National Park Service

U.S. Department of the Interior

Natural Resource Program Center

Natural Resource Condition Assessment

Whitman Mission National Historic Site

Natural Resource Report NPS/UCBN/NRR-2009/118
ON THE COVER

Map of Whitman Mission National Historic Site located in southeast Washington with insets of pictures of various sites in the

park. 
Natural Resource Condition Assessment

Whitman Mission National Historic Site

Natural Resource Report NPS/UCBN/NRR-2009/118

Jack Bell

Northwest Management, Inc.

PO Box 9748

Moscow, ID 83843

Dustin Hinson

AMEC Earth and Environmental, Inc.

11810 North Creek Parkway N

Bothell, WA 98011

June 2009

U.S. Department of the Interior

National Park Service

Natural Resource Program Center

Fort Collins, Colorado
ii

The Natural Resource Publication series addresses natural resource topics that are of interest and 

applicability to a broad readership in the National Park Service and to others in the management 

of natural resources, including the scientific community, the public, and the NPS conservation 

and environmental constituencies. Manuscripts are peer-reviewed to ensure that the information 

is scientifically credible, technically accurate, appropriately written for the intended audience, 

and is designed and published in a professional manner.

Natural Resource Reports are the designated medium for disseminating high priority, current 

natural resource management information with managerial application. The series targets a 

general, diverse audience, and may contain NPS policy considerations or address sensitive issues 

of management applicability. Examples of the diverse array of reports published in this series 

include vital signs monitoring plans; monitoring protocols; "how to" resource management 

papers; proceedings of resource management workshops or conferences; annual reports of 

resource programs or divisions of the Natural Resource Program Center; resource action plans; 

fact sheets; and regularly-published newsletters.

Views, statements, findings, conclusions, recommendations and data in this report are solely 

those of the author(s) and do not necessarily reflect views and policies of the U.S. Department of 

the Interior, NPS. Mention of trade names or commercial products does not constitute 

endorsement or recommendation for use by the National Park Service.

This report is available from the Natural Resource Publications Management Web site 

(http://www.nature.nps.gov/publications/NRPM) on the Internet.

Please cite this publication as:

Bell, J., and D. Hinson. 2009. Natural resource condition assessment: Whitman Mission National 

Historic Site. Natural Resource Report NPS/UCBN/NRR-2009/118. National Park Service, Fort 

Collins, Colorado.

NPS 371/100128, June 2009
iii

Contents

Page

Figures........................................................................................................................................... vii

Tables............................................................................................................................................. ix

Executive Summary....................................................................................................................... xi

Acknowledgements...................................................................................................................... xiii

Introduction..................................................................................................................................... 1

Purpose and Scope................................................................................................................... 1

Study Area ............................................................................................................................... 2

Park Setting......................................................................................................................... 2

Historical Setting ................................................................................................................ 4

Land Cover.......................................................................................................................... 5

Upland Habitats/Species..................................................................................................... 8

Watersheds.......................................................................................................................... 8

Aquatic Habitats/Species.................................................................................................. 10

Climate.............................................................................................................................. 10

Methods......................................................................................................................................... 13

GIS and Geodatabases........................................................................................................... 13

NPS Data Sources.................................................................................................................. 15

Noxious Weeds...................................................................................................................... 16

Upland Assessment................................................................................................................ 16

Aquatic Assessments............................................................................................................. 18

Riparian Habitat............................................................................................................... 18

Benthic Macroinvertebrates.............................................................................................. 19

Results........................................................................................................................................... 23
iv

GIS and Geodatabase............................................................................................................. 23

Upland Site Specific Assessments......................................................................................... 23

VRM – B............................................................................................................................ 27

VRM – C1-H3 ................................................................................................................... 29

VRM – C1-H6 ................................................................................................................... 31

VRM – C2-H5 ................................................................................................................... 33

VRM – D3 ......................................................................................................................... 34

VRM – D4c........................................................................................................................ 37

VRM – F2.......................................................................................................................... 39

Aquatic Site Specific Assessments........................................................................................ 41

Doan Creek ....................................................................................................................... 41

Mill Creek ......................................................................................................................... 43

Benthic Macroinvertebrates.............................................................................................. 46

Threats and Stressors .................................................................................................................... 49

Upland Resources.................................................................................................................. 49

Land Use Changes............................................................................................................ 49

Noxious Weeds.................................................................................................................. 49

Aquatic Resources................................................................................................................. 55

Invasive riparian species .................................................................................................. 55

Recreational use................................................................................................................ 55

Water quantity and quality................................................................................................ 55

Fine sediments .................................................................................................................. 55

Land use............................................................................................................................ 56

Climate Change ..................................................................................................................... 56

Summary and Recommendations ................................................................................................. 59
v

Upland Resources.................................................................................................................. 59

Data Gaps............................................................................................................................... 59

Literature Cited ............................................................................................................................. 63

Appendix A – List of NRCA Geodatabase Data by Theme ......................................................... 67

Appendix B – List of Indicators Analyzed to Calculate Landscape Attribute Values. ................ 66

Appendix C List of Plant Species at NRCA Upland Assessment Points .................................... 71

Appendix D: Aquatic Site Properly Functioning Condition Checklists and Invertebrate Site 

Description Forms......................................................................................................................... 73

vii

Figures

Page

Figure 1. Map of WHMI park boundaries. ..................................................................................... 3

Figure 2. Visitor use days per year at WHMI from 1948-2007...................................................... 4

Figure 3. Map of vegetation types for the WHMI project area. ..................................................... 7

Figure 4. Map of the 6th level HUCs forming the project area for WHMI..................................... 9

Figure 5. Map of precipitation zones in the WHMI project area.................................................. 11

Figure 6. Map of average annual temperature zones in the WHMI project area.......................... 11

Figure 7. Screen capture of the ArcMap Project file for the WHMI project area. ....................... 13

Figure 8. Map of the original VRM units in WHMI..................................................................... 23

Figure 9. Map of current VRM units in WHMI............................................................................ 24

Figure 10. Map of soil types at WHMI......................................................................................... 26

Figure 11. Map of VRM-B and NRCA plot 5 in WHMI.............................................................. 28

Figure 12. Departure from reference condition of the 3 landscape attributes in the Alkali Bottom 

15+PZ ecological site at VRM-B, WHMI (background is of plot 5). .......................................... 28

Figure 13. Map of VRM-C1-H3 in WHMI. ................................................................................. 30

Figure 14. Departure from reference condition of the 3 landscape attributes in the Cool Loamy 9-

15PZ ecological site at VRM-C1-H3, WHMI (background is of plot 3). .................................... 30

Figure 15. Map of VRM-C1-H6 in WHMI. ................................................................................. 32

Figure 16. Departure from reference condition of the 3 landscape attributes in the Loamy 9-15PZ 

ecological site at VRM-C1-H6, WHMI (background is of plot 4)............................................... 32

Figure 17. Map of VRM-C2-H5 in WHMI. ................................................................................. 34

Figure 18. Departure from reference condition of the 3 landscape attributes in the Loamy 9-15PZ 

ecological site at VRM-C2-H5, WHMI (background is of plot 7)............................................... 34

Figure 19. Map of VRM – D3 in WHMI...................................................................................... 36

Figure 20. Departure from reference condition of the 3 landscape attributes in the Alkali Bottom 

9-15PZ ecological site at VRM-D3, WHMI (background is of plot 1)........................................ 36
viii

Figure 21. Map of VRM – D4c in WHMI.................................................................................... 38

Figure 22. Departure from reference condition of the 3 landscape attributes in the Wet Meadow 

9-15PZ ecological site at VRM-D4c, WHMI (background is of plot 2). ..................................... 38

Figure 23. Map of VRM – F2 in WHMI. ..................................................................................... 40

Figure 24. Departure from reference condition of the 3 landscape attributes in the Alkali Bottom 

15+PZ ecological site at VRM-F2, WHMI (background is of plot 6).......................................... 40

Figure 25. Map of the Doan Creek assessment reach in WHMI. ................................................. 41

Figure 26. Photograph of the water diversion pump near the mouth of Doan Creek at WHMI... 42

Figure 27. Map of the Mill Creek assessment reach at WHMI. ................................................... 44

Figure 28. Photograph of Mill Creek assessment site at WHMI. ................................................. 45

Figure 29. Graph of treated acres by species at WHMI from 2002-2005..................................... 53

Figure 30. Maps of IPM treatments for weeds by year at WHMI from 2002-2005..................... 54
ix

Tables

Table 1. List of Ecological Systems with acres and percentage found in the WHMI project area. 6

Table 2. Status of inventories of species taxa for WHMI maintained .......................................... 15

Table 3. Status of inventories of non-biological data for WHMI................................................. 15

Table 4. Eastern Oregon Index of Biotic Integrity (IBI) .............................................................. 22

Table 5. Idaho Stream Macroinvertebrate Index (SMI) Impairment Categories.......................... 22

Table 6. Summary of acres and percent of total area for the current and original VRM units in 

WHMI........................................................................................................................................... 25

Table 7. Summary of soil types and ecological reference sites at WHMI.................................... 27

Table 8. Demographics for the Walla Wall County in the WHMI project area. .......................... 49

Table 9. List of noxious and non-native weeds in WHMI with an ‘x’ indicating the source and 

the ranking by the state of Washington......................................................................................... 51

Table 10. Potential impact from selected threats/stressors to the major resources/processes at 

WHMI........................................................................................................................................... 59

Table 11. Matrix of threats/stressors to major resources areas with ratings for potential impacts 

and the knowledge base for estimates in WHMI. ......................................................................... 61

xi

Executive Summary

The Natural Resource Condition Assessment (NRCA) program is designed to give the managers 

of Whitman Mission National Historic Site (WHMI) a point in time assessment of their natural 

resources. The program is designed to better understand and evaluate existing data concerning 

the condition of natural resources within and adjacent to the park. Both aquatic and upland 

habitats will be assessed and treated separately along with identifying threats and stressors; such 

as invasive species, water pollution, and land development; that pose a significant negative 

impact to WHMI’s natural resources. Information gained from this report will form the basis for 

development of actions to reduce and prevent impairment of WHMI’s natural resources and 

assist in the development of Resource Stewardship Plans.

The study identified a project area composed of 3-6th level Hydrologic Unit Code (HUC) 

watersheds with a 2 km buffer. All available geographical information (GIS) was acquired for 

the project area to create an ArcGIS Map Project File and Geodatabase. This product is used to 

make maps and for analysis of geographically based data. All site-specific data was compiled in 

GIS. Upland data is available in the digital database and the aquatic data is attached to this 

report. Maps and pictures were provided for each upland and aquatic sample site along with a 

description of the site and assessment of condition. 

The upland sites sampled were 7 vegetation restoration management units (VRM) originally 

established in 1984. All were evaluated based on the ecological site, as defined by soil type and 

an established reference condition (Pellant 2005). Each sample site received a 5 level rating for 

condition in 3 landscape attributes; soil stability, hydrologic function, and biotic integrity.

Overall, the soil stability and hydrologic function attributes were in good condition, rated noneslight departure from reference conditions. The biotic integrity attribute in several sites were in 

poor condition, rated slight-moderate departure. The main reason for the poor condition was 

attributed to past land use practices and the presence of noxious weeds.

Mill Creek and Doan Creek were selected for site-specific condition status assessments. Sites 

selected for evaluation were assessed using the “proper functioning condition” (PFC) riparian 

assessment methodology developed by the Bureau of Land Management for lotic, flowing water,

(Prichard et al. 1998). Both aquatic sites were rated “Functional-At-Risk.” The poor condition of 

most sites was attributed to one or more of the following threats; water level fluctuations, 

invasive riparian species, recreational use, fine sediment accumulation, and/or land use.

The development of private lands adjacent to the park is a known threat/stressor to the park’s 

natural resources. The population of Walla Walla County has increased by 4.6% over the past 

seven years. However, parcel level data was not available to predict specific areas of concern and 

recommendations are to pursue acquisition of these records through cooperation with the 

County. Noxious weeds currently pose the greatest threat to WHMI natural resources. 

In WHMI 14 noxious or invasive species have been either listed as important or physically 

inventoried the past 24 years. Of these only 2 were not identified in reports reviewed for this 

report. WHMI has identified 6 of these as species of concern and are targeted in there 

management activities. Over 40 noxious weed species have been identified by the Walla Walla 
xii

County Noxious Weed Control Board as high priority for eradication and control. Only 2 species 

have been identified in the park. Accurate mapping of surrounding lands would allow WHMI

staff to be more strategic in the noxious weed management by being prepared for possible new 

invaders and cooperating on control of existing species.

Climate in the Pacific Northwest is predicted to have warmer, wetter winters with an increase of 

3.1° F. by 2030 coupled with a 5% increase in precipitation (Mote et al. 2005). Precipitation is 

predicted to come more in the form of rain with smaller snow packs with seasonal flows shifting

markedly toward larger winter and spring flows and smaller summer and autumn flows. The 43 

sub-basins in the Columbia River basin have their own sub-basin management plans for fish and 

wildlife but none comprehensively addresses reduced summertime flows under climate change.

Possible impacts to ecosystem processes, communities, and/or species can only be address 

through future natural resource planning based on the predicted climate changes.

Of the 21 threats/stressors (6-natural, 15-human-caused) examined 12 could pose potentially 

high impact to one or more of the major resources/processes; soils, hydrologic, biotic, and air. 

Many of these are not directly manageable by park staff, such as the natural disturbances and 

changes that occur outside the park boundary. Several can be directly managed by the park, like 

invasive plants, and visitor use. Others, like rural development, can have their impact moderated 

or mitigated through planning and cooperation with other resource management agencies and 

private land owners.

Overall, WHMI has many future challenges to achieve the stated desired goal for resource 

management (NPS 2000). Results of this report should assist park managers in identifying when, 

where, and how to improve management practices, justify additional resources, and prepare for 

the changes in environment that will directly impact WHMI natural and cultural resources. 
xiii

Acknowledgements

We wish to begin by thanking Roger Trick, Natural Resource Manager at Whitman Mission 

National Historic Site, for his time and courteous help in all stages of the project. Mr. Trick was 

extremely helpful providing us with valuable background information and was very open in 

sharing his many years of knowledge about the site. Gerald Ladd of AMEC provided great 

assistance in field work. Vaiden Bloch, GIS Specialist, with Northwest Management, Inc. was 

invaluable in preparing the Geodatabase and map project files. We would like to thank the many 

staff at Northwest Management, Inc. for their edits and insightful comments on the manuscript, 

especially Diane Corrao, Administrative Manager. Finally, we are very thankful for all the 

support and help from Lisa Garrett, NPS Upper Columbia Basin Network, and Jason Lyon, NPS 

Nez Perce National Historical Park. They had the vision to develop and implement this project 

and the professionalism and dedication to guide it to completion. 

1

Introduction

Purpose and Scope 

The mission of the National Park Service is “to conserve unimpaired the natural and cultural 

resources and values of the national park system for the enjoyment of this and future 

generations” (National Park Service 1999) To uphold this goal, the Director of the NPS approved 

the Natural Resource Challenge to encourage national parks to focus on the preservation of the 

nation’s natural heritage through science, natural resource inventories, and expanded resource 

monitoring (National Park Service 1999). Through the challenge, 270 parks in the national park 

system were organized into 32 inventory and monitoring networks.

The Upper Columbia Basin Network (UCBN) consists of nine widely separated NPS units 

located in western Montana, Idaho, eastern Washington, and central Oregon. Parks of the Upper 

Columbia Basin Network include: Big Hole National Battlefield (BIHO), City of Rocks National 

Reserve (CIRO), Craters of the Moon National Monument and Preserve (CRMO), Hagerman 

Fossil Beds National Monument (HAFO), John Day Fossil Beds National Monument (JODA), 

Lake Roosevelt National Recreation Area (LARO), Minidoka Internment National Monument 

(MIIN), Nez Perce National Historical Park (NEPE), and Whitman Mission National Historic 

Site (WHMI).

As part of the Natural Resource Challenge, the NPS Water Resources Division received an 

increase in funding to assess natural resource conditions in national park units. Management 

oversight and technical support for this effort is provided by the division’s Watershed Condition 

Assessment (WCA) Program. The WCA Program partnered with the Pacific West Region to 

fund and oversee an assessment at each park in the Upper Columbia Basin Network (UCBN). 

This report documents the results of the Natural Resource Condition Assessment (NRCA) 

completed for Whitman Mission National Historic Site (WHMI). 

Natural resource condition assessments are broad-scope ecological assessments intended to 

develop synthesis “information products” readily usable by park managers for: a) resource 

stewardship planning, and b) reporting to performance measures such as the DOI Strategic Plan’s 

“land health” goals. Three elements are key to making these assessments useful for both 

planning and performance reporting: 

1. Build on data, information, and knowledge already assembled through efforts of the 

NPS I&M Program, other NPS science support programs, and from partner 

collaborators working in and near parks;

2. Emphasize a strong geospatial component for how the assessment is conducted and in 

the resulting information products;

3. Provide narrative and/or semi-quantitative descriptions of science-based reference 

conditions for park resources that will assist parks as they work to define Desired Future 

Conditions through park planning processes. These reference conditions will become 

more refined and quantitative over time. 
2

Information gained from this report will form the basis for development of actions to reduce and 

prevent impairment of park resources through park and partnership efforts. The goals of the 

natural resource condition assessment are to:

• Determine the state of knowledge concerning overall natural resource condition

• Identify information gaps and resource threats

• Assess overall ecosystem health

• Sets the stage to establish the context for management actions and collaboration

This report is designed to give park staff a moment-in-time assessment of the natural resources 

of Whitman Mission National Historic Site. This report will describe the natural resources of the 

park (both aquatic and upland), determine the state of knowledge on their condition using 

existing data or new data collected at priority sites for this project, identify information gaps, 

draw conclusions or hypotheses on the condition of natural resources (unknown, degraded, 

unimpaired), identify resource threats or potential issues affecting ecosystem health, and 

recommend further studies. 

Study Area

Park Setting

WHMI was established in 1936 to preserve the 98.15 acre site (Figure 1) of a mission founded in 

1836 by Marcus and Narcissa Whitman among the Cayuse Indian people of the Inland Pacific 

Northwest. The site was the first American settlement in the Pacific Northwest and became an 

important way station along the Oregon Trail. WHMI is located at the southern extreme of the 

Palouse Prairie region of southeastern Washington approximately 7 miles west of Walla Walla, 

Washington. The topography is generally flat with the elevation ranging from 615’ to 724’ at the 

top of Memorial Hill.

Resource management at this site is dedicated to preserving the archeological, historical and 

landscape values associated with the original Whitman Mission during the time from 1836 to 

1847. These include native vegetation and landscape features that existed during the occupation 

of the mission.

The general management plan for WHMI has 2 major objectives (NPS 2000). The first is to 

protect and preserve the cultural and natural resources of the Whitman Mission. Strategies to 

achieve this objective include: 

• Inventory cultural and natural resources.

• Manage, update, and maintain the park’s resource information database (includes GIS).

• Manage and protect park collections and archives

• Manage and protect park structural landscape component, including monuments, graves, 

and landscape features.

• Implement and sustain a cultural and natural resource program.

• Implement a monitoring program.

• Use IPM/fire to protect park resources.
3

Figure 1. Map of WHMI park boundaries.
4

The second major objective listed in the general management plan is to restore and preserve the 

park’s natural resources, including riparian and wetland areas, and the cultural landscape. 

Strategies listed to achieve this objective include:

• Identify options for Doan Creek and irrigation ditch management and implement the 

selected option.

• Manage vegetation.

• Collaborate with other federal and state agencies in the protection of hydrologic and 

aquatic resources.

WHMI visitation at the park reached a high of 151,800 visitor days in 1976 and has slowly been 

decreasing since to a recent low of 49,337 in 2007 (Figure 2). Visitor days/year has averaged 

63,065 over the past 10 years. There is no over-night camping at WHMI so visitor use is limited 

to day use.

Historical Setting

The Cayuse people were the original inhabitants in the lands surrounding the WHMI. This land 

was called Wai-i-lat-pu, “Place of the People of the Rye Grass.” The Cayuse practiced very little 

crop agriculture, depending instead on a partially nomadic existence that emphasized food 

gathering, raising livestock in the form of horses, and salmon fishing. Fire was used periodically 

by the Cayuse to burn particular areas to increase the production of wild forage and accessibility 

of plant foods, to facilitate hunting and travel. The regularity with which the areas on or near the 

historic site were burned historically cannot be determined, but frequent cultural burning of any 

particular area was probably rare.

WHMI was the first permanent Euro-American settlement in the Inland Northwest. In 1836, Dr. 

Marcus and Narcissa Whitman, along with the Reverend Henry and Eliza Spalding, were sent by 

the American Board of Commissioners for Foreign Missions to minister among the Indians in the

Northwest. The Whitmans established the mission on a large triangle of flat, fertile land formed 

by the Walla Walla River and a tributary, Mill Creek. The Mission was occupied until 1847, 

when the Whitmans and 11 others were killed in an uprising by the Cayuse. 

Figure 2. Visitor use days per year at WHMI from 1948-2007.
5

WHMI is managed as a historical park to preserve 5 major purposes.

1. Document and preserve the establishment of Whitman Mission and the subsequent 

massacre as important events in western pioneer history and settlement. 

2. Tell the story of Whitman Mission as a clash between two cultures and their lack of 

understanding and ability to solve problems peacefully. One culture a white, American 

missionary society and the other, the native culture of the Cayuse

3. Preserve the site of Whitman Mission as an important component of the Oregon Trail. 

The Mission was one of seven aid stations along the trail and provided an important 

respite for emigrants during the early years of the Oregon Trail.

4. To document and memorialize the massacre of the Whitmans and eleven others, which 

lead to an unsuccessful end of the Mission and led to a war between the militia and the

Cayuse in 1848.

5. Preserve the Mission Grounds, the site of the Great Grave, and the memorials to the

Whitmans.

It is likely that the Cayuse used the resources at the site at least periodically for centuries before 

the mission was established. Archeological evidence of modification of natural conditions has 

not been documented. However, soon after the mission was established, an irrigation system was 

developed, crops were planted, and areas were opened to grazing by draft livestock and cattle. A 

considerable number of stock animals moved through the mission from the Oregon Trail, and 

there was ample opportunity for the introduction of exotic plants. The changes that occurred to 

the plants and landscape during the time the mission was extensive; the introduction of domestic 

livestock, exotic plants and agriculture, and the removal of riparian vegetation for fire and 

building wood.

Land Cover

WHMI is located on the southern extreme of the Palouse Prairie Region. Originally, perennial 

bunch grasses flourished in swards over the rolling prairie. Large native herbivores were 

generally absent from the Palouse, and because of this, the grasses evolved with a low resistance 

to grazing. Subsequent grazing by domestic livestock and extensive cultivation for wheat are the 

main reasons native perennial grasslands are now rare on the Palouse prairie.

It is probable that in 1836 at the time the mission was established, a mixture of three plant 

communities occupied the site (Romo and Krueger 1985). The Walla Walla River flowed 

through the site during times of high water. The floodplains along the Walla Walla River and 

nearby Mill Creek were dominated by a narrow plant community consisting of dense tangled 

thickets of willows (Salix spp.), black cottonwood (Populus balsamifera ssp. trichocarpa), redosier dogwood (Cornus stolonifera), blackberries (Rubus spp.), elderberry (Sambucus cerulea), 

and other species common to riparian communities. Intermixed throughout the site was giant 

wild ryegrass (Leymus cinereus) a species preferring a year-round supply of soil moisture and 

occurring primarily on clay bottomlands and seepage areas. It now occurs as scattered large 

bunches of grass, but historically, it may have been more extensive and is the basis for the 

Cayuse name “Wai-i-lat-pu.” Bluebunch wheatgrass (Pseudoroegneria spicata) and Sandberg’s 

bluegrass (Poa secunda) dominated the higher elevation and drier sites.
6

WHMI has 190 plant specimens documented in their herbarium and currently there are no known 

federally listed threatened or endangered plant species, list available at website 

http://science.nature.nps.gov/im/units/ucbn/inventory/index.cfm#table.

Vegetation data was available from the LANDFIRE Program (USFS and USGS 2008). The 

vegetation map was created through a predictive modeling approach using a combination of field 

reference information, 2000 Landsat imagery, and spatially explicit biophysical gradient data.

Map units are derived from National Vegetation Classification System (NVCS) Ecological 

Systems classification (Comer et.al. 2003). The data was clipped by the watershed boundaries

(described in the following section “Watersheds”), then summarized by class (Table 1), and 

mapped (Figure 3) for the 68,271 acre WHMI watershed area.

Table 1. List of Ecological Systems with acres and percentage found in the WHMI project area. 

NVCS Ecological Systems Acres Percentage

Agriculture-Cultivated Crops and Irrigated Agriculture 20,415 29.90%

Agriculture-Pasture/Hay 30,095 44.08%

Columbia Basin Palouse Prairie 291 0.43%

Columbia Plateau Steppe and Grassland 817 1.20%

Developed-High Intensity 191 0.28%

Developed-Low Intensity 5,299 7.76%

Developed-Medium Intensity 2,128 3.12%

Developed-Open Space 5,548 8.13%

Inter-Mountain Basins Big Sagebrush Shrubland 979 1.43%

Inter-Mountain Basins Big Sagebrush Steppe 559 0.82%

Inter-Mountain Basins Mixed Salt Desert Scrub 86 0.13%

Inter-Mountain Basins Montane Riparian Systems 748 1.10%

Introduced Upland Vegetation-Annual Grassland 500 0.73%

Northern Rocky Mountain Dry-Mesic Montane Mixed Conifer Forest 129 0.19%

Northern Rocky Mountain Ponderosa Pine Woodland and Savanna 167 0.25%

Rocky Mountain Montane Riparian Systems 317 0.46%

The land cover within the 3 watersheds of the WHMI project area is dominated by agriculture 

(73.98%). The project area has a significant developed land use type (11.16%) due mainly from 

the town of Walla Walla and the surrounding communities. There is 8.13% of the project area in 

rural development, ‘Developed-Open Space.’ The balance of land (6.93%) in the project area is 

classified as native and non-native dominated grass, shrub, and tree dominated vegetation, which 

is found mainly in the higher elevations of the watersheds.
7

Figure 3. Map of vegetation types for the WHMI project area.
8

Upland Habitats/Species

Wildlife at WHMI is represented primarily by a variety of small rodents. Twenty-seven mammal 

species were confirmed during a 2003 inventory (Rodhouse et al. 2003). The most common 

mammals are cottontail rabbit (Sylvilagus spp.), voles (Microtus spp.), deer mice (Peromyscus 

maniculatus), western harvest mice (Reithrodontomys microps) and northern pocket gopher 

(Thomomys talpoides). Also present are feral house cats, which can be serious predators on small 

rodents and migratory passerine birds. Bird surveys documented 202 species at WHMI 

(Rodhouse et al. 2003). Of the 202 observed bird species 85 were unexpected and not previously 

documented at WHMI. There are no federally listed species known to use or occasionally pass 

through the WHMI. A complete list of mammal, bird, reptile, and amphibian species can be 

found on the UCBN website; 

http://science.nature.nps.gov/im/units/ucbn/inventory/index.cfm#table. 

A total of 3 amphibians and 5 reptiles were documented at WHMI during 2002 (Rodhouse et al. 

2003). Bullfrogs are abundant around the Millpond, Mill Creek, and along the irrigation channel. 

Common garter snakes, gopher snakes and painted turtles have been observed at various 

locations throughout the site. The 2002-2003 inventories confirmed for the first time the 

occurrence of the great basin spadefoot (Spea intermontana) toad.

WHMI has non-native plants in all areas of the park. By 1985, a major emphasis in maintenance 

at the site was on revegetation and the control of non-native plant species (Gilbert 1984, Romo 

and Krueger 1985). Since that time, vegetation management has converted 60% of the site from 

exotic grasses and weeds to grasses that grew in the area during Whitman’s era, or to grasses that 

have the same appearance as the native grasses. These native-appearing grasses will gradually be 

replaced with native species. In 1994, a vegetation plan was developed and implemented for 

Doan Creek and the surrounding area (NPS 2000). In 1997, NPS staff conducted an inventory of 

exotic plant species identified the following six species of concern: field bindweed (Convolvulus 

arvensis), jointed goatgrass (Aegilops cylindrica), poison hemlock (Conium maculatum), yellow 

starthistle (Centaurea solstitialis), Canada thistle (Cirsus Canadensis), and Scotch thistle

(Onopordum acanthium) (NPS 2000). 

Watersheds

River and stream drainages are uniquely identified by hydrologic unit codes (HUC). These are 

geographic areas based on surface topography containing a major river or a group of smaller 

rivers identified by 2 digits representing each level, for a total of 12 digits to describe the lowest 

level (HUC6). The Pacific Northwest is number 17 of the 21 regions (HUC1) in the United 

States. The second level divides the 21 regions into 222 subregions. Subregions are areas drained 

by a river system, a reach of a river and its tributaries, a closed basin, or a group of streams 

forming a coastal drainage area. The third level subdivides the subregions into 352 basins and at 

HUC4 there are 2,149 drainages, referred to as subbasins. 

WHMI is located in the Walla Walla River subbasin (HUC4 – 17070102), which drains an area 

of 1,758 square miles. WHMI lies near the intersection of 3 – 5th level HUCs; Middle Walla 

Walla River (1707010207), Mill Creek-Walla Walla River (1707010202), and Lower Walla 

Walla River (1707010211). Figure 4 is a map of the 3 – 6th level HUC’s that form the project 

area for WHMI; Lower Mill Creek (170701020204), Garrison Creek-Walla Walla River 

(170701020704), and Mud Creek-Walla Walla River (170701021102). 
9

Figure 4. Map of the 6th level HUCs forming the project area for WHMI.
10

Aquatic Habitats/Species

Approximately ten acres of the WHMI is wetland, but not formally classified as such in any 

documents published by NPS, U.S. Army Corps of Engineers, National Wetlands Inventory, or 

Natural Resource Conservation Service. While there are no springs within WHMI, there are 

distinct former stream channels of Doan Creek and the Walla Walla River, which hold water in 

winter and spring. There is a wetland enhancement project planned by WHMI staff to unchannel 

Doan Creek along the northern boundary to allow more water to meander, creating more wetland 

habitat. The U.S. Army Corps of Engineers purchased land that borders the south boundary of 

the NHS and the north bank of the Walla Walla River. The State Department of Fish and 

Wildlife is administering this land as

riparian habitat.

Surface water resources at WHMI include Mill Creek, Doan Creek, the Millpond, and an

irrigation ditch. Mill Creek originates on the western slopes of the Blue Mountains, in 

southeastern Washington, at an elevation of 5,500 feet (USACE 1995). It flows for 15 miles in a 

relatively deep and narrow canyon, through mountainous terrain, and then enters an alluvial fan a 

few miles east of the City of Walla Walla. Mill Creek flows through the northern corner of the 

WHMI property where it collects streamflow from Doan Creek then enters the Walla Walla 

River about 1⁄2 mile west of WHMI. 

Doan Creek is a left bank, spring-fed tributary of Mill Creek. Doan Creek originates three miles 

east of the WHMI and passes through a private airport, a former dairy, and agricultural land 

before entering the site at the northeastern boundary. From there, Doan Creek runs through a 

restored channel continuing west along the northern boundary until joining with Mill Creek. An

irrigation water pumping station draws water out of Doan Creek into the irrigation ditch that 

supplies water to the park and to two downstream irrigators.

Washington Department of Fish and Wildlife (WDFW) has documented habitat for 

rainbow/steelhead trout (Oncorhynchus mykiss), speckled dace (Rhinichthys osculus), redside 

shiner (Richardsonius balteatus), 3 species of sculpins (Cottus spp.), and common carp

(Cyprinus carpio) in Doan Creek (NPS 2003). WDFW also anticipates that the restored habitat 

on the WHMI property can support Chinook salmon Oncorhynchus tshawytscha and coho 

salmon Oncorhynchus kisutch.

The historic Millpond covers about two and one-half acres and is held by earthen dikes. The 

Millpond was restored in 1961, and is located on the eastern end of the mission grounds. The 

irrigation channel from Doan Creek supplies the Millpond with water. Marcus Whitman is 

credited with establishing the first irrigation ditch in this area. At least one irrigation ditch has 

crossed the mission grounds since Whitman’s time. Currently, WHMI is responsible for 

maintaining 5,967 feet of irrigation ditch in accordance with Washington State law. The current 

irrigation ditch provides water for two farms to the west. 

Climate

For the past 50 years the annual precipitation at Walla Walla Airport averages 19.34”/yr with 

17.2” of snow during the winter months . The daily temperature varies as much as 40 degrees 

during the summer (Western Regional Climate Center, 2003). Mean monthly 
11

minimum/maximum temperatures ranges from 27.8°/39.5° F in January to 60.4°/89.2° F in July. 

Prevailing winds year around come from the southwest. Figure 5 and 6 shows the distribution of 

precipitation and average annual temperature zones within the WHMI project area, respectively.

Figure 6. Map of average annual temperature zones in the WHMI project area.

Figure 5. Map of precipitation zones in the WHMI project area

13

Methods

GIS and Geodatabases

The majority of data used in this report is Geographical Information System (GIS) data in tabular 

form tied to spatial features, such as points, lines, and/or polygons. GIS software provides spatial 

analysis capabilities such as overlay, buffer, extraction, and modeling. Results can then be 

displayed in map and tabular form. GIS software ARCMap Version 9.3 was used to store, edit, 

and display data.

A map project file was developed for WHMI using ArcMap software that followed the 

behavioral rules for data in a single Microsoft Access database (Figure 7). Many types of

geographic datasets can be collected within a map project file, including feature classes, attribute 

tables, and raster data sets. The NPS ArcMap 81⁄2 ”x11” template was used in the WHMI map 

project file.

Figure 7. Screen capture of the ArcMap Project file for the WHMI project area.
14

A geographically defined project area was created by selecting 6th level HUC watersheds 

surrounding WHMI. A 2 kilometer buffer was added for mapping purposes (140,344 ac). 

General base map layers and aerial photography were developed to the full project area extent. 

Most layers were clipped to the watershed basin extent for analysis and summarization of 

attributes (68,653 ac).

The map project file was populated with GIS data through an extensive search of NPS sources 

and a multitude of local, state, and federal web sites. Data determined to be useful and accurate 

were re-projected into the North American Datum 1983 (NAD83) and the Universal Transverse 

Mercator (UTM) zone 11 projection. Metadata was generated for each layer in Federal 

Geographic Data Committee (FGDC) compliant format. Metadata describes the source, 

accuracy, data dictionary, projection, datum, and many other details about an individual layer.

Aerial photography was processed and clipped to the project area using LizardTech GeoExpress 

software and converted into a MG3 (MrSid Generation 3) format file. 

Attribute information on the specific data layers clipped to the watershed basin extent were 

summarized in a spreadsheet based on the various attribute parts, lengths, acreage, etc. of the 

various data layers in the map project file.

All GIS data layers were imported into an ArcGIS File Geodatabase using ArcCatalog ver. 9.3 

(ESRI 2006). Feature data sets were created based on theme type. A geodatabase is an ArcMap 

file structure that stores geometry, spatial reference system, attribute datasets, network datasets, 

topologies, and many other features. This GIS format provides a uniform method for storing and 

using GIS data and provides the flexibility to add new information as it becomes available.

Map layers were organized into categories based on general theme type. Although data was not 

available for each theme type, the category directory is included to incorporate data that may 

become available in the future. The general themes used include:

• Air Resources

• Animal

• Geography

• Geology

• Land Process

• Land Use

• Plant

• Stressors

• Water Resources

• Climate

Aerial photography was not included in the geodatabase due to limitation in the processing of 

MG3 file formats. Aerials are included in a separate directory outside the geodatabase. All the 

data, project file and summary table are included on a DVD disk for distribution with this report. 

As a by-product of the search for GIS compatible data, a Microsoft Access database (included on 

DVD) was created for websites with documented GIS data that could be downloaded in various 

formats and is compatible with ESRI’s ArcMap software. The database has a custom query form 

for doing searches on the 3,000+ entries that cover 3 states; Oregon, Washington, and Idaho.
15

NPS Data Sources

Additional non-GIS data was acquired from searches on the internet, such as NPS NatureBib 

(https://science1.nature.nps.gov/naturebib), and from direct contact with local and state 

government agencies. WHMI is in the Upper Columbia Basin Network (UCBN) established 

under the NPS Inventory and Monitoring Program (NPS 1999). Table 2 is the status of 

inventories of the species taxa groups for WHMI. Available data from completed inventories 

were utilized where needed in the report otherwise, the data is directly available at the UCBN 

website http://science.nature.nps.gov/im/units/ucbn/inventory/index.cfm#table. Invasive plant 

species inventories, a subset of vascular plant inventories, are in progress, however no 

inventories are available for fish, invertebrates, or rare plants.

Table 2. Status of inventories of species taxa for WHMI maintained

by the UCBN.

Species Taxa Complete

Year 

Completed

In 

Progress

Not 

Complete

Mammals √ 2003

Birds √ 2003

Amphibians √ 2003

Reptiles √ 2003

Fish √

Invertebrates √

Vascular Plants √ unknown

Rare Plants √

Invasive Plants √

Additional non-biological data sets have been identified by the UCBN as important for park 

management (Table 3). Both the biologic and non-biologic inventories were considered as 

baseline information for development of the UCBN vital signs monitoring plan (Garrett et al. 

2007). Three data sets have not been completed by the UCBN however some park sites may 

have data available from other sources. 

Table 3. Status of inventories of non-biological data for WHMI

maintained by the UCBN.

Non-Biologic Data 

sets Complete

Year 

Completed

In 

Progress

Not 

Complete

Air Quality/Emissions √

Ozone Risk √ 2001

Water Quality √ 1997

Landcover √

Paleo Resources √ 2005

Geology √ 2008

Soils √

Cultural Landscapes √

The UCBN Monitoring Plan (Garrett et al. 2007) identifies a suite of 14 vital signs chosen for

monitoring implementation in the UCBN parks over the next 5 years. Vital signs are “a subset of 
16

physical, chemical, and biological elements and processes of park ecosystems that are selected to 

represent the overall health or condition of park resources with known or hypothesized effects of 

stressors, or elements that have important human values” (NPS-UCBN 

http://science.nature.nps.gov/im/monitor/). Not all vital signs are monitored at each park. WHMI 

has 7 vital signs established for monitoring; stream/river channel characteristics, surface water 

dynamics, water chemistry, aquatic macroinvertebrates, invasive/exotic plants, riparian 

vegetation, and land cover and use (Garrett et al. 2007).

Noxious Weeds

Noxious weeds of importance to WHMI were identified in Garrett et al. 2007. A complete list of 

Washington’s noxious weeds can be found at http://www.nwcb.wa.gov/weed_list/weed_list.htm. 

They are classified into 3 categories based on control requirements; Class A (eradicate), Class B 

(contain) and Class C (control). GIS data on noxious weeds was extracted from a geodatabase 

developed by the UCBN for management of the parks integrated pest management (IPM). The 

geodatabase was maintained for 4 years from 2002-2005. Summary statistics by species and 

maps were developed from the data. State and county level databases were searched for noxious 

weed locations and the Walla Walla County weed superintendent was contacted for unpublished 

data. Available data have been summarized on maps and tables in the Results section. 

Upland Assessment

Vegetation Restoration Management Units (VRM ) for WHMI were first developed by Gilbert 

(1984), later refined by Romo and Krueger (1985), then documented by Garrett and Coyner 

(2003). The VRM units are the basic management unit for WHMI staff and are used for the site 

specific assessment. The assessment method was co‐developed by the Natural Resources 

Conservation Service (NRCS), Agricultural Research Service (ARS), Bureau of Land 

Management (BLM), and the United States Geological Survey (USGS). The method is described 

in the publication “Interpreting Indicators of Rangeland Health” (Pellant et al., 2005). 

Site specific data was collected on August 15, 2008. A complete list of plant species was not 

attempted due to the time of year. Plant species identification followed the species list found at 

the UCBN website, http://science.nature.nps.gov/im/units/ucbn/inventory/index.cfm#table. 

Appendix C is a complete list of all species identified at each plot with percent canopy cover. 

The rangeland health rapid assessment methodology was designed to provide a preliminary 

evaluation of 3 landscape attributes; soil/site stability, hydrologic function, and integrity of the 

biotic community at the ecological site level. It was developed to assist land managers in 

identifying areas that are potentially at risk of degradation and assist in the selection of sites for 

developing monitoring programs. Definitions of these three closely interrelated attributes are:

Soil Site Stability: The capacity of the site to limit redistribution and loss of soil resources 

(including nutrients and organic matter) by wind and water.

Hydrologic Function: The capacity of the site to capture, store, and safely release water 

from rainfall, run‐on (inflow), and snowmelt (where relevant), to resist a reduction in this 

capacity, and to recover this capacity following degradation.

Integrity of the Biotic Community: The capacity of the site to support characteristic 

functional and structural communities in the context of normal variability, to resist loss of

this function and structure due to disturbance, and to recover following disturbance.
17

This technique was developed as a tool for conducting a moment-in-time qualitative assessment 

of rangeland status and as a communication and training tool for assisting land managers and 

other interested people to better understand rangeland ecological processes and their relationship 

to indicators (Pyke at. el. 2002) This method uses soil survey information, ecological site 

descriptions, and appropriate ecological reference areas to qualitatively assess rangeland health. 

As part of the assessment process, 17 indicators relating to these attributes are evaluated and the 

category descriptor or narrative that most closely describes the site is recorded. “Optional 

Indicators” may also be developed to meet local needs. The critical link between observations of 

indicators and determining the degree of departure from the ecological site description and/or 

ecological reference area is part of the interpretation process.

This technique does not provide for just one rating of rangeland health, but is based upon a 

“preponderance of evidence” qualitative approach. It rates each site in the departure from the 

ecological site description/ecological reference area(s) for the three attributes: soil site stability, 

hydrologic function, and biologic integrity. There are 5 categories of departure recognized,

“none to slight,” “slight to moderate,” “moderate,” “moderate to extreme,” and “extreme.”

A slight modification of the methodology was implemented because the park has been under a 

revegetation program since 1985 and all areas of the park have been heavily utilized for farm or 

grazing in the past as documented in Garrett and Coyner (2003). The objective of the WHMI 

general management plan (NPS 2000) is to maintain the visual aspect of the historic period at the 

time the Whitman Mission was active. The plan calls for revegetation using both native and nonnative species along with noxious weed management. Past land management practices have left

WHMI in various states of recovery. The evaluation of indicators 10, 12, 13, 14, 15, and 17 were 

based on the desired vegetation identified for each VRM in Gilbert (1984).

Indicators were converted to a numerical rating to allow calculating a percent departure value. A 

rating from 1 (none to slight) to 5 (extreme) was assigned to the 5 evaluation categories. There 

are 10 indicators for soil site stability and hydrologic function and 9 for biotic integrity. The 

score for each landscape attribute was the sum of the indicators minus the reference conditions;

which was determined to be 10 for soil site stability and hydrologic function and 9 for biotic 

integrity based on a score of 1 for each indicator per attribute. Percent departure for each 

attribute was a proportion calculated by dividing the score by the maximum departure value,(40 

for soil stability and hydrologic function and 35 for biotic integrity) and expressed as a 

percentage. The results are displayed graphically as a percent departure from the reference 

condition. For the narrative the percent departure values are converted back into the associated 

qualitative categories: none to slight (<20%), slight to moderate (20-39%), moderate (40-59%), 

moderate to extreme (60-79%), and extreme (>80%).

A Microsoft Access database was developed for digitally storing site data, comments, and the 17 

indicator values. A GPS point was collected at the center of each sample site along with 4 digital 

pictures taken facing the cardinal directions. Sample sites varied from 1 to 20 acres in size as 

noted in the database. Maps were generated for each VRM depicting evaluation sites and other 

land features. The point data was also placed in the geodatabase for future reference. 
18

Aquatic Assessments

Evaluation of onsite aquatic resources at WHMI included an assessment of the riparian resource 

condition of Doan Creek and Mill Creek and an assessment of the in-stream condition of Mill 

Creek based upon benthic macroinvertebrate indicators. Benthic macroinvertebrates were not 

collected from Doan Creek due to the lack of stream flow during the onsite evaluation.

Riparian Habitat

Riparian habitat serves many functions, including erosion control, stream shading and cooling, 

providing woody debris, insect production, and stream bank stabilization. Riparian areas often 

contain the greatest resource diversity and productivity in the watershed (Barber 2005). Riparian 

areas serve as a buffer between aquatic habitat (e.g., streams and rivers) and upland activities. In 

addition, these areas often contain wetlands where water is filtered, retained, and slowly released 

to the river throughout the year.

Mill Creek and Doan Creek were assessed using the “proper functioning condition” (PFC) 

riparian assessment method developed by the Bureau of Land Management (Prichard et al. 

1998). The PFC method evaluates 17 hydrology, vegetation, and stream geomorphology 

indicators of riparian condition or “health” and subsequently assigns a functionality rating to 

each site.

The “proper functioning condition” of a riparian area refers to the stability of the physical 

system, which in turn is dictated by the interaction of geology, soil, water, and vegetation. A 

properly functioning riparian area is in dynamic equilibrium with its streamflow forces and 

channel processes. The channel adjusts in slope and form to handle larger runoff events with 

limited perturbation of channel characteristics and associated riparian/wetland plant 

communities. Because of this stability, properly functioning riparian areas can maintain fish and 

wildlife habitat, water quality enhancement, and other important ecosystem functions even after 

larger storms. In contrast, nonfunctional systems subjected to the same storms might exhibit 

excessive erosion and sediment loading, loss of fish habitat, loss of associated wetland habitat, 

and so on.

Based on assessments of the hydrologic, vegetative, and geomorphology elements of the riparian 

area, one of the following three functionality ratings is assigned to each site:

Proper Functioning Condition (PFC): Streams and associated riparian areas are functioning 

properly when adequate vegetation, landform, or large woody debris is present to:

1. Dissipate stream energy associated with high waterflows, thereby reducing erosion and 

improving water quality.

2. Filter sediment, capture bedload, and aid floodplain development.

3. Improve floodwater retention and groundwater recharge.

4. Develop root masses that stabilize stream banks against cutting action.

5. Develop diverse ponding and channel characteristics to provide habitat and the water 

depths, durations, temperature regimes, and substrates necessary for fish production, 

waterfowl breeding, and other uses.

6. Support greater biodiversity.
19

Functional‐At Risk: These riparian areas are in functional condition, but an existing soil, water, 

vegetation, or related attribute makes them susceptible to degradation. For example, a stream 

reach may exhibit attributes of a properly functioning riparian system, but it may be poised to 

suffer severe erosion during a large storm in the future due to likely migration of a headcut or 

increased runoff associated with recent urbanization in the watershed. When this rating is 

assigned to a stream reach, its “trend” toward or away from PFC is assessed.

Nonfunctional: These are riparian areas that clearly are not providing adequate vegetation, 

landform, or large woody debris to dissipate stream energy associated with high flows, and thus 

are not reducing erosion, improving water quality, sustaining desirable channel and riparian 

habitat characteristics, and so on as described in the PFC definition. The absence of certain 

physical attributes such as a floodplain where one should exist is an indicator of nonfunctioning 

conditions.

PFC assessment does not refer to the successional stage of the riparian‐wetland vegetation 

community (Biggam et al. 2005). Rather, the evaluation is based on the concept that in order to 

manage for such things as potential natural vegetation communities or desired fish and wildlife 

habitat features, the basic elements of physical stability (e.g., energy dissipation and streambank 

stabilization) must first be in place and functioning properly. For example, a vegetation 

community recovering from a recent fire may be in an early successional stage due to loss of 

trees and shrubs, but that stage may still provide sufficient physical stability for the riparian area 

to accommodate flood flows without significant erosion and channel change. That 

geomorphically stable and “properly functioning” condition allows for recovery of the desired 

features of later successional systems such as in-channel woody debris that creates desired fish 

habitat or riparian tree and shrub layers that provide diverse bird habitats.

During this site visit, the team assessed riparian functional condition on reaches of Mill Creek 

and Doan Creek within WHMI. The stream reach assessments are discussed individually below, 

and each assessment is supported by a detailed PFC assessment checklist in Appendix A.

Benthic Macroinvertebrates

Benthic macroinvertebrates (BMI) are well suited for biomonitoring assessments within rockysubstrate stream habitats for several reasons (Morley 2000; Fore et al. 1996):

1. The macroinvertebrate community is extremely diverse, represented by thousands of 

different species with a variety of feeding strategies.

2. The pollution tolerance levels of macroinvertebrates range from very high to very low.

3. Sampling macroinvertebrates can be performed with relative ease by a single individual 

with simple equipment.

4. The aquatic life spans of macroinvertebrates range from several weeks to several years, 

which provides an indication of stream quality over a period of time, not just the 

sampling window.

5. Unlike fish, macroinvertebrates are fairly limited in mobility, meaning they cannot avoid 

polluted areas. The adults will lay the eggs where they may and the benthic larvae are 

dependent upon the water quality and habitat to survive.

6. The methods for collecting, subsampling, preserving, and identifying macroinvertebrates 

are well established, facilitating comparison of data between sites.
20

7. Macroinvertebrates can be found in any aquatic habitat as long as the water quality is 

high enough to sustain them.

8. Macroinvertebrate communities can recover rapidly from repeated sampling events, 

providing the ability for repeated sampling.

Channel characteristics were observed and BMI samples were collected in the Mill Creek stream 

reach flowing through the northwest corner of the Whitman Mission property on May 14, 2008.

A Surber sampler was used to collect three replicate BMI samples in a single, uniform riffle 

habitat unit within the creek. A Surber sampler was selected to collect BMI because it allows 

sampling a uniform 1-square-foot (144 square inch) area. Sampling began in the downstream 

portion of the riffle and proceeded upstream for the three replicates. At each replicate sampling 

location the following methodology was used:

1. Place Surber sampler on the selected sampling spot with the opening of the nylon net 

facing upstream. Brace the frame and hold it firmly on the creek bottom.

2. Lift the larger rocks resting within the frame and brush off crawling or attached loosely 

organisms so that they drift into the net.

3. Once the larger rocks are removed, disturb the substrate vigorously with a trowel or small 

rake for 60 seconds. This disturbance should extend to a depth of about 10 cm to loosen 

organisms in the interstitial spaces, washing them into the net.

4. Lift Surber out of the water. Tilt the net up and out of the water while keeping the open 

end upstream. This helps to wash the organisms into the receptacle.

5. On the creek bank, empty contents of Surber into large bucket. Rinse Surber and empty 

into bucket until all animals are removed. Great care should be taken in this step to 

collect and preserve all organisms from the Surber sampler as well as from the rocks and 

water in the bucket. Use of a magnifying glass and tweezers is essential. Rinse bucket 

through sieve to remove water from sample. Pick out large debris (sticks and leaves) after 

carefully removing any invertebrates.

6. Use spatula to move sample from sieve into a plastic vial. Fill vial to the top with 

isopropyl alcohol. Put label on inside of vial with name of sampler, date, and location.

Write location and date on top of vial lid.

7. Return to the location of the first sample, walk upstream and collect another sample of 

invertebrates. Repeat this process once more for a total of three replicate samples from 

each site location. The three replicates are combined into one composite sample for 

shipment to the laboratory for analysis.

All BMI samples were shipped to ABR, Incorporated in Forest Grove, Oregon for sorting, 

identification, and analysis. Each sample was processed using standard laboratory sample 

handling and labeling protocols. A Caton gridded tray was used to subsample 500 organisms 

from original samples. Using this subsampling procedure, each sample was evenly distributed 

across a 30-square wire-mesh tray. Individual squares were randomly selected and the contents 

removed and placed into a Petri dish. Macroinvertebrates were removed from the sample 

material under a dissecting microscope. This process was repeated until 525-550 organisms were 

subsampled. The remainder of the sample (the unsorted fraction) was then inspected for large or 

rare taxa that were not encountered during the subsampling procedure; these “large/rare” taxa 

were recorded on the laboratory bench sheet as such and placed in a separate vial. The following 

products resulted from the sample sorting procedure:
21

1. 525-550 macroinvertebrates sorted into a series (4-7) of small vials by order, class, and/or 

phylum.

2. A separate vial containing organisms found during the large-rare search (if performed).

3. Sorted residue material from which the 525-550 organisms were sorted.

4. Unsorted fraction portion of the original sample that was not sorted.

Macroinvertebrate identification also followed standard protocols. Macroinvertebrates were 

identified to the lowest practical taxonomic level, generally genus or species for most taxonomic 

groups, excepting mites, Oligochaetes, microcrustaceans, and Chironomidae.

All raw data were entered into Excel spreadsheets and were crosschecked against paper copies of 

the data for errors and omissions before the data were analyzed. Data were analyzed with a 

multimetric index known as the Benthic Index of Biotic Integrity or B-IBI. The B-IBI utilizes 

information concerning the abundance and composition of a stream’s benthic macroinvertebrate 

community to assess the overall biological integrity of the stream ecosystem. As such, 

“biological integrity” is defined as “the ability to support and maintain a balanced, integrated, 

adaptive community of organisms having a species composition, diversity and functional 

organization comparable to that of natural habitat of the region” (Karr and Dudley 1981). In 

practice, the B-IBI provides quantitative scores for 10 metrics that describe individual key 

attributes of the benthic macroinvertebrate community. Scores for the 10 metrics are summed 

and the cumulative site score is categorized into a level of impairment based on a predetermined 

scale.

Since macroinvertebrate communities differ from region to region, multimetric indexes have 

been developed and calibrated for use within particular regions or states. Currently, no 

multimetric tools are available for use with eastern Washington macroinvertebrate data (Hayslip 

2007), including data from the Mill Creek site. However, multimetric tools are available for use 

in the neighboring regions of northeastern Oregon (OR IBI) and Idaho (Idaho Stream 

Macroinvertebrate Index, or SMI). These tools were used to analyze the Mill Creek data to 

provide a basis for comparison of potential future samples collected at the Mill Creek site. It 

should be noted that Mill Creek occurs in the Columbia Plateau Level III ecoregion, which 

overlaps into northeastern Oregon and portions of northern Idaho suggesting that the use of the 

Oregon IBI and Idaho SMI in analyzing eastern WA macroinvertebrate samples is not 

unrealistic. The Mill Creek site results are presented without suggesting that one of the two 

analysis tools is more appropriate than the other. Categorical scales established for the Idaho 

SMI and the eastern Oregon IBI are detailed below (Table 4 and 5).
22

Table 4. Eastern Oregon Index of Biotic Integrity (IBI)

Impairment Categories.

Rating Index Score Range

No Impairment >41

Moderate Impairment 35-41

High Impairment 27-34

Severe Impairment <27

 Table 5. Idaho Stream Macroinvertebrate Index (SMI) Impairment Categories

Northern Mountains Central and 

Southern Mountains

Basins

Rating Index Score Range

Very Good 84-100 800-100 76-100

Good 65-83 59-79 51-75

Fair 44-64 40-58 34-50

Poor 22-43 20-39 17-33

Very Poor 0-21 0-19 0-16
23

Results

GIS and Geodatabase

The WHMI Geodatabase was populated with 23 shapefiles and images (Appendix A). These are 

all accessible from the ArcGIS Map Project file located on the DVD included with this report. 

Additional copies are available from the Upper Columbia Basin Network’s website 

http://science.nature.nps.gov/im/units/ucbn/reports/. 

Upland Site Specific Assessments

This section is an evaluation of each VRM unit. Figure 8 is a map showing the location of the 

original 5 – VRM units described by Gilbert (1984) and Figure 9 is a map of the current 18 VRM 

units. Table 6 summarizes the acres and percentage of the original and current VRM units.

Figure 8. Map of the original VRM units in WHMI.
24

Figure 9. Map of current VRM units in WHMI.
25

Table 6. Summary of acres and percent of total area for the current and original VRM units in 

WHMI.

VRM Units Unit (ac) Unit (%)

Original 

VRM Units Unit (ac) Unit (%)

B 27.68 29.32% B 27.68 29.32%

C1-H1 0.89 0.95%

C1-H3 3.71 3.93%

C1-H4 2.89 3.07%

C1-H6 3.58 3.79%

C2-H2 1.94 2.06%

C2-H5 1.98 2.10%

C 15.03 15.92%

D1a 5.50 5.83%

D1b 2.84 3.00%

D2 7.12 7.54%

D3 7.82 8.28%

D4a 1.28 1.35%

D4b 0.57 0.60%

D4c 2.13 2.25%

D 26.69 28.27%

E 2.62 2.78% E 9.19 9.73%

F1 7.68 8.13%

F2 6.38 6.76%

F 14.07 14.90%

Monument 0.03 0.03%

Mill Pond 1.75 1.85% Mill Pond 1.75 1.85%

Mill Creek 0.47 0.50%

V 5.56 5.89%
26

Ecological sites are the basic land unit used in the assessment method documented in Pellant 

(2005) and are defined by soil type. For rangeland soils, ecological reference sites have been 

developed by the NRCS across the United States and in Washington they are available online at

http://efotg.nrcs.usda.gov/treemenuFS.aspx. There are 9 soil types in WHMI representing 6 

ecological sites (Figure 10). Table 7 summarizes the area and percentage of each soil type and 

ecological site. Pedigo silt loam is the most abundant soil type (49.39%) and the ecological sites 

Alkali Loamy 15+ PZ (R009XY401WA) and Alkali Loamy 9-15 PZ (R008XY401WA) are the 

most common ecological sites at 49.39% and 17.4%, respectively. 

Figure 10. Map of soil types at WHMI.
27

Table 7. Summary of soil types and ecological reference sites at WHMI.

VRM – B

VRM – B is approximately 27.7 acres (29.32%) located in the south 1/3 of WHMI (Figure 11). 

The unit has historically been used as pasture for livestock grazing, mainly cattle. Since 1986,

grazing has been restricted in this unit to implement a revegetation plan. Garrett and Coyner 

(2003) documented the extensive work completed to plant, burn, spray, and plant the unit to 

control weeds and create a historically acceptable landscape. The unit is mainly a Pedigo silt 

loam soil that is classified as an Alkali Bottom 15+PZ (R009XY401WA) ecological reference 

site. Based on the ecological reference site, the historical climax plant community is wild rye 

(Leymus cinereus) – bluebunch wheatgrass and falls in the Columbia Basin Palouse Prairie 

Ecological System (NatureServe 2009).

One plot was evaluated in the unit (Figure 12). The soil stability and hydrologic function 

attributes were rated as none-slight departure (5.0% and 12.5%, respectively). The biotic

integrity attribute was rated moderate (45.7%) due to the presence of invasive plants and the poor 

condition of perennial plants . The old oxbows of the Walla Walla River were dominated by reed 

canarygrass (Phalaris aurundenacia), which provides excellent soil stability but poor habitat for 

other riparian and native species.

The unit is in relatively good condition for soil and hydrologic function and not a threat for soil 

erosion. The biotic function is in better condition than documented in 1984 and 1985 (Gilbert 

1984, Romo and Krueger 1985). There is excessive build up of litter that may be due in part to 

poor functioning of soil microorganisms. Excessive straw buildup is also frequently seen in 

dryland crop management when converting to a direct seed tillage operation. In these cases, 

burning is generally not recommended as a method for dealing with excessive straw and litter 

(STEEP 2008). Research has found that straw decomposes faster when in contact or near the 

soil. Mowing or rolling in late fall may be the most effective method to facilitate the 

decomposition of the past years’ growth and incorporate it into the soil (STEEP 2008). Over time 

soil fungi and bacteria levels will increase and improve decomposition rates, which may reduce 

the need for mowing in the future.

Soil Map 

Symbol Soil Name Acres Percent

Ecological 

Reference Sheet No.

Ecological Reference 

Sheet Name

Plot 

No.

CaA Catherine silt loam 2.83 2.98% R008XY601 WA Wet Meadow 9-15 PZ 2

EfB Ellisforde silt loam 5.76 6.07% R008XY102 WA Loamy 9-15 PZ 4

HmA Hermiston silt loam 8.79 9.26% RO08XY401 WA Alkali Bottom 9-15 PZ

PmA Pedigo silt loam 46.87 49.39% R009XY401 WA Alkali Bottom 15+ PZ 5, 6

RlF Ritzville silt loam 2.75 2.90% R008XY103 WA Cool Loamy 9-15 PZ 3

SrA Stanfield silt loam 0.40 0.42% R008XY401WA Alkali Bottom 15+ PZ

Tc Terrace escarpments 3.24 3.41% R008XY103 WA Cool Loamy 9-15 PZ 7

TsA Touchet silt loam 7.33 7.72% RO08XY401 WA Alkali Bottom 9-15 PZ

UpA Umapine silt loam 16.93 17.84% R007XY701WA Alkali Bottom 6-9 PZ 1
28

Figure 11. Map of VRM-B and NRCA plot 5 in WHMI.

Figure 12. Departure from reference condition of the 3 landscape 

attributes in the Alkali Bottom 15+PZ ecological site at VRM-B, 

WHMI (background is of plot 5).
29

VRM – C1-H3

VRM – C1-H3 is approximately 3.71 acres (3.93%) of WHMI located on the north side of

Memorial Shaft Hill (Figure 13). The unit was historically used as a pasture for livestock 

grazing, mainly cattle. Records indicate the unit has had no recent grazing and in 1986 a 

revegetation plan was implemented (Gilbert 1984). Garrett and Coyner (2003) documented the 

extensive work completed to plant, burn, spray, and plant the unit to control weeds and create a 

historically acceptable landscape. The unit is mainly a Ritzville silt loam soil that is classified as 

a Cool Loamy 9-15PZ (R008XY103WA) ecological reference site. Based on the ecological 

reference site, the historical climax plant community is Idaho fescue (Festuca idahoensis) -

bluebunch wheatgrass and falls in the Columbia Basin Palouse Prairie Ecological System 

(NatureServe 2009).

One plot was evaluated in the unit (Figure 14). The soil stability and hydrologic function 

attributes were rated as none-slight departure (12.5% and 17.5%, respectively). The biotic 

integrity attribute was rated slight-moderate (31.4%) due to the presence of invasive plants. The 

site is dominated by cheatgrass (Bromus tectorum) and yellow starthistle (Centaurea solstitialis),

but there are a few native species, such as snow buckwheat (Eriogonum niveum), growing in the 

unit. This unit has enough litter and vegetation to protect against soil erosion.

The unit is in relatively good condition for soil and hydrologic function and not a threat for soil 

erosion. The biotic function is in better condition than documented in 1984 and 1985 (Gilbert 

1984, Romo and Krueger 1985). However, there is still a very high dominance of yellow 

starthistle. Continued treatment with herbicide spot spraying will reduce the vigor and health of 

the yellow starthistle while improving the ability of native forbs to establish viable populations.

The hot dry summers experienced at WHMI reduce the competitiveness of native species over 

already established non-native and noxious species. WHMI’s staff has a record of working with 

researchers in weed control and revegetation techniques. Recommendations are to continue this 

cooperation, to find non-native species that can compete with current noxious weeds, and meet 

the objective of restoring a historically acceptable landscape. WHMI staff should continue to 

seek noxious weed control techniques that are species specific such as biological control.
30

Figure 13. Map of VRM-C1-H3 in WHMI.

Figure 14. Departure from reference condition of the 3 landscape 

attributes in the Cool Loamy 9-15PZ ecological site at VRM-C1-H3, 

WHMI (background is of plot 3).
31

VRM – C1-H6

VRM – C1-H6 is approximately 3.58 acres (3.79%) of WHMI located on the top of Memorial 

Shaft Hill and is very similar to VRM – C1-H1, which is 0.89 acres (0.95%) and lies directly to 

the west (Figure 15). The unit was historically used as a pasture for livestock grazing, mainly 

cattle, and as a crop field. Records indicate the unit has had no recent grazing or farming and in 

1986 a revegetation plan was implemented (Gilbert 1984). Garrett and Coyner (2003) 

documented the extensive work completed to plant, burn, spray, and plant the unit to control 

weeds and create a historically acceptable landscape. The unit is mainly an Ellisforde silt loam 

soil that is classified as a Loamy 9-15PZ (R008XY102WA) ecological reference site. Based on 

the ecological reference site, the historical climax plant community is bluebunch wheatgrass –

Sandberg’s bluegrass and falls in the Columbia Basin Palouse Prairie Ecological System 

(NatureServe 2009).

One plot was evaluated in the unit (Figure 16). All 3 landscape attributes; soil stability, 

hydrologic function, and biotic integrity; were rated none-slight departure (5.0%, 5.0%, and 

11.4%, respectively). The site is dominated by bluebunch wheatgrass and bluegrass (Poa sp.) 

with very few noxious weeds. The site was planted in 1991 and has been a very successful.

There were few native forb species detected in the unit, which is due to the noxious weed control 

program. The unit has enough litter and vegetation to protect against soil erosion and is close to 

meeting the reference condition for the ecological site.

The biotic function is in better condition than documented in 1984 and 1985 (Gilbert 1984, 

Romo and Krueger 1985). WHMI staff have recognized the lack of native forb species and in 

2000 changed their noxious weed control program to spot spray with herbicides (Garrett and 

Coyner 2003). The staff also introduced 2 biological control agents for yellow starthistle stands 

on the adjacent hillsides to reduce reproduction capabilities. Even with the hot dry summers 

experienced at WHMI, this unit is proof that under the right conditions a competitive stand of 

native species can be established and maintained. WHMI’s staff has a record of working with 

researchers in weed control and revegetation techniques. Recommendations are to continue this 

cooperation to find noxious weed control techniques that are species specific such as biological 

control.
32

Figure 15. Map of VRM-C1-H6 in WHMI.

Figure 16. Departure from reference condition of the 3 landscape 

attributes in the Loamy 9-15PZ ecological site at VRM-C1-H6, 

WHMI (background is of plot 4).
33

VRM – C2-H5

VRM – C2-H5 is approximately 1.98 acres (2.1%) of WHMI located on the south side of 

Memorial Shaft Hill and is very similar to VRM – C2-H2, which is 1.94 acres (2.06%) and lies 

directly to the northwest (Figure 17). The unit was historically used as a pasture for livestock 

grazing, mainly cattle. Records indicate the unit has had no recent grazing and in 1986 a 

revegetation plan was implemented (Gilbert 1984). Garrett and Coyner (2003) documented the 

extensive work completed to plant, burn, spray, and plant the unit to control weeds and create a 

historically acceptable landscape. The unit is classified as a Terrace escarpment, which did not 

have an ecological site description. Examination of the Walla Walla County soil map revealed 

similar conditions just to the east being classified as an Ellisforde silt loam (15-30% slope). This 

soil type was used for assessment of the ecological site, which is classified as a Loamy 9-15PZ 

(R008XY102WA). Based on the ecological reference site, the historical climax plant community 

is bluebunch wheatgrass/Sandberg’s bluegrass and falls in the Columbia Basin Palouse Prairie 

Ecological System (NatureServe 2009). 

One plot was evaluated in the unit (Figure 18). The soil stability and hydrologic function 

attributes were rated as none-slight departure (7.5% and 17.5%, respectively). The biotic 

integrity attribute was rated moderate (45.7%) due to the presence of invasive plants and the lack 

of perennial species. The site is dominated by cheatgrass (Bromus tectorum) (80% canopy cover)

and yellow starthistle (Centaurea solstitialis) (10% canopy cover), but there are a few native 

species, such as snow buckwheat (Eriogonum niveum), growing in the unit. The unit has enough 

litter and vegetation to protect against soil erosion, especially compared to a reference condition.

These units are in relatively good condition for soil and hydrologic function and not a threat for 

soil erosion even though it has the steepest slopes in WHMI. The biotic function is in similar 

condition as documented in 1984 and 1985 (Gilbert 1984, Romo and Krueger 1985). Even with 

the planting effort following Romo and Krueger (1985) after a wildfire in 1998, the species 

composition has changed little. There is still a dominance of cheatgrass and yellow starthistle in 

the unit. Continued treatment with herbicide spot spraying will reduce the vigor and health of the 

yellow starthistle while improving the ability of native forbs to maintain or increase their

populations. The hot dry summers experienced at WHMI reduce the competitiveness of native 

species over many of the already established non-native and noxious species. Solutions to the 

revegetation effort will require additional efforts following specialist’s recommendations. 

WHMI’s staff has a record of working with researchers in weed control and revegetation 

techniques. Recommendations are to continue this cooperation to find non-native species that 

can compete with current noxious weeds and meet the historical landscape objective. WHMI 

staff should continue to use noxious weed control techniques that are species specific such as 

biological control.
34

Figure 17. Map of VRM-C2-H5 in WHMI.

Figure 18. Departure from reference condition of the 3 landscape 

attributes in the Loamy 9-15PZ ecological site at VRM-C2-H5, 

WHMI (background is of plot 7).
35

VRM – D3

VRM – D3 is approximately 7.28 acres (8.28%) of WHMI located west of the visitor’s center 

bordering the west boundary (Figure 19). The unit was historically used as cropland. Records 

indicate the area has no recent grazing or farming and in 1986 a revegetation plan was 

implemented (Gilbert 1984). Garrett and Coyner (2003) documented the extensive work 

completed to plant, burn, spray, and plant the unit to control weeds and create a historically 

acceptable landscape. The unit has 3 soil types; Hermiston silt loam (4.10 acres), Pedigo silt 

loam (2.27 acres), and Umapine silt loam (1.35 acres). The Hermiston silt loam was used for 

analysis and is classified as an Alkali Bottom 9-15PZ (R008XY401WA) ecological reference 

site. Based on the ecological reference site, the historical climax plant community is basin 

wildrye/bluebunch wheatgrass and falls in the Columbia Basin Palouse Prairie Ecological 

System (NatureServe 2009).

One plot was evaluated in the unit (Figure 19). All 3 landscape attributes; soil stability, 

hydrologic function, and biotic integrity; were rated none-slight departure (12.5%, 15.0%, and 

14.3%, respectively). The site is dominated by tall wheatgrass (Thinopyrum ponticum) with few 

noxious weeds. The site was planted in 1990 and was successfully revegetated. There were few 

native forb species detected in the unit, which is due to the noxious weed control program and 

the lack of available native species. The unit was cropland for many years, which removed all 

native species. The unit has more litter and vegetation than predicted in the ecological reference 

site. This provides protection against soil erosion, but is creating problems for decomposition of 

the past years’ biomass. This is also reflected in the very high rating for soil surface resistance to 

erosion due to the lack of any soil structure in the A or B soil horizons.

All the landscape attribute functions are in better condition than documented in 1984 and 1985 

(Gilbert 1984, Romo and Krueger 1985). WHMI staff have recognized the lack of native forb 

species and use spot spraying in their noxious weed control program (Garrett and Coyner 2003). 

WHMI staff recognize the problem with litter buildup and have used prescribed fire several 

times in the past to reinvigorate the stand (Garrett and Coyner 2003). Burning can have a 

negative impact on soil organic material when repeated too often. The excessive build up of litter 

may be due in part to the poor functioning of soil microorganisms. Excessive straw buildup is 

also frequently seen in dryland crop management when converting to a direct seed tillage 

operation. In these cases, burning is generally not recommended as a method for dealing with 

excessive straw and litter (STEEP 2008). Research has found that straw decomposes faster when 

in contact or near the soil. Mowing or rolling in late fall may be the most effective method to 

facilitate the decomposition of the past years growth and incorporate it into the soil (STEEP 

2008). Over time soil fungi and bacteria levels will increase and improve decomposition rates, 

which may reduce the need for mowing in the future.
36

Figure 19. Map of VRM – D3 in WHMI.

Figure 20. Departure from reference condition of the 3 landscape 

attributes in the Alkali Bottom 9-15PZ ecological site at VRM-D3, 

WHMI (background is of plot 1).
37

VRM – D4c

VRM – D4c is approximately 2.13 acres (2.25%) of WHMI located on the northwest corner of 

the park on the south side of Mill Creek and is very similar to VRM – D4b, which is .57 acres 

(.60%) and lies to the north of Mill Creek (Figure 21). The D4 unit was historically used as a 

pasture for livestock grazing, mainly cattle. Records indicate the unit has had no recent grazing 

and in 1986 a revegetation plan was implemented (Gilbert 1984). Garrett and Coyner (2003) 

documented less work completed in this unit than others in the park due to the lack of access by 

motorized equipment. The unit was treated with prescribed fire in 1987, but has had limited 

spraying or mowing since that time. The unit is a Catherine silt loam soil that is classified as a 

Wet Meadow 9-15PZ (R008XY601WA) ecological reference site. Based on the ecological 

reference site, the historical climax plant community is willow (Salix sp.)/bunchgrass/sedge 

(Carex spp.) and falls in the Columbia Basin Palouse Prairie Ecological System (NatureServe

2009). 

One plot was evaluated in the unit (Figure 22). The soil stability and hydrologic function 

attributes were rated as none-slight departure (12.5% and 17.5%, respectively). The biotic 

integrity attribute was rated slight-moderate (34.3%) due to the presence of invasive plants. The 

site is dominated by Pacific willow (Salix lasiandra)/black cottonwood (Populus balsamifera 

ssp. trichocarpa) with an understory dominated by cheatgrass and reed canarygrass. The unit has 

converted from a shrub/grass dominated community to a tree-dominated community based on

comparison to the ecological reference site. This may be due to the lack of natural wildfires over 

the past 150 years.

The unit is in relatively good condition for soil and hydrologic function and not a threat for soil 

erosion. The biotic function is in a similar condition to that documented in 1984 and 1985 

(Gilbert 1984, Romo and Krueger 1985). There is still a variety of noxious weeds in the unit but 

herbicide spot spraying has reduced their cover and vigor. This unit is a lower priority for 

management being located in a little traveled portion of the park. The tree dominated cover 

meets the historical landscape objective. Recommendations are to continue current noxious weed

management strategies and research potential native or non-native species that could be planted 

to compete with the noxious weeds.
38

Figure 21. Map of VRM – D4c in WHMI.

Figure 22. Departure from reference condition of the 3 landscape 

attributes in the Wet Meadow 9-15PZ ecological site at VRM-D4c, 

WHMI (background is of plot 2).
39

VRM – F2

VRM – F2 is approximately 6.38 acres (6.76%) of WHMI located on the center west portion of 

the park and includes the core of the historical sites in the park (Figure 23). The site sampled is 

actually in the oxbow of the Walla Walla River and represents a semi-riparian community. The 

unit may have been historically used as pasture for livestock but has received very little use for 

several decades. The 1986 revegetation plan treated the oxbow areas in unit B but not the area in 

unit F2 (Gilbert 1984). Garrett and Coyner (2003) did not document work being completed in 

this portion of the unit. The unit is mapped as a Pedigo silt loam soil and is classified as an

Alkali Bottom 15+PZ (R009XY401WA) ecological reference site. Based on the ecological 

reference site, the historical climax plant community is basin wildrye/bluebunch wheatgrass and 

falls in the Columbia Basin Palouse Prairie Ecological System (NatureServe 2009).

One plot was evaluated in the unit (Figure 24). The soil stability and hydrologic function 

attributes were rated as none-slight departure (2.5% and 7.5%, respectively). The biotic integrity 

attribute was also rated none-slight (17.1%). The biological integrity was in good condition but is 

not in a climax condition due to the presence of large willow, black cottonwoods, and black 

locust (Robinia pseudoacacia). The site is dominated by a dense stand of reed canarygrass which 

could imitate the historical stands of great basin wildrye along the Walla Walla River. 

Unfortunately, reed canarygrass is a state listed noxious weed and is a very aggressive 

competitor with native species in riparian areas.

The unit is in relatively good condition for all landscape attribute functions. The biotic function 

is in a similar condition to that documented in 1984 and 1985 (Gilbert 1984, Romo and Krueger 

1985). There are a few of noxious weeds, except for reed canarygrass, in the unit but they are 

reduced in cover and vigor due to treatment with spot spraying, and shading from tree cover. 

This unit is a high priority for management and currently is meeting the historical landscape 

objective. Recommendations are to continue current noxious weeds management strategies and 

research methods for replacing reed canarygrass with a less aggressive species that meets the 

historical landscape criteria for the unit.
40

Figure 23. Map of VRM – F2 in WHMI.

Figure 24. Departure from reference condition of the 3 landscape 

attributes in the Alkali Bottom 15+PZ ecological site at VRM-F2, 

WHMI (background is of plot 6).
41

Aquatic Site Specific Assessments

Doan Creek

Doan Creek is a left bank, spring-fed tributary of Mill Creek located on WHMI (Figure 25). The 

Doan Creek irrigation ditch runs through WHMI and supplies water to the park and to two 

downstream irrigators. Overflow from the irrigation ditch supplies water to the Doan Creek 

channel that was relocated to its approximate historic channel location in the mid-1980s. 

Washington Department of Fish and Wildlife (WDFW) has documented that Doan Creek 

provides habitat for rainbow/steelhead trout (Oncorhynchus mykiss), speckled dace (Rhinichthys 

osculus), redside shiner (Richardsonius balteatus), 3 species of sculpins (Cottus spp.), and 

common carp (Cyprinus carpio) (NPS 2003). WDFW also anticipates that the restored habitat on 

the WHMI property can support Chinook salmon (Oncorhynchus tshawytscha) and coho salmon 

(Oncorhynchus kisutch).

Restoration efforts of the original Doan Creek channel began in 2004 and restored Doan Creek to 

roughly its original water course between the park’s eastern water diversion box and Mill Creek 

(NPS 2003). The stream channel now flows across the northwest border of the park and enters 

Mill Creek 300 feet south of the park’s northwest border. The entire restored waterway contains 

natural meanderings in order to provide habitat suitable for the reintroduction of fish species to 

Figure 25. Map of the Doan Creek assessment reach in WHMI.
42

the creek. The total length of the restored stream with meanderings is approximately 2500 feet. 

Stabilizing structures engineered with rock and wood materials have been installed at points 

where the slope of the channel exceeds -1% to slow the flow of water and dissipate energy. The 

WDFW habitat biologist helped design this restoration alternative as the optimal choice for fish 

habitat within WHMI and concluded there is a high chance that hatchery-reared or native fish 

would enter, survive, and spawn in Doan Creek as a result of the restoration activities (NPS 

2003).

During the May 2008 field assessment, Doan Creek did not have water flow due to irrigation 

withdrawals upstream of the restored reach. However, in the late summer of 2008, a new 

irrigation pump was installed at the downstream end of the restored Doan Creek channel, which 

allows stream flows to persist in the restored channel rather than being diverted upstream (Figure 

26). The goal is to maintain some streamflow in the active restored reach throughout the year and 

to re-establish potential fish passage from Mill Creek to Doan Creek.

Doan Creek is associated with a large, offsite emergent wetland near the upstream portion of the 

restored reach on the northern edge of the WHMI property. This wetland extends to the northeast 

and presents an opportunity for wetland restoration efforts with the neighboring land owner.

Doan Creek is a relatively low gradient stream, which allows potential access to its floodplain. In 

addition, stream sinuosity resulting from restoration activities is sufficient to provide access to 

the floodplain and to promote active channel meandering. However, because Doan Creek is a 

spring-fed system and is largely controlled by irrigation withdrawals, high streamflow events 

Figure 26. Photograph of the water diversion pump near the mouth of Doan 

Creek at WHMI.
43

appear to occur at a relatively infrequent basis. This low flooding frequency limits the extent of 

the existing riparian area and the potential for riparian expansion; however, the associated 

wetland that extends northward from the upstream portion of the restored reach provides an 

opportunity for sufficient hydrology to expand at least a portion of the riparian area.

Vegetation on Doan Creek is dominated by willow stake plantings resulting from recent 

revegetation efforts. Until recently, the site was dominated by reed canary grass, which is 

currently being treated through the use of a black plastic ground cover material allowing newly 

planted native vegetation to establish while helping to minimize reed canary grass seed 

germination. The willow stakes and newly emerging herbaceous vegetation along the stream 

appear vigorous and capable of withstanding any high streamflow events; however, much of the 

existing stream bank contains little, if any, ground cover and is susceptible to erosion until the 

plantings establish. Other than the engineered large woody debris used in restoring the stream 

channel, sources of large woody debris are lacking and will not be available until the newly 

planted woody vegetation matures significantly.

The existing Doan Creek channel characteristics are adequate to dissipate the generally low 

volume of flow that is conveyed through the channel. This is primarily due to the recent 

restoration activities. A sinuous stream channel has been created through the use of large woody 

debris and rock that provides a vertically stable stream with natural lateral movement and 

sediment processing.

The PFC evaluation of the Doan Creek stream reach on the WHMI property resulted in a 

summary determination of “Functional – At Risk” (Appendix A). This determination means that 

the riparian areas are in functional condition, but an existing soil, water, vegetation, or related 

attribute makes them susceptible to degradation. Since the Doan Creek channel is in the process 

of being restored on the WHMI property, it is well on its way to becoming properly functioning; 

however, channels that have recently been restored are often susceptible to damaging high flows 

and potential erosion due to newly emerging, immature riparian vegetation growth along the 

stream banks. Doan Creek will need several years of natural flows to establish a healthy 

equilibrium and become properly functioning. In particular, the stream system will need to 

experience more channel forming flows and establish a healthy density of riparian vegetation to 

transition to a balanced stream capable of processing sediment, minimizing onsite erosion, and 

dissipating flows.

Mill Creek

Mill Creek, a tributary to the Walla Walla River, originates on the western slopes of the Blue 

Mountains in southeastern Washington at an elevation of 5,500 feet (USACE 1995). It flows for 

15 miles in a relatively deep and narrow canyon through mountainous terrain, before entering an 

alluvial fan a few miles east of the City of Walla Walla. Mill Creek enters the Walla Walla River

about 6 miles west of the city at River Mile (RM) 33.6. Just upstream of Mill Creek’s confluence 

with the Walla Walla River, it flows through the northern corner of the WHMI where it collects 

streamflow from Doan Creek (Figure 27). At this location and throughout the alluvial fan 

described above, Mill Creek flows through irrigated agriculture land and provides a large source 

of irrigation water to local farm fields. To accommodate farming, Mill Creek has been 

channelized or confined through the use of levees and/or rip rap. This channel confinement 

results in limited floodplain interaction, which prevents typical energy dissipation expected in a 
44

natural stream system. Levees and rip rap banks have also limited lateral movement of the 

channel and have minimized the potential extent of the Mill Creek riparian area.

Onsite riparian vegetation consists of a narrow strip of both young and mature willow and 

cottonwood trees as well as dense coverage of invasive species, including reed canarygrass, 

which is preventing native understory colonization (Figure 28). The existing riparian vegetation 

lacks the diversity of native species and age classes necessary to maintain a healthy stream 

system onsite. The riparian vegetation that is present is vigorous and contains root masses 

capable of withstanding high streamflow events and protecting the stream banks from erosion,

however, vegetative ground cover is inadequate to dissipate energy during high flows or provide 

sufficient large woody debris to the stream channel.

Figure 27. Map of the Mill Creek assessment reach at WHMI.
45

The large woody debris present in the onsite Mill Creek stream channel and associated riparian 

floodplain is inadequate to dissipate stream energy in a stream of this size. The lack of access to 

the floodplain also inhibits Mill Creek’s ability to dissipate stream energy during high flows.

Mill Creek contains a few small meanders but is limited in its movement due to the confining 

rip-rap stream banks and levees. Because stream energy cannot dissipate laterally, Mill Creek is 

vertically unstable and attempts to dissipate energy through down cutting on stream banks.

Erosion is most likely due to farming. The railroad grade and trestle upstream do not seem to be

a significant cause of erosion.

The PFC evaluation of the Mill Creek stream reach on the WHMI property resulted in a 

summary determination of “Functional – At Risk” (Appendix A). This determination means that 

the riparian areas are in functional condition, but an existing soil, water, vegetation, or related 

attribute makes them susceptible to degradation. The confinement of the Mill Creek channel (i.e., 

rip rap, earthen levees) creates an unnatural system that is susceptible to degradation. As a result, 

the stream is trending away from proper functioning condition and will continue trending 

downward unless channel confinement pressure is reduced through levee setback that allows 

natural stream sinuosity and floodplain connectivity to be re-established. In its current state, Mill 

Creek stream flow dissipation occurs in higher gradient reaches through down cutting, which 

results in vertical instability and potential mass wasting of the stream bank, further exacerbating 

the sediment problem in aggrading low gradient stream reaches. The most evident effects of 

sedimentation at the Mill Creek site include reductions in pool habitat, increased cobble 

embeddedness, lower salmonid reproductive success, and increased bank erosion due to forced 

lateral channel adjustment.

Figure 28. Photograph of Mill Creek assessment site at WHMI.
46

Mill Creek water quality monitoring conducted by Starkey (2009) in 2008 indicated the stream is 

in poor to fair condition. Water chemistry data were collected from May–October 2008 and 

compared with Washington Department of Ecology thresholds. Starkey (2009) indicated water 

chemistry parameters of primary concern at this site include high water temperatures, high pH, 

and low dissolved oxygen concentrations.

Benthic Macroinvertebrates

The majority of the substrate at the Mill Creek invertebrate assessment site was comprised of 

inorganic material (95%), while the remaining 5% of the material was organic in nature. The 

assessment team estimated that 25-30% of the substrate was comprised of fine sediments; 

however, cobbles appeared fairly clean of cemented sediments and had an estimated 

embeddedness of 10%. Stream shading at the invertebrate sampling site was estimated at 15% 

due to the prevalence of reed canary grass and other herbaceous vegetation along the stream 

bank rather than substantial overstory vegetation. Invertebrates were sampled from a 21.0 m long 

riffle averaging 0.3 m in depth, 2.0 m in width, and 0.8 m/sec surface velocity. At this location, 

the overall stream channel was 12.2 m in width.

Mill Creek received an Idaho Stream Macroinvertebrate Index (SMI) score of 28, corresponding 

to “poor” ecological conditions in the “Basins” region. Mill Creek received a similarly low 

Oregon IBI score of 16, suggesting “severely impaired” ecological conditions. These results 

indicate Mill Creek, as it flows through the WHMI property, is not currently supporting and 

maintaining a balanced community of organisms that has the composition, diversity, and 

functional organization comparable to that of a natural habitat within the same region.

Macroinvertebrate samples collected at the WHMI Mill Creek site by Starkey (2009) in 2008 

indicate that the water quality within Mill Creek is fair. This result is based on general 

comparisons between onsite macroinvertebrate composition and the composition of comparable 

streams within the region utilizing a general index of integrity known as the Hilsenhoff Biotic 

Index (HBI). The HBI indicated organic pollution appears to significantly affect onsite water 

quality. 

Perturbations occurring upstream of the sampling site are often the primary cause for poor 

conditions at the sampling site. While a single BMI sample is not enough to compare and 

contrast degradation occurring throughout the watershed, it can be used as a baseline 

measurement from which future BMI samples at the individual site can be compared. The

comparison of B-IBI scores from year to year will help managers test the effectiveness of 

management actions occurring near the site and upstream in the watershed. It is always difficult 

to pinpoint the exact cause of ecological conditions at a site based on the B-IBI score; however, 

several common correlations exist between a B-IBI score and conditions or practices occurring 

within a watershed. B-IBI scores have been shown to positively correlate with vegetative cover, 

riparian tree density, water quantity and quality, and substrate particle size (EVS Environmental 

2004). Conversely, a negative correlation is often evident between B-IBI scores and the amount 

of developed land or urbanization occurring upstream in the watershed. Observations of 

conditions within the Mill Creek watershed match closely with these correlations. Vegetative 

cover and riparian tree density have been reduced throughout the watershed over the past century 

to provide opportunities for agriculture (Barber 2005). Irrigation water withdrawals, agriculture 

practices, and urbanization have lead to poor water quantity and quality throughout Mill Creek 
47

(USACE 1995). Land use throughout the watershed has resulted in increased erosion, which 

subsequently leads to sedimentation, cobble embeddedness, and reduced salmonid productivity. 

Urbanization and land development continue to occur upstream of the sampled Mill Creek site, 

which increases impervious surfaces and flashy tendencies of Mill Creek flows.

49

Population 

County State 2000 2006

% 

Change

Persons

/mi2 BP1

 2006

BP1 /1000 

people Size - mi2

Walla Walla Washington 55,180 57,721 4.6% 43.4 290 0.20 1,270

Washington 5,894,121 6,395,798 8.5% 88.6 50,033 7.82 66,544

1

 Building Permits

Table 8. Demographics for the Walla Wall County in the WHMI project area.

Threats and Stressors

Threats and stressors are defined as a condition or situation, occurrence, or factor causing a 

negative impact to a natural resource. These can be further divided into naturally occurring or 

human-caused depending on their source. This section reports on 3 upland and 5 aquatic threats 

and stressors. Climate change is treated as a threat to upland and aquatic natural resources.

Upland Resources

Upland resource threats at WHMI include wildfire, land use change, and noxious weeds. Each 

upland resource threat is described in more detail below including discussions of potential 

strategies to address upland resource risks.

Land Use Changes

The Walla Walla River Subbasin includes all or part of five counties in Washington and Oregon; 

Walla Walla and Columbia Counties in Washington and Umatilla, Union and Wallowa Counties 

in Oregon. WHMI is located in Walla Walla County and Table 8 is a summary of the population 

change in the county from 2000 to 2006 (U.S. Census Bureau 2007). Relative to the State of 

Washington, Walla Walla County is growing more slowly than the State and has a lower 

population density. Development is much lower than the state average relative to building 

permits issued on a per capita basis. 

Walla Walla County projects a population of 15,792 by 2025 in the rural areas of the county 

based on the 2004 population of 12,462 and a 1.34% annual growth rate (WWCBC 2007). Of 

benefit to WHMI, is the policy of Walla Walla County to direct most growth into urban growth 

areas. Unfortunately, all of the urban growth areas lie upstream from WHMI and could 

potentially impact the quantity and/or quality of water in Mill Creek. WHMI staff will need to

work closely with Walla Walla County staff and adjacent landowners to maintain the visual 

landscape outside the park boundaries in order to meet the objectives established in the General 

Management Plan.

Noxious Weeds

Romo and Krueger (1985) developed a list of 6 noxious weeds for WHMI and recommended 

different control and revegetation methods. WHMI staff conducted a noxious weed inventory in 

1997 and identified4 species noted by Romo and Krueger (1985) and 2 new species (NPS 2000). 

Garrett et al. (2007) developed a list of important noxious and non-native plant species based on 

the knowledge of NPS park staff while developing the UCBN Inventory and Monitoring Plan.

This report identified 4 of the species from the 1997 list and added an additional 3 noxious weed 
50

species to those previously identified as important. During site specific field work for this report 

only one additional species, bull thistle (Cirsium vulgare), was identified that was not previously 

mentioned in the above reports.

Table 9 is a list of noxious and invasive plant species referenced in the previous reports. There 

have been 12 species listed at least once since 1985 that were identified as important to control at 

WHMI. In addition there are 3 noxious weed species not mentioned in any reports but found in 

the plant species list maintained by the UCBN; hoary cress (Cardaria draba), spotted knapweed 

(Centaurea maculosa), and diffuse knapweed (Centaurea diffusa).

Washington State’s Noxious Weed law classifies noxious weeds into one of 3 categories; Class 

A, B, or C (WSNWCB 2009). Class A species (35 spp.) are limited in distribution and are the 

highest priority for prevention and eradication. Class B species (71 spp.) are limited in 

distribution within one or more of the 10 regions in the state. Class C species (31 spp.) are 

considered widespread in the state and control requirements are determined by each county. 

County weed control boards are required to list the Class B species that must be contained to 

prevent further spread. Walla Walla County is located in Region 10 and Table 9 includes the 42 

Class B species identified as a priority by the Walla Walla County Weed Control Board. 

Currently, only 2 speciesof the 42-Class B species listed by Walla Walla County Weed Board, 

diffuse and spotted knapweed, have been identified in WHMI.

In 2002, the UCBN created a database management system for tracking noxious weed control 

efforts at WHMI called the Integrated Pest Management Geodatabase (IPMG). The IPMG used 

ArcGIS software to map and managed data collected by WHMI staff. The data was maintained 

from 2002 to 2005. The dataset was summarized by year to provide an estimate of the level of 

effort being exerted by WHMI staff to control noxious weeds on the 98.15 acres of the park. 

Figure 29 is a graph of the number of acres treated by species and year from 2002 to 2005. Total 

acres treated by year was 34.33 acres (2002), 26.88 acres (2003, 74.37 acres (2004), and 49.79 

acres (2005). The areas treated are displayed in Figure 30.

Invasive and noxious weeds are a major threat to WHMI cultural and natural resources. WHMI 

weed control efforts since 1985 have improved many of the VRM units in the park. Some VRM 

units still require extensive work to achieve the stated objective of restoring and maintaining the 

historical landscape. Good management will require the continuation of the extensive levels of 

effort to control noxious weeds and to revegetate areas dominated by undesirable species. WHMI 

staff will need to continue working closely with other agencies and local landowners to protect 

from the many invasive species found in surrounding areas.
51

Common Name Scientific Name Washington 

State Class 

Romo and 

Krueger 1985

Inventory 1997Monitoring Plan 

2007

NRCA Plots 

2008

Species ListWalla Walla 

County

Quackgrass Elymus repens x x

Poison Hemlock Conium maculatum B x x x x x

Spikeweed Hemizonia pungens C x x x

Diffuse Knapweed Centaurea diffusa B x x

Yellow Starthistle Centaurea solstitialis B x x x x x

Canada Thistle Cirsium arvense C x x x x x

Field bindweed Convuvulus arvensis C x x x

Kochia Kochia scoparia B x x

Scotch thistle Onopordum acanthium B x x x x x

Jointed goatgrass Aegilops cylindrica C x x

Canary Reed Grass Phalaris arundinacea C x x x

Bull Thistle Cirsium vulgare C x x

Hoarycress Cardaria draba C x

Spotted Knapweed Centaurea maculosa B x x

Common Bugloss Anchusa officinalis B x

Dalmatian Toadflax Linaria genistifolia B x

Austrian fieldcress Rorippa austriaca B x

Blackgrass Alopecurus myosuroides B x

Blueweed Echium vulgare B x

Camelthorn Alhagi maurorum B x

Common Catsear Hypochaeris radicata B x

Common Fennel Foeniculum vulgare B x

Smooth Cordgrass Apartina alterniflora B x

Fanwort Cabomba caroliniana B x

Gorse Ulex europaeus B x

Oxtongue Hawkweed Picris hieracioides B x

Mouseear Hawkweed Hieracium pilosella B x

Orange Hawkweed Hieracium aurantiacum B x

Polar Hawkweed Hieracium atratum B x

Smooth Hawkweed Hieracium laevigatum B x

Yellow Hawkweed Hieracium caespitosum B x

Robert Herb Geranium robertianum B x

Indigobush Amorpha fruticosa B x

Black Knapweed Centaurea nigra B x

Brown Knapweed Centaureau jacea B x

Table 9. List of noxious and non-native weeds in WHMI with an ‘x’ indicating the source 

and the ranking by the state of Washington.
52

Common Name Scientific Name Washington State 

Class 

Romo and 

Krueger 1985

Inventory 1997Monitoring Plan 

2007

NRCA Plots 2008Species ListWalla Walla 

County

Meadow Knapweed Centaureau jacea x nigra B x

Russian Knapweed Acroptilon repens B x x

Lepyrodiclis Lepyrodiclis holosteoides B x

Oxeye Daisy Leucanthemum vulgare B x

Parrotfeather Myriophyllum aquaticum B x

Perennial Pepperweed Lepidium latifolium B x

Policeman's Helmet Impateins glandulifera B x

Scotch Broom Cytisus scoparius B x

Laurel Spurge Daphne laureola B x

Leafy Spurge Euphorbia esula B x

Sulfur Cinquefoil Potentilla recta B x

Swainsonpea Sphaerophysa salsula B x

Tansy Ragwort Senecio jacobaea B x

Musk Thistle Carduus nutans B x

Plumeless Thistle Carduus acanthoides B x

Water Primrose Ludwigia hexapetala B x

Wild Chervil Anthriscus sylvestris B x

Yellow Floating Heart Nymphoides peltata B x

Yellow nutsedge Cyperus esculentus B x

Table 9. (continued)
53

Figure 29. Graph of treated acres by species at WHMI from 2002-2005.
54

Figure 30. Maps of IPM treatments for weeds by year at WHMI from 2002-2005. 
55

Aquatic Resources

Aquatic resource threats at WHMI include invasive riparian species, recreational use, water 

quantity and quality, fine sediments, and land use. Each aquatic resource threat is described in 

more detail below in addition to discussions of potential strategies to address the risks that are 

threatening aquatic resources.

Invasive riparian species

Reed canarygrass dominates Mill Creek’s stream banks. Reed canarygrass is a concern because it 

forms large, single-species stands that prevents establishment of other species. Since restoration 

of Doan Creek started, invasive plant species have been prevented from establishing in the 

project area and constant management will be required to maintain this condition. Prevention of 

new reed canarygrass invasions is the most efficient and cost effective invasive species 

management. Prevention of reed canarygrass can be most efficiently accomplished by

maintaining complex native herbaceous canopies. Reed canarygrass seed germination requires

light penetration to the soil surface, which is prevented by shade from trees and shrubs. 

Recreational use

Recreational use in the vicinity of Mill Creek and Doan Creek on the WHMI property is a 

common occurrence due to tourists visiting the park each year. It is important to manage use of 

the onsite aquatic resources in a way that educates the public without compromising the integrity 

of the resource. This can be accomplished by ensuring healthy vegetated riparian buffers exist 

around Mill and Doan Creek to protect instream resources from surrounding land use impacts. 

Park managers should also educate the public about the importance of restricting access within 

riparian areas and staying on park trails. An educational riparian area sign and platform that 

allows tourists to view the newly emerging Doan Creek riparian area would be good additions to 

the park.

Water quantity and quality

Water withdrawals for irrigation reduce water quantity and are a critical concern for Mill Creek 

and Doan Creek, especially during the late summer. Water quantity can limit fish production due 

to reduced fish passage, spawning habitat, and rearing habitat. Water quality is often tied to 

water quantity, especially in the arid regions of the western U.S. This is the case for Mill Creek

and Doan Creek. Water temperatures are regulated by the quantity of water flowing in a stream 

channel and have been reported as a problem in these watersheds (Barber 2005). High water 

temperatures can also inhibit a stream’s ability to produce salmonid species, which require cool, 

clean water during all phases of their life history. In addition, fecal coliform bacteria problems 

within streams are often exacerbated by low flows and high stream temperatures. To address 

water quantity and quality concerns, it is recommended that managers prioritize maintenance of 

natural flows as much as possible during the summer low flow period (July – October).

Fine sediments

High sediment loading is one of the habitat factors identified as limiting salmonid productivity in 

the Mill Creek watershed (Barber 2005). Fines deposited on streambeds after salmonids have 

spawned reduce the survival from egg to fry if levels are excessive. Fine sediment also affects 

the number and diversity of invertebrates, which provides an important food resource for 

salmonids. Fine material is generally produced in the uplands, transported to a stream, and is 

either deposited on the banks or enters the stream. As channels migrate laterally, streambanks are 
56

eroded and fine material enters the stream. Fine materials in the stream often lead to cobble 

embeddedness, which results in reduced salmonid productivity.

Timber harvest, grazing, agricultural practices, development and cut banks along roadways have 

all resulted in accelerated sediment production and delivery to the greater Walla Walla River 

basin’s surface waters compared to historic conditions (Barber 2005). It is difficult to manage 

sediment loading onsite that is occurring as a result of upstream land use activities. It is possible 

to help control and prevent fine sediments from entering Mill and Doan Creeks on the WHMI 

property. In some cases, particularly in smaller streams like Doan Creek, wood can be used to 

retain sediment (creating step pools along steeper gradient reaches), promote bed and bank 

stability, and thereby reduce the volume of sediment delivered to downstream reaches. Another 

effective way to reduce non-point sources of sediment on the WHMI property is to ensure 

densely vegetated riparian buffers exist to trap sediments prior to delivery to the stream. Much of 

the sediment problem in the Mill Creek watershed is due to channelization of the stream from

agricultural activities adjacent to stream banks. Levee setback on the WHMI property would be 

another way to allow some natural sediment processing to occur onsite. Levee setback would 

allow the stream to laterally migrate and deposit sediments into a network of secondary channels, 

off-channel habitat, and/or a floodplain bench during high flows.

Land use

Agricultural activities in the Mill Creek watershed throughout the last century have resulted in 

channelization of the stream, loss of floodplain habitat, and a reduction in vegetative density and 

overall width of riparian areas. In addition, urbanization and land development in the greater 

Walla Walla region is occurring, which exacerbates water quality problems and often results in 

flashy stream flows due to the increased rate of storm water runoff. Mill Creek on the WHMI 

property is channelized and could be improved by setting back levees to allow for natural stream 

processes to occur (e.g., floodplain connection, sediment processing, fish habitat development, 

etc.). Widening riparian areas and increasing riparian plant density would also help cool stream 

water (through shading and groundwater reconnection) and minimize delivery of onsite fine 

sediment to the stream.

Climate Change

The Intergovernmental Panel on Climate Change (IPCC) is a scientific intergovernmental body 

set up by the World Meteorological Organization and by the United Nations Environment 

Program. The IPCC Working Group II focuses on climate change impacts, adaptation, and 

vulnerability. Parry et al. (2007) published a technical summary of their most recent findings. 

Listed below are a few of the notable findings from the report:

• Observational evidence from all continents and most oceans show that many natural 

systems are being affected by regional climate changes, particularly temperature 

increases.

• A global assessment of data since 1970 has shown it is likely that anthropogenic warming 

has had a discernible influence on many physical and biological systems.

• Other effects of regional climate changes on natural and human environments are 

emerging, although many are difficult to discern due to adaptation and non-climatic 

drivers.
57

• Some large-scale climate events have the potential to cause very large impacts, especially 

after the 21st century.

• Impacts of climate change will vary regionally but, aggregated and discounted to the 

present, they are very likely to impose net annual costs, which will increase over time as 

global temperatures increase.

• Vulnerability to climate change can be exacerbated by the presence of other stresses.

• Future vulnerability depends not only on climate change but also on development 

pathway.

• Many impacts can be avoided, reduced, or delayed by mitigation.

The IPCC Working Group II published reports on many areas of the world. North America was 

addressed by Field et al. (2007) and they documented three observable connections between 

climate change and terrestrial ecosystems. They found changes in seasonal timing of life-cycle 

events and phenology, plant growth or primary production, and biogeographic distribution. They 

also noted that direct impacts on organisms have indirect effects on ecological mechanisms

(competition, herbivory, disease) and disturbance (wildfire, hurricanes, human activities).

Plants green-up and flower earlier in the spring and leaf fall occurs later in the fall. Primary 

production has increased in North American forests over the past 10 years (Boisvenue and 

Running 2006). Nesting and breeding occurs earlier, migration is earlier for migratory species, 

and some species are shifting home ranges to higher elevations or to more northern latitudes.

A warming climate encourages wildfires through a longer summer period that further reduces 

fuel moisture promoting easier ignition and faster spread (Running 2006). Westerling et al. 

(2006) found that in the last three decades the wildfire season in the western U.S. has increased 

by 78 days and burn durations of fires greater than 1,000 hectares in area have increased from 

7.5 to 37.1 days, in response to a spring/summer warming of 0.87°C.

The Joint Institute for the Study of Atmosphere and Oceans (JISAO) is a cooperative institute 

between the National Oceanic and Atmospheric Administration (NOAA) and the University of 

Washington. JISAO has published a report titled “Impacts of climate variability and change in 

the Pacific Northwest” (Mote et al. 2005). Their modeling predicts warmer, wetter winters, an 

increase of 3.1° F. by 2030 and a 5% increase in precipitation. Precipitation would come more in 

the form of rain with smaller snow packs. 

The predicted climate changes project little change in the annual flow of the Columbia River, but 

seasonal flows will shift markedly toward larger winter and spring flows and smaller summer 

and autumn flows (Hamlet and Lettenmaier, 1999). The changes in flows will likely coincide 

with increased water demand, principally from regional growth, but also induced by climate

change. Climate change is also projected to impact urban water supplies within the basin. For 

example, a 2°C warming projected for the 2040s would increase demand for water in Portland, 

Oregon by 1.5 billion gallons per year with an additional demand of 5.5 billion gallons per year

from population growth, while decreasing supply by 1.3 billion gallons per year (Mote et al., 

2003). The 43 sub-basins in the Columbia River basin have their own sub-basin management 

plans for fish and wildlife, but none comprehensively addresses reduced summertime flows 

caused by climate change.
58

The direct and indirect impact of these predicted changes in climate on natural resources at 

WHMI is a complex and difficult issue to address. Changes could be positive or negative 

depending on the ecosystem processes, communities, and/or species under consideration. WHMI 

managers should review which plant and animal communities and/or species of special interest

and address the possible impacts of the predicted changes in climate to each on individually. 

Where possible, plans could be developed to mitigate potential negative impacts to communities 

and/or species.
59

Summary and Recommendations

Upland Resources

This report examined 7 site-specific areas in WHMI vegetation restoration management units 

using a rapid resource assessment methodology (Pellant 2005). The results and recommendations 

for each site is found in the results section of this report. General threats/stressors thought to be 

the most important to management of WHMI’s natural resources were examined using available 

information. These were land use change and noxious weeds for upland habitats and water level 

fluctuations, invasive riparian species, recreational use, water quality, and fine sediments for 

aquatic habitats. Climate change was considered capable of affecting both habitats. 

Due to the lack of consistent quantitative information on these threats/stressors, impacts were

evaluated in a qualitative manner. Table 10 is an overall estimate of the potential impact to the 3 

major resource areas; soil, hydrologic, and biotic. The actual impact from these threats/stressors 

to any specific site will vary depending on the existing natural resource and landscape setting.

Table 11 is a summary of the potential impacts to WHMI natural resources from the 

threats/stressors identified by Garrett et al. (2007). Rankings were based on literature and 

database research and are the professional judgment of the authors. There is, in fact, very little 

documented information available to assess possible threats/stressors to WHMI natural 

resources.

Data Gaps

Many types of information were not available for this report. We have summarized important 

data that would improve natural resource management by WHMI staff. We did not estimate cost 

or indicate agency responsibility due to the extensive nature of the data. This report will 

hopefully provide guidance to WHMI staff on future data collection efforts within and outside 

the park. Below is a list of the major data gaps:

Threats/Stressors Major Resources/Processes

Upland Habitats Soils Hydrologic Biotic

Land use change

Noxious weeds

Aquatic Habitats

Invasive Riparian Species

Recreational Use

Water Quantity and Quality 

Fine Sediments

All Habitats

Climate Change

Key to Rating for Threats/Stressors

Potential impact to resource High Moderate Low

Table 10. Potential impact from selected threats/stressors to the major 

resources/processes at WHMI.
60

1. Accurate and standardized land cover/use mapping for the project area that meets 

National Map Accuracy Standards (+ 40’) and is repeatable over time. This information 

is very important for any watershed modeling of water quality attributes and other 

resource values. The NPS Inventory and Monitoring Program is currently researching 

methods to standardized developing land use maps for long term monitoring.

2. Land ownership maps in digital format, like county parcel maps, with information on 

owner name and address and any records on what has been developed on the parcel. This 

information could allow WHMI staff to be proactive in monitoring land development 

adjacent to the park in a cost efficient and timely manner. Data is currently available 

online at http://wallawallawa.taxsifter.com/taxsifter/t-parcelsearch.asp but was not 

available digitally.

3. Noxious weed maps in digital format on adjacent private and public lands within the 

project boundary. Currently, no county, state, federal, or other organization collect and 

map noxious weed locations in the WHMI project area. Managers would be more aware 

of possible new invaders and could develop better management strategies for existing 

species with this information. County and state agencies have legal requirements for 

tracking noxious weeds and would be the best partners for developing this information in 

digital format.
61

Table 11. Matrix of threats/stressors to major resources areas with ratings for potential impacts 

and the knowledge base for estimates in WHMI.

Threats/Stressors Major Resources/Processes

Natural Disturbances Soils Hydrologic Biotic Air

Wildfires 2 2 1 3

Flooding 3 3 3 3

Drought 4 3 2 4

Landslides 2 1 4 4

Exotic diseases 4 4 2 4

Climate Change 4 2 3 4

Human-cause Disturbances

Invasive plants/noxious weeds 2 2 1 4

Livestock grazing 1 1 1 4

Fire management practices 3 2 1 2

NPS management activities 3 3 3 4

Forest management practices 2 1 1 4

Visitor use 3 2 1 3

Landscape/landuse changes 2 1 2 3

Exotic animals 4 4 1 3

Hunting 4 4 2 4

Rural development 3 2 2 4

Air pollution 3 3 4 2

Water pollution 4 1 1 4

Utilities/industry 3 2 2 2

Air traffic 4 4 3 3

Heavy metal contamination 2 1 2 4

Key to Rating for Threats/Stressors

Potential impact to resource High Moderate Low Unknown

Knowledge Base 1 = Good 2 = Fair 3 = Poor 4=Inferential

63

Literature Cited

Anglin, Donald, Darren Gallion, Marshall Barrows, Coutney Newlon, and Ryan Koch. 2008. 

Current Status of Bull Trout Abundance, Connectivity, and Habitat Conditions in the 

Walla Walla Basin. U.S. Fish and Wildlife Service.

Barber, Mike. 2005. Walla Walla Watershed WRIA 32 Level 1 Assessment. Economic and 

Engineering Services, Inc.

Boisvenue, C. and S.W. Running, 2006: Impacts of climate change on natural forest productivity

- evidence since the middle of the 20th century. Global Change Biololgy, 12, 862-882.

Bonneville Power Administration. 2004. Walla Walla Subbasin Plan. Northwest Power Planning 

Council. Portland, Oregon.

Comer, P., D. Faber-Langendoen, R. Evans, S. Gawler, C. Josse, G. Kittel, S. Menard, M. Pyne,

M. Reid, K. Schulz, K. Snow, and J. Teague. 2003. Ecological Systems of the United 

States: A Working Classification of U.S. Terrestrial Systems. NatureServe, Arlington, 

Virginia

Environnemental Systems Research Institute. 2006. ArcGIS 9, Using ArcGIS Desktop.

Environnemental Systems Research Institute

Field, C.B., L.D. Mortsch,, M. Brklacich, D.L. Forbes, P. Kovacs, J.A. Patz, S.W. Running and 

M.J. Scott. 2007. North America. Climate Change 2007: Impacts, Adaptation and 

Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the 

Intergovernmental Panel on Climate Change, M.L. Parry, O.F. Canziani, J.P. Palutikof, 

P.J. van der Linden and C.E. Hanson, Eds., Cambridge University Press, Cambridge, UK, 

617-652.

Garrett, L. K. and J. Coyner. 2003. History of Vegetation Restoration, Whitman Mission 

National Historic Site. Cooperative Agreement No. CA9000-95-018, National Park 

Service, Fort Collins, Colorado

Garrett, L. K., T. J. Rodhouse, G. H. Dicus, C. C. Caudill, and M. R. Shardlow. 2007. Upper 

Columbia Basin Network vital signs monitoring plan. Natural Resource Report 

NPS/UCBN/NRR—2007/002. National Park Service, Fort Collins, Colorado. 

Gilbert, C. A. 1984. Landscape Study and Management Alternatives for Revegetation Whitman

Mission National Historic Site. National Park Service, Pacific Northwest Region, 

Cultural Resources Division.

Hamlet, A. and D. Lettenmaier. 1999. Effects of climate change on hydrology and water

resources in the Columbia River Basin. Journal of American Water Resources

Association, 35, 1597-1623.

Mahoney, Brian, Craig Contor, Stacy Schumacher, and Jesse Schwartz. 2007. Fluvial Movement

of Radio Tagged Adult Bull Trout in the Walla Walla River, northeastern Oregon - Draft. 

Confederated Tribes of the Umatilla Indian Reservation and Oregon Department of Fish 

and Wildlife.
64

Mahoney, Brian, Michael Lambert, Preston Bronson, Travis Olsen, and Jesse Schwartz. 2007. 

Walla Walla Basin Natural Production Monitoring and Evaluation Project. Confederated 

Tribes of the Umatilla Indian Reservation and Walla Walla Community College, 

Prepared for US Department of Energy.

National Park Service (NPS). 2000. General Management Plan for Whitman Mission National 

Historic Site. U.S. Department of Interior, National Park Service.

National Park Service (NPS). 2008. Whitman Mission National Historic Site Doan Creek 

Restoration Project Environmental Assessment. Online.

http://www.nps.gov/archive/whmi/manage/doancreek/doancreek.htm#tc. Accessed 1 

January 2009.

Natural Resource Conservation Service (NRCS). 2008. Walla Walla County electronic Field

Office Technical Guide. Online. http://efotg.nrcs.usda.gov/treemenuFS.aspx. Accessed 1 

January 2009.

NatureServe. 2009. NatureServe Explorer – Ecological Communities and Systems. U.S. 

Geologic 

Survey. Online. http://www.NatureServe.org/explorer/servlet/NatureServe?init=Ecol.

Accessed 1 January 2009.

Pacific Groundwater Group. 1995. Initial Watershed Assessment Water Resources Inventory

Area 22 Walla Walla River Watershed. Open-File Technical Report 95-11. Walla Walla 

Watershed Initial Assessment, Draft 1995, WR-95-159.

Parry, M.L., O.F. Canziani, J.P. Palutikof and Co-authors. 2007. Technical Summary. Climate 

Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II 

to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, 

M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson, Eds., 

Cambridge University Press, Cambridge, UK, 23-78.

Pyke, D. A., J. E. Herrick, P. Shaver, and M. Pellant. 2002. Rangeland health attributes and 

indicators for qualitative assessment. Journal of Range Management. 55:584-297. 

Rodhouse, T., A. St. John and L. Garrett. 2003. 2002-2003 Vertebrate Inventory Whitman

Mission National Historic Site. University of Idaho, Moscow, Idaho 62 pp.

Romo, J. and W. Krueger. 1985. Weed Control and Revegetation Alternatives for Whitman 

MissionNational Historic Site. Oregon State University, CPSU/OSU 85-9. 56 pp.

Running, S.W., 2006: Is global warming causing more larger wildfires? Science, 313, 927-928.

Seaber, Paul R., F. Paul Kapinos, and George L. Knapp. 1987. Hydrologic Unit Maps. U.S. 

Geological Survey Water Supply Paper 2294.

Starkey, E. N. 2009. Upper Columbia Basin Network Integrated Water Quality Annual Report 

2008: Nez Perce National Historical Park (NEPE) and Whitman Mission National 

Historic Site (WHMI). DRAFT Natural Resource Technical Report 

NPS/UCBN/NRTR—2009/xxx. National Park Service, Fort Collins, Colorado.
65

U.S. Army Corps of Engineers (USACE). 1995. Mill Creek Master Plan - Technical Report: 

Volume 2. USACE Walla Walla District report. 357pp.

U.S. Census Bureau, 2007, State and County QuickFacts. Online.

http://quickfacts.census.gov/qfd/index.html Accessed 1 January 2009.

U.S. Forest Service and U.S. Geological Survey. 2008. LANDFIRE National Data Products.

Online. http://www.landfire.gov/products_national.php. Accessed 1 January 2009.

Solutions to Environmental and Economic Problems (STEEP). 2008. PNW Conservation Tillage

Handbook.. Washington State University, Oregon State University and University of 

Idaho. Online. http://pnwsteep.wsu.edu/tillagehandbook/index.htm. Accessed 1 January 

2009.

Walla Walla County Board of Commissioners.(WWCBC). 2007. Walla Walla County 

Comprehensive Plan.Online. http://www.co.wallawalla.wa.us/departments/comdev/WallaWallaCountyComprehensivePlan.shtml. 

Accessed 1 January 2009.

Washington State Noxious Weed Control Board (WSNWCB). 2009. Washington State Noxious 

Weed List. Washington State Department of Agriculture. Online. 

http://www.nwcb.wa.gov/documents/weed%20lists/State%20Weed%20List%202009.pdf

. Accessed 1 March 2009. 

Westerling, A. L., H. G. Hidalgo, D. R. Cayan, and T. W. Swetnam. 2006. Warming and earlier

spring increase western U.S. forest wildfire activity. Science, 313, 940-943.

Western Regional Climate Center. 2003. Washington Climate Summaries. Desert Research

Institute, Reno, Nevada. Online. http://www.wrcc.dri.edu/summary/climsmwa.html.

Accessed 1 January 2009.

Wissmar, Robert C., Jeanette E. Smith, Bruce A. McIntosh, Hiram W. Li, Gordon H. Reeves,

and James R. Sedell. 1994. Ecological health of river basins in forested regions of eastern 

Washington and Oregon. Gen. Tech. Rep. PNW-GTR-326. Portland, OR: U.S. 

Department of Agriculture, Forest Service, Pacific Northwest Research Station. 65 p. 

(Everett, Richard L., assessment team leader; Eastside forest ecosystem health 

assessment; Hessburg, Paul F., science team leader and tech. ed., Volume III: 

assessment.)

67

Appendix A – List of NRCA Geodatabase Data by Theme

Theme Layer Name

Air Resources

Animal

Climate

Precipitation Precipitation_1

Temperature whmi_temp_avg

Geography

Roads whmi_roads

Natural Resource Plots nrca_plots

Park Boundary whmi_parkbndy

Public Land Survey System WA PLSS_Wa

Public Land Survey System OR PLSS_Or

Project Bounday whmi_projbndy

Cities whmi_city_bndy

Geology

Soils-County Surveys whmi_soils

Geology whmi_geology

Park Soils whmi_park_soil

Land _Process

Landuse

Plant

Integrated Pest Management 2002-2005 whmi_ipm_02_05

Vegetation Restoration Management Units whmi_vrm

Stressors

Water Resources

Watershed Basin - 6th HUC whmi_basins

Streams streams

Lakes Water_Bodies

Water (303d listed) Oregon streams_303d_or

Water (303d listed) Washington streams_303d_wa

Springs water_sources

Monitoring Stations whmi_env_monitoring_stations

Raster Data

Digital Elevation Model whmi_dem

Existing Vegetation whmi_evt

Hillshade whmi_hlsd

Color Aerial Imagery whmi_aerial.sid

Appendix B – List of Indicators Analyzed to Calculate Landscape Attribute Values.

Plot No. VRM Unit

Ecological 

Reference Code Soil Name 1. Rills

2. 

Waterflow

3. 

Pedestal 4. Bare 5. Gullies 6. Wind 7. Litter

8. Soil 

Surface

9. Soil 

Degredati

on

1 D3 R007XY701WA UpA - Umapine silt loam N-S N-S N-S S-M N-S N-S N-S M-E S-M

2 D4c R008XY601WA CaA - Catherine silt loam N-S N-S N-S S-M N-S N-S N-S M M

3 C1-H3 R008XY103WA Rlf - Ritsville silt loam N-S N-S N-S S-M N-S N-S N-S M M

4 C1-H6 R008XY102WA EfB - Ellisforde silt loam N-S N-S N-S N-S N-S N-S N-S S-M S-M

5 B R009XY401WA PmA - Pedigo silt loam N-S N-S N-S N-S N-S N-S N-S S-M S-M

6 F2 R009XY401WA PmA - Pedigo silt loam N-S N-S N-S N-S N-S N-S N-S N-S S-M

7 C2-H5 R008XY103WA Tc - Terrace escarpments N-S N-S N-S N-S N-S N-S N-S S-M M

69
Appendix B (continued).

Plot No.

VRM 

Units

Ecological 

Reference Code Soil Name

10. Plant 

Canopy 

Cover

11. 

Compaction

12. 

Function 

Structure

13. Plant 

Mortality

14. Litter 

Amount

15. Annual 

Production

16. 

Invasive 

Species

17. 

Reproduc

tion

1 D3 R007XY701WA UpA - Umapine silt loam S-M N-S S-M N-S N-S N-S S-M N-S

2 D4c R008XY601WA CaA - Catherine silt loam S-M N-S M S-M S-M M M S-M

3 C1-H3 R008XY103WA Rlf - Ritsville silt loam M N-S M N-S N-S M M-E S-M

4 C1-H6 R008XY102WA EfB - Ellisforde silt loam N-S N-S S-M S-M N-S N-S N-S N-S

5 B R009XY401WA PmA - Pedigo silt loam N-S N-S E M M-E M M M

6 F2 R009XY401WA PmA - Pedigo silt loam S-M N-S E N-S M-E N-S M M

7 C2-H5 R008XY103WA Tc - Terrace escarpments M N-S M-E S-M M M E M

70
71

Appendix C List of Plant Species at NRCA Upland 

Assessment Points

 Aerial Cover by Plot

Species Name

Growth 

Form

NonNative Noxious 1 2 3 4 5 6 7

Salix lasiandra tree 60 20

Populus trichocarpa tree 30 20

Robina pseudo-acacia tree 5

Chrysothamnus nauseosus shrub 10 1

Sambucus cerulea shrub 0.5

Pseudoroegeneria spicata grass

Apera interrupta grass X 0.5

Thinopyrum intermedium grass X 30

Thinopyrum ponticum grass X 60 40

Bromus japonicus grass X 20

Bromus tectorum grass X 50 50 10 60 80

Koeleria macrantha grass 2

Leymus cinereus grass 2

Poa secunda grass 10 1

Phalaris arundinacea grass 90

Achillea millefolium forb 2 0.5

Amsinckia lycopsoides forb 3

Asparagus officinalis forb X 1 1 0.5

Centaurea solstitialis forb X X 30 10

Cirsium arvense forb X X 0.5 1 0.5

Cirsium vulgare forb X X 5

Conium maculatum forb X X 2 1

Convuvulus arvensis forb X X 5

Descurainia richardsonii forb 0.5 5 2

Dipsacus sylvestris forb X 1 2

Eriogonum niveum forb 2 1 20 15

Galium aparine forb X 25

Hemizonia pungens forb X X 0.5

Lactuca serriola forb X 0.5 0.5 0.5

Lamium amplixicaule forb X 0.5 0.5 0.5

Lupinus leucophyllus forb 0.5

73

Appendix D: Aquatic Site Properly Functioning Condition 

Checklists and Invertebrate Site Description Forms
74

Lotic Standard Checklist

Name of Riparian-Wetland Area: WHMI – Doan Creek______________________________

Date: 5/13/08___Segment/Reach ID: Restored reach___________ Acres: _______________

ID Team Observers: Hinson, Ladd_______________________________________________

Yes No N/A HYDROLOGY

X 1) Floodplain above bankfull is inundated in “relatively frequent” events

X 2) Where beaver dams are present they are active and stable

X 3) Sinuosity, width/depth ratio, and gradient are in balance with the 

landscape setting (i.e., landform, geology, and bioclimatic region)

X 4) Riparian-wetland area is widening or has achieved potential extent

X 5) Upland watershed is not contributing to riparian-wetland degradation

Yes No N/A VEGETATION

X 6) There is diverse age-class distribution of riparian-wetland vegetation 

(recruitment for maintenance/recovery)

X 7) There is diverse composition of riparian-wetland vegetation for 

maintenance/recovery)

X 8) Species present indicate maintenance of riparian-wetland soil 

moisture characteristics

X 9) Streambank vegetation is comprised of those plants or plant 

communities that have root masses capable of withstanding high 

streamflow events

X 10) Riparian-wetland plants exhibit high vigor

X 11) Adequate riparian-wetland vegetative cover is present to protect 

banks and dissipate energy during high flows

X 12) Plant communities are an adequate source of coarse and/or large 

woody material (for maintenance/recovery)

Yes No N/A EROSION/DEPOSITION

X 13) Floodplain and channel characteristics (i.e., rocks, overflow 

channels, coarse and/or large woody material) are adequate to dissipate 

energy

X 14) Point bars are revegetating with riparian-wetland vegetation

X 15) Lateral stream movement is associated with natural sinuosity

X 16) System is vertically stable

X 17) Stream is in balance with the water and sediment being supplied by 

the watershed (i.e., no excessive erosion or deposition)
75

Remarks (numbers correspond to checklist items)

Doan Creek is a spring-fed system and is controlled for irrigation purposes, which results in low 

frequency of flood events. Flood indicators are not present.

Beaver dams and beaver activity are absent.

Doan Creek has been recently restored and artificially engineered to function appropriately.

Irrigation control activities are currently keeping water out of the channel from approximately 

mid-May to August.

Re-vegetated channel consists of planted willow stakes and newly emergent herbaceous species.

Planted willow stakes along reach are thriving, which indicates maintenance of soil moisture 

content.

Willows on stream bank have root masses that are capable of withstanding high streamflow 

events.

Plants show new vibrant growth and are vigorous in appearance.

Although willow stakes have been planted, they are not dense enough, nor have enough other 

woody and herbaceous species established themselves at this time.

Newly planted woody species could potentially provide a source of large woody debris, but 

adequate sources are not currently present.

Engineered placement of large woody debris is adequate to dissipate energy.

Point bars not currently present, likely due to the freshly restored channel that has not had a 

chance to convey channel-forming flows yet.

Engineered meanders and sinuosity present.

Summary Determination

Functional Rating: Trend for Functional – At Risk:

Proper Functioning Condition _____ Upward __X__

Functional – At Risk __X__ Downward _____

Nonfunctional _____ Not Apparent _____

Unknown _____

Additional notes:

1. Since this channel is in the process of being restored, it is well on its way to becoming 

properly functioning. It will need to experience more channel forming flows to transition to a 

balanced stream capable of processing sediment and dissipating flows.

Are factors contributing to unacceptable conditions outside the control of the manager?

Yes __X__

No _____

If yes, what are those factors?

_X_ Flow regulations ___ Mining activities ___ Upstream channel conditions

___ Channelization ___ Road encroachment ___ Oil field water discharge

___ Augmented flows _X_ Other (specify) Recent restoration activities_______
76

Lotic Standard Checklist

Name of Riparian-Wetland Area: WHMI – Mill Creek_______________________________

Date: 5/14/08___Segment/Reach ID: Entire reach on NPS property Acres: ______________

ID Team Observers: Hinson, Ladd_______________________________________________

Yes No N/A HYDROLOGY

X 1) Floodplain above bankfull is inundated in “relatively frequent” events

X 2) Where beaver dams are present they are active and stable

X 3) Sinuosity, width/depth ratio, and gradient are in balance with the 

landscape setting (i.e., landform, geology, and bioclimatic region)

X 4) Riparian-wetland area is widening or has achieved potential extent

X 5) Upland watershed is not contributing to riparian-wetland degradation

Yes No N/A VEGETATION

X 6) There is diverse age-class distribution of riparian-wetland vegetation 

(recruitment for maintenance/recovery)

X 7) There is diverse composition of riparian-wetland vegetation for 

maintenance/recovery)

X 8) Species present indicate maintenance of riparian-wetland soil 

moisture characteristics

X 9) Streambank vegetation is comprised of those plants or plant 

communities that have root masses capable of withstanding high 

streamflow events

X 10) Riparian-wetland plants exhibit high vigor

X 11) Adequate riparian-wetland vegetative cover is present to protect 

banks and dissipate energy during high flows

X 12) Plant communities are an adequate source of coarse and/or large 

woody material (for maintenance/recovery)

Yes No N/A EROSION/DEPOSITION

X 13) Floodplain and channel characteristics (i.e., rocks, overflow 

channels, coarse and/or large woody material) are adequate to dissipate 

energy

X 14) Point bars are revegetating with riparian-wetland vegetation

X 15) Lateral stream movement is associated with natural sinuosity

X 16) System is vertically stable

X 17) Stream is in balance with the water and sediment being supplied by 

the watershed (i.e., no excessive erosion or deposition)
77

Remarks (numbers correspond to checklist items)

1. Channel confinement and channelization present due to farming and railroad bridge crossing 

at upstream end of reach. Flood indicators are not present.

2. Beaver dams and beaver activity are absent.

4. High banks keep stream from meandering and increasing riparian width; potential exists for 

much larger riparian with bank setback.

5. Farmland and railroad bed erosion.

6. Well-established older individuals present as well as younger age classes; however middle age 

classes are absent.

Canarygrass and larger willow/cottonwood species present; need more native diversity.

Willows and cottonwood will withstand high streamflow events.

Greater than 50% of bank not protected by erect woody vegetation.

Not enough sources of large woody debris for channel maintenance.

No floodplain connection or access to LWD outside confined channel.

Point bars small and without established vegetation due to velocities in confined channel.

No lateral movement because the reach is channelized.

Channel confinement causing accelerated downcutting.

Summary Determination

Functional Rating: Trend for Functional – At Risk:

Proper Functioning Condition _____ Upward _____

Functional – At Risk __X__ Downward __X__

Nonfunctional _____ Not Apparent _____

Unknown _____

Additional notes:

1. Channel confinement (i.e., rip rap) and channelization creates an unnatural system that is not 

dissipating energy at full potential.

Are factors contributing to unacceptable conditions outside the control of the manager?

Yes __X__

No _____

If yes, what are those factors?

_X_ Flow regulations ___ Mining activities ___ Upstream channel conditions

_X_ Channelization ___ Road encroachment ___ Oil field water discharge

___ Augmented flows _X_ Other (specify) Railroad trestle at upstream end of reach__
78

Invertebrate Site Description Form

Name of Riparian-Wetland Area: ____Whitman Mission_(WHMI)_______________________

Date: __5/14/2008_Segment/Reach ID: _Mill Creek 1______________Stream: __Mill Creek__

ID Team Observers: __Hinson, Ladd________________________________________

Stream Channel

Description Yes/No

Channelized Y

Stream Substrate and Shoreline Condition 

Description Percent 

(%)

Inorganic Substrate 95

Organic Substrate 5

Embeddedness 10

Sediment 25-30

Stream Shading 15

Site Measurements

Description Meters

Stream Width 12.2

Surface Velocity (m/s) 0.8

Water Depth (Average) 0.3

Riffle Length 21.0

Riffle Width (Average) 2.0
The Department of the Interior protects and manages the nation’s natural resources and cultural heritage; provides scientific and 

other information about those resources; and honors its special responsibilities to American Indians, Alaska Natives, and 

affiliated Island Communities.

NPS 371/100128, June 2009
National Park Service

U.S. Department of the Interior

Natural Resource Program Center

1201 Oakridge Drive, Suite 150

Fort Collins, CO 80525

www.nature.nps.gov

EXPERIENCE YOUR AMERICA TM