaluated with quantitative ecological risk assessments and other screening measures. 

Potential effects to environmental quality would be based upon pesticide characteristics of environmental 

fate (water solubility, soil mobility, soil persistence, and volatilization) and other quantitative screening 

tools. Ecological risk assessments as well as characteristics of environmental fate and potential to 

degrade environmental quality for pesticides would be documented in Chemical Profiles (see Section 

7.5). These profiles would include threshold values for quantitative measures of ecological risk 

assessments and screening tools for environmental fate that represent minimal potential effects to species 

and environmental quality. In general, only pesticide uses with appropriate BMPs (see Section 4.0) for 

habitat management and cropland/facilities maintenance on refuge lands that would potentially have 

minor, temporary, or localized effects on refuge biological and environmental quality (threshold values 

not exceeded) would be approved. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-15

7.1 Overview of Ecological Risk Assessment

An ecological risk assessment process would be used to evaluate potential adverse effects to biological 

resources as a result of a pesticide(s) proposed for use on refuge lands. It is an established quantitative 

and qualitative methodology for comparing and prioritizing risks of pesticides and conveying an estimate 

of the potential risk for an adverse effect. This quantitative methodology provides an efficient mechanism 

to integrate best available scientific information regarding hazard, patterns of use (exposure), and doseresponse relationships in a manner that is useful for ecological risk decision-making. It would provide an 

effective way to evaluate potential effects where there is missing or unavailable scientific information 

(data gaps) to address reasonable, foreseeable adverse effects in the field as required under 40 CFR Part 

1502.22. Protocols for ecological risk assessment of pesticide uses on the refuge were developed through 

research and established by the US Environmental Protection Agency (2004). Assumptions for these risk 

assessments are presented in Section 6.2.3. 

The toxicological data used in ecological risk assessments are typically results of standardized laboratory 

studies provided by pesticide registrants to the US Environmental Protection Agency (USEPA) to meet 

regulatory requirements under the Federal Insecticide, Fungicide and Rodenticide Act of 1996 (FIFRA). 

These studies assess the acute (lethality) and chronic (reproductive) effects associated with short- and 

long-term exposure to pesticides on representative species of birds, mammals, freshwater fish, aquatic 

invertebrates, and terrestrial and aquatic plants. Other effects data publicly available would also be 

utilized for risk assessment protocols described herein. Toxicity endpoint and environmental fate data are 

available from a variety of resources. Some of the more useful resources can be found in 

Section 7.5. 

Table 1. Ecotoxicity tests used to evaluate potential effects to birds, fish, and mammals to establish 

toxicity endpoints for risk quotient calculations. 

Species Group Exposure Measurement endpoint 

Bird

Acute Median Lethal Concentration (LC50) 

Chronic No Observed Effect Concentration (NOEC) or

No Observed Adverse Effect Concentration (NOAEC)1 

Fish 

Acute Median Lethal Concentration (LC50) 

Chronic No Observed Effect Concentration (NOEC) or

No Observed Adverse Effect Concentration (NOAEC)2

Mammal Acute Oral Lethal Dose (LD50) 

Chronic No Observed Effect Concentration (NOEC) or

No Observed Adverse Effect Concentration (NOAEC)3

1

Measurement endpoints typically include a variety of reproductive parameters (e.g., number of eggs, 

number of offspring, eggshell thickness, and number of cracked eggs). 

2

Measurement endpoints for early life stage/life cycle typically include embryo hatch rates, time to 

hatch, growth, and time to swim-up. 

3

Measurement endpoints include maternal toxicity, teratogenic effects or developmental anomalies, 

evidence of mutagenicity or genotoxicity, and interference with cellular mechanisms such as DNA 

synthesis and DNA repair. 

7.2 Determining Ecological Risk to Fish and Wildlife 

The potential for pesticides used on the refuge to cause direct adverse effects to fish and wildlife would be 

evaluated using USEPA’s Ecological Risk Assessment Process (US Environmental Protection Agency 

2004). This deterministic approach, which is based upon a two-phase process involving estimation of 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-16 Appendix K. Integrated Pest Management

environmental concentrations and then characterization of risk, would be used for ecological risk 

assessments. This method integrates exposure estimates (estimated environmental concentration [EEC] 

and toxicological endpoints [e.g., LC50 and oral LD50]) to evaluate the potential for adverse effects to 

species groups (birds, mammals, and fish) representative of legal mandates for managing units of the 

NWRS. This integration is achieved through risk quotients (RQs) calculated by dividing the EEC by 

acute and chronic toxicity values selected from standardized toxicological endpoints or published effect 

(Table 1). 

RQ = EEC/Toxicological Endpoint 

The level of risk associated with direct effects of pesticide use would be characterized by comparing 

calculated RQs to the appropriate Level of Concern (LOC) established by US Environmental Protection 

Agency (1998 [Table 2]). The LOC represents a quantitative threshold value for screening potential 

adverse effects to fish and wildlife resources associated with pesticide use. The following are four 

exposure-species group scenarios that would be used to characterize ecological risk to fish and wildlife on 

the refuge: acute-listed species, acute-nonlisted species, chronic-listed species, and chronic-nonlisted 

species. 

Acute risk would indicate the potential for mortality associated with short-term dietary exposure to 

pesticides immediately after an application. For characterization of acute risks, median values from LC50

and LD50 tests would be used as toxicological endpoints for RQ calculations. In contrast, chronic risks 

would indicate the potential for adverse effects associated with long-term dietary exposure to pesticides 

from a single application or multiple applications over time (within a season and over years). For 

characterization of chronic risks, the no observed concentration (NOAEC) or no observed effect 

concentration (NOEC) for reproduction would be used as toxicological endpoints for RQ calculations. 

Where available, the NOAEC would be preferred over a NOEC value. 

Listed species are those federally designated as threatened, endangered, or proposed in accordance with 

the Endangered Species Act of 1973 (16 USC 1531-1544, 87 Stat. 884, as amended-Public Law 93-205). 

For listed species, potential adverse effects would be assessed at the individual level because loss of 

individuals from a population could detrimentally impact a species. In contrast, risks to nonlisted species 

would consider effects at the population level. A RQ<LOC would indicate the proposed pesticide use 

“may affect, not likely to adversely effect” individuals (listed species) and it would not pose an 

unacceptable risk for adverse effects to populations (non-listed species) for each taxonomic group (Table 

2). In contrast, a RQ>LOC would indicate a “may affect, likely to adversely affect” for listed species and 

it would also pose unacceptable ecological risk for adverse effects to nonlisted species. 

 

Table 2. Presumption of unacceptable risk for birds, fish, and mammals (US Environmental Protection 

Agency 1998). 

Risk Presumption Level of Concern

Listed Species Non-listed Species

Acute Birds 0.1 0.5

Fish 0.05 0.5

Mammals 0.1 0.5

Chronic Birds 1.0 1.0

Fish 1.0 1.0

Mammals 1.0 1.0
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-17

7.2.1 Environmental exposure 

Following release into the environment through application, pesticides would experience several different 

routes of environmental fate. Pesticides which would be sprayed can move through the air (e.g., particle 

or vapor drift) and may eventually end up in other parts of the environment such as non-target vegetation, 

soil, or water. Pesticides may be bound to soil particles or organic matter and may be transformed by soil 

micro-organisms or chemical processes. Pesticides applied directly to the soil may be washed off the soil 

into nearby bodies of surface water (e.g., surface runoff) or may percolate through the soil to lower soil 

layers and groundwater (e.g., leaching) (Baker and Miller 1999, Pope et. al. 1999, Butler et. al. 1998, 

Ramsay et. al. 1995, EXTOXNET 1993a). Pesticides which would be injected into the soil may also be 

subject to the latter two fates. 

The aforementioned possibilities are by no means complete, but it does indicate movement of pesticides 

in the environment is very complex with transfers occurring continually among different environmental 

compartments. In some cases, these exchanges occur not only between areas that are close together, but it 

also may involve transportation of pesticides over long distances (Barry 2004, Woods 2004). 

7.2.1.1 Terrestrial exposure 

The estimated environmental concentration (ECC) for exposure to terrestrial wildlife would be quantified 

using an USEPA screening-level approach (US Environmental Protection Agency 2004). This screeninglevel approach is not affected by product formulation because it evaluates pesticide active ingredient(s). 

This approach would vary depending upon the proposed pesticide application method: spray or granular. 

7.2.1.1.1 Terrestrial-spray application 

For spray applications, exposure would be determined using the Kanaga nomogram method (US 

Environmental Protection Agency 2005a, US Environmental Protection Agency 2004, Pfleeger et al. 

1996) through the USEPA’s Terrestrial Residue Exposure model (T-REX) version 1.2.3 (US 

Environmental Protection Agency 2005b). To estimate the maximum (initial) pesticide residue on short 

grass (<20 cm tall) as a general food item category for terrestrial vertebrate species, T-REX input 

variables would include the following from the pesticide label: maximum pesticide application rate 

(pounds active ingredient [acid equivalent]/acre) and pesticide half-life (days) in soil. Although there are 

other food item categories (tall grasses; broadleaf plants and small insects; and fruits, pods, seeds and 

large insects), short grass was selected because it would yield maximum EECs (240 ppm per lb ai/acre) 

for worse-case risk assessments. Short grass is not representative of forage for carnivorous species (e.g., 

raptors), but it would characterize the maximum potential exposure through the diet of avian and 

mammalian prey items. Consequently, this approach would provide a conservative screening tool for 

pesticides that do not biomagnify. 

For RQ calculations in T-REX, the model would require the weight of surrogate species and Mineau 

scaling factors (Mineau et. al. 1996). Body weights of bobwhite quail and mallard are included in T-REX 

by default, but body weights of other organisms (Table 3) would be entered manually. The Mineau 

scaling factor accounts for small-bodied bird species that may be more sensitive to pesticide exposure 

than would be predicted only by body weight. Mineau scaling factors would be entered manually with 

values ranging from 1 to 1.55 that are unique to a particular pesticide or group of pesticides. If specific 

information to select a scaling factor is not available, then a value of 1.15 would be used as a default. 

Alternatively, zero would be entered if it is known that body weight does not influence toxicity of 

pesticide(s) being assessed. The upper bound estimate output from the T-REX Kanaga nomogram would 

be used as an EEC for calculation of RQs. This approach would yield a conservative estimate of 

ecological risk. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-18 Appendix K. Integrated Pest Management

Table 3. Average body weight of selected terrestrial wildlife species frequently used in research to 

establish toxicological endpoints (Dunning 1984). 

Species Body Weight (kg) 

Mammal (15 g) 0.015 

House sparrow 0.0277 

Mammal (35 g) 0.035 

Starling 0.0823 

Red-winged blackbird 0.0526 

Common grackle 0.114 

Japanese quail 0.178 

Bobwhite quail 0.178 

Rat 0.200 

Rock dove (aka pigeon) 0.542 

Mammal (1000 g) 1.000 

Mallard 1.082 

Ring-necked pheasant 1.135 

7.2.1.1.2 Terrestrial – granular application 

Granular pesticide formulations and pesticide-treated seed would pose a unique route of exposure for 

avian and mammalian species. The pesticide is applied in discrete units which birds or mammals might 

ingest accidentally with food items or intentionally as in the case of some bird species actively seeking 

and picking up gravel or grit to aid digestion or seed as a food source. Granules may also be consumed 

by wildlife foraging on earthworms, slugs or other soft-bodied soil organisms to which the granules may 

adhere. 

Terrestrial wildlife RQs for granular formulations or seed treatments would be calculated by dividing the 

maximum milligrams of active ingredient (ai) exposed (e.g., EEC) on the surface of an area equal to 1 

square foot by the appropriate LD50 value multiplied by the surrogate’s body weight (Table 3). An 

adjustment to surface area calculations would be made for broadcast, banded, and in-furrow applications. 

An adjustment also would be made for applications with and without incorporation of the granules. 

Without incorporation, it would be assumed that 100% of the granules remain on the soil surface 

available to foraging birds and mammals. Press wheels push granules flat with the soil surface, but they 

are not incorporated into the soil. If granules are incorporated in the soil during band or T-band 

applications or after broadcast applications, it would be assumed only 15% of the applied granules remain 

available to wildlife. It would be assumed that only 1% of the granules are available on the soil surface 

following in-furrow applications. 

EECs for pesticides applied in granular form and as seed treatments would be determined considering 

potential ingestion rates of avian or mammalian species (e.g., 10-30% body weight/day). This would 

provide an estimate of maximum exposure that may occur as a result of granule or seed treatment spills 

such as those that commonly occur at end rows during application and planting. The availability of 

granules and seed treatments to terrestrial vertebrates would also be considered by calculating the loading 

per unit area (LD50/ft2

)for comparison to USEPA Level of Concerns (US Environmental Protection 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-19

Agency 1998). The T-REX version 1.2.3 (US Environmental Protection Agency 2005b) contains a 

submodel which automates Kanaga exposure calculations for granular pesticides and treated seed. 

The following formulas will be used to calculate EECs depending upon the type of granular pesticide 

application: 

• In-furrow applications assume a typical value of 1% granules, bait, or seed remain unincorporated. 

mg a.i./ft.

2 

= [(lbs. product/acre)(% a.i.)(453,580 mg/lbs)(1% exposed))] / {[(43,560 ft.

2

/acre)/(row 

spacing (ft.))] / (row spacing (ft.)} 

or 

mg a.i./ft

2 

= [(lbs product/1000 ft. row)(% a.i.)(1000 ft row)(453,580 mg/lb.)(1% exposed) 

EEC = [(mg a.i./ft.

2

)(% of pesticide biologically available)] 

• Incorporated banded treatments assume that 15% of granules, bait, seeds are unincorporated. 

mg a.i./ft.

2 

= [(lbs. product/1000 row ft.)(% a.i.)(453,580 mg/lb.)(1-% incorporated)] / (1,000 ft.)(band 

width (ft.)) 

EEC = [(mg a.i./ft.

2

)(% of pesticide biologically available)] 

• Broadcast treatment without incorporation assumes 100% of granules, bait, seeds are

unincorporated. 

mg a.i./ft.

2 

= [(lbs. product/acre)(% a.i.)(453,590 mg/lb.)] / (43,560 ft.

2

/acre) 

EEC = [(mg a.i./ft.

2

)(% of pesticide biologically available)] 

Where: 

• % of pesticide biologically available = 100% without species specific ingestion rates 

• Conversion for calculating mg a.i./ft.

2 

using ounces: 453,580 mg/lb. /16 = 28,349 mg/oz. 

The following equation would used to calculate a RQ based on the EEC calculated by one of the above 

equations. The EEC would divided by the surrogate LD50 toxicological endpoint multiplied by the body 

weight (Table 3) of the surrogate. 

RQ = EEC / [LD50 (mg/kg) * body weight (kg)] 

As with other risk assessments, a RQ>LOC would be a presumption of unacceptable ecological risk. A 

RQ<LOC would be a presumption of acceptable risk with only minor, temporary, or localized effects to 

species. 

7.2.1.2 Aquatic exposure 

Exposures to aquatic habitats (e.g., wetlands, meadows, ephemeral pools, water delivery ditches) would 

be evaluated separately for ground-based pesticide treatments of habitats managed for fish and wildlife 

compared with cropland/facilities maintenance. The primary exposure pathway for aquatic organisms 

from any ground-based treatments likely would be particle drift during the pesticide application. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-20 Appendix K. Integrated Pest Management

However, different exposure scenarios would be necessary as a result of contrasting application 

equipment and techniques as well as pesticides used to control pests on agricultural lands (especially 

those cultivated by cooperative farmers for economic return from crop yields) and facilities maintenance 

(e.g., roadsides, parking lots, trails) compared with other managed habitats on the refuge. In addition, 

pesticide applications may be done <25 feet of the high water mark of aquatic habitats for habitat 

management treatments; whereas, no-spray buffers (≥25 feet) would be used for croplands/facilities 

maintenance treatments. 

7.2.1.2.1 Habitat treatments

For the worst-case exposure scenario to non-target aquatic habitats, EECs (Table 4) would be would be 

derived from Urban and Cook (1986) that assumes an intentional overspray to an entire, non-target water 

body (1-foot depth) from a treatment <25 feet from the high water mark using the max application rate 

(acid basis [see above]). However, use of BMPs for applying pesticides (see Section 4.2) would likely 

minimize/eliminate potential drift to non-target aquatic habitats during actual treatments. If there would 

be unacceptable (acute or chronic) risk to fish and wildlife with the simulated 100% overspray 

(RQ>LOC), then the proposed pesticide use may be disapproved or the PUP would be approved at a 

lower application rate to minimize/eliminate unacceptable risk to aquatic organisms (RQ=LOC).

Table 4. Estimated Environmental Concentrations (ppb) of pesticides in aquatic habitats (1 foot depth) 

immediately after direct application (Urban and Cook 1986). 

Lbs/acre EEC (ppb)

0.10 36.7

0.20 73.5

0.25 91.9

0.30 110.2

0.40 147.0

0.50 183.7

0.75 275.6

1.00 367.5

1.25 459.7

1.50 551.6

1.75 643.5

2.00 735.7

2.25 827.6

2.50 919.4

3.00 1103.5

4.00 1471.4

5.00 1839

6.00 2207

7.00 2575

8.00 2943

9.00 3311

10.00 3678

7.2.1.2.2 Cropland/facilities maintenance treatments 

Field drift studies conducted by the Spray Drift Task Force, which is a joint project of several agricultural 

chemical businesses, were used to develop a generic spray drift database. From this database, the 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-21

AgDRIFT computer model was created to satisfy USEPA pesticide registration spray drift data 

requirements and as a scientific basis to evaluate off-target movement of pesticides from particle drift and 

assess potential effects of exposure to wildlife. Several versions of the computer model have been 

developed (i.e., v2.01 through v2.10). The Spray Drift Task Force AgDRIFT® model version 2.01 (SDTF 

2003, AgDRIFT 2001) would be used to derive EECs resulting from drift of pesticides to refuge aquatic 

resources from ground-based pesticide applications >25 feet from the high water mark. The Spray Drift 

Task Force AgDRIFT model is publicly available at http://www.agdrift.com. At this website, click 

“AgDRIFT 2.0” and then click “Download Now” and follow the instructions to obtain the computer 

model. 

The AgDRIFT model is composed of submodels called tiers. Tier I Ground submodel would be used to 

assess ground-based applications of pesticides. Tier outputs (EECs) would be calculated with AgDRIFT 

using the following input variables: max application rate (acid basis [see above]), low boom (20 inches), 

fine to medium droplet size, EPA-defined wetland, and a 

≥25-foot distance (buffer) from treated area to water. 

7.2.2 Use of information on effects of biological control agents, pesticides, degradates, and adjuvants

NEPA documents regarding biological and other environmental effects of biological control agents, 

pesticides, degradates, and adjuvants prepared by another federal agency, where the scope would be 

relevant to evaluation of effects from pesticide uses on refuge lands, would be reviewed. Possible source 

agencies for such NEPA documents would include the Bureau of Land Management, US Forest Service, 

National Park Service, US Department of Agriculture-Animal and Plant Health Inspection Service, and 

the military services. It might be appropriate to incorporate by reference parts or all of existing 

document(s). Incorporating by reference (40 CFR 1502.21) is a technique used to avoid redundancies in 

analysis. It also would reduce the bulk of a Service NEPA document, which only would identify the 

documents that are incorporated by reference. In addition, relevant portions would be summarized in the 

Service NEPA document to the extent necessary to provide the decision maker and public with an 

understanding of relevance of the referenced material to the current analysis. 

In accordance with the requirements set forth in 43 CFR 46.135, the Service would specifically 

incorporate through reference ecological risk assessments prepared by the US Forest Service 

(http://www.fs.fed.us/r6/invasiveplant-eis/Risk-Assessments/Herbicides-Analyzed-InvPlant-EIS.htm) and 

Bureau of Land Management (http://www.blm.gov/wo/st/en/prog/more/veg_eis.html). These risk 

assessments and associated documentation also are available in total with the administrative record for the 

Final Environmental Impact Statement entitled Pacific Northwest Region Invasive Plant Program – 

Preventing and Managing Invasive Plants (US Forest Service 2005) and Vegetation Treatments Using 

Herbicides on Bureau of Land Management Lands in 17 Western States Programmatic EIS (PEIS)

(Bureau of Land Management 2007). In accordance with 43 CRF 46.120(d), use of existing NEPA 

documents by supplementing, tiering to, incorporating by reference, or adopting 

previous NEPA environmental analyses would avoid redundancy and unnecessary paperwork.

As a basis for completing “Chemical Profiles” for approving or disapproving refuge PUPs, ecological risk 

assessments for the following herbicide and adjuvant uses prepared by the US Forest Service would be 

incorporated by reference:

• 2,4-D 

• Chlorosulfuron

• Clopyralid 

• Dicamba

• Glyphosate 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-22 Appendix K. Integrated Pest Management

• Imazapic

• Imazapyr

• Metsulfuron methyl 

• Picloram

• Sethoxydim 

• Sulfometuron methyl 

• Triclopyr 

• Nonylphenol polyethylate (NPE) based surfactants

As a basis for completing “Chemical Profiles” for approving or disapproving refuge PUPs, ecological risk 

assessments for the following herbicide uses as well as evaluation of risks associated with pesticide 

degradates and adjuvants prepared by the Bureau of Land Management would be incorporated by 

reference:

• Bromacil

• Chlorsulfuron 

• Diflufenzopyr 

• Diquat 

• Diuron 

• Fluridone 

• Imazapic

• Overdrive (diflufenzopyr and dicamba) 

• Sulfometuron methyl 

• Tebuthiuron 

• Pesticide degradates and adjuvants (Appendix D – Evaluation of risks from degradates, 

polyoxyethylene-amine (POEA) and R-11, and endocrine disrupting chemicals) 

7.2.3 Assumptions for ecological risk assessments 

There are a number of assumptions involved with the ecological risk assessment process for terrestrial 

and aquatic organisms associated with utilization of the US Environmental Protection Agency’s (2004) 

process. These assumptions may be risk neutral or may lead to an over- or under-estimation of risk from 

pesticide exposure depending upon site-specific conditions. The following describes these assumptions, 

their application to the conditions typically encountered, and whether or not they may lead to 

recommendations that are risk neutral, underestimate, or overestimate ecological risk from potential 

pesticide exposure. 

• Indirect effects would not be evaluated by ecological risk assessments. These effects include the 

mechanisms of indirect exposure to pesticides: consuming prey items (fish, birds, or small 

mammals), reductions in the availability of prey items, and disturbance associated with pesticide 

application activities.

• Exposure to a pesticide product can be assessed based upon the active ingredient. However, 

exposure to a chemical mixture (pesticide formulation) may result in effects that are similar or 

substantially different compared to only the active ingredient. Non-target organisms may be exposed 

directly to the pesticide formulation or only various constituents of the formulation as they dissipate 

and partition in the environment. If toxicological information for both the active ingredient and 

formulated product are available, then data representing the greatest potential toxicity would be 

selected for use in the risk assessment process (US Environmental Protection Agency 2004). As a 

result, this conservative approach may lead to an overestimation of risk characterization from 

pesticide exposure.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-23

• Because toxicity tests with listed or candidate species or closely related species are not available, data 

for surrogate species would be most often used for risk assessments. Specifically, bobwhite quail and 

mallard duck are the most frequently used surrogates for evaluating potential toxicity to federally 

listed avian species. Bluegill sunfish, rainbow trout, and fathead minnow are the most common 

surrogates for evaluating toxicity for freshwater fishes. However, sheep’s head minnow can be an 

appropriate surrogate marine species for coastal environments. Rats and mice are the most common 

surrogates for evaluating toxicity for mammals. Interspecies sensitivity is a major source of 

uncertainty in pesticide assessments. As a result of this uncertainty, data is selected for the most 

sensitive species tested within a taxonomic group (birds, fish, and mammals) given the quality of the 

data is acceptable. If additional toxicity data for more species of organisms in a particular group are 

available, the selected data will not be limited to the species previously listed as common surrogates. 

• The Kanaga nomogram outputs maximum EEC values that may be used to calculate an average daily 

concentration over a specified interval of time, which is referred to as a time-weighted-average 

(TWA). The maximum EEC would be selected as the exposure input for both acute and chronic risk 

assessments in the screening-level evaluations. The initial or maximum EEC derived from the 

Kanaga nomogram represents the maximum expected instantaneous or acute exposure to a pesticide. 

Acute toxicity endpoints are determined using a single exposure to a known pesticide concentration 

typically for 48 to 96 hours. This value is assumed to represent ecological risk from acute exposure 

to a pesticide. On the other hand, chronic risk to pesticide exposure is a function of pesticide 

concentration and duration of exposure to the pesticide. An organism’s response to chronic pesticide 

exposure may result from either the concentration of the pesticide, length of exposure, or some 

combination of both factors. Standardized tests for chronic toxicity typically involve exposing an 

organism to several different pesticide concentrations for a specified length of time (days, weeks, 

months, years or generations). For example, avian reproduction tests include a 10-week exposure 

phase. Because a single length of time is used in the test, time response data is usually not available 

for inclusion into risk assessments. Without time response data it is difficult to determine the 

concentration which elicited a toxicological response.

• Using maximum EECs for chronic risk estimates may result in an overestimate of risk, particularly 

for compounds that dissipate rapidly. Conversely, using TWAs for chronic risk estimates may 

underestimate risk if it is the concentration rather than the duration of exposure that is primarily 

responsible for the observed adverse effect. The maximum EEC would be used for chronic risk 

assessments although it may result in an overestimate of risk. TWAs may be used for chronic risk 

assessments, but they will be applied judiciously considering the potential for an underestimate or 

overestimate of risk. For example, the number of days exposure exceeds a Level of Concern may 

influence the suitability of a pesticide use. The greater the number of days the EEC exceeds the Level 

of Concern translates into greater the ecological risk. This is a qualitative assessment, and is subject 

to reviewer’s expertise in ecological risk assessment and tolerance for risk.

• The length of time used to calculate the TWA can have a substantial effect on the exposure estimates 

and there is no standard method for determining the appropriate duration for this estimate. The TREX model assumes a 21-week exposure period, which is equivalent to avian reproductive studies 

designed to establish a steady-state concentration for bioaccumulative compounds. However, this 

does not necessarily define the true exposure duration needed to elicit a toxicological response. 

Pesticides, which do not bioaccumulate, may achieve a steady-state concentration earlier than 21 

weeks. The duration of time for calculating TWAs will require justification and it will not exceed the 

duration of exposure in the chronic toxicity test (approximately 70 days for the standard avian 

reproduction study). An alternative to using the duration of the chronic toxicity study is to base the 

TWA on the application interval. In this case, increasing the application interval would suppress both 

the estimated peak pesticide concentration and the TWA. Another alternative to using TWAs would 

be to consider the number of days that a chemical is predicted to exceed the LOC.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-24 Appendix K. Integrated Pest Management

• Pesticide dissipation is assumed to be first-order in the absence of data suggesting alternative 

dissipation patterns such as bi-phasic. Field dissipation data would generally be the most pertinent for 

assessing exposure in terrestrial species that forage on vegetation. However, this data is often not 

available and it can be misleading particularly if the compound is prone to “wash-off”. Soil half-life 

is the most common degradation data available. Dissipation or degradation data that would reflect the 

environmental conditions typical of refuge lands would be utilized, if available. 

• For species found in the water column, it would be assumed that the greatest bioavailable fraction of 

the pesticide active ingredient in surface waters is freely dissolved in the water column.

• Actual habitat requirements of any particular terrestrial species are not considered, and it is assumed 

that species exclusively and permanently occupy the treated area, or adjacent areas receiving pesticide 

at rates commensurate with the treatment rate. This assumption would produce a maximum estimate 

of exposure for risk characterization. This assumption would likely lead to an overestimation of 

exposure for species that do not permanently and exclusively occupy the treated area (US 

Environmental Protection Agency 2004). 

• Exposure through incidental ingestion of pesticide contaminated soil is not considered in the USEPA 

risk assessment protocols. Research suggests <15% of the diet can consist of incidentally ingested 

soil depending upon species and feeding strategy (Beyer et al. 1994). An assessment of pesticide 

concentrations in soil compared to food item categories in the Kanaga nomogram indicates incidental 

soil ingestion will not likely increase dietary exposure to pesticides. Inclusion of soil into the diet 

would effectively reduce the overall dietary concentration compared to the present assumption that 

the entire diet consists a contaminated food source (Fletcher et al. 1994). An exception to this may be 

soil-applied pesticides in which exposure from incidental ingestion of soil may increase. Potential for 

pesticide exposure under this assumption may be underestimated for soil-applied pesticides and 

overestimated for foliar-applied pesticides. The concentration of a pesticide in soil would likely be 

less than predicted on food items. 

• Exposure through inhalation of pesticides is not considered in the USEPA risk assessment protocols. 

Such exposure may occur through three potential sources: spray material in droplet form at time of 

application, vapor phase with the pesticide volatilizing from treated surfaces, and airborne 

particulates (soil, vegetative matter, and pesticide dusts). The USEPA (1990) reported exposure from 

inhaling spray droplets at the time of application is not an appreciable route of exposure for birds. 

According to research on mallards and bobwhite quail, respirable particle size (particles reaching the 

lung) in birds is limited to maximum diameter of 2 to 5 microns. The spray droplet spectra covering 

the majority of pesticide application scenarios indicate that less than 1% of the applied material is 

within the respirable particle size. This route of exposure is further limited because the permissible 

spray drop size distribution for ground pesticide applications is restricted to ASAE medium or coarser 

drop size distribution. 

• Inhalation of a pesticide in the vapor phase may be another source of exposure for some pesticides 

under certain conditions. This mechanism of exposure to pesticides occurs post application and it 

would pertain to those pesticides with a high vapor pressure. The USEPA is currently evaluating 

protocols for modeling inhalation exposure from pesticides including near-field and near-ground air 

concentrations based upon equilibrium and kinetics-based models. Risk characterization for exposure 

with this mechanism is unavailable.

• The effect from exposure to dusts contaminated with the pesticide cannot be assessed generically as 

partitioning issues related to application site soils and chemical properties of the applied pesticides 

render the exposure potential from this route highly situation specific. 

• Dermal exposure may occur through three potential sources: direct application of spray to terrestrial 

wildlife in the treated area or within the drift footprint, incidental contact with contaminated 

vegetation, or contact with contaminated water or soil. Interception of spray and incidental contact 

with treated substrates may pose risk to avian wildlife (Driver et al. 1991). However, available 

research related to wildlife dermal contact with pesticides is extremely limited, except dermal toxicity 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-25

values are common for some mammals used as human surrogates (rats and mice). The USEPA is 

currently evaluating protocols for modeling dermal exposure. Risk characterization may be 

underestimated for this route of exposure, particularly with high risk pesticides such as some 

organophosphates or carbamate insecticides. If protocols are established by the USEPA for assessing 

dermal exposure to pesticides, they will be considered for incorporation into pesticide assessment 

protocols. 

• Exposure to a pesticide may occur from consuming surface water, dew or other water on treated 

surfaces. Water soluble pesticides have potential to dissolve in surface runoff and puddles in a treated 

area may contain pesticide residues. Similarly, pesticides with lower organic carbon partitioning 

characteristics and higher solubility in water have a greater potential to dissolve in dew and other 

water associated with plant surfaces. Estimating the extent to which such pesticide loadings to

drinking water occurs is complex and would depend upon the partitioning characteristics of the active 

ingredient, soils types in the treatment area, and the meteorology of the treatment area. In addition, 

the use of various water sources by wildlife is highly species-specific. Currently, risk 

characterization for this exposure mechanism is not available. The USEPA is actively developing 

protocols to quantify drinking water exposures from puddles and dew. If and when protocols are 

formally established by the USEPA for assessing exposure to pesticides through drinking water, these 

protocols will be incorporated into pesticide risk assessment protocols.

• Risk assessments are based upon the assumption that the entire treatment area would be subject to 

pesticide application at the rates specified on the label. In most cases, there is potential for uneven 

application of pesticides through such plausible incidents such as changes in calibration of application 

equipment, spillage, and localized releases at specific areas in or near the treated field that are 

associated with mixing and handling and application equipment as well as applicator skill. 

Inappropriate use of pesticides and the occurrence of spills represent a potential underestimate of risk. 

It is likely not an important factor for risk characterization. All pesticide applicators are required to 

be certified by the state in which they apply pesticides. Certification training includes the safe storage, 

transport, handling, and mixing of pesticides, equipment calibration and proper application with 

annual continuing education. 

• The USEPA relies on Fletcher (1994) for setting the assumed pesticide residues in wildlife dietary 

items. The USEPA (2004) “believes that these residue assumptions reflect a realistic upper-bound 

residue estimate, although the degree to which this assumption reflects a specific percentile estimate 

is difficult to quantify”. Fletcher’s (1994) research suggests that the pesticide active ingredient 

residue assumptions used by the USEPA represent a 95th percentile estimate. However, research 

conducted by Pfleeger et al. (1996) indicates USEPA residue assumptions for short grass was not 

exceeded. Behr and Habig (2000) compared USEPA residue assumptions with distributions of 

measured pesticide residues for the USEPA’s UTAB database. Overall residue selection level will 

tend to overestimate risk characterization. This is particularly evident when wildlife individuals are 

likely to have selected a variety of food items acquired from multiple locations. Some food items 

may be contaminated with pesticide residues whereas others are not contaminated. However, it is 

important to recognize differences in species feeding behavior. Some species may consume whole 

above-ground plant material, but others will preferentially select different plant structures. Also, 

species may preferentially select a food item although multiple food items may be present. Without 

species specific knowledge regarding foraging behavior characterizing ecological risk other than in 

general terms is not possible.

• Acute and chronic risk assessments rely on comparisons of wildlife dietary residues with LC50 or 

NOEC values expressed as concentrations of pesticides in laboratory feed. These comparisons 

assume that ingestion of food items in the field occurs at rates commensurate with those in the 

laboratory. Although the screening assessment process adjusts dry-weight estimates of food intake to 

reflect the increased mass in fresh-weight wildlife food intake estimates, it does not allow for gross 

energy and assimilative efficiency differences between wildlife food items and laboratory feed. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-26 Appendix K. Integrated Pest Management

Differences in assimilative efficiency between laboratory and wild diets suggest that current 

screening assessment methods are not accounting for a potentially important aspect of food 

requirements.

• There are several other assumptions that can affect non-target species not considered in the risk 

assessment process. These include possible additive or synergistic effects from applying two or more 

pesticides or additives in a single application, co-location of pesticides in the environment, 

cumulative effects from pesticides with the same mode of action, effects of multiple stressors (e.g., 

combination of pesticide exposure, adverse abiotic and biotic factors) and behavioral changes induced 

by exposure to a pesticide. These factors may exist at some level contributing to adverse affects to 

non-target species, but they are usually characterized in the published literature in only a general 

manner limiting their value in the risk assessment process.

• It is assumed that aquatic species exclusively and permanently occupy the water body being assessed. 

Actual habitat requirements of aquatic species are not considered. With the possible exception of 

scenarios where pesticides are directly applied to water, it is assumed that no habitat use 

considerations specific for any species would place the organisms in closer proximity to pesticide use 

sites. This assumption produces a maximum estimate of exposure or risk characterization. It would 

likely be realistic for many aquatic species that may be found in aquatic habitats within or in close 

proximity to treated terrestrial habitats. However, the spatial distribution of wildlife is usually not 

random because wildlife distributions are often related to habitat requirements of species. Clumped 

distributions of wildlife may result in an under- or over-estimation of risk depending upon where the 

initial pesticide concentration occurs relative to the species or species habitat. 

• For species found in the water column, it would be assumed that the greatest bioavailable fraction of 

the pesticide active ingredient in surface waters is freely dissolved in the water column. Additional 

chemical exposure from materials associated with suspended solids or food items is not considered 

because partitioning onto sediments likely is minimal. Adsorption and bioconcentration occurs at 

lower levels for many newer pesticides compared with older more persistent bioaccumulative 

compounds. Pesticides with RQs close to the listed species level of concern, the potential for 

additional exposure from these routes may be a limitation of risk assessments, where potential 

pesticide exposure or risk may be underestimated. 

• Mass transport losses of pesticide from a water body (except for losses by volatilization, degradation 

and sediment partitioning) would not be considered for ecological risk assessment. The water body 

would be assumed to capture all pesticide active ingredients entering as runoff, drift, and adsorbed to 

eroded soil particles. It would also be assumed that pesticide active ingredient is not lost from the 

water body by overtopping or flow-through, nor is concentration reduced by dilution. In total, these 

assumptions would lead to a near maximum possible water-borne concentration. However, this 

assumption would not account for potential to concentrate pesticide through the evaporative loss. 

This limitation may have the greatest impact on water bodies with high surface-to-volume ratios such 

as ephemeral wetlands, where evaporative losses are accentuated and applied pesticides have low 

rates of degradation and volatilization. 

• For acute risk assessments, there would be no averaging time for exposure. An instantaneous peak 

concentration would be assumed, where instantaneous exposure is sufficient in duration to elicit acute 

effects comparable to those observed over more protracted exposure periods (typically 48 to 96 

hours) tested in the laboratory. In the absence of data regarding time-to-toxic event, analyses and 

latent responses to instantaneous exposure, risk would likely be overestimated. 

• For chronic exposure risk assessments, the averaging times considered for exposure are 

commensurate with the duration of invertebrate life-cycle or fish-early life stage tests (e.g., 21-28 

days and 56-60 days, respectively). Response profiles (time to effect and latency of effect) to 

pesticides likely vary widely with mode of action and species and should be evaluated on a case-bycase basis as available data allow. Nevertheless, because the USEPA relies on chronic exposure 

toxicity endpoints based on a finding of no observed effect, the potential for any latent toxicity effects 
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Appendix K. Integrated Pest Management K-27

or averaging time assumptions to alter the results of an acceptable chronic risk assessment prediction 

is limited. The extent to which duration of exposure from water-borne concentrations overestimate or 

underestimate actual exposure depends on several factors. These include the following: localized 

meteorological conditions, runoff characteristics of the watershed (e.g., soils, topography), the 

hydrological characteristics of receiving waters, environmental fate of the pesticide active ingredient, 

and the method of pesticide application. It should also be understood that chronic effects studies are 

performed using a method that holds water concentration in a steady state. This method is not likely 

to reflect conditions associated with pesticide runoff. Pesticide concentrations in the field increase 

and decrease in surface water on a cycle influenced by rainfall, pesticide use patterns, and degradation 

rates. As a result of the dependency of this assumption on several undefined variables, risk associated 

with chronic exposure may in some situations underestimate risk and overestimate risk in others. 

• There are several other factors that can affect non-target species not considered in the risk assessment 

process. These would include the following: possible additive or synergistic effects from applying 

two or more pesticides or additives in a single application, co-location of pesticides in the 

environment, cumulative effects from pesticides with the same mode of action, effects of multiple 

stressors (e.g., combination of pesticide exposure, adverse abiotic [not pesticides] and biotic factors), 

and sub-lethal effects such as behavioral changes induced by exposure to a pesticide. These factors 

may exist at some level contributing to adverse affects to non-target species, but they are not routinely 

assessed by regulatory agencies. Therefore, information on the factors is not extensive limiting their 

value for the risk assessment process. As this type of information becomes available, it would be 

included, either quantitatively or qualitatively, in this risk assessment process. 

• USEPA is required by the Food Quality Protection Act to assess the cumulative risks of pesticides 

that share common mechanisms of toxicity, or act the same within an organism. Currently, USEPA 

has identified four groups of pesticides that have a common mechanism of toxicity requiring 

cumulative risk assessments. These four groups are: the organophosphate insecticides, N-methyl 

carbamate insecticides, triazine herbicides, and chloroacetanilide herbicides. 

7.3 Pesticide Mixtures and Degradates 

Pesticide products are usually a formulation of several components generally categorized as active 

ingredients and inert or other ingredients. The term active ingredient is defined by the FIFRA as 

preventing, destroying, repelling, or mitigating the effects of a pest, or it is a plant regulator, defoliant, 

desiccant, or nitrogen stabilizer. In accordance with FIFRA, the active ingredient(s) must be identified by 

name(s) on the pesticide label along with its relative composition expressed in percentage(s) by weight. 

In contrast, inert ingredient(s) are not intended to affect a target pest. Their role in the pesticide 

formulation is to act as a solvent (keep the active ingredient is a liquid phase), an emulsifying or 

suspending agent (keep the active ingredient from separating out of solution), or a carrier such as clay in 

which the active ingredient is impregnated on the clay particle in dry formulations. For example, if 

isopropyl alcohol would be used as a solvent in a pesticide formulation, then it would be considered an 

inert ingredient. FIFRA only requires that inert ingredients identified as hazardous and associated percent 

composition, and the total percentage of all inert ingredients must be declared on a product label. Inert 

ingredients that are not classified as hazardous are not required to be identified. 

The USEPA (September 1997) issued Pesticide Regulation Notice 97-6 which encouraged manufacturers, 

formulators, producers, and registrants of pesticide products to voluntarily substitute the term “other 

ingredients” for “inert ingredients” in the ingredient statement. This change recognized that all 

components in a pesticide formulation potentially could elicit or contribute to an adverse effect on nontarget organisms and, therefore, are not necessarily inert. Whether referred to as “inerts” or “other 

ingredients,” these constituents within a pesticide product have the potential to affect species or 

environmental quality. The USEPA categorizes regulated inert ingredients into the following four lists 

(http://www.epa.gov/opprd001/inerts/index.html): 
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K-28 Appendix K. Integrated Pest Management

• List 1 – Inert Ingredients of Toxicological Concern 

• List 2 – Potentially Toxic Inert Ingredients

• List 3 – Inerts of Unknown Toxicity

• List 4 – Inerts of Minimal Toxicity 

Several of the List 4 compounds are naturally-occurring earthen materials (e.g., clay materials, simple 

salts) that would not elicit toxicological response at applied concentrations. However, some of the inerts 

(particularly the List 3 compounds and unlisted compounds) may have moderate to high potential toxicity 

to aquatic species based on MSDSs or published data. 

Comprehensively assessing potential effects to non-target fish, wildlife, plants, and/or their habitats from 

pesticide use is a complex task. It would be preferable to assess the cumulative effects from exposure to 

the active ingredient, its degradates, and inert ingredients as well as other active ingredients in the spray 

mixture. However, it would only be feasible to conduct deterministic risk assessments for each 

component in the spray mixture singly. Limited scientific information is available regarding ecological 

effects (additive or synergistic) from chemical mixtures that typically rely upon broadly encompassing 

assumptions. For example, the US Forest Service (2005) found that mixtures of pesticides used in land 

(forest) management likely would not cause additive or synergistic effects to non-target species based 

upon a review of scientific literature regarding toxicological effects and interactions of agricultural 

chemicals (ATSDR 2004, US EPA-ORD 2000). Moreover, information on inert ingredients, adjuvants, 

and degradates is often limited by the availability of and access to reliable toxicological data for these 

constituents. 

Toxicological information regarding “other ingredients” may be available from sources such as the 

following: 

• TOMES (a proprietary toxicological database including USEPA’s IRIS, the Hazardous Substance 

Data Bank, the Registry of Toxic Effects of Chemical Substances [RTECS]). 

• USEPA’s ECOTOX database, which includes AQUIRE (a database containing scientific papers 

published on the toxic effects of chemicals to aquatic organisms). 

• TOXLINE (a literature searching tool). 

• Material Safety Data Sheets (MSDSs) from pesticide suppliers. 

• Other sources such as the Farm Chemicals Handbook. 

Because there is a lack of specific inert toxicological data, inert(s) in a pesticide may cause adverse 

ecological effects. However, inert ingredients typically represent only a small percentage of the pesticide 

spray mixture, and it would be assumed that negligible effects would be expected to result from inert 

ingredient(s). 

Although the potential effects of degradates should be considered when selecting a pesticide, it is beyond 

the scope of this assessment process to consider all possible breakdown chemicals of the various product 

formulations containing an active ingredient. Degradates may be more or less mobile and more or less 

hazardous in the environment than their parent pesticides (Battaglin et al. 2003). Differences in 

environmental behavior (e.g., mobility) and toxicity between parent pesticides and degradates would 

make assessing potential degradate effects extremely difficult. For example, a less toxic and more 

mobile, bioaccumulative, or persistent degradate may have potentially greater effects on species and/or 

degrade environmental quality. The lack of data on the toxicity of degradates for many pesticides would 

represent a source of uncertainty for assessing risk.

An USEPA-approved label specifies whether a product can be mixed with one or more pesticides. 

Without product-specific toxicological data, it would not possible to quantify the potential effects of these 
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Appendix K. Integrated Pest Management K-29

mixtures. In addition, a quantitative analysis could only be conducted if reliable scientific information 

allowed a determination of whether the joint action of a mixture would be additive, synergistic, or 

antagonistic. Such information would not likely exist unless the mode of action would be common 

among the chemicals and receptors. Moreover, the composition of and exposure to mixtures would be 

highly site- and/or time-specific and, therefore, it would be nearly impossible to assess potential effects to 

species and environmental quality.

To minimize or eliminate potential negative effects associated with applying two or more pesticides as a 

mixture, the use would be conducted in accordance with the labeling requirements. Labels for two or 

more pesticides applied as a mixture should be completely reviewed, where products with the least 

potential for negative effects would be selected for use on the refuge. This is especially relevant when a 

mixture would be applied in a manner that may already have the potential for an effect(s) associated with 

an individual pesticide (e.g., runoff to ponds in sandy watersheds). Use of a tank mix under these 

conditions would increase the level of uncertainty in terms of risk to species or potential to degrade 

environmental quality.

Adjuvants generally function to enhance or prolong the activity of pesticide. For terrestrial herbicides, 

adjuvants aid in the absorption into plant tissue. Adjuvant is a broad term that generally applies to 

surfactants, selected oils, anti-foaming agents, buffering compounds, drift control agents, compatibility 

agents, stickers, and spreaders. Adjuvants are not under the same registration requirements as pesticides 

and the USEPA does not register or approve the labeling of spray adjuvants. Individual pesticide labels 

identify types of adjuvants approved for use with it. In general, adjuvants compose a relatively small 

portion of the volume of pesticides applied. Selection of adjuvants with limited toxicity and low volumes 

would be recommended to reduce the potential for the adjuvant to influence the toxicity of the pesticide.

7.4 Determining Effects to Soil and Water Quality 

The approval process for pesticide uses would consider potential to degrade water quality on and off 

refuge lands. A pesticide can only affect water quality through movement away from the treatment site. 

After application, pesticide mobilization can be characterized by one or more of the following (Kerle et 

al. 1996): 

• Attach (sorb) to soil, vegetation, or other surfaces and remain at or near the treated area;

• Attach to soil and move off-site through erosion from run-off or wind; 

• Dissolve in water that can be subjected to run-off or leaching. 

As an initial screening tool, selected chemical characteristics and rating criteria for a pesticide can be 

evaluated to assess potential to enter ground and/or surface waters. These would include the following: 

persistence, sorption coefficient (Koc), groundwater ubiquity score (GUS), and solubility. 

Persistence, which is expressed as half-life (t1⁄2), represents the length of time required for 50% of the 

deposited pesticide to degrade (completely or partially). Persistence in the soil can be categorized as the 

following: non-persistent <30 days, moderately persistent = 30 to 100 days, and persistent >100 days 

(Kerle et. al. 1996). Half-life data is usually available for aquatic and terrestrial environments.

Another measure of pesticide persistence is dissipation time (DT50). It represents the time required for 

50% of the deposited pesticide to degrade and move from a treated site; whereas, half-life describes the 

rate for degradation only. As for half-life, units of dissipation time are usually expressed in days. Field 

or foliar dissipation time is the preferred data for use to estimate pesticide concentrations in the 

environment. However, soil half-life is the most common persistence data cited in published literature. 

If field or foliar dissipation data is not available, soil half-life data may be used. The average or 
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K-30 Appendix K. Integrated Pest Management

representative half-life value of most important degradation mechanism will be selected for quantitative 

analysis for both terrestrial and aquatic environments.

Mobility of a pesticide is a function of how strongly it is adsorbed to soil particles and organic matter, its 

solubility in water, and its persistence in the environment. Pesticides strongly adsorbed to soil particles, 

relatively insoluble in water, and not environmentally persistent would be less likely to move across the 

soil surface into surface waters or to leach through the soil profile and contaminate groundwater. 

Conversely, pesticides that are not strongly adsorbed to soil particles, are highly water soluble, and are 

persistent in the environment would have greater potential to move from the application site (off-site 

movement). 

The degree of pesticide adsorption to soil particles and organic matter (Kerle et. al. 1996) is expressed as 

the soil adsorption coefficient (Koc). The soil adsorption coefficient is measured as micrograms of 

pesticide per gram of soil (μg/g) that can range from near zero to the thousands. Pesticides with higher 

Koc values are strongly sorbed to soil and, therefore, would be less subject to movement. 

Water solubility describes the amount of pesticide that will dissolve in a known quantity of water. The 

water solubility of a pesticide is expressed as milligrams of pesticide dissolved in a liter of water (mg/l or 

ppm). Pesticide with solubility <0.1 ppm are virtually insoluble in water, 100-1000 ppm are moderately 

soluble, and >10,000 ppm highly soluble (US Geological Survey 2000). As pesticide solubility increases, 

there would be greater potential for off-site movement. 

The Groundwater Ubiquity Score (GUS) is a quantitative screening tool to estimate a pesticide’s potential 

to move in the environment. It utilizes soil persistence and adsorption coefficients in the following 

formula. 

GUS = log10 (t1⁄2) x [4 - log10 (Koc)]

The potential pesticide movement rating would be based upon its GUS value. Pesticides with a GUS <0.1 

would considered to have an extremely low potential to move toward groundwater. Values of 1.0-2.0 

would be low, 2.0-3.0 would be moderate, 3.0-4.0 would be high, and 

>4.0 would have a very high potential to move toward groundwater. 

Water solubility describes the amount of pesticide dissolving in a specific quantity of water, where it is 

usually measured as mg/l or parts per million (ppm). Solubility is useful as a comparative measure 

because pesticides with higher values are more likely to move by run-off or leaching. GUS, water 

solubility, t1⁄2, and Koc values are available for selected pesticides from the OSU Extension Pesticide 

Properties Database at http://npic.orst.edu/ppdmove.htm. Many of the values in this database were 

derived from the SCS/ARS/CES Pesticide Properties Database for Environmental Decision Making 

(Wauchope et al. 1992).

Soil properties influence the fate of pesticides in the environment. The following six properties are 

mostly likely to affect pesticide degradation and the potential for pesticides to move off-site by leaching 

(vertical movement through the soil) or runoff (lateral movement across the soil surface). 

• Permeability is the rate of water movement vertically through the soil. It is affected by soil 

texture and structure. Coarse textured soils (e.g., high sand content) have a larger pore size and 

they are generally more permeable than fine textured soils (i.e., high clay content). The more 

permeable soils would have a greater potential for pesticides to move vertically down through the 

soil profile. Soil permeability rates (inches/hour) are usually available in county soil survey 

reports. 
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Appendix K. Integrated Pest Management K-31

• Soil texture describes the relative percentage of sand, silt, and clay. In general, greater clay 

content with smaller the pore size would lower the likelihood and rate water that would move 

through the soil profile. Clay also serves to adsorb (bind) pesticides to soil particles. Soils with 

high clay content would adsorb more pesticide than soils with relatively low clay content. In 

contrast, sandy soils with coarser texture and lower water holding capacity would have a greater 

potential for water to leach through them. Coarse texture soils permit higher rates of gas exchange 

than clay soils and may influence microbial transformation rates depending on whether the 

primary decomposition pathway is aerobic or anaerobic.

• Soil structure describes soil aggregation. Soils with a well developed soil structure have looser, 

more aggregated, structure that would be less likely to be compacted. Both characteristics would 

allow for less restricted flow of water through the soil profile resulting in greater infiltration.

• Organic matter would be the single most important factor affecting pesticide adsorption in soils. 

Many pesticides are adsorbed to organic matter which would reduce their rate of downward 

movement through the soil profile. Also, soils high in organic matter would tend to hold more 

water, which may make less water available for leaching. 

• Soil moisture and infiltration rates (related to the composition of different sized particles as well 

as physical features such as soil density) affects how fast water would move through the soil. If 

soils are already wet or saturated before rainfall or irrigation, excess moisture would runoff rather 

than infiltrate into the soil profile. Soil moisture also would influence microbial and chemical 

activity in soil, which effects pesticide degradation. 

• Soil pH would influence chemical reactions that occur in the soil which in turn determines 

whether or not a pesticide will degrade, rate of degradation, and, in some instances, which 

degradation products are produced. 

Based upon the aforementioned properties, soils most vulnerable to groundwater contamination would be 

sandy soils with low organic matter. In contrast, the least vulnerable soils would be well-drained clayey 

soils with high organic matter. Consequently, pesticides with the lowest potential for movement in 

conjunction with appropriate best management practices (see below) would be used in an IPM framework 

to treat pests while minimizing effects to non-target biota and protecting environmental quality.

Along with soil properties, the potential for a pesticide to affect water quality through run-off and 

leaching would consider site-specific environmental and abiotic conditions including rainfall, water table 

conditions, and topography (Huddleston 1996). 

• Water is necessary to separate pesticides from soil. This can occur in two basic ways. Pesticides 

that are soluble move easily with runoff water. Pesticide-laden soil particles can be dislodged and 

transported from the application site in runoff. The concentration of pesticides in the surface 

runoff would be greatest for the first runoff event following treatment. The rainfall intensity and 

route of water infiltration into soil, to a large extent, determine pesticide concentrations and losses 

in surface runoff. The timing of the rainfall after application also would have an effect. Rainfall 

interacts with pesticides at a shallow soil depth (1⁄4 to 1⁄2 inch), which is called the mixing zone 

(Baker and Miller 1999). The pesticide/water mixture in the mixing zone would tend to leach 

down into the soil or runoff depending upon how quickly the soil surface becomes saturated and 

how rapidly water can infiltrate into the soil. Leaching would decrease the amount of pesticide 

available near the soil surface (mixing zone) to runoff during the initial rainfall event following 

application and subsequent rainfall events. 

• Terrain slope would affect the potential for surface runoff and the intensity of runoff. Steeper 

slopes would have greater potential for runoff following a rainfall event. In contrast, soils that are 

relatively flat would have little potential for runoff, except during intense rainfall events. In 

addition, soils in lower areas would be more susceptible to leaching as a result of receiving 

excessive water from surrounding higher elevations.
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K-32 Appendix K. Integrated Pest Management

• Depth to groundwater would be an important factor affecting the potential for pesticides to leach 

into groundwater. If the distance from the soil surface to the top of the water table is shallow, 

pesticides would have less distance to travel to reach groundwater. Shallower water tables that 

persist for longer periods would be more likely to experience groundwater contamination. Soil 

survey reports are available for individual counties. These reports provide data in tabular format 

regarding the water table depths and the months during which it is persists. In some situations, a 

hard pan exists above the water table that would prevent pesticide contamination from leaching. 

7.5 Determining Effects to Air Quality

Pesticides may volatilize from soil and plant surfaces and move from the treated area into the atmosphere. 

The potential for a pesticide to volatilize is determined by the pesticide’s vapor pressure which would be 

affected by temperature, sorption, soil moisture, and the pesticide’s water solubility. Vapor pressure is 

often expressed in mm Hg. To make these numbers easier to compare, vapor pressure may be expressed 

in exponent form (I x 10-7), where I represents a vapor pressure index. In general, pesticides with I<10 

would have a low potential to volatilize; whereas, pesticides with I>1,000 would have a high potential to 

volatilize (Oregon State University 1996). Vapor pressure values for pesticides are usually available in 

the pesticide product MSDS or the USDA Agricultural Research Service (ARS) pesticide database.

7.6 Preparing a Chemical Profile 

The following instructions would be used by Service personnel to complete Chemical Profiles for 

pesticides. Specifically, profiles would be prepared for pesticide active ingredients (e.g., glyphosate, 

imazapic) that would be contained in one or more trade name products that are registered and labeled with 

USEPA. All information fields under each category (e.g., Toxicological Endpoints, Environmental Fate) 

would be completed for a Chemical Profile. If no information is available for a specific field, then “No 

data is available in references” would be recorded in the profile. Available scientific information would 

be used to complete Chemical Profiles. Each entry of scientific information would be shown with 

applicable references. 

Completed Chemical Profiles would provide a structured decision-making process utilizing quantitative 

assessment/screening tools with threshold values (where appropriate) that would be used to evaluate 

potential biological and other environmental effects to refuge resources. For ecological risk assessments 

presented in these profiles, the “worst-case scenario” would be evaluated to determine whether a pesticide 

could be approved for use considering the maximum single application rate specified on pesticide labels 

for habitat management and croplands/facilities maintenance treatments pertaining to refuges. Where the 

“worst-case scenario” likely would only result in minor, temporary, and localized effects to listed and 

non-listed species with appropriate BMPs (see Section 5.0), the proposed pesticide’s use in a PUP would 

have a scientific basis for approval under any application rate specified on the label that is at or below 

rates evaluated in a Chemical Profile. In some cases, the Chemical Profile would include a lower 

application rate than the maximum labeled rate in order to protect refuge resources. As necessary, 

Chemical Profiles would be periodically updated with new scientific information or as pesticides with the 

same active ingredient are proposed for use on the refuge in PUPs. 

Throughout this section, threshold values (to prevent or minimize potential biological and environmental 

effects) would be clearly identified for specific information presented in a completed Chemical Profile. 

Comparison with these threshold values provides an explicit scientific basis to approve or disapprove 

PUPs for habitat management and cropland/facilities maintenance on refuge lands. In general, PUPs 

would be approved for pesticides with Chemical Profiles where there would be no exceedances of 

threshold values. However, BMPs are identified for some screening tools that would minimize/eliminate 

potential effects (exceedance of the threshold value) as a basis for approving PUPs. 
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Appendix K. Integrated Pest Management K-33

Date: Service personnel would record the date when the Chemical Profile is completed or updated. 

Chemical Profiles (e.g., currently approved pesticide use patterns) would be periodically reviewed and 

updated, as necessary. The most recent review date would be recorded on a profile to document when it 

was last updated. 

Trade Name(s): Service personnel would accurately and completely record the trade name(s) from the 

pesticide label, which includes a suffix that describes the formulation (e.g., WP, DG, EC, L, SP, I, II or 

64). The suffix often distinguishes a specific product among several pesticides with the same active 

ingredient. Service personnel would record a trade name for each pesticide product with the same active 

ingredient. 

Common chemical name(s): Service personnel would record the common name(s) listed on the 

pesticide label or material safety data sheet (MSDS) for an active ingredient. The common name of a 

pesticide is listed as the active ingredient on the title page of the product label immediately following the 

trade name, and the MSDS, Section 2: Composition/ Information on Ingredients. A Chemical Profile is 

completed for each active ingredient. 

Pesticide Type: Service personnel would record the type of pesticide for an active ingredient as one of 

the following: herbicide, dessicant, fungicide, fumigant, growth regulator, insecticide, pisicide, or 

rodenticide. 

EPA Registration Number(s): This number (EPA Reg. No.) appears on the title page of the label and 

MSDS, Section 1: Chemical Product and Company Description. It is not the EPA Establishment 

Number that is usually located near it. Service personnel would record the EPA Reg. No. for each trade 

name product with an active ingredient based upon PUPs. 

Pesticide Class: Service personnel would list the general chemical class for the pesticide (active 

ingredient). For example, malathion is an organophosphate and carbaryl is a carbamate. 

CAS (Chemical Abstract Service) Number: This number is often located in the second section 

(Composition/Information on Ingredients) of the MSDS. The MSDS table listing components usually 

contains this number immediately prior to or following the % composition. 

Other Ingredients: From the most recent MSDS for the proposed pesticide product(s), Service 

personnel would include any chemicals in the pesticide formulation not listed as an active ingredient that 

are described as toxic or hazardous, or regulated under the Superfund Amendments and Reauthorization 

Act (SARA), Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), 

Toxic Substances Control Act (TSCA), Occupational Safety and Health Administration (OSHA), State 

Right-to-Know, or other listed authorities. These are usually found in MSDS sections titled “Hazardous 

Identifications”, “Exposure Control/Personal Protection”, and “Regulatory Information”. If 

concentrations of other ingredients are available for any compounds identified as toxic or hazardous, then 

Service personnel would record this information in the Chemical Profile by trade name. MSDS(s) may be 

obtained from the manufacturer, manufacturer’s website or from an on-line database maintained by Crop 

Data Management Systems, Inc. (see list below). 

Toxicological Endpoints 

Toxicological endpoint data would be collected for acute and chronic tests with mammals, birds, and fish. 

Data would be recorded for species available in the scientific literature. If no data are found for a 

particular taxonomic group, then “No data available is references” would be recorded as the data entry. 
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K-34 Appendix K. Integrated Pest Management

Throughout the Chemical Profile, references (including toxicological endpoint data) would be cited using 

parentheses (#) following the recorded data. 

Mammalian LD50: For test species in the scientific literature, Service personnel would record available 

data for oral lethal dose (LD50) in mg/kg-bw (body weight) or ppm-bw. Most common test species in 

scientific literature are the rat and mouse. The lowest LD50 value found for a rat would be used as a 

toxicological endpoint for dose-based RQ calculations to assess acute risk to mammals (see Table 1 in 

Section 7.1). 

Mammalian LC50: For test species in the scientific literature, Service personnel would record available 

data for dietary lethal concentration (LC50) as reported (e.g., mg/kg-diet or ppm-diet). Most common test 

species in scientific literature are the rat and mouse. The lowest LC50 value found for a rat would be used 

as a toxicological endpoint for diet-based RQ calculations to assess acute risk (see Table 1 in Section 7.1). 

Mammalian Reproduction: For test species listed in the scientific literature, Service personnel would

record the test results (e.g., Lowest Observed Effect Concentration [LOEC], Lowest Observed Effect 

Level [LOEL], No Observed Adverse Effect Level [NOAEL], No Observed Adverse Effect 

Concentration [NOAEC]) in mg/kg-bw or mg/kg-diet for reproductive test procedure(s) (e.g., 

generational studies [preferred], fertility, new born weight). Most common test species available in 

scientific literature are rats and mice. The lowest NOEC, NOAEC, NOEL, or NOAEL test results found 

for a rat would be used as a toxicological endpoint for RQ calculations to assess chronic risk (see Table 1 

in Section 7.1). 

Avian LD50: For test species available in the scientific literature, Service personnel would record values 

for oral lethal dose (LD50) in mg/kg-bw or ppm-bw. Most common test species available in scientific 

literature are the bobwhite quail and mallard. The lowest LD50 value found for an avian species would be 

used as a toxicological endpoint for dose-based RQ calculations to assess acute risk (see Table 1 in 

Section 7.1). 

Avian LC50: For test species available in the scientific literature, Service personnel would record values 

for dietary lethal concentration (LC50) as reported (e.g., mg/kg-diet or ppm-diet). Most common test 

species available in scientific literature are the bobwhite quail and mallard. The lowest LC50 value found 

for an avian species would be used as a toxicological endpoint for dietary-based RQ calculations to assess 

acute risk (see Table 1 in Section 7.1). 

Avian Reproduction: For test species available in the scientific literature, Service personnel would

record test results (e.g., LOEC, LOEL, NOAEC, NOAEL) in mg/kg-bw or mg/kg-diet consumed for 

reproductive test procedure(s) (e.g., early life cycle, reproductive). Most common test species available 

in scientific literature are the bobwhite quail and mallard. The lowest NOEC, NOAEC, NOEL, or 

NOAEL test results found for an avian species would be used as a toxicological endpoint for RQ 

calculations to assess chronic risk (see Table 1 in Section 7.1). 

Fish LC50: For test freshwater or marine species listed in the scientific literature, Service personnel 

would record a LC50 in ppm or mg/L. Most common test species available in the scientific literature are 

the bluegill, rainbow trout, and fathead minnow (marine). Test results for many game species may also 

be available. The lowest LC50 value found for a freshwater fish species would be used as a toxicological 

endpoint for RQ calculations to assess acute risk (see Table 1 in Section 7.1). 

Fish Early Life Stage (ELS)/Life Cycle: For test freshwater or marine species available in the scientific 

literature, Service personnel would record test results (e.g., LOEC, NOAEL, NOAEC, LOAEC) in ppm 

for test procedure(s) (e.g., early life cycle, life cycle). Most common test species available in the 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-35

scientific literature are bluegill, rainbow trout, and fathead minnow. Test results for other game species 

may also be available. The lowest test value found for a fish species (preferably freshwater) would be 

used as a toxicological endpoint for RQ calculations to assess chronic risk (see Table 1 in Section 7.1). 

Other: For test invertebrate as well as non-vascular and vascular plant species available in the scientific 

literature, Service personnel would record LC50, LD50, LOEC, LOEL, NOAEC, NOAEL, or EC50 

(environmental concentration) values in ppm or mg/L. Most common test invertebrate species available 

in scientific literature are the honey bee and the water flea (Daphnia magna). Green algae (Selenastrum 

capricornutum) and pondweed (Lemna minor) are frequently available test species for aquatic nonvascular and vascular plants, respectively.

Ecological Incident Reports: After a site has been treated with pesticide(s), wildlife may be exposed to 

these chemical(s). When exposure is high relative to the toxicity of the pesticides, wildlife may be killed 

or visibly harmed (incapacitated). Such events are called ecological incidents. The USEPA maintains a 

database (Ecological Incident Information System) of ecological incidents. This database stores 

information extracted from incident reports submitted by various federal and state agencies and nongovernment organizations. Information included in an incident report is date and location of the incident, 

type and magnitude of affects observed in various species, use(s) of pesticides known or suspected of 

contributing to the incident, and results of any chemical residue and cholinesterase activity analyses 

conducted during the investigation. 

Incident reports can play an important role in evaluating the effects of pesticides by supplementing

quantitative risk assessments. All incident reports for pesticide(s) with the active ingredient and 

associated information would be recorded. 

Environmental Fate

Water Solubility: Service personnel would record values for water solubility (Sw), which describes the 

amount of pesticide that dissolves in a known quantity of water. Sw is expressed as mg/L (ppm). 

Pesticide Sw values would be categorized as one of the following: insoluble <0.1 ppm, moderately 

soluble = 100 to 1000 ppm, highly soluble >10,000 ppm (US Geological Survey 2000). As pesticide Sw

increases, there would be greater potential to degrade water quality through run-off and leaching. 

Sw would be used to evaluate potential for bioaccumulation in aquatic species [see Octanol-Water 

Partition Coefficient (Kow) below]. 

Soil Mobility: Service personnel would record available values for soil adsorption coefficient (Koc

[μg/g]). It provides a measure of a chemical's mobility and leaching potential in soil. Koc values are 

directly proportional to organic content, clay content, and surface area of the soil. Koc data for a pesticide 

may be available for a variety of soil types (e.g., clay, loam, sand). 

Koc values would be used in evaluating the potential to degrade groundwater by leaching (see Potential to 

Move to Groundwater below).

Soil Persistence: Service personnel would record values for soil half-life (t1⁄2), which represents the 

length of time (days) required for 50% of the deposited pesticide to degrade (completely or partially) in 

the soil. Based upon the t1⁄2 value, soil persistence would be categorized as one of the following: nonpersistent <30 days, moderately persistent = 30 to 100 days, and persistent >100 days (Kerle et. al. 1996). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-36 Appendix K. Integrated Pest Management

Threshold for Approving PUPs: 

If soil t1⁄2 ≤100 days, then a PUP would be approved without additional BMPs to protect water quality. 

If soil t1⁄2 >100 days, then a PUP would only be approved with additional BMPs specifically to protect 

water quality. One or more BMPs such as the following would be included in the Specific Best 

Management Practices (BMPs) section to minimize potential surface run-off and leaching that can 

degrade water quality: 

• Do not exceed one application per site per year. 

• Do not use on coarse-textured soils where the ground water table is <10 feet and average annual 

precipitation >12 inches.

• Do not use on steep slopes if substantial rainfall is expected within 24 hours or ground is 

saturated. 

Along with Koc, soil t1⁄2 values would be used in evaluating the potential to degrade groundwater by 

leaching (see Potential to Move to Groundwater below). 

Soil Dissipation: Dissipation time (DT50) represents the time required for 50% of the deposited pesticide 

to degrade and move from a treated site; whereas, soil t1⁄2 describes the rate for degradation only. As for 

t1⁄2, units of dissipation time are usually expressed in days. Field dissipation time would be the preferred 

data for use to estimate pesticide concentrations in the environment because it is based upon field studies 

compared to soil t1⁄2, which is derived in a laboratory. However, soil t1⁄2 is the most common persistence 

data available in the published literature. If field dissipation data is not available, soil half-life data would 

be used in a Chemical Profile. The average or representative half-life value of most important 

degradation mechanism would be selected for quantitative analysis for both terrestrial and aquatic 

environments. 

Based upon the DT50 value, environmental persistence in the soil also would be categorized as one of the 

following: non-persistent <30 days, moderately persistent = 30 to 100 days, and persistent >100 days. 

Threshold for Approving PUPs: 

If soil DT50 ≤100 days, then a PUP would be approved without additional BMPs to protect water quality. 

If soil DT50 >100 days, then a PUP would only be approved with additional BMPs specifically to protect 

water quality. One or more BMPs such as the following would be included in the Specific Best 

Management Practices (BMPs) section to minimize potential surface run-off and leaching that can 

degrade water quality: 

• Do not exceed one application per site per year. 

• Do not use on coarse-textured soils where the ground water table is <10 feet and average annual 

precipitation >12 inches.

• Do not use on steep slopes if substantial rainfall is expected within 24 hours or ground is 

saturated. 

Along with Koc, soil DT50 values (preferred over soil t1⁄2) would be used in evaluating the potential to 

degrade groundwater by leaching (see Potential to Move to Groundwater below), if available. 

Aquatic Persistence: Service personnel would record values for aquatic t1⁄2, which represents the length 

of time required for 50% of the deposited pesticide to degrade (completely or partially) in water. Based

upon the t1⁄2 value, aquatic persistence would be categorized as one of the following: non-persistent <30 

days, moderately persistent = 30 to 100 days, and 

persistent >100 days (Kerle et. al. 1996). 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-37

Threshold for Approving PUPs: 

If aquatic t1⁄2 ≤100 days, then a PUP would be approved without additional BMPs to protect water quality. 

If aquatic t1⁄2 >100 days, then a PUP would only be approved with additional BMPs specifically to protect 

water quality. One or more BMPs such as the following would be included in the Specific Best 

Management Practices (BMPs) section to minimize potential surface run-off and leaching that can 

degrade water quality: 

• Do not exceed one application per site per year. 

• Do not use on coarse-textured soils where the ground water table is <10 feet and average annual 

precipitation >12 inches.

• Do not use on steep slopes if substantial rainfall is expected within 24 hours or ground is 

saturated. 

Aquatic Dissipation: Dissipation time (DT50) represents the time required for 50% of the deposited 

pesticide to degrade or move (dissipate); whereas, aquatic t1⁄2 describes the rate for degradation only. As 

for t1⁄2, units of dissipation time are usually expressed in days. Based upon the DT50 value, environmental 

persistence in aquatic habitats also would be categorized as one of the following: non-persistent <30 

days, moderately persistent = 30 to 100 days, and 

persistent >100 days. 

Threshold for Approving PUPs: 

If aquatic DT50 ≤100 days, then a PUP would be approved without additional BMPs to protect water 

quality. 

If aquatic DT50 >100 days, then a PUP would only be approved with additional BMPs specifically to 

protect water quality. One or more BMPs such as the following would be included in the Specific Best 

Management Practices (BMPs) section to minimize potential surface run-off and leaching that can 

degrade water quality: 

• Do not exceed one application per site per year. 

• Do not use on coarse-textured soils where the ground water table is <10 feet and average annual 

precipitation >12 inches.

• Do not use on steep slopes if substantial rainfall is expected within 24 hours or ground is 

saturated. 

Potential to Move to Groundwater: Groundwater Ubiquity Score (GUS) = log10(soil t 1⁄2) x [4 – 

log10(Koc)]. If a DT50 value is available, it would be used rather than a t 1⁄2 value to calculate a GUS score. 

Based upon the GUS value, the potential to move toward groundwater would be recorded as one of the 

following categories: extremely low potential<1.0, low - 1.0 to 2.0, moderate - 2.0 to 3.0, high - 3.0 to 

4.0, or very high>4.0. 

Threshold for Approving PUPs: 

If GUS ≤4.0, then a PUP would be approved without additional BMPs to protect water quality. 

If GUS>4.0, then a PUP would only be approved with additional BMPs specifically to protect water 

quality. One or more BMPs such as the following would be included in the Specific Best Management 

Practices (BMPs) section to minimize potential surface run-off and leaching that can degrade water 

quality: 

• Do not exceed one application per site per year. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-38 Appendix K. Integrated Pest Management

• Do not use on coarse-textured soils where the ground water table is <10 feet and average annual 

precipitation >12 inches.

• Do not use on steep slopes if substantial rainfall is expected within 24 hours or ground is 

saturated. 

Volatilization: Pesticides may volatilize (evaporate) from soil and plant surfaces and move off-target 

into the atmosphere. The potential for a pesticide to volatilize is a function of its vapor pressure that is 

affected by temperature, sorption, soil moisture, and the pesticide’s water solubility. Vapor pressure is 

often expressed in mm Hg. To make these values easier to compare, vapor pressure would be recorded by 

Service personnel in exponential form (I x 10-7), where I represents a vapor pressure index. In general, 

pesticides with I<10 would have low potential to volatilize; whereas, pesticides with I >1,000 would have 

a high potential to volatilize (Oregon State University 1996). Vapor pressure values for pesticides are 

usually available in the pesticide product MSDS or the USDA Agricultural Research Service (ARS) 

pesticide database (see References). 

Threshold for Approving PUPs: 

If I ≤1000, then a PUP would be approved without additional BMPs to minimize drift and protect air 

quality. 

If I>1000, then a PUP would only be approved with additional BMPs specifically to minimize drift and 

protect air quality. One or more BMPs such as the following would be included in the Specific Best 

Management Practices (BMPs) section to reduce volatilization and potential to drift and degrade air 

quality: 

• Do not treat when wind velocities are <2 or >10 mph with existing or potential inversion 

conditions. 

• Apply the large-diameter droplets possible for spray treatments.

• Avoid spraying when air temperatures >85o

F.

• Use the lowest spray height possible above target canopy. 

• Where identified on the pesticide label, soil incorporate pesticide as soon as possible during or 

after application. 

 

Octanol-Water Partition Coefficient (Kow): The octanol-water partition coefficient (Kow) is the 

concentration of a pesticide in octanol and water at equilibrium at a specific temperature. Because octanol 

is an organic solvent, it is considered a surrogate for natural organic matter. Therefore, Kow would be used 

to assess potential for a pesticide to bioaccumulate in tissues of aquatic species (e.g., fish). If Kow >1000 

or Sw<1 mg/L AND soil t1⁄2>30 days, then there would be high potential for a pesticide to bioaccumulate 

in aquatic species such as fish (US Geological Survey 2000). 

Threshold for Approving PUPs: 

If there is not a high potential for a pesticide to bioaccumulate in aquatic species, then the PUP would be 

approved. 

If there is a high potential to bioaccumulate in aquatic species (Kow>1000 or Sw<1 mg/L AND soil t1⁄2>30 

days), then the PUP would not approved, except under unusual circumstances where approval would 

only be granted by the Washington Office. 

Bioaccumulation/Bioconcentration: The physiological process where pesticide concentrations in tissue 

would increase in biota because they are taken and stored at a faster rate than they are metabolized or 

excreted. The potential for bioaccumulation would be evaluated through bioaccumulation factors (BAFs) 

or bioconcentration factors (BCFs). Based upon BAF or BCF values, the potential to bioaccumulate 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-39

would be recorded as one of the following: low – 0 to 300, moderate – 300 to 1000, or high >1000 

(Calabrese and Baldwin 1993). 

Threshold for Approving PUPs: 

If BAF or BCF≤1000, then a PUP would be approved without additional BMPs. 

If BAF or BCF>1000, then a PUP would not approved, except under unusual circumstances where 

approval would only be granted by the Washington Office. 

Worst-Case Ecological Risk Assessment

Max Application Rates (acid equivalent): Service personnel would record the highest application rate 

of an active ingredient (ae basis) for habitat management and cropland/facilities maintenance treatments 

in this data field of a Chemical Profile. These rates can be found in Table CP.1 under the column heading 

“Max Product Rate – Single Application (lbs/acre – AI on acid equiv basis)”. This table would be 

prepared for a chemical profile from information specified in labels for trade name products identified in 

PUPs. If these data are not available in pesticide labels, then write “NS” for “not specified on label” in 

this table. 

EECs: An estimated environmental concentration (ECC) represents potential exposure to fish and 

wildlife (birds and mammals) from using a pesticide. EECs would be derived by Service personnel using 

an USEPA screening-level approach (US Environmental Protection Agency 2004). For each max 

application rate [see description under Max Application Rates (acid equivalent)], Service personnel 

would record 2 EEC values in a Chemical Profile; these would represent the worst-case terrestrial and 

aquatic exposures for habitat management and croplands/facilities maintenance treatments. For terrestrial 

and aquatic EEC calculations, see description for data entry under Presumption of Unacceptable 

Risk/Risk Quotients, which is the next field for a Chemical Profile. 

Presumption of Unacceptable Risk/Risk Quotients: Service personnel would calculate and record 

acute and chronic risk quotients (RQs) for birds, mammals, and fish using the provided tabular formats 

for habitat management and/or cropland/facilities maintenance treatments. RQs recorded in a Chemical 

Profile would represent the worst-case assessment for ecological risk. See Section 7.2 for discussion 

regarding the calculations of RQs. 

For aquatic assessments associated with habitat management treatments, RQ calculations would be based 

upon selected acute and chronic toxicological endpoints for fish and the EEC would be derived from 

Urban and Cook (1986) assuming 100% overspray to an entire 1-foot deep water body using the max 

application rate (ae basis [see above]). 

For aquatic assessments associated with cropland/facilities maintenance treatments, RQ calculations 

would be done by Service personnel based upon selected acute and chronic toxicological endpoints for 

fish and an EEC would be derived from the aquatic assessment in AgDRIFT® model version 2.01 under 

Tier I ground-based application with the following input variables: max application rate (acid basis [see 

above]), low boom (20 inches), fine to medium/coarse droplet size, 20 swaths, EPA-defined wetland, and 

25-foot distance (buffer) from treated area to water. 

See Section 7.2.1.2 for more details regarding the calculation of EECs for aquatic habitats for habitat 

management and cropland/facilities maintenance treatments. 

For terrestrial avian and mammalian assessments, RQ calculations would be done by Service personnel

based upon dietary exposure, where the “short grass” food item category would represent the worst-case 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-40 Appendix K. Integrated Pest Management

scenario. For terrestrial spray applications associated with habitat management and cropland/facilities 

maintenance treatments, exposure (EECs and RQs) would be determined using the Kanaga nomogram 

method through the USEPA’s Terrestrial Residue Exposure model (T-REX) version 1.2.3. T-REX input 

variables would include the following: max application rate (acid basis [see above]) and pesticide halflife (days) in soil to estimate the initial, maximum pesticide residue concentration on general food items 

for terrestrial vertebrate species in short (<20 cm tall) grass. 

For granular pesticide formulations and pesticide-treated seed with a unique route of exposure for 

terrestrial avian and mammalian wildlife, see Section 7.2.1.1.2 for the procedure that would be used to 

calculate RQs. 

All calculated RQs in both tables would be compared with Levels of Concern (LOCs) established by 

USEPA (see Table 2 in Section 7.2). If a calculated RQ exceeds an established LOC value (in brackets 

inside the table), then there would be a potential for an acute or chronic effect (unacceptable risk) to 

federally listed (T&E) species and nonlisted species. See Section 7.2 for detailed descriptions of acute 

and chronic RQ calculations and comparison to LOCs to assess risk. 

Threshold for approving PUPs: 

If RQs≤LOCs, then a PUP would be approved without additional BMPs. 

If RQs>LOCs, then a PUP would only be approved with additional BMPs specifically to minimize 

exposure (ecological risk) to bird, mammal, and/or fish species. One or more BMPs such as the 

following would be included in the Specific Best Management Practices (BMPs) section to reduce 

potential risk to non-listed or listed species:

• Lower application rate and/or fewer number of applications so RQs ≤LOCs

• For aquatic assessments (fish) associated with cropland/facilities maintenance, increase the 

buffer distance beyond 25 feet so RQs≤LOCs. 

Justification for Use: Service personnel would describe the reason for using the pesticide based control 

of specific pests or groups of pests. In most cases, the pesticide label will provide the appropriate 

information regarding control of pests to describe in the section. 

Specific Best Management Practices (BMPs): Service personnel would record specific BMPs 

necessary to minimize or eliminate potential effects to non-target species and/or degradation of 

environmental quality from drift, surface runoff, or leaching. These BMPs would be based upon 

scientific information documented in previous data fields of a Chemical Profile. Where necessary and 

feasible, these specific practices would be included in PUPs as a basis for approval. 

If there are no specific BMPs that are appropriate, then Service personnel would describe why the 

potential effects to refuge resources and/or degradation of environmental quality is outweighed by the 

overall resource benefit(s) from the proposed pesticide use in the BMP section of the PUP. See Section 

4.0 of this document for a complete list of BMPs associated with mixing and applying pesticides 

appropriate for all PUPs with ground-based treatments that would be additive to any necessary, chemicalspecific BMPs. 

References: Service personnel would record scientific resources used to provide data/information for a 

chemical profile. Use the number sequence to uniquely reference data in a chemical profile.

The following on-line data resources are readily available for toxicological endpoint and environmental 

fate data for pesticides:
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-41

1. California Product/Label Database. Department of Pesticide Regulation, California Environmental 

Protection Agency. (http://www.cdpr.ca.gov/docs/label/labelque.htm#regprods) 

2. ECOTOX database. Office of Pesticide Programs, US Environmental Protection Agency, 

Washington, DC. (http://cfpub.epa.gov/ecotox/) 

3. Extension Toxicology Network (EXTOXNET) Pesticide Information Profiles. Cooperative effort of 

University of California-Davis, Oregon State University, Michigan State University, Cornell 

University and University of Idaho through Oregon State University, Corvallis, Oregon. 

(http://extoxnet.orst.edu/pips/ghindex.html) 

4. FAO specifications and evaluations for plant protection products. Pesticide Management Unit, Plant 

Protection Services, Food and Agriculture Organization, United Nations. 

(http://www.fao.org/WAICENT/FAOINFO/AGRICULT/AGP/AGPP/Pesticid/) 

5. Human health and ecological risk assessments. Pesticide Management and Coordination, Forest 

Health Protection, US Department of Agriculture, US Forest Service. 

(http://www.fs.fed.us/foresthealth/pesticide/risk.htm) 

6. Pesticide Chemical Fact Sheets. Clemson University Pesticide Information Center. 

(http://entweb.clemson.edu/pesticid/Document/Labels/factshee.htm) 

7. Pesticide Fact Sheets. Published by Information Ventures, Inc. for Bureau of Land Management, 

Dept. of Interior; Bonneville Power Administration, U.S. Dept. of Energy; and Forest Service, US 

Department of Agriculture. (http://infoventures.com/e-hlth/pesticide/pest-fac.html) 

8. Pesticide Fact Sheets. National Pesticide Information Center. (http://npic.orst.edu/npicfact.htm) 

9. Pesticide Fate Database. US Environmental Protection Agency, Washington, DC. 

(http://cfpub.epa.gov/pfate/home.cfm).

 

10. Pesticide product labels and material safety data sheets. Crop Data Management Systems, Inc. 

(CDMS) (http://www.cdms.net/pfa/LUpdateMsg.asp) or multiple websites maintained by 

agrichemical companies. 

11. Registered Pesticide Products (Oregon database). Oregon Department of Agriculture. 

(http://www.oda.state.or.us/dbs/pest_products/search.lasso) 

12. Regulatory notes. Pest Management Regulatory Agency, Health Canada, Ontario, Canada. 

(http://www.hc-sc.gc.ca/pmra-arla/) 

13. Reptile and Amphibian Toxicology Literature. Canadian Wildlife Service, Environment Canada, 

Ontario, Canada. (http://www.cws-scf.ec.gc.ca/nwrc-cnrf/ratl/index_e.cfm) 

14. Specific Chemical Fact Sheet – New Active Ingredients, Biopesticide Fact Sheet and Registration 

Fact Sheet. U.S Environmental Protection Agency, Washington, DC. 

(http://www.epa.gov/pestidides/factsheets/chemical_fs.htm) 

15. Weed Control Methods Handbook: Tools and Techniques for Use in Natural Areas. The Invasive 

Species Initiative. The Nature Conservancy. (http://tnsweeds.ucdavis.edu/handbook.html) 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-42 Appendix K. Integrated Pest Management

16. Wildlife Contaminants Online. US Geological Survey, Department of Interior, Washington, D.C. 

(http://www.pwrc.usgs.gov/contaminants-online/) 

17. One-liner database. 2000. US Environmental Protection Agency, Office of Pesticide Programs, 

Washington, D.C. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-43

Chemical Profile

Date:

Trade Name(s): Common Chemical Name(s):

Pesticide Type: EPA Registration Number:

Pesticide Class: CAS Number:

Other Ingredients:

Toxicological Endpoints

Mammalian LD50:

Mammalian LC50:

Mammalian Reproduction:

Avian LD50:

Avian LC50:

Avian Reproduction:

Fish LC50:

Fish ELS/Life Cycle:

Other:

Ecological Incident Reports

Environmental Fate

Water solubility (Sw):

Soil Mobility (Koc):

Soil Persistence (t1⁄2):

Soil Dissipation (DT50): 

Aquatic Persistence (t1⁄2):

Aquatic Dissipation (DT50): 

Potential to Move to Groundwater 

(GUS score):

Volatilization (mm Hg):

Octanol-Water Partition Coefficient (Kow):

Bioaccumulation/Biocentration: BAF:`

BCF:

Worst Case Ecological Risk Assessment

Max Application Rate 

(ai lbs/acre – ae basis)

Habitat Management:

Croplands/Facilities Maintenance:

EECs Terrestrial (Habitat Management):

Terrestrial (Croplands/Facilities Maintenance):

Aquatic (Habitat Management):

Aquatic (Croplands/Facilities Maintenance): 

Habitat Management Treatments:

Presumption of Unacceptable Risk Risk Quotient (RQ)

Listed (T&E) Species Nonlisted Species

Acute Birds [0.1] [0.5]

Mammals [0.1] [0.5]

Fish [0.05] [0.5]

Chronic Birds [1] [1]

Mammals [1] [1]
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-44 Appendix K. Integrated Pest Management

Fish [1] [1]

Cropland/Facilities Maintenance Treatments:

Presumption of Unacceptable Risk Risk Quotient (RQ)

Listed (T&E) Species Nonlisted Species

Acute Birds [0.1] [0.5]

Mammals [0.1] [0.5]

Fish [0.05] [0.5]

Chronic Birds [1] [1]

Mammals [1] [1]

Fish [1] [1]

Justification for Use:

Specific Best Management 

Practices (BMPs):

References:

Table CP.1 Pesticide Name

Trade 

Namea

Treatment 

Typeb 

Max Product 

Rate – Single 

Application 

(lbs/acre or 

gal/acre)

Max Product

Rate -Single 

Application 

(lbs/acre - AI on 

acid equiv basis)

Max Number 

of 

Applications 

Per Season

Max Product 

Rate Per Season 

(lbs/acre/season 

or 

gal/acre/season)

Minimum 

Time Between 

Applications 

(Days)

a

From each label for a pesticide identified in pesticide use proposals (PUPs), Service personnel would record application 

information associated with possible/known uses on Service lands.

b

Treatment type: H – habitat management or CF – cropland/facilities maintenance. If a pesticide is labeled for both types of 

treatments (uses), then record separate data for H and CF applications. 

7.0 References

AgDrift 2001. A user’s guide for AgDrift 2.04: a tiered approach for the assessment of spray drift of 

pesticides. Spray Drift Task Force, PO Box 509, Macon, Missouri. 

ATSDR (Agency for Toxic Substances and Disease Registry) US Department of Health and Human 

Services. 2004. Guidance Manual for the Assessment of Joint Toxic Action of Chemical Mixtures. US 

Department of Health and Human Services, Public Health Service, ATSDR, Division of Toxicology. 62 

plus Appendices. 

Barry, T. 2004. Characterization of propanil prune foliage residues as related to propanil use patterns in 

the Sacramento Valley, CA. Proceedings of the International Conference on Pesticide Application for 

Drift Management. Waikoloa, Hawaii. 15 pages.

Baker, J. and G. Miller. 1999. Understanding and reducing pesticide losses. Extension Publication PM 

1495, Iowa State University Extension, Ames, Iowa. 6 pages. 

Battaglin, W.A., E.M. Thurman, S.J. Kalkhoff, and S.D. Porter. 2003. Herbicides and Transformation 

Products in Surface Waters of the Midwestern United States. Journal of the American Water Resources 

Association (JAWRA) 39(4):743-756. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix K. Integrated Pest Management K-45

Brooks, M.L., D'Antonio, C.M., Richardson, D.M., Grace, J.B., Keeley, J.E. and others. 2004. Effects of 

invasive alien plants on fire regimes. BioScience 54:77-88. 

Bureau of Land Management. 2007. Vegetation treatments using herbicides on Bureau of Land 

Management Lands in 17 western states Programmatic EIS (PEIS). Washington Office, Bureau of Land 

Management. 

Butler, T., W. Martinkovic, and O.N. Nesheim. 1998. Factors influencing pesticide movement to ground 

water. Extension Publication PI-2, University of Florida, Cooperative Extension Service, Gainesville, FL. 

4 pages.

Calabrese, E.J. and L.A. Baldwin. 1993. Performing Ecological Risk Assessments. Lewis Publishers, 

Chelsea, MI.

Center, T.D., Frank, J.H., and Dray Jr., F.A. 1997. Biological Control. Strangers in Paradise: Impact and 

Management of Nonindigenous Species in Florida. P.245-263. 

Cox, R.D., and V.J. Anderson. 2004. Increasing native diversity of cheatgrass-dominated rangeland 

through assisted succession. Journal of Range Management 57:203-210. 

Dunning, J.B. 1984. Body weights of 686 species of North American birds. Western Bird Banding 

Association. Monograph No. 1. 

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K-46 Appendix K. Integrated Pest Management

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Protocol: NatureServe.

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groundwater from pesticide contamination. Extension Publication EB1644, Washington State University 

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Chemistry 21: 659-671. 

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Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

K-48 Appendix K. Integrated Pest Management
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix L. Transportation Access Analysis L-1 

Appendix L. Transportation Access Analysis

Ridgefield National Wildlife Refuge

Ridgefield, Washington
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

L-2 Appendix L. Transportation Access Analysis
U.S. Fish & Wildlife Service published by FHWA

Transportation Access Analysis

Ridgefield National Wildlife Refuge

Ridgefield, Washington

Ridgefield

NATIONAL WILDLIFE REFUGE

Carty Unit

U.S. Fish & Wildlife Service 

Department of the Interior 

Transportation Access Analysis

Ridgefield National Wildlife Refuge

Ridgefield, Washington

Prepared for:

Ridgefield National Wildlife Refuge

U.S. Fish and Wildlife Service

Division of Planning and Visitor Services

911 NE 11th Avenue

Portland, OR 97232-4181

Prepared by:

Western Federal Lands Highway Division

Federal Highway Administration

610 East Fifth Street

Vancouver, WA 98661-3801

May 2009

Table of Contents

 6

 9

11

19

21 

26 

26 

29 

31 

35 

38

41

Introduction

Alternatives

Graphic Summary of Alternatives

Alternative For Refuge Access 

Access Alternatives 

Comparison of Alternatives

Alternative 1

Alternative 2

Alternative 3

Alternative 4

Alternative 5

Summary of Key Issues

Ridgefield

NATIONAL WILDLIFE REFUGE

Carty Unit

U.S. Fish & Wildlife Service 

Department of the Interior 
 | Ridgefield National Wildlife Refuge Transportation Access Analysis

Transportation Access Analysis

Ridgefield National Wildlife Refuge

May 2009

Executive Summary

Introduction

The purpose of this report is to provide the US Fish and Wildlife Service 

(USFWS) with an analysis of their current transportation needs and 

alternatives for meeting those needs within the Ridgefield National 

Wildlife Refuge (NWR).

The intent is to give the USFWS information they can use in the decision 

making process for providing public access to the Refuge, which is one of 

their objectives. Likewise, the USFWS can use the information from this 

report to assist with the development of a plan called the Ridgefield NWR 

Comprehensive Conservation Plan (CCP). The CCP is a management plan 

for improving fish and wildlife habitat conditions and Refuge infrastructure 

for wildlife and public use on the Refuge over the next 15 years.
Ridgefield National Wildlife Refuge Transportation Access Analysis | 

Current Transportation Conditions

The existing transportation system has several problems. The existing 

at-grade railroad crossing into the River “S” Unit is dangerous. The 

narrow, winding entrance road, and the one-lane bridge into the River 

“S” Unit and to the auto tour route are too narrow for existing and future 

Refuge visitors. The pedestrian access to the Oaks to Wetlands Wildlife 

Trail and to the Cathlapotle Plank house in the Carty Unit does not 

comply with the Americans with Disabilities Act (ADA) guidelines.

In addition to being too narrow, the existing bridge accessing the Refuge 

River “S” Unit has a remaining lifespan of about seven years. If the bridge 

is not repaired or replaced, it eventually will become unusable.

Transportation Needs

For the Ridgefield NWR, the USFWS needs a transportation system that: 

allows visitors safe, efficient access to the Refuge; accommodates the 

volume and types of traffic for current and future uses; and that provides 

ADA access for those with disabilities. In addition to providing for all of 

the needs above, the USFWS has to have a transportation system that 

meets the Refuge’s primary objective of the long-term protection and 

enhancement of fish, wildlife, and their habitat.
 | Ridgefield National Wildlife Refuge Transportation Access Analysis

Criteria Used to Rank and Compare Alternatives

Refuge Resources compares impacts of the alternatives to the Refuge’s 

wildlife, habitats, and cultural resources; and the Refuge’s ability to 

conduct its wildlife and habitat management activities. 

Safety and ADA Compliance compares the relative safety of each 

alternative, and how well each alternative meets ADA guidelines. 

Accommodates Increased Visitation compares how well each alternative 

accommodates projected increases in visitation.

Impact to Visitors compares how well each alternative meets the Refuge’s 

goal of quality opportunities for waterfowl hunting, wildlife observation 

and photography, fishing, interpretation, and environmental education. 

Included in this analysis is the quality of visitor experience provided, 

ease of visitor access, and how well each alternative minimizes conflicts 

between or within different user groups. 

Impact to Community compares impacts of the alternatives to neighboring 

landowners and/or renters, and the local community. This includes 

impacts of increased visitor traffic through neighborhoods and through 

town, impacts of constructed elements on view-sheds, and impacts of 

the alternatives on community development projects (for example the 

proposed Port of Ridgefield development). 

Cost/Feasibility compares costs of land acquisition, construction, and 

maintenance. It also includes with feasibility of implementing the 

alternative (i.e. Section 4(f ) and NEPA compliance).
Ridgefield National Wildlife Refuge Transportation Access Analysis | 

Alternatives

Through the public scoping process and subsequent development of the 

draft CCP, the Refuge has developed five alternatives addressing public 

access. All of the proposed alternatives, with the exception of the “No Build” 

alternative, includes replacing the current pedestrian bridge at the Carty 

Unit with a bridge that meets ADA guidelines. 

Alternative 1 – The ‘No Build’ alternative. Access to the Refuge would 

remain unchanged and without improvements, other than repair of the 

existing bridge to the River “S” Unit, or replacement with a like structure.

Alternative 2 – Acquire the parcel of land that the current entrance road 

traverses, from Hillhurst Road to the River “S” Unit. Widen the existing 

entrance road from Hillhurst Road to the bridge. Replace the single-lane 

bridge spanning Lake River with an elevated, two-lane bridge spanning 

Lake River and the railroad tracks.

Alternative 3 – Create a new access point into the Refuge from the Port 

of Ridgefield’s overpass. The Port of Ridgefield is planning to construct 

a bridge over the railroad tracks from the junction of Main Street and 

State Route 501/Pioneer Street to the Port property. The new access point 

would branch from the Port’s proposed bridge, over Lake River and the 

houseboat community to the River “S” Unit. 

In addition, construction of an access road from the end of the new bridge, 

south to the existing auto tour route would be necessary. This road would 

be about 0.75 miles long and would run along the base of the existing dike. 

It would be asphalt at the toe of the bridge and graveled thereafter.

Alternative 4 – Similar to alternative 3, this would create a new access 

point into the Refuge from the Port of Ridgefield’s property (north of 

the houseboat community). Once the Port of Ridgefield’s bridge across 

the railroad tracks is complete, a smaller bridge would be constructed 
10 | Ridgefield National Wildlife Refuge Transportation Access Analysis

from the Port side of Lake River to the Refuge River “S” Unit that would 

include a lift span for larger vessels. Like alternative 3, an access road 

would be constructed to connect this access point to the auto tour route. 

Alternative 5 – Under this alternative, a southern access from the 

Ridgeport Dairy Unit would be reopened. Work under this alternative 

would include reconstructing State Route 501 (Lower River Road) from 

milepost 11 to milepost 12.5, widening the road from one lane to two lanes, 

and constructing an approximately 4-mile-long access road north through 

the Ridgeport Dairy Unit to the auto tour route on the River “S” Unit.
Ridgefield National Wildlife Refuge Transportation Access Analysis | 11

Graphic Summary of Alternatives by Criteria

Refuge Resources Safety & ADA 

Compliance

Increased 

Visitation

Impacts to 

Visitors

Impacts to 

Community Cost & Feasibility

Alt 1 Green Red Red Yellow* Red Green

Alt 2 Yellow Green Green Green Green Orange 

Alt 3 Yellow Green Green Yellow Red Red 

Alt 4 Yellow Green Green Yellow Green Yellow

Alt 5 Red Green Green Red Orange Red 

 *Rating if the existing bridge to the River “S” Unit is replaced. Otherwise rating would be red.

Key for color coding:

Green No impact or slight impact, or fully meets criteria

Yellow Minor impact, or somewhat meets these criteria

Orange Moderate impact, or significant obstacles to meeting criteria

Red Major impact, or does not meet criteria
12 | Ridgefield National Wildlife Refuge Transportation Access Analysis

Introduction

The purpose of this report is to provide the USFWS with an analysis of their 

current transportation needs and alternatives for meeting those needs within the 

Ridgefield National Wildlife Refuge (NWR).

The intent is to give the USFWS information they can use in the decision making 

process for providing public access to the Refuge, which is one of their objectives. 

Likewise, the USFWS can use the information from this report to assist with the 

development of the Ridgefield NWR Comprehensive Conservation Plan (CCP).

The CCP is a management plan for improving fish and wildlife habitat conditions 

and Refuge infrastructure for wildlife and public use on the Refuge over the next 

15 years. This transportation analysis will become an appendix to the CCP. To 

“provide...a 

management plan 

for improving 

fish and wildlife 

habitat conditions 

and Refuge 

infrastructure, for 

wildlife and public 

use on Ridgefield 

NWR over the next 

15 years.”
Ridgefield National Wildlife Refuge Transportation Access Analysis | 13

better understand the need for this transportation analysis and the CCP, 

a history of the Refuge and the reason it exists is helpful.

History of the Ridgefield National Wildlife Refuge

Along with three other Refuges in the Willamette Valley of Oregon, the 

Ridgefield NWR was established in 1965 to secure vital winter habitat for 

dusky Canada geese and other wintering waterfowl. An additional purpose 

of the Ridgefield NWR was to provide waterfowl hunting opportunities.

The Ridgefield NWR has about 5,300 acres of marshes, grasslands and 

woodlands. The Refuge consists of five different units, and a variety 

of wildlife can be found on the Refuge. Waterfowl, sandhill cranes, 

shorebirds, and a great variety of songbirds stop at the Refuge during 

spring and fall migrations. Some bird species such as mallards, great blue 

herons, and red-tailed hawks are year-round residents that nest on the 

Refuge. Black-tailed deer are the largest mammal on the Refuge. Coyote, 

raccoon, skunk, beaver, river otter and brush rabbits are occasionally seen.

For the Ridgefield NWR as a whole, the main objective is to protect and 

enhance fish, wildlife, and their habitat. At the same time, the USFWS 

offers wildlife-dependent public use in designated portions of the Refuge. 

The Carty Unit has a trail open year-round, and the River “S” Unit has a 

trail open seasonally and an Auto Tour Route open year-round. Access to 

duck blinds is available seasonally.

In order to manage these different uses in the most effective manner, 

the USFWS is in the process of developing the Ridgefield NWR 

Comprehensive Conservation Plan, which this transportation analysis will 

be part of.
14 | Ridgefield National Wildlife Refuge Transportation Access Analysis

Ridgefield NWR Comprehensive Conservation Plan

The Comprehensive Conservation Plan (CCP) will provide the USFWS, 

the National Wildlife Refuge System (NWRS), Refuge partners, and 

citizens with a management plan for improving fish and wildlife habitat 

conditions and Refuge infrastructure for wildlife and public use on the 

Ridgefield NWR over the next 15 years. An approved CCP will ensure that 

the USFWS manages the Refuge to achieve its purpose, vision, goals, and 

objectives and fulfills the mission of the NWRS.

More specifically, the purpose of the CCP is to provide reasonable, 

scientifically grounded guidance for the long-term conservation of native 

plants and animals and for improving the Refuge’s grassland, wetland, 

riparian, and oak woodland habitats. The CCP will identify appropriate 

actions for protecting and sustaining the cultural and biological features 

of the Refuge, its wintering waterfowl populations and habitats, the 

migratory landbird, waterbird, and shorebird populations that use the 

Refuge, and threatened, endangered, or rare species.

A final and vital purpose of the CCP is to provide guidance on, and 

evaluation of, the public-use programs on the Refuge.
Ridgefield National Wildlife Refuge Transportation Access Analysis | 15

Current Public Access to the Ridgefield NWR

Currently, the public is provided access to the Ridgefield NWR through 

the Carty Unit and the River “S” Unit.

Access to the Carty Unit is pedestrian access only. People can park near 

the Refuge headquarters and access the Oaks to Wetlands Wildlife Trail 

and the Cathlapotle Plank house via a pedestrian bridge. The pedestrian 

bridge that accesses the Carty Unit is very steep and does not meet the 

American’s with Disabilities Act (ADA) requirements.

Access to the River “S” Unit is open to vehicles and pedestrians. The 

existing infrastructure includes a 4.2-mile auto tour route and a 1.2-mile 

seasonal hiking trail. Visitors access this unit from Hillhurst Road via a 

single-lane road through private property (the USFWS has an easement 

for the access road) to an at-grade rail crossing of the Burlington Northern 

Santa Fe (BNSF) Railway. They then cross Lake River on a 330-foot-long, 

single-lane, wooden bridge to a parking lot and the auto tour route.

The existing one-lane road and bridge are too narrow for the types and 

volume of traffic accessing the Refuge, and they do not provide for safe 

access to the Refuge. Furthermore, information that the USFWS collected 

indicates that vehicle traffic and visitation is increasing on the Refuge, 

and they expect that trend to continue. In addition, the existing at-grade 

railroad crossing is directly adjacent to the narrow, winding entrance road 

on one side and the one-lane bridge on the other side. The combination 

creates a dangerous situation that needs to be corrected.

However, the existing easement through private land will limit the options 

to correct the existing deficiencies along the current alignment because 

no agreement with the current land owner is in place to make changes to 

the access road. Furthermore, the intent behind the original agreement is 

that someday access to the Refuge would be moved. In fact, the easement 

granted to the Refuge stipulates that the easement shall remain in effect 

until such time that a southern access point can be developed at the 
16 | Ridgefield National Wildlife Refuge Transportation Access Analysis

Ridgeport Dairy Unit, although no time restrictions exist in terms of 

expiration for this easement.

Furthermore, the only southern route that could be developed for access 

to the Refuge is State Route 501, and this road has several problems.

In the spring of 2004, the Washington State Department of 

Transportation (WSDOT) closed a section of State Route 501 adjacent to 

the southern end of the Refuge because of heavy erosion. The WSDOT 

never repaired the route, and in 2006 they transferred jurisdiction of 

this section of State Route 501 to Clark County. Clark County has not 

reopened this road, and no plans for reconstruction of this route are found 

in the Clark County 2008-2013 Transportation Improvement Program.

Exsisting single lane bridge at Lake River
Ridgefield National Wildlife Refuge Transportation Access Analysis | 17

Furthermore, the Clark County Parks and Recreation 2006 Regional Trail 

and Bikeway Systems Plan identify this route as a potential extension of 

the Lewis and Clark Greenway Trail for bicycle and pedestrian use.

This Southern access would have an impact to the Refuge administrative 

maintenance and operations functions. This alternative would not provide 

direct access from the Refuge headquarters office to the auto tour route 

and duck blinds. A 30-mile detour through Vancouver would be required 

to bring staff vehicles and heavy equipment from the Refuge headquarters 

and shop in Ridgefield to the River S Unit.

As discussed in Alternative 3, reopening this connection of State Route 

501 into the Refuge may reignite earlier plans to build a State highway 

through the Refuge from Lower River Road to Pioneer Street.

Transportation Needs

For the Ridgefield NWR, the USFWS needs a transportation system that: 

allows visitors safe, efficient access to the Refuge; accommodates the 

volume and types of traffic for current and future uses; and that provides 

ADA access for those with disabilities. In addition to providing for all of 

the needs above, the USFWS has to have a transportation system that 

meets the Refuge’s primary objective of the long-term protection and 

enhancement of fish, wildlife, and their habitat.
18 | Ridgefield National Wildlife Refuge Transportation Access Analysis

Goals and Objectives

To help identify appropriate solutions, the USFWS identified the following 

goals and objectives as the most important to the Refuge:

Refuge Purpose and Resources

-Conserve native plant and wildlife, with emphasis on dusky Canada geese 

and other waterfowl; sandhill cranes; and Federally listed species

-Conserve and enhance grassland, wetland, riparian, and oak woodland 

habitats for wildlife

-Protect cultural resources 

-Provide quality waterfowl hunting opportunities

Wildlife Dependent Public Uses

-Provide quality opportunities for waterfowl hunting, wildlife observation 

and photography, fishing, interpretation, and environmental education

-Reduce impacts of public use on the Refuge’s wildlife, habitat, and cultural 

resources

-Reduce/minimize conflicts between user groups

Refuge Transportation Access

-Provide safe, unobstructed, and the most direct access to the River “S” unit 

for both visitors and Refuge staff

-Provide access to the Carty Unit that meets ADA guidelines

-Accommodate projected increases in visitation and vehicle traffic to and 

from the Refuge

-Accommodate access for heavy vehicles/equipment needed for construction, 

maintenance and habitat management

Other Criteria

-Cost, design feasibility and sustainability

-Coordination/cooperation with neighboring landowners (Port of Ridgefield, 

BNSF, private landowners)

-Impacts to Refuge visitors, neighboring landowners, and the local 

community 

-NEPA and Section 4(f) considerations
Ridgefield National Wildlife Refuge Transportation Access Analysis | 19

Alternatives for Refuge Access

To address the problems and concerns with the Refuge’s current 

transportation access, the USFWS developed five different alternatives. 

Each alternative is based on meeting the National Wildlife Refuge System 

mission, the purpose of the Refuge and needs for transportation access. 

In addition, consideration is given to the cost of construction, design 

feasibility and sustainability; impact to the gateway communities and 

visitor experience; followed by a summary of Section 4(f) Regulation 

and National Environmental Policy Act (NEPA) implications of each 

alternative.

To ensure that consideration was given to all these factors, the USFWS 

developed a list of criteria that was used to compare and rank the five 

alternatives.

Criteria Used to Rank and Compare Alternatives

Refuge Resources compares impacts of the alternatives to the Refuge’s 

wildlife, habitats, and cultural resources; and the Refuge’s ability to 

conduct its wildlife and habitat management activities. 

-Green means that the alternative has minimal or no impacts compared to 

the ‘No Action’ alternative. 

-Yellow indicates that the alternative would have minor negative impacts 

on the Refuge’s ability to manage or provide habitat (which could be 

minimized relatively easily through design or mitigation). 

-Orange means moderate impacts that would be difficult to mitigate. 

-Red means major impacts that would prevent the Refuge from meeting its 

purposes. 

Included in this analysis is anticipated impacts to wildlife, habitat, and 

cultural resources caused by increased visitation, and the impacts of the 

alternative on Refuge operations (staff travel time, fuel expenditures, 

ability to get heavy equipment to work sites).
20 | Ridgefield National Wildlife Refuge Transportation Access Analysis

Safety and ADA Compliance compares the relative safety of each 

alternative, and how well each alternative meets ADA guidelines. 

-Green means the alternative addresses existing safety concerns and is 

ADA compliant.

-Yellow means there are some safety concerns, but these could be mitigated 

through design, signage, and regulations.

-Orange means significant concerns that would be difficult to mitigate.

-Red means concerns significant enough that the alternative should not be 

implemented.

Accommodates Increased Visitation compares how well each alternative 

accommodates projected increases in visitation.

-Green meaning the alternative can accommodate significant increases in 

visitation.

-Red meaning that visitation above the present level cannot be 

accommodated without significant negative impacts to the visitor 

experience, or to wildlife and habitat resources.

Impact to Visitors compares how well each alternative meets the Refuge’s 

goal of quality opportunities for waterfowl hunting, wildlife observation 

and photography, fishing, interpretation, and environmental education. 

Included in this analysis is the quality of visitor experience provided, 

ease of visitor access, and how well each alternative minimizes conflicts 

between or within different user groups. 

-Green means the alternative allows for quality public use, with easy access 

and minimal conflicts between or within user groups. 

-Yellow through red means lower quality and/or increasing conflicts. 

Impact to Community compares impacts of the alternatives to neighboring 

landowners and/or renters, and the local community. This includes 

impacts of increased visitor traffic through neighborhoods and through 

town, impacts of constructed elements on view-sheds, and impacts of 
Ridgefield National Wildlife Refuge Transportation Access Analysis | 21

the alternatives on community development projects (for example the 

proposed Port of Ridgefield development).

-Green to red means little or no impacts to high impacts.

Cost/Feasibility compares costs of land acquisition, construction, and 

maintenance. It also includes with feasibility of implementing the 

alternative (ie NEPA compliance and Section 4(f)).

-Green to red means low cost and basic NEPA process to high cost and 

more complex NEPA process.

Access Alternatives

Through the public scoping process and subsequent development of the 

draft CCP, the Refuge has developed five alternatives addressing public 

access. All of the proposed alternatives, with the exception of the “No 

Build” alternative, include replacing the current pedestrian bridge at the 

Carty Unit with a bridge that meets ADA guidelines. 

Alternative 1 – The “No Build” alternative

•Access to the Refuge would remain unchanged and without improvements, 

other than repair of the existing bridge to the River “S” Unit, or 

replacement with a like structure.
22 | Ridgefield National Wildlife Refuge Transportation Access Analysis

Alternative 2 – Retain the existing access points with improvements. 

These improvements would include:

•Acquire the 33-acre parcel of land the current entrance road traverses, 

from Hillhurst Road to the River “S” Unit. (Current access is granted 

through an easement.)

•Widen and pave the existing entrance road from Hillhurst Road to the 

beginning of the bridge across Lake River.

•Replace the single lane bridge spanning Lake River with a two lane bridge 

spanning Lake River and the railroad tracks.
Ridgefield National Wildlife Refuge Transportation Access Analysis | 23

Alternative 3 – Create a new access point into the Refuge from the Port 

of Ridgefield’s overpass. The Port of Ridgefield is planning to construct a 

bridge over the railroad tracks from the junction of Main Street and State 

Route 501/Pioneer Street to the Port property. 

Alternative 3 includes:

•Build a branch off of the Port of Ridgefield’s proposed bridge that would 

access the River “S” Unit from downtown Ridgefield at the junction of 

Main Street and State Route 501/Pioneer Street.

•Construct an access road from the end of the new bridge, south to the 

existing auto tour route. This road would be about 0.75 miles long and run 

along the base of the existing dike. It would be asphalt at the toe of the 

bridge and graveled thereafter.
24 | Ridgefield National Wildlife Refuge Transportation Access Analysis

Alternative 4 – Again building from the Port of Ridgefield’s plan to 

construct a bridge over the railroad tracks from the junction of Main 

Street and State Route 501/Pioneer Street to the Port property, 

Alternative 4 includes:

•Build a smaller, two lane bridge with a lift-span from the Port of 

Ridgefield’s property, north of the houseboat community, over Lake River 

to access the River “S” Unit.

•Construct an access road from the end of the new bridge, south to the 

existing auto tour route. This road would be about 0.75 miles long and 

run along the base of the exiting dike. It would be asphalt at the toe of the 

bridge and graveled thereafter.

•The existing bridge would be removed and the easement from Hillhurst 

Road to the existing bridge would be abandoned.
Ridgefield National Wildlife Refuge Transportation Access Analysis | 25

Alternative 5 – Reopen a southern access from the Ridgeport Dairy Unit. 

Alternate 5 includes:

•Reconstruction of State Route 501/Lower River Road from mile post 

marker 11 for approximately 1 1⁄2 miles. Widen this from one lane to two 

lanes.

•Construct an approximately 4 mile access road north through the 

Ridgeport Dairy Unit to the auto tour route on River “S” Unit.

•The existing access point at Hillhurst Road and bridge would be retained 

for use by USFWS and emergency vehicles only.
26 | Ridgefield National Wildlife Refuge Transportation Access Analysis

Comparison of Alternative

Alternative 1 (No Build)

Refuge Resources: In the short term, no additional impacts to Refuge 

resources are expected under this alternative. However, the existing 

bridge has a limited remaining lifespan (estimated at 10 years in 2005). If 

the bridge is not repaired or replaced with a like structure, eventually it 

will become unusable. The Refuge’s ability to manage habitat will remain 

the same only if the bridge is repaired or replaced. If the bridge fails or 

becomes unsafe to use, this will have a major impact on Refuge operations 

and will require closure of the River ‘S’ Unit to public use.

Safety & ADA compliance: The one-lane, graveled entrance road is narrow, 

has blind corners, and is prone to slumping and washouts. Two cars can 

pass each other, but with difficulty. Trees also fall across the road. The 

current easement does not allow for widening or improvement of the 

road. In addition, the easement does not include the width necessary for 

the automatic gate when it is in the open position. The at-grade railroad 

crossing is dangerous and increases the potential for accidents. At times, 

visitors have been trapped on the River S Unit for up to 5 hours when 

trains have stopped on the tracks. The Refuge is concerned with the 

potential for visitors to be trapped on the Refuge in an emergency situation. 

These problems are likely to increase because the BNSF plans to increase 

both the number and speed of trains between Seattle and Portland. The 

existing pedestrian bridge to the Carty Unit is not accessible to visitors 

with disabilities. 

Key Issues: 

The ‘No Build’ 

alternative does 

not adequately 

address safety 

issues of the 

at-grade rail 

crossing, 

increased 

visitation, and 

ADA access 

concerns

Refuge 

Resources

Safety & ADA 

Compliance

Increased 

Visitation

Impacts to 

Visitors

Impacts to 

Community Cost & Feasibility

Alt 1 Green Red Red Yellow* Red Green

	 *Rating if the existing bridge is replaced. Otherwise rating would be red.
Ridgefield National Wildlife Refuge Transportation Access Analysis | 27

Accommodates Increased Visitation: The current trend of increased 

visitation to the Refuge is likely to continue, albeit at a slower rate than in 

alternatives 3 and 4. The narrow entrance road and one-lane bridge would 

continue to limit the ability of the Refuge to accommodate significantly 

increased visitation without negative impacts to visitor’s experiences. For 

example: traffic backups when trains pass; difficulty of passing on the 

one-lane road; visitors having to wait for opposing traffic to cross the onelane bridge. If present visitation trends continue, the situation is likely to 

become untenable. 

Impact to Visitors: The current entrance road, which winds through a 

wooded canyon, provides a gradual transition from a suburban to a rural 

(Refuge) environment that enhances the visitor experience. However, 

as previously noted, there are significant safety concerns with the 

current entrance road. Traffic backups when trains pass have a negative 

impact to the visitor experience. The Refuge’s ability to provide public 

use opportunities will remain the same only if the bridge is repaired or 

replaced. If the bridge fails or becomes unsafe to use, this will require 

closure of the River ‘S’ Unit to public use. The Refuge would no longer be 

able to operate the auto tour route or the waterfowl hunting program.

Impact to Community: The property through which the existing entrance 

road runs is slated for residential development. When this occurs, more 

than 100,000 Refuge visitors per year will be routed through a residential 

neighborhood. This will be especially problematic during the hunting 

season, when hunters begin to stack up on the entrance road at 4 in the 

morning.

Cost/Feasibility: This is the lowest cost of all alternatives. The cost of 

this alternative would include replacement of the aging one-lane bridge 

and moving or replacing the automatic gate when private land along the 

entrance road is developed.
28 | Ridgefield National Wildlife Refuge Transportation Access Analysis

NEPA and 4(f): Under Alternative 1 no action would be taken. Because 

no federal action would be taken, there would be no requirements under 

NEPA or under Section 4(f). Of all the alternatives, this one would have 

the least costs associated with environmental clearance.

Existing pedestrian bridge over railroad tracks
Ridgefield National Wildlife Refuge Transportation Access Analysis | 29

 Alternative 2 Improve Current Access

Refuge Resources: Impacts to habitat/wildlife would be short-term during 

construction. However, significant tree felling on the Hillhurst Road 

parcel would be necessary to widen the entrance road. There would be 

minor impacts to wildlife and habitat because of the larger footprint 

for the bridge footing. Impacts to federally listed species are slight. The 

widened entrance road and bridge would benefit Refuge operations.

Safety & ADA compliance: Safety along the entrance road would 

be improved by widening. Implementation of this alternative would 

require the purchase of land to allow for road improvement and bridge 

construction. Elimination of the at-grade railroad crossing would increase 

safety. The existing bridge to the Carty Unit would be replaced with a new 

bridge that would be accessible to visitors with disabilities. 

Accommodates Increased Visitation: This alternative would accommodate 

the anticipated increased visitation. The current trend of increasing 

visitation is likely to continue, albeit at a slower rate than in Alternative 

3. Removal of the at-grade railroad crossing would decrease the possibility 

of traffic backups on the entrance road and on the auto tour route.

Impact to Visitors: The current entrance road, which winds through a 

wooded canyon, provides a gradual transition from a suburban to a rural 

(Refuge) environment, and therefore, enhances the visitor experience. 

Widening the road would enhance the visitor experience and increase 

safety. The visitor experience would be further improved compared to 

Alternative 1 because traffic on the entrance road would not back up when 

trains pass.

Refuge 

Resources

Safety & ADA 

Compliance

Increased 

Visitation

Impacts to 

Visitors

Impacts to 

Community

Cost & 

Feasibility

Alt 2 Yellow Green Green Green Green Orange

Key Issues:

The success of 

Alternative 2 hinges 

on two things: The 

ability to procure 

the parcel of land 

adjacent to the 

River “S” Unit; 

The availability 

of funding. This 

alternative meets 

the Purpose and 

Need, as well as the 

evaluation criteria. 

However, the cost of 

constructing a twolane bridge with 

sufficient height and 

length to clear both 

the railroad tracks 

and the navigable 

waters of Lake River 

is high.
30 | Ridgefield National Wildlife Refuge Transportation Access Analysis

Impact to Community: Of all the alternatives, Alternative 2 would have 

the lowest impact to the community. The purchase of land adjoining the 

entrance road would eliminate potential of routing Refuge traffic through 

a residential neighborhood. However, this alternative does not provide the 

linkages to community development projects or to pedestrian and bicycle 

trails that alternatives 3 and 4 do.

Cost/Feasibility: The cost of building the bridge to eliminate the at-grade 

crossing and span navigable waters will be high. Land acquisition will be 

necessary to improve the entrance road and to build the bridge.

NEPA and 4(f): Under Alternative 2, issues related to NEPA and to 

Section 4(f) would be less complicated than with alternatives 3, 4, and 

5. It is possible that Alternative 2 could be cleared under NEPA with 

a Categorical Exclusion (CE) and could be cleared under Section 4(f) 

requirements with an exemption or a programmatic agreement. Of all the 

action alternatives (alternatives 2 through 5), this one would be the least 

costly and take the least amount of time for environmental clearance.
Ridgefield National Wildlife Refuge Transportation Access Analysis | 31

Alternative 3 Link to Port of Ridgefield Proposed Bridge

The Port of Ridgefield (Port) currently is analyzing alternatives for a 

Rail Overpass Project to provide a safer and more efficient passage from 

downtown Ridgefield across the BNSF Railroad tracks into the Port and 

waterfront area. The preferred alternative for the Rail Overpass Project 

proposes an overpass from the intersection of State Route 501/Pioneer 

Street and N. Main Avenue in downtown Ridgefield.

Alternative 3 would tie directly into the Port’s preferred alternative. Tying 

into the proposed Rail Overpass would create a new access point into the 

River “S” Unit. Alternative 3 would span the railroad tracks and Lake 

River. A new entrance road would be constructed, which would connect to 

the existing auto tour road in the River “S” Unit.

Refuge Resources: Minor additional impacts to Refuge resources (habitat) 

would occur because of the larger area required for the bridge footings and 

because the construction of a connector road along the toe of the dike to 

the auto tour route would be required. A small seasonal wetland, located 

at the toe of the levee in East Hall Field, would be impacted under this 

alternative. There is the potential for light to moderate decreases in wildlife 

use of the north end of the River “S” Unit because of vehicular traffic on the 

two-lane road. Impacts to federally listed species would be slight.

Safety & ADA compliance: This alternative would result in a safer overall 

system than for Alternative 1 because visitors would no longer use the 

existing entrance road. This alternative eliminates the at-grade rail 

crossing to the River ‘S’ Unit. The existing bridge to the Carty Unit would 

be replaced with a new bridge that would be accessible to visitors with 

disabilities. 

Refuge 

Resources

Safety & ADA 

Compliance

Increased 

Visitation

Impacts to 

Visitors

Impacts to 

Community

Cost & 

Feasibility

Alt 3 Yellow Green Green Yellow Red Red

Key Issues: 

This alternative 

would increase 

the transportation 

footprint on the 

Refuge, would 

negatively impact 

a houseboat 

community, and 

would reduce the 

number of duck 

blinds available for 

the hunting user 

group. The cost of 

mitigating impacts 

to the houseboat 

community and of 

constructing the 

bridge would be 

high.
32 | Ridgefield National Wildlife Refuge Transportation Access Analysis

Accommodates Increased Visitation: This alternative would accommodate 

increased visitation. However, this alternative also is likely to cause 

visitation to increase at higher rates than current projections (see 

discussion below). 

Impact to Visitors: There are both positive and negative aspects to this 

alternative. This alternative likely would cause visitation to increase at 

higher rates than what the Refuge experiences currently. Because the 

Refuge would be accessed directly from downtown Ridgefield, the entrance 

is more visible and the Refuge is therefore likely to get more casual 

visitors. This alternative also is likely to increase the number of local 

visitors making short, frequent visits to the Refuge. 

At a certain level of visitation, the quality of the visitor experience will be 

compromised to the point where measures to reduce auto traffic or limit 

visitor numbers will need to be taken. The character of the entrance would 

be changed from the gradual transition to a rural environment provided 

by the current entrance road, to a much more “urban” experience (going 

directly from town, over a high 2 lane span, to the Refuge).

On the other hand, this alternative would have the potential for linking the 

Refuge to walking and bicycling trails, which could decrease motor vehicle 

use and increase pedestrian use. This would have several benefits, such as 

decreasing vehicle emissions and increasing health benefits for visitors.

There is the potential for people who did not intend to visit the 

Refuge to take the left-hand turn to the Refuge; they would then 

have to double back on the Refuge. The straight stretch of twolane road linking the bridge to the auto tour route is more likely to 

encourage speeding. 

Two hunting blinds would need to be moved; however, Refuge 

staff feels that this can be accomplished without decreasing hunting 

opportunities. This would, however, create a tighter hunting environment.
Ridgefield National Wildlife Refuge Transportation Access Analysis | 33

Impact to Community: There are both positive and negative aspects to 

this alternative. It eliminates the potential of Refuge traffic through a 

residential neighborhood. It provides a much tighter link between the 

town of Ridgefield and the Refuge because the Refuge can be accessed 

directly from downtown. This alternative also would provide a direct 

link between the Refuge and the Port of Ridgefield’s proposed waterfront 

development (and in the future to biking trails and walking trails). On 

the other hand, recent discussions with the Ridgefield gateway committee 

indicates that they would be opposed to this alternative because of the 

visual barrier the elevated bridge would create. 

The proposed site for the new bridge would span a houseboat community 

on Lake River. Houseboats would need to be relocated for Alternative 3. 

Right of way acquisition in this industrial zoned area could be expensive. 

A review would be needed to determine whether Alternative 3 would 

result in “...disproportionately high and adverse human health and 

environmental effects on minorities and low-income populations.” This 

would include the short-term (construction related) and the long-term 

impacts and benefits to the houseboat community.

Cost/Feasibility: This alternative has the highest cost of all alternatives 

because of the size of the bridge and because of the high cost of right of 

way acquisition in the industrial-zoned area on the east side of Lake River. 

An approximately 0.75-mile-long new access road from the end of the 

off ramp of the bridge on Refuge property south to the existing auto 

tour route would need to be constructed. The Refuge originally proposed 

placing the new road alignment along the top of a dike that parallels 

Lake River. During a scoping field trip on December 19, 2007, between 

the WFLHD and the Refuge, Rich Barrows, Geotechnical Engineer for the 

WFLHD, suggested the new road alignment should follow the toe of the 

existing dike because it would have far less impacts than increasing the 

size of the dike in order to accommodate two lanes of traffic. Paralleling 

the toe of the dike would minimize wildlife disturbance and impacts to 

habitat.
34 | Ridgefield National Wildlife Refuge Transportation Access Analysis

NEPA and 4(f): Alternative 3 would be more difficult to clear than Alternative 

2. Alternative 3 would need to be evaluated under either an Individual or 

Programmatic Evaluation for Section 4(f) impacts, and Alternative 3 would cost 

more and take longer to clear through the NEPA process than Alternative 2.

Cathlapotle Plank house in the Carty Unit
Ridgefield National Wildlife Refuge Transportation Access Analysis | 35

Alternative 4 Build a Bridge from Port Property

Refuge Resources: This alternative would result in additional minor impacts to 

Refuge resources (habitat) because of the area required for the bridge footings 

and because construction of a connector road along the toe of the dike to the auto 

tour route would be required. A small seasonal wetland, located at the toe of the 

levee in East Hall Field, would be impacted under this alternative. There is the 

potential for light to moderate decrease in wildlife use of the north end of the 

River “S” Unit because of auto traffic on the two-lane road. Impacts to federally 

listed species would be slight.

Safety & ADA compliance: This alternative would result in a safer overall system 

than for Alternative 1 because visitors would no longer use the existing entrance 

road. This alternative eliminates the at-grade rail crossing to the River ‘S’ Unit. 

The existing bridge to the Carty Unit would be replaced with a new bridge that 

would be accessible to visitors with disabilities. 

Accommodates Increased Visitation: This alternative would accommodate 

increased visitation. However, this alternative also is likely to cause visitation 

to increase at higher rates than the Refuge experiences currently (see discussion 

below). 

Impact to Visitors: There are both positive and negative aspects to this alternative. 

This alternative likely would cause visitation to increase at higher rates than what 

the Refuge experiences currently. Because the Refuge would be accessed directly 

from downtown Ridgefield, the entrance is more visible and the Refuge is therefore 

likely to get more casual visitors. This alternative also is likely to increase the 

number of local visitors making short, frequent visits to the Refuge.

Refuge 

Resources

Safety & ADA 

Compliance

Increased 

Visitation

Impacts to 

Visitors

Impacts to 

Community Cost & Feasibility

Alt 4 Yellow Green Green Yellow Green Yellow

Key Issues: 

This alternative 

assumes the 

completion 

of the Port of 

Ridgefield Rail 

Overpass.
36 | Ridgefield National Wildlife Refuge Transportation Access Analysis

At a certain level of visitation, the quality of the visitor experience will be 

compromised to the point where measures to reduce auto traffic or limit visitor 

numbers will need to be taken. The character of the entrance would be changed 

from the gradual transition to a rural environment provided by the current 

entrance road, to a much more “urban” experience.

On the other hand, this alternative would have the potential for linking the 

Refuge to walking and bicycling trails, which could decrease motor vehicle use 

and increase pedestrian use. This would have several benefits, such as decreasing 

vehicle emissions and increasing health benefits for visitors.

There is the potential for people who did not intend to visit the Refuge to take the 

left-hand turn to the Refuge; they would then have to double back on the Refuge. 

The straight stretch of two-lane road linking the bridge to the auto tour route is 

more likely to encourage speeding.

Two hunting blinds would need to be moved; however, Refuge staff feels that 

this can be accomplished without decreasing hunting opportunities. This would, 

however, create a tighter hunting environment.

Impact to Community: This alternative eliminates the potential of Refuge traffic 

through a residential neighborhood. It provides a much tighter link between the 

town of Ridgefield and the Refuge because the Refuge can be accessed directly 

from downtown. This alternative also would provide a direct link between the 

Refuge and the Port of Ridgefield’s proposed waterfront development. In the future, 

there also would be the potential to develop transportation linkages from the 

Refuge to waking and bicycling trails.

Cost/Feasibility: Costs associated with this alternative are lower than Alternative 

3 due to the some what smaller bridge and lower cost of right of way acquisition in 

the industrialized-zone area on the east side of Lake River.

An approximately 0.75-mile-long new access road from the end of the off ramp 

of the bridge on Refuge property south to the existing auto tour route would 

need to be constructed. The Refuge originally proposed placing the new road 

alignment along the top of a dike that parallels Lake River. During a scoping field 
Ridgefield National Wildlife Refuge Transportation Access Analysis | 37

trip on December 19, 2007, between the WFLHD and the Refuge, Rich Barrows, 

Geotechnical Engineer for the WFLHD, suggested the new road alignment 

should follow the toe of the existing dike because it would have far less impacts 

than increasing the size of the dike in order to accommodate two lanes of traffic. 

Paralleling the toe of the dike would minimize impacts to wildlife.

NEPA and 4(f): Alternative 4 would require a similar effort as Alternative 3 

for environmental clearance. Alternative 4 would need to be evaluated under 

either an Individual or Programmatic Evaluation for Section 4(f) impacts, and 

Alternative 4 would have similar costs and take about the same amount of time 

to clear through the NEPA process as Alternative 3.

Deterioration of existing State Route 501
38 | Ridgefield National Wildlife Refuge Transportation Access Analysis

Alternative 5 Reopen Southern Access

Refuge Resources: Under this alternative, major negative impacts to Refuge 

purposes species (dusky Canada geese and sandhill cranes) would occur. The 

road would be placed through or adjacent to their core habitat areas, including an 

important roost site for sandhill cranes (Campbell Lake). Likewise, there would 

be major negative impacts to Refuge operations because of the distance from 

the Refuge headquarters to this proposed entrance. A 30-mile detour through 

Vancouver would be necessary to get Refuge vehicles and heavy equipment from 

the Refuge headquarters in Ridgefield to the River “S” Unit. This would result in 

increased driving time, staff time, and fuel costs. This alternative could benefit 

cooperative grazers by providing them with more direct access to pastures. This 

alternative would, however, require new gates and fencing, which would increase 

costs. The entire road, from Lower River Road parking lot to River S would need 

to be upgraded (it is currently only one lane.) This would require removing Oregon 

ash trees in an area of high-quality habitat with a fairly intact under-story.

Safety & ADA compliance: Under this alternative, safe access would be provided. 

This alternative would eliminate the at-grade railroad crossing. The potential 

for more law enforcement issues may increase because of the distance from this 

entrance to the Refuge Headquarters; however, this could be offset by the potential 

for an increased amount of vehicle traffic on the Refuge, which may lessen the 

attractiveness of the south end to vandals.

Accommodates Increased Visitation: This alternative could accommodate 

increased visitation. However, visitation would be unlikely to increase at current 

rates (and possibly would decline) because the southern access point is less 

conveniently located than the current one. 

Key Issues: 

Alternative 5 

impacts core 

habitat for 

dusky Canada 

geese and 

sandhill cranes, 

and it does 

not provide 

direct access 

for Refuge 

maintenance.

Refuge 

Resources

Safety & ADA 

Compliance

Increased 

Visitation

Impacts to 

Visitors

Impacts to 

Community Cost & Feasibility

Alt 5 Red Green Green Red Orange Red
Ridgefield National Wildlife Refuge Transportation Access Analysis | 39

Impact to Visitors: Currently, many visitors make short, frequent visits to the 

Refuge (i.e. for their lunch hour or an afternoon) and these visitors would be put 

off by a greatly increased drive time to the Refuge entrance. This alternative also 

would greatly increase the difficulty of conducting the waterfowl hunting program 

because of the distance from the entrance to the Refuge Headquarters. Likewise, 

under this alternative, the ability of Refuge staff to conduct special bird viewing 

tours would be eliminated because of the increased drive time from the Refuge 

Headquarters. 

Some visitors, especially “hard-core” birders, may appreciate the increased 

access to the south end of the Refuge and the lower visitor numbers; however, 

the increased disturbance to wildlife under this alternative may end up reducing 

wildlife use of the area and therefore, viewing opportunities. Potentially, the 

Refuge (with the exception of the Carty Unit) would need to be closed seasonally 

to public use to prevent unacceptable levels of disturbance to wildlife. 

Impact to Community: This alternative would hinder the cooperative efforts 

between the Refuge and the City of Ridgefield, would hinder the ability to put on 

the Bird Fest, and would hinder the ability for Ridgefield to promote itself as a 

gateway community to the Refuge and to link to Port development. The reduced 

visitation could decrease economic benefit of the Refuge to the community. On the 

positive side, this alternative eliminates the potential for Refuge traffic through a 

residential neighborhood and does not impact houseboat residents.

Cost/Feasibility: Although a new bridge is not required under this alternative, 

implementing Alternative 5 would require repair and widening of the existing 

dike, which is severely eroded at several points. Additionally, it would require 

that 4 miles of road from the Lower River Road parking lot to the River “S” Unit 

be upgraded (it is currently only one lane). The portion of the road through the 

Roth Unit would need to be elevated to prevent flooding. The Refuge does not 

own the dike or dike road. Based on previous discussions, it appears unlikely 

that the County would abandon its right of way. To date the County has not 

expressed interest in repairing or maintaining the dike and road for its own needs. 

Implementing this alternative would require purchase of right of way with a 

maintenance agreement in order for the USFWS to fund repair/construction.
40 | Ridgefield National Wildlife Refuge Transportation Access Analysis

NEPA and 4(f) – This alternative would meet some of the transportation needs 

of the Refuge, but the noise and visual impacts through one of the Refuge’s prime 

foraging and roosting areas for dusky Canada geese and sandhill cranes is not 

consistent with Refuge purposes. Alternative 5 would be the least optimal and 

probably the most complicated in terms of cost, schedule, and clearance under 

NEPA and the Section 4(f) process.

Photography By Roxanne Bash

Ridgefield Wildlife Refuge
Ridgefield National Wildlife Refuge Transportation Access Analysis | 41

For additional information please see the 

Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

or contact: Robert Flores, Project Leader, 360-887-4106

Summary of Key Issues 

Alternative 1 – The ‘No Build’ alternative does not adequately address safety issues of the at-grade rail crossing, increased visitation, and ADA access concerns

Alternative 2 –The success of Alternative 2 hinges on two things: The ability to 

procure the parcel of land adjacent to the River “S” Unit; The availability of funding. This alternative meets the Purpose and Need, as well as the evaluation criteria. However, the cost of constructing a two-lane bridge with sufficient height and 

length to clear both the railroad tracks and the navigable waters of Lake River 

is high.

Alternative 3 – This alternative would increase the transportation footprint on the 

Refuge, would negatively impact a houseboat community, and would reduce the 

number of duck blinds available for the hunting user group. The cost of mitigating 

impacts to the houseboat community and of constructing the bridge would be high.

Alternative 4 – This alternative assumes the completion of the Port of Ridgefield 

Rail Overpass.

Alternative 5 – Alternative 5 impacts core habitat for dusky Canada geese and 

sandhill cranes, and it does not provide direct access for Refuge maintenance.
U.S. Department of Transportation

Federal Highway Administration

610 E 5th Street

Vancouver, WA 98661

http://www.wfl.fhwa.dot.gov

(360) 619-7700

1-866-890-6230

TTY 1-800-833-6384

May 2009
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix M. Land Protection Plan M-1

Appendix M. Land Protection Plan

Ridgefield National Wildlife Refuge

Clark County, Washington

Prepared by: 

U.S. Fish and Wildlife Service 

Region 1 

911 N.E. 11th Avenue, 3rd Floor West 

Portland, Oregon 97232 

503-231-2231 

800-662-8933 

May 2010 

U.S. Department of the Interior 

Fish and Wildlife Service
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

M-2 Appendix M. Land Protection Plan

Table of Contents

Land Protection Plan 

Ridgefield National Wildlife Refuge

Clark County, Washington 

1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-3 

1.2 Project Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-3 

1.3 Threats to and Condition of the Biological Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-4 

1.4 Habitat Protection Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-6 

1.5 Land Protection Priorities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .M-9 

1.6 Funding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-10 

1.7 Conceptual Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-10 

1.8 Coordination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M-12 

Figure 1. Map of Ridgefield National Wildlife Refuge Inholdings . . . . . . . . . . . . . . . . . . . . . . . M-7 

Table 1. Land Protection Priorities for Ridgefield National Wildlife Refuge Inholdings . . . . . . M-9 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix M. Land Protection Plan M-3

Land Protection Plan

Ridgefield National Wildlife Refuge

Clark County, Washington 

1.1 INTRODUCTION

This Land Protection Plan (LPP) provides a description of the biological resources, threats to the 

resources, habitat protections needed, and land acquisition methods for private and State held lands 

within the existing approved boundary of the Ridgefield National Wildlife Refuge. Individual tracts 

within the approved boundaries and their priority for acquisition are depicted in Table 1. Contingent 

upon funding availability, the Service would purchase fee title or easement interests from willing 

sellers of privately owned land. There is also the potential for entering into cooperative management 

agreements with the Washington Department of Natural Resources and the Washington Department 

of Transportation for tracts within the approved boundary. Should the U.S. Fish and Wildlife Service 

(Service) acquire these tracts, this LPP describes in conceptual terms the proposed management. 

Specific management actions and their associated impacts are evaluated elsewhere in the 

Comprehensive Conservation Plan. 

Potential expansion of the refuge acquisition boundary will be considered separately as part of a 

larger land protection planning study for the Lower Columbia River area (see Chapter 2 of this CCP, 

Actions Common to All Alternatives, page 2-6). 

On May 18, 1965, the Migratory Bird Commission, under the authority of the Migratory Bird Treaty 

Act of 1929, approved the establishment of Ridgefield National Wildlife Refuge and identified a 

6,130.8-acre acquisition boundary for the Refuge. Since the Refuge was established the acquisition 

boundary has been modified to encompass 6,170 acres. To date, a total of 5,217.7 acres within the 

approved boundary are currently under fee title, agreement, or lease. As opportunities arise with 

willing sellers, the Service may either enter into management agreements or directly purchase lands

within the approved boundary. Until lands are formally acquired, owners of land within a refuge 

boundary retain all the rights, privileges, and responsibilities of land ownership. Additionally, secure 

and well managed in-holdings may similarly serve purpose species and resources. Expanding the 

Refuge through acquisitions help meet the National Wildlife Refuge System goals of preserving, 

restoring, and enhancing, in their natural state ecosystems (when practicable), all endangered or 

threatened species, migratory birds, anadromous fish, and a natural diversity and abundance of fish, 

wildlife, and plants on refuge lands. Acquiring lands within the approved boundary helps the Refuge 

fulfill its purposes and ensures that the land will be managed for wildlife needs in perpetuity. 

1.2 PROJECT DESCRIPTION

This project involves a review and prioritization of the inholdings at Ridgefield National Wildlife 

Refuge. The inholdings were evaluated based on their wildlife value and the protection of wetlands, 

managed pastures, oak woodlands, mixed coniferous forest, floodplain forests, and associated 

riparian communities. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

M-4 Appendix M. Land Protection Plan

1.3 THREATS TO AND CONDITION OF THE BIOLOGICAL RESOURCES

This section describes the biological resources associated with each inholding tract, the threats facing 

them, and their current condition. The locations of the tracts are shown in Figure 1.

Tracts 18, 22, 27 and 42

These tracts account for approximately 994 acres within the approved Refuge boundary, between Gee 

Creek and the Lewis River. The tracts are discussed collectively due to their location near the north 

boundary of the Refuge and common habitat types. Tract 18 represents approximately 992 acres of the 

total acreage. The remaining three tracts are very small parcels on the periphery of Tract 18. All parcels 

are in private ownership. 

The habitat of Tract 18 includes bottomland riparian forest including Pacific willow, Oregon ash, and 

black cottonwood stands. The tract also contains creeks, sloughs, wetlands, and lakes that are 

hydrologically linked to both river levels and tidal influences. These low velocity backwaters are 

important to anadromous fish for off-channel rearing sites. In addition, Tract 18 contains Lancaster Lake, 

which was formerly connected to the Gee Creek system, but is now separated by an earthen dike. The 

uplands of Tract 18 are populated by oak woodlands, grasslands, and pastures. A large forested knoll 

(“Middle Lands”), composed of Grande Ronde basalt exposed by Ice Age floods, was historically logged 

but reforested by the Morgan family after they acquired the property in the 1940s.

The primary economic use of Tract 18 is cattle grazing and waterfowl hunting leases. Interspersed 

wetlands and grazed pastures, combined with minimal human activity on these private properties, have 

created conditions favorable to wintering waterfowl. A limited number of hunting leases are let, creating 

a minor disturbance during the winter period. With the land owner’s permission, Tract 18 contains a 

seasonal portion of the Refuge’s Oaks to Wetlands Trail. Refuge visitation along the trail likely 

represents a larger disturbance to adjoining wetlands in Tract 18 than uses derived from the private parcel. 

Property ownership has been secure with parcels passing between generations. Barring any major 

management changes, these parcels are generally secure and are in good stewardship. 

Tract 24

This 306-acre parcel is on the northwest corner of Bachelor Island. The parcel is a membership-owned 

private waterfowl hunting club, Bachelor Island Conservation Farms. The majority of the tract is 

comprised of Canvasback Lake. Canvasback Lake is a regular roosting location for sandhill cranes (State 

endangered) in Washington. Canvasback Lake also supports a significant number of waterfowl, 

shorebirds, and wading birds. Tract 24 contains bottomland riparian forests consisting of Pacific willow, 

Oregon ash, and black cottonwood forests. Several small upland areas are farmed by members of the 

hunting club. These agricultural practices attract wintering waterfowl that forage on the grains. The 

parcel is largely undeveloped with the exception of a small building and a roadway connecting the 

building to the remainder of the parcel. The primary use of the land is for waterfowl hunting which 

includes a small farming operation. The club contains a limited number of lifetime members to maintain 

a quality hunting program. The club also hunts limited days throughout the season to maintain program 

quality.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix M. Land Protection Plan M-5

The land ownership of Tract 24 is currently stable and the tract’s management is consistent with wildlife 

values. Over time, the parcel will transition into new club members bringing the potential of commercial 

interests and development. Even minor infrastructure changes on the parcel could significantly reduce 

wetland values and impact sandhill cranes and other waterbirds. 

Tracts 40, 40a (Roth Lowlands)

Tracts 40 (43 acres) and 40a (2 acres) contains a mixture of riparian bottomland forest, wet meadows 

during seasonal flood events, and pastures between Lake River and Campbell Lake. The two parcels are 

in a single private ownership. The riparian forests are comprised of Pacific willow in the lower elevation 

flats transitioning to black cottonwood. These riparian forests are home to resident and migrant 

neotropical songbirds. Scattered individual Oregon white oaks occupy the highest terraces above the 

influence of frequent flood events. Scattered oak trees throughout the area have value in attracting and 

sustaining oak obligate wildlife species like slender-billed white-breasted nuthatches. Dusky Canada 

geese and other waterfowl are known to concentrate in the pastures and wet meadows of this parcel. 

The primary economic use of these parcels is cattle grazing and waterfowl hunting leases. The parcel 

contains several hunt blinds that are leased to waterfowl hunters. Acquisition of Tract 40 is important to 

preclude future development or commercial interests that would detract for its overall value to wildlife. 

Disturbance is a major threat to wildlife on the Roth property and adjoining Refuge land. Depending on 

the season, disturbance can be either hunting or agricultural practices. Hunting in this area is in close 

proximity to roosting sandhill cranes which are highly susceptible to disturbance. Disturbances occurring 

on the parcel may additionally reduce dusky Canada goose and waterfowl use on adjacent Refuge 

pastures and wetlands. 

Tract 2 (Washington Department of Transportation)

Tract 2 is a narrow, linear, approximately 32-acre parcel that lies within the east side of the Refuge’s 

Ridgeport Dairy Unit, parallel to Lake River. The parcel is predominantly pasture and wet meadow, with 

a narrow strip of riparian vegetation along Lake River. Tract 2 is contiguous with a tract of land owned by 

WA DOT, a west right of way for State Route 501 that lies outside the current acquisition boundary 

between Campbell Lake and the Roth Lowlands Addition. Being a property of the State, Tract 2 has 

secure ownership. However, the parcel has eminent threats with the continued industrial and public use 

development within the Vancouver Bottoms increasing the demand for corridors to link transportation, 

services, utilities, and communities. Development of a transportation corridor east of Post Office and

Campbell Lakes would reduce wildlife sanctuary values in the Roth and Ridgeport Dairy Units. The 

wetlands, fields, and lakes of the Roth and Ridgeport Dairy Units hold high densities of dusky Canada 

geese, swans, and other waterfowl. Campbell Lake is also a primary roosting location for sandhill cranes 

(State endangered) in Washington. 

Tract 2aa (Washington DNR)

Tract 2aa includes approximately 180 acres on the southwest shoreline of Bachelor Island. It largely 

consists of dredge spoils deposited from river channel maintenance. Over time, riparian bottomland 

forests have pioneered this accreted terrain. The inlet of a historic blind slough was filled, plugging the 

entrance and establishing Turtle Lake of Bachelor Island. The lake, shoreline, and riparian forests created 

by the dredge deposits are now property of the Washington Department of Natural Resources (DNR). 

Turtle Lake sees considerable waterfowl use including ducks, geese, and swans. Turtle monitoring has 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

M-6 Appendix M. Land Protection Plan

established high densities of painted turtles in Turtle Lake. Notably, the sandy soil substrate and light 

vegetative cover in uplands adjacent to Turtle Lake create ideal conditions for turtle nesting. The forests 

support riparian obligate resident wildlife and neotropical migrants. The riparian forest has supported up 

to two nesting pairs of bald eagles. 

With the land in the public domain, there are limited economic or commercial activities on this parcel. 

The parcel does, however, see significant public use throughout the year. Waterfowl hunters are known 

to moor their boats on the shore of the island and hike into Turtle Lake to hunt. In defiance of State 

Regulations, several permanent blinds have been constructed on Turtle Lake. Several years ago, a hunt 

blind was constructed in the top of a cottonwood tree for pass shooting geese. This tree was cut down in 

protest by hunters along the shoreline of Bachelor Island. Presumably, the tree blind was impacting 

hunters using the shoreline. The following waterfowl season a second tree blind was constructed and 

remains in the canopy of the forests. Year-round kayakers and canoeists use the shoreline of Bachelor 

Island for a picnic area, rest spot, and hiking. Spring and summer bring large surges in public use. The 

beach is a popular spot for summer beach camping. Arriving by boat, campers will spend extended 

periods along the shoreline. Lacking facilities, the campers will dig pit toilets in the woods and higher 

terraces. Campers will erect driftwood in the sand as a frame for tarp covered shanties. Often these 

structures are left standing at the end of the camping season with deteriorated tarps littering the beach. 

Associated with summer shoreline camping is bank fishing and water sports. These include boating, jet 

skis, and tow-behind water toys. Bachelor Island is immediately opposite the Sauvie Island clothingoptional beach. With increasing frequency, nudists are boating to Bachelor Island in search of a more 

remote or secluded location. Between public use and materials deposited along the beach from the river, 

the shoreline is littered with trash and debris. Floodwaters have brought in large chemical drums and rafts 

of tires. Contaminants must be considered, both intentionally dumped or deposited by flood events. 

Another concern with the parcel is its attraction to those conducting illegal activities and the law 

enforcement required to prevent these activities. 

Tract 2b (Washington DNR)

This approximately 7.4-acre tract includes waters surrounding a 3.6-acre island at the confluence of Gee 

Creek and the Columbia River. With the land in the public domain, there are limited economic or 

commercial activities on this parcel. Previous attempts to acquire this parcel from DNR were deemed not 

in the interest of the State.

Tract 2c (Washington DNR)

This approximately 170-acre tract includes the navigable waters (below mean high tide) of Bachelor 

Slough and a portion of Lake River, from the northern tip of Bachelor Island to the northern tip of the 

River ‘S’ Unit (River ‘S’ Point). With the land in the public domain, there are limited economic or 

commercial activities on this parcel. The primary activities currently occurring on this parcel are 

motorized and nonmotorized boating, e.g. kayaking. In the past the Refuge desired to acquire rights or an 

easement to this tract in order to control hunting. 

1.4 HABITAT PROTECTION METHODS

With regard to the private land, the Service would pursue either fee title or easement interests from 

willing sellers. The Service would pursue a cooperative management agreement with Washington DNR 

for Tract 2aa, and with the Washington Department of Transportation for Tract 2.
2aa

40a

40

2c

2

122°45'0"W

45°45'0"N 45°45'0"N

Produced in the Division of Realty & Refuge Information

Portland, Oregon

Land Status Current to: 3/25/2010

Map Date: 03/25/2010

Basemap: 24k USGS Quad

Meridian: Boise

File: 10-099-1.mxd

UTM ZONE 10

NAD 83

0 1 0.5 Miles

0 1 0.5

Kilometers

Scale: 1:20,000

T 4 N

T 3 N

T 4 N

T 3 N

R 1 W R 1 E

Legend

USFWS Approved Acquisition Boundary

USFWS Managed

State Inholdings

Private Inholdings

Private Inholdings

2 - WDOT ~35 gis acres

2aa - Washington DNR 227.40ac

2b - Wash. State ~11 gis acres

2c - Wash. State ~170 gis acres

18 - Plas Newydd Farm 1,087.62ac

22 - Jerry Petrof, et al 1.70ac

24 - Bachelor Island Farms 227.40ac

27 - Mary Mongrain <1.00ac

40 - Roth 42ac

40a - Roth 2ac

42 - James Joyce <1.00ac

Assessors Acreage
M-8 Appendix M. Land Protection Plan
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix M. Land Protection Plan M-9

1.5 LAND PROTECTION PRIORITIES

The Service assigned each property a Tract Number associated with the name of the landowner and 

provided the County Assessor’s Parcel Number (APN) for each parcel (Table 1). The Service also 

assigned each parcel a priority for protection based on the value of the parcel for conservation and 

management purposes. A preferred method of protection was determined for each parcel as well, 

considering the options of cooperative agreement, fee title, and easement. Service policy is to acquire 

the minimum interest in land necessary to achieve refuge resource conservation goals and to include 

entire ownerships (mainly for appraisal purposes) in the project area, even though only a portion may 

contain wildlife habitat of interest.

Table 1. Land Protection Priorities for Ridgefield National Wildlife Refuge 

Service 

Tract

Number

Landowner of 

Record

County APN

Number and Parcel 

Acreage1

Parcel

Acreage Within 

Refuge 

Boundary2

Protection

Priority3

Preferred

Protection

Method4

18 Plas Newydd Farm 217593-000 (575.68 ac; 

447.69 within Refuge 

boundary)

217798-000 (247.91 ac)

218003-000 (232.95 ac)

217594-000 (24.06 ac)

992.43 (GIS 

acres)

1 F

22 Jerry Petroff, et al. 217800-000 (1.7 ac) 1.70 1 F

27 Mary E. Mongrain 218005-000 (3.5 ac) .11 1 F

42 James Joyce 218030-000 (2.5 ac) .02 1 F

24 Bachelor Island 

Farms, Inc.

218560-000 (227.4 ac) 305.6 (GIS acres) 2 F

2 Washington 

Department of 

Transportation

N/A (32.37 ac) 32.37 (GIS acres) 3 C

40 Sidney Roth 220429-000 (45.35 ac) 43 4 F

40a Sidney Roth 190130-000 (9.05 ac) 2 4 F

2aa Washington 

Department of 

Natural Resources

218551-000 (180 ac) 180 (GIS acres) 5 C

2b Washington DNR N/A (7.4 ac) 7.4 (GIS acres) 6 C

2c Washington DNR N/A (170 ac) 170 (GIS acres) 7 C

1

Total parcel acreages, including areas outside Refuge acquisition boundary. Acreages do not include water bodies 

within parcels. 

2 Includes water bodies within Refuge acquisition boundary

3

Protection priorities are in the order of “1,” “2,” “3,” etc. with “1” being the highest priority for

acquisition.

4 The preferred method of protection is symbolized “C” for cooperative agreement between

agencies and “F” for fee title acquisition from willing sellers.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

M-10 Appendix M. Land Protection Plan

1.6 FUNDING 

Federal funds to acquire these lands could become available primarily through annual appropriations 

by Congress from the Land and Water Conservation Fund, Migratory Bird Conservation Fund 

monies, and Bonneville Power Administration mitigation funds. 

1.7 CONCEPTUAL MANAGEMENT

Lands acquired by the Service would be managed as part of the National Wildlife Refuge System 

under the National Wildlife Refuge System Administration Act of 1966, as amended. The following 

discussion covers the proposed management for the unacquired tracts within the approved acquisition 

boundary of Ridgefield National Wildlife Refuge. 

Tracts 18, 22, 27 and 42: These parcels contain several habitat types that would compliment refuge 

management and conservation efforts: tidal wetlands, a large permanent wetland (Lancaster Lake), 

managed pastures, floodplain/riparian forest, oak woodlands, and coniferous forest. Acquisition of 

this land would consolidate the Refuge’s boundary from the Burlington Northern Santa Fe Railroad 

line west to the Columbia River, and from the current Carty Unit boundary north to the Lewis River. 

Service acquisition would permanently safeguard the landscape from future commercial interest and 

threats, and protect habitats found on these parcels. Baseline surveys and surveys for rare species 

would be conducted. 

Tract 18 contains several hundred acres of improved pastures, largely consisting of introduced 

“tame” pasture grasses. Cattle grazing and related activities on Tract 18 have maintained pastures 

well suited for wintering waterfowl on these parcels. Existing pasture areas would be managed to 

provide green browse for Canada and cackling geese. However, if ecologically feasible, a portion of 

acquired grasslands may be restored to native plant communities: wet meadow, emergent wetland, 

native upland prairie, floodplain/riparian forest, and/or oak woodland. Site conditions and adjacency 

to intact tracts of these habitats would dictate suitable restoration locations for these native plant 

communities. For example, low elevation grasslands adjoining remnant riparian areas are well suited 

for expansion of riparian areas through either direct planting or exposing soils to natural seedfall. 

Acquisition of lands could afford the Service the opportunity to restore these communities to 

sufficient widths and complexities to achieve a full array of beneficial ecological functions to support 

a diverse array of riparian dependant plants and animals. Management of floodplain and riparian 

forest areas would involve reducing nonnative invasive plant species and reestablishing components 

of the native shrub/herbaceous layer, where necessary. 

Oregon white oak habitats in Southwestern Washington are rare and declining. Oregon white oak 

woodlands are a priority habitat for conservation efforts in the State of Washington. The Refuge’s 

woodlands represent some of the most intact remnants of oak communities in the area. Acquisition 

of adjoining oak communities would be important to protect and manage an intact contiguous 

woodland for oak obligate species. Oak woodlands acquired by the Service would be protected from 

fragmentation. Management of the woodlands may include Himalayan blackberry control along 

woodland edges with herbicide or mechanically. Coniferous forests occur predominately above the 

floodplain on the basalt knoll (“Middle Lands”) of Tract 18. Acquired forested uplands within Tract 

18 would be managed to protect water quality in the lower Gee Creek watershed, and provide habitat 

for migratory landbirds and rare plant species. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

Appendix M. Land Protection Plan M-11

Management of tidal wetlands would retain Columbia River hydrology, allowing for movements of 

anadromous salmonids (listed, proposed for listing, or candidates for listing under the Endangered 

Species Act) from the Columbia River to Refuge rearing habitats. The feasibility of restoring the 

historic connection of Lancaster Lake to Gee Creek could be explored for its potential to provide 

additional off-channel rearing habitat for juvenile salmonids. If acquired by the Service, these parcels 

could also be considered in feasibility studies for the reintroduction of Federally and State-listed 

species such as Columbian white-tailed deer and western pond turtle. 

Tract 24: 

Canvasback Lake would be managed to provide habitat for breeding and migrating waterfowl. Active 

management would reduce invasive plant species while promoting native tall and short emergent 

plant species. With removal of a small dike and water control structure, Canvasback Lake could be 

reconnected to the Columbia River. Management options would assess the restoration of Columbia 

River hydrology, allowing for movements of anadromous salmonids from the Columbia River to 

Refuge rearing habitats. Tracts of floodplain/riparian forest on this parcel would complement 

Refuge’s efforts to restore forest to the south of this parcel, and create a larger contiguous blocks of 

riparian/floodplain forest on Bachelor Island. 

Acquisition of the parcel would consolidate the Service’s ownership of all of Canvasback 

Lake and secure the largest waterbody within the Refuge’s approved boundary. Acquisition of the 

Parcel would help the Refuge meet its purposes and ensure that the land will be managed for wildlife 

needs in perpetuity. Securing sandhill crane roosts from human disturbance and development 

pressures is a regional priority due to limited known crane roosts in the area. 

Parcels 40, 40a: The acquisition of Parcels 40 and 40a would help meet Refuge goals by securing 

known dusky Canada goose, sandhill crane, and waterfowl habitat while reducing disturbance threats 

to established sanctuary areas of the Refuge. Cattle grazing and related activities on Parcel 40 have 

maintained pastures well suited for wintering waterfowl. Portions of the tracts could be considered 

for riparian restoration to create a wider riparian corridor along Lake River. 

Parcel 2: Acquisition of Parcel 2 would preclude activities and development along this parcel and 

protect the core sanctuary areas and habitat values within the south end of the Refuge. The Service 

would greatly reduce future threats to this tract and adjoining critical habitats within sanctuary areas 

by purchasing or acquiring management authority of Parcel 2. Depending upon site conditions this 

parcel could continue to be managed primarily as improved pasture, or could be considered for 

riparian restoration to create a wider riparian corridor along Lake River. 

Parcel 2aa: Inclusion of this parcel in the Refuge must be cautiously evaluated based upon the 

historic degree of non-wildlife dependent public uses, the potential of these uses to expand, the effort 

it may take to manage or regulate public use, and potential contaminants within the floodplain. 

Acquisition of this parcel would reduce disturbance to a nesting colony of great blue herons, and 

would secure a larger contiguous area of bottomland/riparian forest on Bachelor Island. The parcel 

could be evaluated as a potential reintroduction site for western pond turtles. If the parcel were 

acquired, existing public uses would have to be evaluated for appropriateness and compatibility. 

Parcels 2b and 2c: Parcels 2b and 2c are lands designated as navigable waters by the State of 

Washington. Therefore even if the lands were acquired by the Service, current use of these waters by 

motorized and nonmotorized boats would continue. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

M-12 Appendix M. Land Protection Plan

1.8 COORDINATION

The Service held public scoping meetings in Ridgefield and Vancouver, Washington on 

September 14 and 20, 2006, regarding development of the Comprehensive Conservation Plan (CCP) 

for the Ridgefield National Wildlife Refuge. The Service provided a Planning Update describing the 

CCP effort at the public scoping meetings and to the Refuge’ mailing list. The purpose, need, and 

alternatives for the conservation and management of refuge fish, wildlife, and plants and protection 

of their habitat was presented and discussed at the public scoping meetings.

Prior to the public scoping meetings, the Service sent letters to the Washington Department of Fish 

and Wildlife, the Oregon Department of Fish and Wildlife, the Chinook Indian Tribe, Cowlitz Indian 

Tribe, Clark County, Congressional officials, and other interested organizations and individuals 

informing them of the development of the CCP and inviting their participation. 

This Land Protection Plan was issued for public review and comment as part of the Ridgefield NWR 

Draft Comprehensive Conservation Plan and Environmental Assessment (DCCP/EA). The plan was 

also provided as CDs to a mailing list of 432 recipients, and were made available on the FWS Region 

1 Planning website. Printed copies of the DCCP/EA were available upon request. The 30-day review

occurred from June 16 through July 16, 2010. We did not receive specific comments regarding the 

land protection plan, and no changes have been made at this time. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-1 

Appendix N. Comments and Responses

Table of Contents

Introduction ........................................................................................................................................ N-2

N.1 Doug Hargin, Washington Waterfowl Association, June 25, 2010 ....................................... N-3

N.2 Marc Krsul, Ridgefield Junction Neighborhood Association, June 2010 ............................. N-5

N.3 Timothy C. Bourdet, July 11, 2010 ....................................................................................... N-8

N.4 Dan Latkovich, July 12, 2010................................................................................................ N-9

N.5 Joe Swenson, July 12, 2010 ................................................................................................. N-12

N.6 Jeff Boechler, North Willamette Watershed District Manager, Oregon Department of 

Fish and Wildlife, July 14, 2010 ......................................................................................... N-13

N.7 Arland D. Richardson, July 14, 2010 .................................................................................. N-16

N.8 Albert O’Connor, July 15, 2010 .......................................................................................... N-19

N.9 Karen Wood, July 15, 2010 ................................................................................................. N-20

N.10 Nathan Pamplin, Deputy Assistant Director, Washington Department of Fish and 

Wildlife, July 15, 2010 ........................................................................................................ N-22

N.11 Russ Kashow, July 15, 2010................................................................................................ N-25

N.12 Gretchen Starke, Vancouver Audubon Society, July 16, 2010 ........................................... N-26

N.13 Brent Grening, Port of Ridgefield, July 16, 2010 ................................................................ N-29

N.14 Scott Ririe, July 16, 2010 .................................................................................................... N-33

N.15 Joe Hendrix, July 16, 2010 .................................................................................................. N-35

N.16 A.G. Hackett, July 16, 2010 ................................................................................................ N-37
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-2 Appendix N. Comments and Responses

Introduction

The Service made the Ridgefield NWR Draft CCP and Environmental Assessment, including draft 

Compatibility Determinations, available for review and comment for a 30-day period consistent with 

Service NEPA and National Wildlife Refuge System Administration Act requirements. Planning 

updates and copies of the Draft CCP/EA on CD were mailed to 432 recipients, and both the planning 

update and the Draft CCP/EA were posted on the Region 1 Planning website. A news release was 

also sent to regional and local media outlets. The public review and comment period closed on July 

16, 2010. 

The Service received written comment letters from 16 interested parties: 10 individual commenters, 

the Washington Department of Fish and Wildlife, the Oregon Department of Fish and Wildlife, and 

the Port of Ridgefield; and four nongovernmental organizations: the Washington Waterfowl 

Association, Lower Columbia River Chapter; the Vancouver Audubon Society; and the Ridgefield 

Junction Neighborhood Association. 

Following are our response to those comments. The comments received did not address any topics 

which have not already been addressed in the NEPA planning process for the Ridgefield NWR CCP. 

Responding to these comments did not require changes to the Ridgefield NWR CCP, or to the 

Compatibility Determinations included with the CCP. At the request of the Washington Department 

of Fish and Wildlife, we included a strategy for sandhill crane monitoring in the CCP (Chapter 2, 

Objective 7.2) since it was consistent with both refuge purposes and the CCP goals and objectives. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-3 

N.1 Doug Hargin, Washington Waterfowl Association, June 25, 2010
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-4 Appendix N. Comments and Responses

Response 1.

Service Response to Washington Waterfowl Association 

Thank you for your comment. We have considered your request to combine Alternatives 3 and 4, 

thereby adding 250 acres to the hunting program. Being based adjacent to a major metropolitan 

area, the refuge is important to many user groups and is visited by thousands of people each year 

that engage in a variety of recreational activities. Opening additional refuge wetland areas to any 

public use through this planning process would effectively reduce the refuge’s value to wintering 

waterfowl, dusky Canada geese, and other purpose species. A major resource concern is the loss 

of suitable habitat for ducks, geese, swans, cranes, and other purposes species. It is estimated

that over half of the historic riverine wetlands, including 90% of tidally influenced freshwater 

wetlands, in the lower Columbia River have been lost or substantially degraded. During the 

lifetime of the CCP, there will be a continuing trend of loss, degradation, and fragmentation of 

wildlife habitat coupled with burgeoning population growth in the Portland-Vancouver 

metropolitan area. These factors will put greater pressure on wetland obligate species, including 

swans, ducks, geese, herons, and sandhill cranes. Wildlife will place higher demands on the 

remaining wetlands, as they congregate in greater densities in suitable habitat. For these reasons, 

it is not feasible to significantly increase the number of acres for any public use on the refuge. 

Hunting is a very important public use on the refuge and is included in the 1964 Consolidated 

Report of the Proposed Ridgefield National Wildlife Refuge as a justification for the refuge’s

establishment. The refuge has stated our commitment to maintaining at least the current number 

of hunt blinds and area of influence to provide a significant number of hunting opportunities. 

Blind locations may need to be changed to permit safe operation of the new access road and 

bridge described in Alternative 2, but the refuge is committed to establishing new blinds to 

replace those lost. As stated in our many discussions with the hunting community and as 

described in the CCP, the refuge considers the impact on hunting opportunities when conducting 

wetland and pasture management as well as crop production (i.e. local waterfowl flyways, 

baiting issues, etc.). The refuge is required to consider a large number of factors in developing 

and operating the public use program including public interests, safety, impacts to resources, and 

how these programs achieve refuge purposes. This process is described in detail in Appendices 

A and B in the CCP (Appropriate Use and Compatibility Determinations). 

In developing the CCP, the refuge must consider the goals and objectives contained in the Pacific 

Flyway Management Plan for the Dusky Canada Goose (2008) and the Northwest 

Oregon/Southwest Washington Canada Goose Agricultural Depredation Control Plan (1998). As 

a signatory to these plans, the Service has agreed to take steps to increase the numbers of these 

birds using the Refuge through both public use management and habitat management. As you 

are aware, dusky Canada goose numbers have been declining and remain well below 

management goals. Cackling Canada geese populations are also below management goals. Both 

these species, but especially the cackling geese, make use of the pastures and wetlands on 

Bachelor Island. The refuge has decided that maintaining the existing sanctuary area on 

Bachelor Island and implementing various habitat improvements described in the CCP will help 

these species reach established management goals, while still providing significant public use 

opportunities on the refuge. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-5 

N.2 Marc Krsul, Ridgefield Junction Neighborhood Association, June 2010
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-6 Appendix N. Comments and Responses
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-7 

Response 2.

Service Response to Ridgefield Junction Neighborhood Association

Thank you for your comments of support for future safe access needs of the refuge. Your comment 

concerning the Carty collection is consistent with strategies within Goal 2.5.1 to pursue funding and 

space to store/curate artifact collections currently stored off-site. Your comments are also consistent 

with strategies within Goal 2.6.3 to produce exhibits incorporating artifacts found on the refuge. It 

would be desirable to integrate the Carty collection into the exhibitory of a future Nature Center. 

Your comments relating to Section 1.8.2 address Issues Outside the Scope of the CCP. Funding 

timelines required that the placement of a Nature Center and location of a Pedestrian Bridge be 

addressed in a separate Environmental Assessment. During initial scoping of the various alternatives 

for the Nature Center, the Refuge discussed the project and sought comments from the Port and the 

residents of Ridgefield on numerous occasions. We held public meetings, presented project updates 

to the public through local media outlets, and solicited public and agency comments. 

As part of the EA, the Refuge did state our commitment to working with the City of Ridgefield to 

improve the connectivity with downtown Ridgefield through the future City of Ridgefield public trail 

which would parallel NW Main Ave. and join the Refuge trail system through the southern boundary 

of the Carty Unit near the proposed Nature Center. 

For additional information on the Visitor Center, the final version of the Environmental Assessment 

and Finding of No Significant Impact is available at the Refuge’s website. The public comment 

period for this EA has closed and the Finding of No Significant Impact was issued on April 29, 2010. 

 

A Visitor Center sited on Port property would require a road to be built to transport participants in 

our environmental and cultural education programs to the Carty Unit and Plankhouse. This road 

would require considerable amounts of wetland fill and would require the refuge to obtain a Section 

404 permit from the Corps of Engineers. With regard to impacts to jurisdictional wetlands, the Corps 

can only permit the “least environmentally-damaging practicable alternative (LEDPA).” The 

proposed Visitor Center site on the Carty Unit is a practicable alternative that would have fewer 

wetland impacts and thus is the only alternative that meets the LEDPA criteria. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-8 Appendix N. Comments and Responses

N.3 Timothy C. Bourdet, July 11, 2010

Response 3.

Service Response to Timothy C. Bourdet

Your comments request that proposals consider the loss of public lands to hunting and fishing. 

Additionally, you request that public lands be opened to hunting and fishing opportunities. Please 

note that all Alternatives within the Draft CCP/EA include maintaining hunting and fishing programs 

on the Ridgefield National Wildlife Refuge. With the ongoing loss of undeveloped land in the 

vicinity of the refuge, refuge lands are becoming even more important to wildlife. The Refuge has 

sought to comply with provisions in the Pacific Flyway Management Plan for the Dusky Canada 

Goose (2008) and the Northwest Oregon/Southwest Washington Canada Goose Agricultural 

Depredation Control Plan (1998). As signatories to these plans, the Service has agreed to take steps 

to increase the numbers of these birds using the Refuge through both public use management and 

habitat management. The refuge recognizes the importance of providing public recreation 

opportunities, but also recognizes the importance of sanctuary areas to dusky Canada geese and 

cackling geese, both of which are below their target populations. Therefore the Refuge has decided 

not to convert the existing sanctuary areas to public use areas. Hunting and fishing are appropriate 

uses of the Refuge System when compatible, that is when they do not materially interfere with or 

detract from the fulfillment of the mission of the Refuge System or the purposes for which the refuge 

was established. Please consult Appendix B for hunting and fishing Compatibility Determinations 

that describe the scope of these public uses and the stipulations necessary to ensure that these public 

uses are compatible.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-9 

N.4 Dan Latkovich, July 12, 2010 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-10 Appendix N. Comments and Responses

Response 4. 

Service Response to Dan Latkovich 

Thank you for your comment. The Draft CCP/EA has not proposed expansion of wildlife

observation/photography into habitat for wintering waterfowl due to conflicts with resource 

protection. In developing the CCP, the refuge must consider the goals and objectives contained in the 

Pacific Flyway Management Plan for the Dusky Canada Goose (2008) and the Northwest 

Oregon/Southwest Washington Canada Goose Agricultural Depredation Control Plan (1998). As a 

signatory to these plans, the Service has agreed to take steps to increase the numbers of these birds 

using the Refuge through both public use management and habitat management. As you are aware, 

dusky Canada goose numbers have been declining and remain well below management goals. 

Cackling Canada geese populations are also below management goals. Both these species, but 

especially the cackling geese, make use of the pastures and wetlands on Bachelor Island. The refuge 

has decided that maintaining the existing sanctuary area on Bachelor Island and implementing 

various habitat improvements described in the CCP will help these species reach established 

management goals, while still providing significant public use opportunities on the refuge. 

The Draft CCP/EA supports waterfowl hunting as a compatible and appropriate use at the Ridgefield 

National Wildlife Refuge. Under all alternatives within the DCCP/EA, the refuge will continue to 

provide, at minimum, its current waterfowl hunting opportunity. Alternative 4 proposes a slight 

increase in the overall acreage of the hunt program. Hunting is a very important public use on the 

refuge and is included in the 1964 Consolidated Report of the Proposed Ridgefield National Wildlife 

Refuge as a justification for the establishment of the refuge. The refuge has stated our commitment 

to maintaining at least the current number of hunt blinds and area of influence to provide a significant 

number of hunting opportunities. Blind locations may need to be changed to permit safe operation of 

the new access road and bridge described in Alternative 2, but the refuge is committed to establishing 

new blinds to replace those lost. As stated in our many discussions with the hunting community and 

as described in the CCP, the refuge considers the impact on hunting opportunities when conducting 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-11

wetland and pasture management as well as crop production (i.e. local waterfowl flyways, baiting 

issues, etc.). The refuge is required to consider a large number of factors in developing and operating 

the public use program including public interests, safety, impacts to resources, and how these 

programs achieve refuge purposes. This process is described in detail in Appendices A and B 

(Appropriate Use Findings and Compatibility Determinations) in the CCP. 

Opening both River ‘S’ Unit and Bachelor Island unit to public uses through this planning process 

would effectively reduce the refuge’s value to wintering waterfowl, dusky Canada geese, and other 

purposes species. A major resource concern is the loss of suitable habitat for ducks, geese, swans, 

cranes, and other purposes species. It is estimated that over half of the historic riverine wetlands, 

including 90% of tidally influenced freshwater wetlands, in the lower Columbia River have been lost 

or substantially degraded. During the lifetime of the CCP, there will be a continuing trend of loss, 

degradation, and fragmentation of wildlife habitat coupled with burgeoning population growth in the 

Portland-Vancouver metropolitan area. These factors will put greater pressure on wetland obligate 

species, including swans, ducks, geese, herons, and sandhill cranes. Wildlife will place higher 

demands on the remaining wetlands, as they congregate in greater densities in suitable habitat. For 

these reasons, it is not feasible to significantly increase the number of acres for any public use on the 

refuge.

The placement of the bridge proposed in Alternative 2 is conceptual and its location is limited by the 

Port of Ridgefield’s plans for their economic revitalization (Miller’s Crossing) of their property. But 

given the presumed location of the bridge, Blind 4 would be situated very near the bridge. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-12 Appendix N. Comments and Responses

N.5 Joe Swenson, July 12, 2010

Response 5. 

Service Response to Joe Swenson

Thank you for your comments. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-13

N.6 Jeff Boechler, North Willamette Watershed District Manager, Oregon 

Department of Fish and Wildlife, July 14, 2010
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-14 Appendix N. Comments and Responses

Response 6.

Service Response to Oregon Department of Fish and Wildlife

Throughout the development of the alternatives, the Refuge has sought to comply with provisions in 

the Pacific Flyway Management Plan for the Dusky Canada Goose (2008) and the Northwest 

Oregon/Southwest Washington Canada Goose Agricultural Depredation Control Plan (1998). As a 

signatory to these plans, the Service has agreed to take steps to increase the numbers of these birds 

using the Refuge through both public use management and habitat management. Since the Service is 

a cooperating wildlife agency for the welfare and management of the dusky Canada goose 

population, refuge management actions will continue to adhere to the recommendations prescribed in 

the Pacific Flyway Management Plan for the Dusky Canada Goose. To protect dusky Canada geese, 

the refuge’s hunt program tiers to the annual recommendations of the Pacific Flyway Council 

regarding annual harvest quotas designed to protect dusky populations. The Refuge maintains its 

own quota (currently 5 birds) and prohibits on-refuge goose hunting once the refuge’s annual dusky 

harvest quota has been reached (see Appendix B, Compatibility Determination-Waterfowl Hunting). 

To ensure compliance to season limits for dusky Canada geese and other waterfowl, the refuge’s hunt 

program conducts periodic law enforcement sweeps, has a staff present on all hunt days, requires 

mandatory check in/out for all hunters, and operates an on-site check station serving only the 

refuge’s hunt program. These measures are all intended to minimize the potential impacts to dusky 

Canada geese populations within the framework of the Pacific Flyway Management Plan for the 

Dusky Canada Goose. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-15

Starting in the mid-1990s staff of the Ridgefield National Wildlife Refuge also started to note 

delayed migration of cackling geese. In 1998 the refuge implemented area closures on the River ‘S’ 

Unit until May 1st to prevent undue disturbance to migrating waterfowl. This date is consistent with 

all alternatives within the Draft CCP/EA. If further migration delays continue, the Refuge has 

mechanisms to implement changes to the seasonal opening and closing of public use areas. Also, the 

refuge has extended weekly goose surveys into late April to ensure that counts and collar search data 

are collected for migrating geese to assist us in determining the needs of geese using the refuge. 

The refuge acknowledges the value of annual coordination with Oregon Department of Fish and 

Wildlife and Washington Department of Fish and Wildlife in the management of shared resources 

and wildlife. Please see Section 2.3.1, Features Common to all Alternatives, which states that the 

Service would continue to maintain regular discussions with the Washington and Oregon 

Departments of Fish and Wildlife (WDFW and ODFW). Key topics of discussion would include 

management of dusky Canada geese, cackling geese, and other waterfowl; depredation; updates of 

waterfowl management and depredation plans; wildlife monitoring; hunting and fishing seasons and 

regulations; and management of Federal and State-listed species. 

The refuge examined alternatives that would remove hunt blinds from the southern portion of the 

hunt area to help reduce the harvest of dusky Canada geese and re-route the Auto Tour Route to 

reduce goose and crane disturbance in the southern portion of the River S Unit. Public and agency 

input was also solicited. Visitors who use the Auto Tour route were strongly opposed to re-routing 

the route, even on a seasonal basis. Hunters were opposed to removing the hunt blinds from this 

area, since these blinds typically provide quality duck hunting opportunities. Any major 

reconfiguration of the auto tour route on the River ‘S’ Unit would route public use through areas 

proximal to waterfowl habitat. The proposed shortened route would provide public access to the 

vicinity of Ruddy Lake, north Rest Lake, and South Big Meadow. Portions of all of these fields 

could be considered areas frequently used by dusky Canada and cackling geese. The proposed 

shortened route would include the dike along north Rest Lake which is used as a roost for dusky 

Canada and cackling geese. Data that show a direct link between the auto tour route in its current 

configuration and declines in wildlife use are lacking. Goose surveys before and after the tour route 

was expanded to its current configuration do not show a clear trend. Without compelling evidence 

that the current auto tour route has reduced wildlife use, the Preferred Alternative in the Draft 

CCP/EA proposed the route remain in its current location and seasonality, except for eliminating a 

small jog protruding into Swartz Field. 

The Refuge appreciates your support of Section 2.4.7, Objective 7.5 to partner with the Columbian 

White-tailed Deer Recovery Team to conduct a feasibility study for the establishment of a viable 

population of CWT deer. Outreach and coordination with interested parties (agencies, NGOs, 

agricultural organizations, and landowners) will be a critical part of determining the feasibility of any 

introduction. The feasibility study will examine the potential of animal dispersal and subsequent 

impacts to recreational activities, proximal landowners, and local depredation. Establishment of a 

population of CWT deer will require a shift and/or the addition of refuge resources for CWT 

management and protection. Refuge biological resources are currently focused on wetland and 

pasture management for dusky Canada geese, cackling geese, sandhill cranes, and other waterfowl. 

The feasibility study will identify additional tasks that may be required, including, but not limited to 

predator management, crop production, forest restoration, and invasive species control. The 

feasibility study will also identify the status of any CWT deer that would be relocated. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-16 Appendix N. Comments and Responses

N.7 Arland D. Richardson, July 14, 2010
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-17

Response 7.

Service Response to Arland D. Richardson

Thank you for your input on the topic of access and transportation issues at the refuge. The 

Transportation Access Analysis prepared May 2009 by the Western Federal Lands Highway Division 

(Appendix L) analyzed the option of replacing the River ‘S’ Bridge in its current location with a 

bridge that spans both Lake River and the BNSF railroad tracks. This report showed that the road 

from Hillhurst to the bridge would need to be widened. To accommodate this widening, a significant 

number of trees would have to be removed in an area with steep slopes that is subject to frequent 

slides. The cost of the project is also high based upon the span required to eliminate the at-grade 

railroad crossing and span Lake River (a navigable waterway). The project would also require land 

acquisition to place the existing roadway and project’s footprint into refuge ownership. 

The Service road that cuts through Midlands Field was discussed internally by the planning team as a 

route to seasonally truncate the auto tour route, and presented in public meetings and informational 

documents. Besides truncating the auto tour route, this would also take the auto tour route away 

from hunt blinds 16, 17, 18, and 19. Unfortunately, Midlands Field and the west shoreline of Rest 

Lake are considered areas frequently used by foraging and roosting dusky Canada geese and a newly 

developed road would likely result in additional disturbance to dusky Canada geese. Additionally, 

use of this road would have the auto tour route border the majority of Rest Lake, potentially 

expanding disturbance to an important wetland within the sanctuary portions of the River ‘S’ Unit. 

The refuge does recognize the importance of wetlands along the auto tour route and has proposed 

straightening of the southeast corner of the tour route to reduce disturbance to dusky Canada geese 

and sandhill cranes using Schwartz Field. 

We have considered your request to combine Alternatives 3 and 4, thereby adding 250 acres to the 

hunting program. During the development of the various Alternatives, the Refuge conducted three 

public meetings with opportunities for public comments, met with numerous user groups, and 

provided information updates through the mail, on-line and through local media outlets. Throughout 

this process, we received comments from many users, including but not limited to hunters, 

photographers, birders, and environmental educators. Throughout the CCP development, we have 

sought to provide user groups with compatible recreation opportunities while fulfilling our mission to 

provide high quality habitat for migrating and wintering dusky Canada geese, cackling geese, 

sandhill cranes and other waterfowl. Throughout the development of the alternatives, the Refuge 

also sought to comply with treaty obligations under the Migratory Bird Act provisions in the Pacific 

Flyway Management Plan for the Dusky Canada Goose (2008) and the Northwest Oregon/Southwest 

Washington Canada Goose Agricultural Depredation Control Plan (1998). As signatories to these 

plans, the Service has agreed to take steps to increase the numbers of these birds using the Refuge 

through both public use management and habitat management. Opening additional refuge wetland 

areas to any public use through this planning process would effectively reduce the refuge’s value to 

wintering waterfowl, dusky Canada geese, and other purposes species. A major resource concern is 

the loss of suitable habitat within the lower Columbia River area for ducks, geese, swans, cranes, and 

other purposes species. It is estimated that over half of the historic riverine wetlands, including 90% 

of tidally influenced freshwater wetlands, in the lower Columbia River have been lost or substantially 

degraded. During the lifetime of the CCP, there will be a continuing trend of loss, degradation, and 

fragmentation of wildlife habitat coupled with burgeoning population growth in the PortlandVancouver metropolitan area. These factors will put greater pressure on wetland obligate species, 

including swans, ducks, geese, herons, and sandhill cranes. Wildlife will place higher demands on the 

remaining wetlands, as they congregate in greater densities in suitable habitat. For these reasons, it is 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-18 Appendix N. Comments and Responses

not feasible to significantly increase the number of acres for any public use on the refuge. The refuge 

has not proposed any reduction in the number of hunt blinds. One or two blinds may be removed to 

allow safe operation of the new access road from the Port to the Auto Tour Route. However, these 

would be replaced by new blinds that could be installed following the relocation of the existing 

Waterfowl Check Station. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-19

N.8 Albert O’Connor, July 15, 2010

Response 8.

Service Response to Albert O’Connor 

During the development of the various Alternatives, the Refuge conducted three public meetings 

with opportunities for public comments, met with numerous user groups, and provided informational 

updates via email, website and through local media outlets. Throughout this process, we received 

comments from many users, including but not limited to hunters, photographers, birders, and 

environmental educators. Throughout the CCP development, we have sought to provide user groups 

with compatible recreation opportunities while fulfilling our mission to provide high quality habitat 

for migrating and wintering dusky Canada geese, cackling geese, sandhill cranes and other 

waterfowl. A major factor has been our need to comply with provisions in the Pacific Flyway 

Management Plan for the Dusky Canada Goose (2008) and the Northwest Oregon/Southwest 

Washington Canada Goose Agricultural Depredation Control Plan (1998). As a signatory to these 

plans, the Service has agreed to take steps to increase the numbers of these birds using the Refuge 

through both public use management and habitat management. In addition, current land use patterns 

show a continual loss of undeveloped land in the vicinity of the refuge, increasing the importance of 

refuge lands to wildlife. The refuge recognizes the importance of sanctuary areas to dusky Canada 

geese and cackling geese, both of which are below their target populations. Bachelor Island provides 

sanctuary and high quality habitat for dusky Canada geese and a large number of cackling geese. It 

is also an important foraging and roosting area for sandhill cranes. Therefore, because of pressures on 

species in need of protection and the habitat needs of these species, the Refuge has decided not to 

convert sanctuary areas such as Bachelor Island, to public use areas. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-20 Appendix N. Comments and Responses

N.9 Karen Wood, July 15, 2010
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-21

Response 9. 

Service Response to Karen Wood 

Thank you for your comments. The refuge is committed to providing high quality habitat for our 

priority species as well as opportunities for wildlife-dependent recreation and public use.
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-22 Appendix N. Comments and Responses

N.10 Nathan Pamplin, Deputy Assistant Director, Washington Department of 

Fish and Wildlife, July 15, 2010
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-23

Response 10.

Service Response to Washington Department of Fish and Wildlife

Thank you for your comment concerning reducing the auto tour route during critical use periods for 

dusky Canada and cackling geese. Any major reconfiguration of the auto tour route on the River ‘S’ 

Unit would route public use through areas proximal to waterfowl habitat. The proposed shortened 

route would be routed in the vicinity of Ruddy Lake, Rest Lake, and South Big Meadow. Portions of 

all of these fields and wetlands are frequently used by both dusky Canada geese and cackling geese. 

Data that show a direct link between the auto tour route in its current configuration and declines in 

wildlife use are lacking. Goose surveys before and after the tour route was expanded to its current 

configuration do not show a clear trend. Without compelling evidence that the current auto tour 

route has reduced wildlife use, the Preferred Alternative in the Draft CCP/EA proposed the route 

remain in its current location and seasonality, except for eliminating a small jog to reduce 

disturbance to sandhill cranes and dusky geese using Schwartz Field. 

We appreciate and agree with your comments on the importance of sanctuary areas for dusky Canada 

geese and cackling geese. The refuge considers the goals and objectives contained in the Pacific 

Flyway Management Plan for the Dusky Canada Goose (2008) and the Northwest Oregon/Southwest 

Washington Canada Goose Agricultural Depredation Control Plan (1998) when planning any action. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-24 Appendix N. Comments and Responses

As a signatory to these plans, the Service has agreed to take steps to increase the numbers of these 

birds using the Refuge through both public use management and habitat management. The refuge 

has decided that maintaining the existing sanctuary areas on the refuge and implementing various 

habitat improvements described in the CCP will help these species reach established goals. 

Recently, refuge staff has noted periodic summer observations of sandhill cranes on the Bachelor 

Island Unit. In recognition of the breeding potential of sandhill cranes in the region, a strategy will 

be added to Chapter 2.4.7, Objective 7.2 (Conduct Surveys) related to the monitoring for cranes 

during the breeding season and documentation of nesting attempts. Under the preferred Alternative 

of the Draft CCP/EA, large contiguous sanctuary areas would be maintained with adequate potential 

nesting habitat for sandhill cranes on the Bachelor Island, Roth, and Ridgeport Dairy Units. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-25

N.11 Russ Kashow, July 15, 2010

Response 11.

Service response to Russ Kashow

Thank you for your comments. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-26 Appendix N. Comments and Responses

N.12 Gretchen Starke, Vancouver Audubon Society, July 16, 2010
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-27

Response 12.

Services Response to Vancouver Audubon Society

Thank you for your comments and support of the refuge. Your point is well taken that protection of 

sensitive species from undue disturbance is important in the planning of any public use program. 

All six priority public uses (defined in the Refuge Improvement Act to include hunting, fishing, 

wildlife observation, photography, environmental education and interpretation) are considered to be 

appropriate uses. The refuge then goes through a detailed assessment process to determine whether 

they are compatible with refuge purposes and to what extent they will affect refuge management 

actions and other wildlife-dependent recreational activities (see Appendices A and B, Appropriate 

Use Findings and Compatibility Determinations, for more specific information). An important part 

of the planning process is determining which public uses would be allowed (i.e. are appropriate and 

compatible) and what conditions would have to be in place to prevent the use from detracting from 

the refuge purposes, which are “to provide wintering habitat for dusky Canada goose and other 

waterfowl,” “provide breeding and migration use by waterfowl,” and “provide substantial public 

shooting opportunities.” By policy, any public use may not materially interfere with or detract from 

the fulfillment of the mission of the Refuge System or purposes for which the refuge was established. 

In order to comply with our refuge purposes, and as signatories to the Pacific Flyway Management 

Plan for the Dusky Canada Goose (2008) and the Northwest Oregon/Southwest Washington Canada 

Goose Agricultural Depredation Control Plan (1998), the Service is committed to increase the 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-28 Appendix N. Comments and Responses

numbers of these birds using the Refuge through both public use management and habitat 

management. Habitat improvements and the maintenance of sanctuary areas are important 

components in managing for dusky Canada geese and cackling geese, as the populations of both 

species are currently below management goals. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-29

N.13 Brent Grening, Port of Ridgefield, July 16, 2010
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-30 Appendix N. Comments and Responses
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-31
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-32 Appendix N. Comments and Responses

Response 13. 

Service Response to Port of Ridgefield

Thank you for your comments and strong support for Refuge’s mission and purposes, and for the 

facilities needs on Ridgefield National Wildlife Refuge (specifically, a bridge to River ‘S’ Unit, a 

footbridge to Carty Unit, and a Nature Center/Office).

Funding timelines required that the Refuge prepare a separate Environmental Assessment for the 

construction and operation of a Nature Center and associated pedestrian bridge. During initial 

scoping of the various alternatives for the Nature Center, the Refuge discussed the project and sought 

comments from the Port of Ridgefield (Port), City of Ridgefield, and the residents of Ridgefield on 

numerous occasions. We held public meetings and a workshop, presented project updates to the 

public through local media outlets, and solicited public and agency comments. The public comment 

for the Nature Center Environmental Assessment has closed, and a Finding of No Significant Impact 

was issued on April 29, 2010. 

As part of the Nature Center EA, the Refuge did state our commitment to working with the City of 

Ridgefield to improve the connectivity with downtown Ridgefield through the future City of 

Ridgefield public trail that would parallel NW Main Avenue and join the Refuge trail system through 

the southern boundary of the Carty Unit near the proposed Nature Center. 

As part of the Environmental Assessment process, the refuge used a traffic study produced by 

Kittleson & Associates, Inc., who were contracted by the Service. The traffic study included a 

review of the Port’s 2007 traffic study. The refuge’s study concluded that the Nature Center would 

have minimal impact to the traffic operations along the adjacent roadway network. 

Many of your concerns were addressed in the Nature Center EA. For additional information on the 

Nature Center, the final version of the Environmental Assessment and Finding of No Significant 

Impact is available at the Ridgefield National Wildlife Refuge website.

A Nature Center sited on Port property would require a road to be built to transport participants in 

our environmental and cultural education programs to the Carty Unit and Plankhouse. The lack of 

such access would severely prevent the Refuge from meeting our environmental and cultural 

education goals. This road would require considerable amounts of wetland fill and would require the 

refuge to obtain a Section 404 permit from the Corps of Engineers. With regard to impacts to 

jurisdictional wetlands, the Corps can only permit the “least environmentally-damaging practicable 

alternative (LEDPA).” The proposed Visitor Center site on the Carty Unit is a practicable alternative 

that would have fewer wetland impacts and thus is the only alternative that meets the LEDPA 

criteria. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-33

N.14 Scott Ririe, July 16, 2010

Response 14. 

Service Response to Scott Ririe

Thank you for your comments. During the development of the various Alternatives, the Refuge 

conducted three public meetings with opportunities for public comments, met with numerous user 

groups, and provided informational updates on-line and through local media outlets. Throughout this 

process, we received comments from many users including, but not limited to, hunters, 

photographers, birders, and environmental educators. Throughout the CCP development, we have 

sought to provide user groups with compatible recreation opportunities while fulfilling our mission to 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-34 Appendix N. Comments and Responses

provide high quality habitat for migrating and wintering dusky Canada geese, cackling geese, 

sandhill cranes and other waterfowl. All alternatives except the current management alternative 

(Alternative 1) would provide additional public use opportunities in terms of a new seasonal walking 

trail. Alternatives 2 and 3 will also provide new wildlife viewing opportunities along the new 

1.1- mile access road. 

During the development of alternatives, the refuge received numerous public comments in favor of 

maintaining the existing auto tour route. As described in our preferred alternative, the refuge 

proposes to maintain the existing auto tour route with the exception of eliminating the turn in the 

southeast corner of the route. Eliminating this turn will decrease disturbance to sandhill cranes and 

dusky Canada geese using Schwartz Field, while preserving wildlife viewing opportunities. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-35

N.15 Joe Hendrix, July 16, 2010

Response 15.

Service Response to Joe Hendrix

Hunting is an appropriate use of the Refuge System when compatible. It is also considered a priority 

public use of the Refuge System and therefore receives enhanced consideration over non-priority 

uses. On Ridgefield National Wildlife Refuge hunting is considered a compatible public use within 

the scope and stipulations described in the Compatibility Determinations in Appendix B. Most of 

Ridgefield NWR was purchased under the authority of the Migratory Bird Conservation Act (Act). 

The Act states the amount of the Refuge open to waterfowl hunting, up to the maximum 40%, is 

variable and subject to the mandate that the Refuge meet the needs of wildlife first. Throughout the 

development of the alternatives, the Refuge has sought to comply with provisions in the Pacific 

Flyway Management Plan for the Dusky Canada Goose (2008) and the Northwest Oregon/Southwest 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-36 Appendix N. Comments and Responses

Washington Canada Goose Agricultural Depredation Control Plan (1998). As a signatory to these 

plans, the Service has agreed to take steps to increase the numbers of these birds using the Refuge 

through both public use management and habitat management. In addition, current land use patterns 

in southwest Washington and northwest Oregon show a continual loss of undeveloped land in the 

vicinity of the refuge, increasing the importance of refuge lands to wildlife. Because of urban growth 

the refuge recognizes the importance of providing sanctuary areas to dusky Canada geese and 

cackling geese, both of which are below their target populations. Dusky Canada goose numbers in 

particular, have been in a long-term decline and the refuge is committed to improving our habitat 

management to benefit this species. Bachelor Island provides high quality habitat and is used by 

dusky Canada geese and a large number of cackling geese. It is also an important foraging and 

roosting area for sandhill cranes. Therefore the Refuge has decided not to convert sanctuary areas 

such as Bachelor Island, to public use areas. 

During the development of the various Alternatives, the Refuge conducted three public meetings 

with opportunities for public comments, met with numerous user groups (including three meetings 

with the Washington Waterfowl Association), and provided informational updates on-line and 

through local media outlets. Throughout this process, we received comments from many users 

including, but not limited to, hunters, photographers, birders, and environmental educators. 

Throughout the CCP development, we have sought to provide user groups with compatible recreation 

opportunities while fulfilling our mission to provide high quality habitat for migrating and wintering 

dusky Canada geese, cackling geese, sandhill cranes, and other waterfowl. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan

Appendix N. Comments and Responses N-37

N.16 A.G. Hackett, July 16, 2010

Response 16.

Service Response to A.G. Hackett 

Your comments state that the Draft CCP/EA intends to reduce or eliminate waterfowl hunting at the 

Ridgefield National Wildlife Refuge. Please reference Chapter 2, Features Common to All 

Alternatives, specifically the section titled “Maintain waterfowl hunting opportunities.” This section 

states the refuge will continue to provide, at minimum, its current waterfowl hunting opportunity. 

The location of hunt areas and blinds vary by Alternatives within the Draft CCP/EA. Specifically, 

Goal 2.6.1 identifies a range of alternatives that would maintain or potentially increase acreage of the 

waterfowl hunting area and how the hunting blinds would be relocated to maintain opportunity. 

During the development of the various alternatives, the Refuge conducted public meetings with 

opportunities for public comments, met with numerous user groups (including three meetings with 

the Washington Waterfowl Association), and provided informational updates on-line and through 

local media outlets. The Refuge consulted with the Washington and Oregon Departments of Fish and 

Wildlife. Throughout this process, we received comments from many users including, but not 

limited to, hunters, photographers, birders, and environmental educators. These comments led to 

modifications of the alternatives throughout the development of the plan to try to best meet the needs 

of the various user groups while accomplishing our mission to provide high quality habitat for 

migrating and wintering dusky Canada geese, cackling geese, sandhill cranes, and other waterfowl. 

The refuge recognizes the importance of wildlife-dependent recreation such as hunting and is

committed to providing hunting opportunities. Under the preferred alternative, the waterfowl hunt 

area remains the same as the existing conditions, and the hunter check station would be relocated to 

the current Auto Tour entrance. This will allow the refuge to construct one or two additional hunt 

blinds in the Teal Marsh area to compensate for the loss of blind 4, which would have to be removed 

to safely operate the new bridge and access road. 
Ridgefield National Wildlife Refuge Comprehensive Conservation Plan 

N-38 Appendix N. Comments and Responses
U.S. Department of the Interior

U.S. Fish & Wildlife Service

Ridgefield National Wildlife Refuge

28908 NW Main Ave.

Ridgefield, WA 98642-0457

Phone: 360/887-4106

Fax: 360/887-4109

http://www.fws.gov

National Wildlife Refuge System Information

1 800/344 WILD

September 2010

The mission of the U.S. Fish & Wildlife Service

is working with others to conserve, protect, and

enhance fish, wildlife, and plants and their habitats

for the continuing benefit of the American people.

Cover Photo:

Cackling geese

©Dave Renwald