Recovery Plan 

for the Coterminous 

United States Population 

of Bull Trout

(Salvelinus confluentus)

U.S. Fish & Wildlife Service

Original color cover illustration of bull trout by Joel Sartore 

with Wade Fredenberg.

National Geographic stock, used with permission.
Recovery Plan

for the

Coterminous United States Population of

Bull Trout

(Salvelinus confluentus)

Pacific Region

U.S. Fish and Wildlife Service

Portland, Oregon

Approved: X

 Regional Director, Pacific Region

 U.S. Fish and Wildlife Service

 Date: X
i

DISCLAIMER

Recovery plans delineate reasonable actions that are believed to be required to recover and 

protect listed species. We, the U.S. Fish and Wildlife Service, publish recovery plans, sometimes 

with the assistance of recovery teams, contractors, State agencies, Tribal agencies, and other 

affected and interested parties. Objectives will be attained and necessary funds made available 

subject to budgetary and other constraints affecting the parties involved, as well as the need to 

address other priorities. Recovery plans do not obligate other parties to undertake specific actions 

and may not represent the views nor the official positions or approval of any individuals or 

agencies involved in recovery plan formulation, other than our own. They represent our official 

position only after they have been signed by the Regional Director or Director as approved. 

Recovery plans are reviewed by the public and submitted for peer review before we adopt them as 

approved final documents. Approved recovery plans are subject to modification as dictated by 

new findings, changes in species status, and the completion of recovery actions.

NOTICE OF COPYRIGHTED MATERIAL

Permission to use copyrighted illustrations and images in this recovery plan has been 

granted by the copyright holders. These illustrations are not placed in the public domain by 

their appearance herein. They may not be copied or otherwise reproduced, except in their 

printed context within this document, without the written consent of the copyright holder.

Literature citation:

U.S. Fish and Wildlife Service. 2015. Recovery plan for the coterminous United States 

population of bull trout (Salvelinus confluentus). Portland, Oregon. xii + 179 pages.

An electronic copy of this recovery plan is also available at:

http://www.fws.gov/pacific/ecoservices/endangered/recovery/plans.html and

http://www.fws.gov/endangered/species/recovery-plans.html

Cover illustration of bull trout by Joel Sartore with Wade Fredenberg. National 

Geographic stock, used with permission. 
ii

Acknowledgments

The U.S. Fish and Wildlife Service gratefully acknowledges the contributions of the 

numerous individuals who have worked tirelessly towards the conservation and recovery of bull 

trout (see USFWS 2015 for a list of individuals and organizations).
iii

Executive Summary

Recovery Plan for the Coterminous United States

Population of Bull Trout

CURRENT STATUS OF THE SPECIES

In November 1999, the U.S. Fish and Wildlife Service (Service) listed all populations of 

bull trout within the coterminous United States as a threatened species pursuant to the Endangered 

Species Act of 1973, as amended (Act) (64 FR 58910; November 1, 1999). Our 1999 listing 

applied to one distinct population segment (DPS) of bull trout within the coterminous United 

States by including bull trout in the Coastal-Puget Sound populations (Olympic Peninsula and 

Puget Sound regions) and Saint Mary-Belly River populations (east of the Continental divide in 

Montana) with previous listings of three separate distinct population segments of bull trout in the 

Columbia River, Klamath River, and Jarbidge River basins (63 FR 31647, June 10, 1998; 64 FR 

17110, April 8, 1999). 

Our most recent 5-year status review for bull trout was completed on April 8, 2008, and 

concluded that listing the species as “threatened” remained warranted range-wide in the 

coterminous United States. Based on this status review, in our most recent recovery report to 

Congress (USFWS 2012) we reported that bull trout were generally “stable” overall range-wide 

(species status neither improved nor declined during the reporting year), with some core area 

populations decreasing, some stable, and some increasing. The combination of core habitat (i.e., 

habitat that could supply all elements for the long-term security of bull trout) and a core 

population (a group of one or more local bull trout populations that exist within core habitat) 

constitutes a core area, the basic unit on which to gauge recovery within a recovery unit. Since 

the listing of bull trout, there has been very little change in the general distribution of bull trout in 

the coterminous United States, and we are not aware that any known, occupied bull trout core 

areas have been extirpated. Additionally, since the listing of bull trout, numerous conservation 

measures have been and continue to be implemented across its coterminous range. These 

measures are being undertaken by a wide variety of local and regional partnerships, including 

State fish and game agencies, State and Federal land management and water resource agencies, 

Tribal governments, power companies, watershed working groups, water users, ranchers, and 

landowners. In many cases these bull trout conservation measures incorporate or are closely 

interrelated with ongoing work for the recovery of salmon and steelhead, which are limited by 

many of the same threats. The Service has compiled a comprehensive overview of conservation 
iv

actions and successes since 1999 for bull trout in each recovery unit referenced in this recovery 

plan.

HABITAT REQUIREMENTS AND DISTRIBUTION

Of all the native salmonids in the Pacific Northwest of the United States, bull trout 

generally have the most specific habitat requirements (Rieman and McIntryre 1993), which are 

often referred to as “the four Cs”: Cold, Clean, Complex, and Connected habitat. This includes 

cold water temperatures (often less than 12 degrees Celsius [54 degrees Fahrenheit]), complex 

stream habitat including deep pools, overhanging banks and large woody debris, and connectivity 

between spawning and rearing (SR) areas and downstream foraging, migration, and overwintering 

(FMO) habitats.

Within the coterminous United States, bull trout currently occur in the Columbia River 

and Snake River basins in Washington, Oregon, Montana, Idaho, and Nevada; Puget Sound and 

Olympic Peninsula watersheds in Washington; the Saint Mary basin in Montana; and the Klamath 

River basin of south-central Oregon. At the time of their coterminous United States listing in 

1999, bull trout, although still widely distributed, were estimated to have been extirpated from 

approximately 60 percent of their historical range. 

FACTORS AFFECTING THE SPECIES

Our listing rule that determined threatened status for the coterminous United States

population of bull trout (USFWS 1999a) included a detailed evaluation of threats to bull trout at a 

landscape scale and a tabular analysis describing which threat factors acted on each individual 

subpopulation. However, the analysis was not quantitative and did not determine the threats that 

were deemed most significant in affecting bull trout at finer scales. 

Based on our most recent status review (USFWS 2008a), historical habitat loss and 

fragmentation, interaction with nonnative species, and fish passage issues are widely regarded as 

the most significant primary threat factors affecting bull trout. The order of those threats and their 

potential synergistic effects vary greatly by core area and among local populations, and is 

described in greater detail in the recovery unit implementation plans (RUIPs) for each of the six 

recovery units included in this recovery plan. In some core areas within their extant range, bull 

trout experience no major threats and maintain healthy populations throughout most or all 

available habitat; some bull trout core areas experience limited but significant threats, but still 

retain strong populations in most available habitat; and some continue to experience severe and 

systemic threats and harbor relatively small populations that have been reduced to a limited 

portion of available habitat. 

Additionally, climate change effects were not considered as a factor affecting bull trout at 

the time of listing in 1999. Since that time, several climate change assessments or studies have 
v

been published or are currently underway assessing the possible effects of climate change on bull 

trout. The results of these efforts will allow us to better understand how climate change may 

influence bull trout and help to identify suitable conservation actions to ensure that bull trout 

persist in the face of climate change.

STRATEGIC PLAN FOR RECOVERY

The primary strategy for recovery of bull trout in the coterminous United States is to: (1) 

conserve bull trout so that they are geographically widespread across representative habitats and 

demographically stable1 in six recovery units; (2) effectively manage and ameliorate the primary 

threats2 in each of six recovery units at the core area scale such that bull trout are not likely to 

become endangered in the foreseeable future; (3) build upon the numerous and ongoing 

conservation actions implemented on behalf of bull trout since their listing in 1999, and improve

our understanding of how various threat factors potentially affect the species; (4) use that 

information to work cooperatively with our partners to design, fund, prioritize, and implement 

effective conservation actions in those areas that offer the greatest long-term benefit to sustain 

bull trout and where recovery can be achieved; and (5) apply adaptive management principles to 

implementing the bull trout recovery program to account for new information. 

Although bull trout were believed to have undergone a significant reduction in their 

historical range prior to the time of their listing in 1999, the species continues to be found in 

suitable habitats and is geographically widespread across numerous major river basins in five 

western states. While the purpose of the Act is to protect and recover threatened or endangered 

species and the ecosystems upon which they exist, the Act does not necessarily require a species, 

in this case bull trout, to be recovered throughout its historical range or even in any set proportion

of the currently suitable habitat. Instead, the Act requires that we recover threatened species such 

as bull trout such that they no longer are likely to become endangered within the foreseeable 

future throughout all or a significant part of their range. 

In summary, ecologically viable populations of bull trout are necessary to produce stable 

core areas, which in turn will result in viable recovery units. The recovery principles described in 

this recovery plan take into account the threats and physical or biological needs of bull trout 

throughout its range and focus on range-wide recovery needs. This approach to achieving 

recovery should ensure adequate conservation of genetic diversity, life history features, and broad 

 1 Demographically Stable: A ‘recovered’ bull trout population described in terms of size, age structure, and density. 

Implies that bull trout populations, at the local population, core area or recovery unit scale, interact with their 

surrounding environment so that their population scale status is stable or increasing based on measurements and 

calculations of population size, density, and age structure. (i.e., ecologically viable).

2 Threat factors known or likely (i.e., non-speculative) to negatively impact bull trout populations at the core area 

level, and accordingly require management actions to assure bull trout persistence to a degree necessary that bull 

trout will not be at risk of extirpation within that core area in the foreseeable future (approximately 50 years).
vi

geographical representation (i.e., adequate spatial distribution) of bull trout populations in the six 

recovery units that comprise the coterminous population of bull trout.

RECOVERY GOALS, OBJECTIVES AND CRITERIA

The ultimate goal of this recovery strategy is to manage threats and ensure sufficient 

distribution and abundance to improve the status of bull trout throughout their extant range in the 

coterminous United States so that protection under the Act is no longer necessary. When this is 

achieved, we expect that:

• Bull trout will be geographically widespread across representative habitats and 

demographically stable in each recovery unit;

• The genetic diversity and diverse life history forms of bull trout will be conserved to the 

maximum extent possible; and

• Cold water habitats essential to bull trout will be conserved and connected.

Specifically, the recovery plan outlines actions necessary to:

• Effectively manage and ameliorate primary threats. We will focus on effectively 

managing and ameliorating the primary threats identified for each recovery unit at the core 

area scale such that bull trout will respond and persist well into the future.

• Work cooperatively with partners to implement bull trout recovery actions. This 

includes: acknowledging and building upon the numerous and ongoing conservation 

actions that have already been implemented throughout much of the range of bull trout 

since the time of listing, and utilizing existing and new information, including decision 

support tools (e.g., structured decision making (SDM), climate change considerations) in 

developing and prioritizing conservation actions in each recovery unit.

• Adaptively manage the bull trout recovery program. Because the effectiveness of 

many of the recovery actions described in this recovery plan, as well as future climate 

effects, are not yet completely understood or fully predictable, we will apply adaptive 

management principles to future monitoring, implementation, and other recovery actions 

for bull trout. Specific recovery actions for bull trout in each of the six recovery units are 

described in the RUIPs. 

Bull trout population status remains strong in some core areas. However, we acknowledge 

that despite our best conservation efforts identified in this recovery plan, it is possible that some 

existing bull trout core areas may become extirpated due to various factors including the effects of 

small populations, isolation, and climate change. Thus, our current approach to developing 

recovery criteria and necessary recovery actions for bull trout is intended to ensure adequate 

conservation of genetic diversity, life history features, and broad geographical representation of 

remaining bull trout populations, while acknowledging that a small number of local extirpations 
vii

may occur without preventing recovery if threats are successfully managed in most core areas.

Specifically, we have developed a recovery plan that: (1) focuses on the identification and 

effective management of known threat factors to bull trout; (2) acknowledges that some extant 

bull trout core area habitats will likely change (and may be lost) over time due to climate change 

effects; and (3) identifies and focuses recovery actions in those areas where success is likely to 

meet our goal of ensuring the conservation of genetic diversity, life history features, and broad 

geographical representation of remaining bull trout populations. Additionally, while the recovery 

plan recognizes that all existing bull trout core areas within the six recovery units contribute to the 

overall conservation of the species, we do not intend that all currently occupied core areas 

identified in this recovery plan must be recovered in order to meet the recovery criteria for the 

listed entity. We recognize that recovery at the recovery unit scale will require improvement in 

bull trout local populations relative to the time of listing and their habitats in some core areas, 

while other core areas will need to be “maintained” into the foreseeable future. 

The recovery criteria in this recovery plan represent our best assessment of the conditions 

that would most likely result in a determination that listing under the Act is no longer required. 

For bull trout, these conditions will be met when sufficient conservation actions have been 

implemented to ameliorate the primary threats in suitable habitats. If the primary threats have 

been effectively managed in each recovery unit, the long-term persistence of bull trout should be 

ensured. The Service may initiate an assessment of whether recovery has been achieved and 

delisting is warranted when the following have been accomplished in each recovery unit:

- For the Coastal, Mid-Columbia, and Upper Snake Recovery Units: Primary threats are 

effectively managed in at least 75 percent of all core areas, representing 75 percent or more of 

bull trout local populations within each of these three recovery units (as identified in Table 1).

- For the Columbia Headwaters Recovery Unit: Primary threats are effectively managed in 75 

percent of simple core areas and 75 percent of complex core areas, representing 75 percent or 

more of bull trout local populations in both simple and complex core areas.

- For the Klamath and Saint Mary Recovery Units, all primary threats are effectively managed 

in all existing core areas, representing all existing local populations. In addition, in the 

Klamath Recovery Unit, because 9 of 17 known local populations have already been 

extirpated and the remainder are significantly imperiled and require active management of 

threats, effective threat management is necessary in 100 percent of core areas, and the 

geographic range of bull trout within this recovery unit will need to be expanded through 

reestablishment of extirpated local populations.

- In recovery units where shared FMO habitat outside core areas has been identified, 

connectivity and habitat in shared FMO areas should be maintained in a condition sufficient 

for regular bull trout use and successful dispersal among the connecting core areas for those 

core areas to meet the criterion.
viii

If threats are effectively managed as described in Table 1 (i.e., 75 percent threshold in the 

Coastal, Mid-Columbia, Upper Snake, and Columbia Headwaters Recovery Units, and 100 

percent for the Klamath and Saint Mary Recovery Units), we expect that bull trout will respond 

accordingly and reflect the biodiversity principles of resilience, redundancy, and representation. 

Specifically, achieving the proposed recovery criteria in each recovery unit would result in 

geographically widespread and demographically stable local bull trout populations within the 

range of natural variation, with their essential cold water habitats connected to allow their diverse 

life history forms to persist into the foreseeable future. Therefore, the species would be brought 

to the point where the protections of the Act are no longer necessary.

If recovery criteria are met in a recovery unit in the future, the Service may initiate an 

assessment of whether recovery has been achieved. We may consider, in coordination with our 

partners and consistent with applicable law at the time, whether pursuing the potential 

reclassification of the listed coterminous United States population of bull trout into multiple 

distinct population segments (DPSs) is a possible approach to delisting.

RECOVERY ACTIONS

Recovery of bull trout will entail effectively managing threats to ensure the long-term 

persistence of populations and their habitats, ensuring the security of multiple interacting groups 

of bull trout, and providing habitat conditions and access to them that allow for the expression of 

various life history forms within each of six recovery units. The recovery plan references 

associated comprehensive RUIPs for each recovery unit with an implementation schedule that 

includes core area-specific recovery actions. These RUIPs may be individually updated in the 

future independently of the Recovery Plan, as appropriate to reflect new information about 

threats, distribution, or management actions within a recovery unit. Recovery actions for bull 

trout, developed in cooperation with Federal, State, tribal, local, and other partners, fall generally 

into four categories:

1. Protect, restore, and maintain suitable habitat conditions for bull trout.

2. Minimize demographic threats to bull trout by restoring connectivity or populations where 

appropriate to promote diverse life history strategies and conserve genetic diversity.

3. Prevent and reduce negative effects of nonnative fishes and other nonnative taxa on bull trout. 

4. Work with partners to conduct research and monitoring to implement and evaluate bull trout 

recovery activities, consistent with an adaptive management approach using feedback from 

implemented, site-specific recovery tasks, and considering the effects of climate change
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TOTAL ESTIMATED COST OF RECOVERY

The total estimated cost of recovery, based on the recovery unit specific estimates 

identified in the RUIP implementation schedules, is 

as follows:

Coastal Recovery Unit: $379,208,000

Klamath Recovery Unit: $37,655,000

Mid-Columbia Recovery Unit: $562,491,000

Upper Snake Recovery Unit: $14,535,000

Columbia Headwaters Recovery Unit: $528,665,000

Saint Mary Recovery Unit: $38,240,000

A large proportion of these costs represent actions that benefit bull trout but that may be

already independently mandated through other environmental and legal processes (e.g., Federal 

Energy Regulatory Commission dam relicensing, Superfund restoration actions, National Forest 

Management Act, Clean Water Act and State water regulations), or coincide with ongoing or 

planned recovery actions for federally listed salmon and steelhead. The overlap in habitat 

requirements of bull trout and salmon results in substantial synergy in the recovery actions 

needed. Further discussion of such interrelated costs associated with land management and

salmonid recovery is provided in the six RUIPs.

The total cost of recovery is only an estimate and may change substantially as efforts to 

recover the species continue. Detailed cost breakdowns for each recovery unit, with expected 

annual costs for the first 5 years of recovery implementation, are provided in the implementation 

schedules of the six RUIPs.

ESTIMATED DATE OF RECOVERY

The implementation schedules of the Columbia Headwaters, Mid-Columbia, Coastal, and 

Upper Snake RUIPs project recovery implementation costs based on an estimated timeframe of 

25 years for recovery. In the Saint Mary Recovery Unit, where major elements of the recovery 

strategy are discrete actions to address passage and entrainment issues in the Saint Mary River, 

the RUIP estimates a timeframe of 10 to 25 years for recovery. In the Klamath Recovery Unit, 

where threats are generally the most severe and many extirpated local populations of bull trout 

will require reintroduction, the RUIP estimates a timeframe of 50 to 70 years for recovery. These 

estimates are subject to modification based on future circumstances. However, if recovery actions 
x

are successfully implemented, we maintain that recovery criteria can be met in the respective 

recovery units within these timeframes.
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TABLE OF CONTENTS

I. INTRODUCTION .................................................................................................................1

A. Overview............................................................................................................................ 1

B. Status of the Species .......................................................................................................... 2

1. New Information ................................................................................................................3

2. Life History and Ecology ...................................................................................................4

3. Distribution.........................................................................................................................7

4. Population Abundance and Trend......................................................................................7

5. Habitat Use and Condition .................................................................................................9

6. Factors Affecting the Species.............................................................................................9

Factor A. The Present or Threatened Destruction, Modification, or Curtailment of Its 

Habitat or Range ..................................................................................................................11

Factor B. Overutilization for Commercial, Scientific, or Educational Purposes................13

Factor C. Disease or Predation............................................................................................14

Factor D. Inadequacy of Existing Regulatory Mechanisms ...............................................15

Factor E. Other Natural or Manmade Factors Affecting its Continued Existence .............17

7. Bull Trout Genetics and Population Structure .................................................................20

8. Bull Trout Conservation Successes..................................................................................21

9. Critical Habitat .................................................................................................................22

C. Previous Recovery Planning Efforts................................................................................ 22

II. STRATEGIC PLAN FOR RECOVERY.............................................................................24

A. Overview.......................................................................................................................... 24

B. Recovery Strategy............................................................................................................ 25

C. Recovery Units................................................................................................................. 33

D. Recovery Goals, Objectives, and Criteria........................................................................ 43

E. How Much Is Enough? .................................................................................................... 45

F. Bull Trout Recovery Criteria ........................................................................................... 46

G. Distinct Population Segment(s) and the Coterminous United States Population ............ 48

H. Recovery Actions............................................................................................................. 50
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III. IMPLEMENTATION FRAMEWORK – RECOVERY UNIT IMPLEMENTATION 

PLANS............................................................................................................................................54

IV. REFERENCES ....................................................................................................................57

A. Literature Cited ................................................................................................................ 57

B. In Litt. References............................................................................................................ 69

V. APPENDICES ...........................................................................................................................70

APPENDIX A. Glossary of Terms ............................................................................................ 71

APPENDIX B. Bull Trout Recovery Unit Maps and Description............................................. 77

APPENDIX C. Future Bull Trout Status Review or Delisting Process..................................... 92

APPENDIX D. Summary of the Comments Received on the Revised Draft Recovery Plan for 

the Coterminous United States Population of Bull Trout (Salvelinus confluentus): Two 

Comment Periods: September 4 thru December 3, 2014; and June 4 thru July 20, 2015........... 95

APPENDIX E. Assessment Tool for Describing Effective Management of Threats in Bull 

Trout Core Areas and Six Recovery Units that Comprise the Coterminous Population of Bull 

Trout. ........................................................................................................................................ 146

APPENDIX F. Comparison of Current and Former Core Area and Recovery Unit 

Classifications........................................................................................................................... 164

APPENDIX G. Role of the Bull Trout Recovery Plan in Interagency Consultation, Cooperation 

with States, Coordination with Tribes, Habitat Conservation Planning, Recovery Permits, and 

Protective Regulations............................................................................................................... 174
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LIST OF FIGURES

Figure 1. Mature bull trout...............................................................................................................1

Figure 2. Distribution of 2008 NatureServe status assessment tool scores for each of the six bull 

trout recovery units...........................................................................................................................9

Figure 3. Hierarchical relationship of bull trout geographic classification units...........................34

Figure 4. Locations of the six bull trout recovery units in the coterminous United States............36

Figure 5. Map of the Coastal Recovery Unit. ................................................................................38

Figure 6. Map of the Klamath Recovery Unit. ..............................................................................39

Figure 7. Map of the Mid-Columbia Recovery Unit. ....................................................................40

Figure 8. Map of the Upper Snake Recovery Unit. .......................................................................41

Figure 9. Map of the Columbia Headwaters Recovery Unit. ........................................................42

Figure 10. Map of the Saint Mary Recovery Unit. ........................................................................43

LIST OF TABLES

Table 1. Recovery (Delisting) Criteria: For each recovery unit, number of core areas (and local 

populations) where threats must be effectively managed; reaching this ‘threshold’ would initiate 

the delisting evaluation process. .....................................................................................................47
1

I. Introduction

A. Overview

Bull trout (Salvelinus confluentus) are members of the char subgroup of the family 

Salmonidae and are native to waters of western North America (Figure 1). In the United States, 

bull trout range widely through the Columbia River and Snake River basins, extending east to 

headwater streams in Idaho and Montana (including the Saint Mary headwaters east of the 

continental divide), into Canada and southeast Alaska, and to the Puget Sound and Olympic 

Peninsula watersheds of western Washington and the Klamath River basin of south-central 

Oregon (Cavender 1978; Howell and Buchanan 1992; USFWS 1999). Historically bull trout 

also occurred in the Sacramento River basin in California. In general, the current distribution of 

bull trout is fragmented and localized within the boundaries of its historical range.

Figure 1. Mature bull trout. Photograph by Joel Sartore with Wade Fredenberg, National 

Geographic stock, used with permission.
2

In June 1998, we listed two distinct population segments (DPS) of bull trout in the 

Columbia River and Klamath River basins as threatened (63 FR 31647, June 10, 1998). The 

Jarbidge River distinct population segment of bull trout was emergency listed as endangered (63 

FR 42737; August 11, 1998) and was later listed as threatened (64 FR 17110; April 8, 1999). 

Subsequently, in November 1999, we listed all populations of bull trout within the coterminous 

United States as a threatened species pursuant to the Endangered Species Act of 1973, as 

amended (Act) (64 FR 58910; November 1, 1999). Our final listing defined one DPS by adding

bull trout in the Coastal-Puget Sound populations (Olympic Peninsula and Puget Sound regions) 

and Saint Mary-Belly River populations (east of the Continental divide in Montana) to the 

previous listings. Based on our 2008 5-year status review (USFWS 2008a), bull trout have a 

recovery priority number of 9C on a scale of 1 (highest) to 18 (lowest (USFWS 1983), indicating 

that: (1) this population is a distinct population segment of a species; (2) the coterminous United 

States population is subject to a moderate degree of threat(s); (3) the recovery potential is high; 

and (4) the degree of potential conflict with construction or other development projects during 

recovery is high.

Between 2002 and 2004, we completed three separate draft bull trout recovery plans. In 

2002, we completed a draft recovery plan that addressed bull trout populations within the 

Columbia, Saint Mary-Belly, and Klamath River basins (USFWS 2002b) and included individual 

chapters for 24 separate recovery units. In 2004, we developed draft recovery plans for the 

Coastal-Puget Sound drainages in western Washington, including two recovery unit chapters 

(USFWS 2004b), and for the Jarbidge River in Nevada (USFWS 2004c). Those draft recovery 

plans were not finalized, but they have served to identify recovery actions across the range of the

species and to provide a framework for implementing numerous recovery actions by our partner 

agencies, local working groups, and others with an interest in bull trout conservation. 

In completing this recovery plan, we incorporated and built upon: (1) new information

received during the September 2014 public and peer review comment period; (2) new 

information found in numerous reports and studies regarding bull trout life history, ecology, etc., 

including a variety of implemented conservation actions, since the 2002 and 2004 draft recovery 

plans; and (3) recovery criteria revised from those proposed in the 2002 and 2004 draft recovery 

plans to focus on effective management of threats to bull trout at the core area level and deemphasize achieving targeted point estimates of abundance of adult bull trout (demographics) in 

each core area.

B. Status of the Species

In 1999, when we listed all bull trout in the coterminous United States as one distinct 

population segment we found that “... sufficient evidence exists in each of the population 
3

segments that demonstrate they are threatened by a variety of past and ongoing threats” that were 

generally consistent across the bull trout’s range. Since the time of the listings of bull trout in 

1998 and 1999 (USFWS 1998a, 1998b, 1999a, 1999b), a great deal of new information has been 

collected on the status of bull trout, factors affecting the species, and ongoing conservation 

actions implemented throughout its coterminous United States range.

1. New Information

New information used in developing this recovery plan is found in a variety of 

documents, including several U.S. Fish and Wildlife Service (Service) documents: draft recovery 

plans (USFWS 2004b, 2004c), proposed and final critical habitat rules (USFWS 2002a, 2004a; 

2005a, 2010a), Service Science Team Report (Whitesel et al. 2004), Bull Trout Core Area 

Templates (USFWS 2005b, 2009), Bull Trout Core Area Conservation Status Assessment 

(USFWS 2005c), revised Designation of Critical Habitat for Bull Trout (USFWS 2010a), and a

5-year Review (USFWS 2008a). In addition, new information is described in documents 

compiled by the five States (Montana, Idaho, Nevada, Washington, and Oregon) in which bull 

trout are found (Gamblin and Snyder 2005; M. Hagener in litt. 2005; M. Hanson in litt. 2005; R. 

Haskin in litt. 2005; IDFG 2005a; 2005b). A bull trout conservation strategy was published for 

U.S. Forest Service lands in western Montana (USFS 2013). Other new information includes 

articles describing bull trout population trends and probability of persistence in Idaho (High et al.

2008; Meyer et al. 2014); research on the larger role of climate change in affecting the status of 

bull trout throughout their range (Dunham et al. 2003; Rieman et al. 2007; Porter and Nelitz 

2009; Isaak et al. 2010, 2011; Wenger et al. 2011; Leppi et al. 2012; Luce et al. 2013; Sawaske

et al. 2014), and ensuring that management and restoration efforts focus on conservation 

priorities (Auerbach et al. 2015; Barnas, et al. 2015).

At the time of the listings, the assessment of the status of bull trout and its threats was 

reported by subpopulation. The Service identified 187 subpopulations range-wide in the 

Columbia, Klamath, Jarbidge, Saint Mary-Belly, and Coastal-Puget Sound DPSs. During the 

recovery planning process beginning in 2002, new information on fish movement supported 

refining the delineation of the 187 subpopulations into 121 bull trout core areas. Subsequently, 

we requested additional information regarding the status of bull trout for the purpose of 

designating critical habitat and refining the delineation of core areas, resulting in further 

refinement of our classification to comprise 109 currently occupied bull trout core areas, as well 

as 6 historically occupied core areas and 1 research needs area, totaling 116 (see Appendix F, 

Comparison of Current and Former Core Areas and Recovery Unit Classifications). During this 

period we also distinguished two types of core areas for conservation purposes: complex core 

areas and simple core areas. Complex core areas are core areas that contain multiple local 
4

populations; they are typically situated in a larger patch of habitat, often occupied by bull trout of 

both the migratory life history form and the resident form, and include a diverse pattern of 

connected spawning and rearing (SR) habitats and foraging, migratory, and overwintering 

(FMO) habitats. Simple core areas are core areas that contain a single local population; typically 

they are situated in a smaller patch of habitat that may not include FMO stream habitat (e.g., an 

isolated headwater lake with a single SR stream) and sometimes include only the resident life 

history form or a very simple migratory pattern.

To update the most recent information on bull trout status and their threats, we developed 

the Core Area Templates (USFWS 2005b, 2005c) with the most recent update being completed 

in 2009 (USFWS 2009). These documents represented a compilation, core area by core area, of 

the newest information since listing on population status, threats, habitat, regulatory 

mechanisms, and conservation efforts. This information was used in the bull trout core area 

conservation status assessment model to rank the conservation status of each of the 109 occupied 

core areas.

2. Life History and Ecology

Bull trout express both resident and migratory life history strategies (Rieman and 

McIntyre 1993). Resident forms of bull trout complete their entire life cycle in the tributary (or 

nearby) streams in which they spawn and rear. Migratory bull trout spawn in tributary streams, 

where juvenile fish rear for 1 to 4 years before migrating to either a lake (adfluvial form) (Downs 

et al. 2006), river (fluvial form) (Fraley and Shepard 1989), or in certain coastal areas, to 

saltwater (anadromous) (Cavender 1978, McPhail and Baxter 1996; Washington Department of 

Fish and Wildlife. et al. 1997; Goetz et al. 2004; Brenkman and Corbett 2005; Jeanes and 

Morello 2006; Brenkman et al. 2007). Resident and migratory forms may be found together, and 

either form may give rise to offspring exhibiting either resident or migratory behavior (Rieman 

and McIntyre 1993, Brenkman et al. 2007, Homel et al. 2008).

The size and age of bull trout at maturity depends upon habitat capacity and subsequent

life history strategy. Resident fish tend to be smaller than migratory fish at maturity and produce 

fewer eggs (Fraley and Shepard 1989, Al-Chokhachy and Budy 2008). Bull trout normally reach 

sexual maturity in 4 to 7 years (Johnston et al. 2007); they frequently live for 10 years and 

occasionally for 20 years or more (McPhail and Baxter 1996, Al-Chokhachy and Budy 2008). 

Of native salmonids in the Pacific Northwest of the United States, bull trout have the 

most specific habitat requirements (Rieman and McIntyre 1993), which are often referred to as 

“the four Cs”: Cold, Clean, Complex, and Connected habitat. These requirements include cold 

water temperatures compared to other salmonids (often less than 12 degrees Celsius [54 degrees 
5

Fahrenheit]); the cleanest stream substrates; complex stream habitat including deep pools, 

overhanging banks and large woody debris; and connectivity between spawning and rearing 

areas and downstream FMO habitats.

Habitat components that influence bull trout distribution and abundance include water 

temperature, cover, channel form and stability, valley form, spawning and rearing substrate, and 

migratory corridors (Fraley and Shepard 1989; Hoelscher and Bjornn 1989; Sedell and Everest 

1991; Howell and Buchanan 1992; Pratt 1992; Rieman and McIntyre 1993, 1995; Rich 1996; 

Watson and Hillman 1997, Shellberg 2002, Al-Chokhachy et al. 2010).

Migratory corridors link seasonal habitats for all bull trout life histories. For example, in 

Montana and northern Idaho, migratory bull trout make extensive migrations in the Flathead 

River system (Fraley and Shepard 1989). Resident bull trout in tributaries of the Bitterroot River 

move downstream to overwinter in tributary pools (Jakober 1995). Migratory (allacustrine) bull 

trout in the Pend Oreille River drainage make complex post-spawning migrations (Dupont et al. 

2007). Anadromous bull trout on the Olympic Peninsula migrate extensively between the ocean 

and riverine habitat in multiple coastal watersheds (Brenkman and Corbett 2005). The ability to 

migrate is important to the persistence of bull trout as it allows them to seasonally or temporally 

occupy habitat that may be advantageous on an intermittent basis (Rieman and McIntyre 1993; 

M. Gilpin, in litt. 1997; Rieman et al. 1997, Dunham and Rieman 1999, Muhlfeld and Marotz 

2005). In essence, bull trout aggregations can function as complex metapopulations (see 

Whitesel et al. 2004). Migrations facilitate gene flow among local populations when individuals 

from different local populations interbreed, or stray, to non-natal streams. Local populations that 

are extirpated by catastrophic events may also become reestablished by bull trout migrants

(Rieman et al. 1997).

Bull trout depend on cold streams, although individual fish can be found in larger, 

warmer river systems throughout the Columbia River basin (Fraley and Shepard 1989; Rieman 

and McIntyre 1993, 1995; Buchanan and Gregory 1997; Rieman et al. 1997; Ripley et al. 2005; 

Rieman et al. 2006). Water temperature above 15 degrees Celsius (59 degrees Fahrenheit) is 

believed to especially limit juvenile bull trout distribution, which may partially explain the 

patchy distribution within watersheds (Fraley and Shepard 1989; Rieman and McIntyre 1995; 

Dunham et al. 2003, McMahon et al. 2007). Spawning areas are often associated with 

cold-water springs, groundwater infiltration, and the coldest streams in a given watershed (Pratt 

1992; Rieman and McIntyre 1993; Rieman et al. 1997; Baxter and McPhail 1999, Baxter et al. 

1999). Goetz (1989) suggested optimum water temperatures for juvenile rearing of about 7 to 8 

degrees Celsius (44 to 46 degrees Fahrenheit) and optimum water temperatures for egg 

incubation of 2 to 4 degrees Celsius (35 to 39 degrees Fahrenheit). 
6

Preferred spawning habitat consists of low-gradient stream reaches with loose, clean 

gravel (Fraley and Shepard 1989) and water temperatures of 5 to 9 degrees Celsius (41 to 48 

degrees Fahrenheit) in late summer to early fall (Goetz 1989). Land use and water use may also 

influence spawning behavior and distribution (Starcevich et al. 2010). In the Swan River, 

Montana, abundance of bull trout redds (spawning areas) was positively correlated with the 

extent of bounded alluvial valley reaches, which are likely areas of groundwater to surface water 

exchange (Baxter and McPhail, 1999). Survival of bull trout embryos planted in stream areas of 

groundwater upwelling used by bull trout for spawning were significantly higher than embryos 

planted in areas of surface water recharge not used by bull trout for spawning (Baxter and 

McPhail 1999). Pratt (1992) indicated that increases in fine sediment reduce egg survival and 

emergence.

Bull trout typically spawn from August to November during periods of decreasing water 

temperatures. Water temperatures during spawning vary, but generally range from 4 to 10 

degrees Celsius (39 to 51 degrees Fahrenheit) (Howell et al. 2010). Redds are often constructed 

in stream reaches fed by springs or near other sources of cold groundwater (Goetz 1989; Pratt 

1992; Rieman and McIntyre 1993). Migratory bull trout frequently begin spawning migrations 

as early as April and have been known to move upstream as far as 250 kilometers (155 miles) to 

spawning grounds in Montana (Fraley and Shepard 1989; Swanberg 1997). In Idaho, bull trout 

moved 109 kilometers (67.5 miles) from Arrowrock Reservoir to spawning areas in the 

headwaters of the Boise River (Flatter 1998). In the Blackfoot River, Montana, bull trout began 

spring migrations to spawning areas in response to increasing temperatures (Swanberg 1997). 

Depending on water temperature, egg incubation is normally 100 to 145 days (Pratt 1992), and 

after hatching, young fry remain in the substrate. Time from egg deposition to emergence of fry 

may surpass 200 days. Fry normally emerge from early April through May, depending on water 

temperatures and increasing stream flows (Pratt 1992; Ratliff and Howell 1992; McPhail and 

Baxter 1996).

Bull trout are opportunistic feeders, with food habits primarily a function of size and life 

history strategy. Resident and juvenile migratory bull trout prey on terrestrial and aquatic 

insects, macro-zooplankton, and small fish (Goetz 1989; Donald and Alger 1993). Adult

migratory bull trout feed primarily on a wide variety of resident and anadromous fish species 

(Fraley and Shepard 1989; Brown 1992; Donald and Alger 1993; Guy et al. 2011). In coastal 

areas of western Washington, bull trout feed on forage fish species such as Pacific herring 

(Clupea pallasi), Pacific sand lance (Ammodytes hexapterus), and surf smelt (Hypomesus 

pretiosus) in near shore marine areas and the ocean (WDFW et al. 1997, Goetz et al. 2004).
7

3. Distribution

At the time of their coterminous United States listing in 1999, bull trout were still widely 

distributed although they had been extirpated from approximately 60 percent of their historical 

range (Quigley and Arbelbide 1997; Rieman et al. 1997; USFWS 1999). For example, although 

bull trout still existed in most river basins where they were found historically, they had been 

likely extirpated in the McCloud River basin, California; the upper Deschutes, North and South 

Fork Santiam, and Clackamas River basins, Oregon; the White Salmon, lower Nisqually, Satsop, 

Lake Chelan, Okanagan, Sanpoil, and Kettle River basins, Washington; and locally in numerous 

tributaries and in salt water, lake, and mainstem river environments in other areas. These 

declines resulted largely from habitat degradation and fragmentation, blockage of migratory 

corridors, poor water quality, past fisheries management practices, and the introduction and 

subsequent proliferation of nonnative fish species.

Since 1999, there has been very little change in the general distribution of bull trout in the 

coterminous United States and we are not aware that any known, occupied bull trout core areas 

have been extirpated. Advancements in radiotelemetry and hydroacoustic technology have been 

used to better understand bull trout movement patterns. Tracking movements of individual fish 

has greatly informed the proper application of fish passage technology, furthered the 

identification of metapopulation dynamics, contributed to verification of genetic patterns, and 

aided in assessment of movement timing and limiting factors. Radiotelemetry has contributed to 

the identification of previously undocumented migrations of anadromous bull trout in near-shore 

waters of Washington State (Brenkman and Corbett 2005), of fluvial bull trout of the Columbia 

River region of central Washington (USFWS 2001), and in the Snake River in Idaho (Chandler 

et al. 2001). These methods, in combination with stream temperature and habitat data, predictive 

distribution models (Isaak et al. 2009, 2015; USGS 2011; Falke et al. 2015), and newly 

developed environmental DNA survey methods (Wilcox et al. 2013, 2014), are improving our 

ability to assess bull trout distribution and identify watersheds where bull trout are at risk of 

extirpation.

4. Population Abundance and Trend

We completed a 5-year status review of bull trout on April 8, 2008 (USFWS 2008a), and 

found that listing the species as “threatened” remained warranted range-wide in the coterminous 

United States. We evaluated the status of the 121 core areas recognized at that time (see 

Appendix F for crosswalk with current classification); of those, 23 exhibited population trends 

that were declining from slightly to severely, 18 were stable, 14 were increasing, and 66 were 

unknown. We also found that 75 core areas had substantial or moderate, imminent threats, with 
8

the remainder being less threatened (substantial or moderate, imminent threats not necessarily 

equivalent to ‘primary threats’ as defined in this document). We concluded that the “foreseeable 

future” for evaluating actions affecting bull trout and their recovery was from 4 to 10

generations, or roughly 28 to 70 years. Based on the 2008 5-year status review, we reported in 

our most recent recovery report to Congress (USFWS 2012) that bull trout were “stable” overall 

range-wide (species status neither improved nor declined during the reporting year), with some 

core area populations decreasing, some stable, and some increasing.

Subsequent to completion of the 2008 5-year review, we worked with State, Federal and

Tribal agency biologists to update bull trout status information for each of 118 core areas

(currently occupied or historical) that were identified in February, 2009, with updated 

information in Service “core area template” files, or documents for each core area capturing 

2009 status and threats information. From these data we and our partners developed a relative 

ranking of all bull trout core areas range-wide, using criteria in the updated NatureServe status 

assessment tool (Faber-Langendoen et al. 2009). This tool consists of a spreadsheet that 

generates conservation status rank scores for species or other biodiversity elements based on 

various user inputs of status and threats. We used nine factors to score bull trout status and 

threats: (1) linear distance of occupancy; (2) number of occurrences, or local populations; (3) 

adult population size; (4) environmental specificity; (5) intrinsic vulnerability [4 and 5 were the 

same for the species across all areas scored]; (6) short-term trend; (7) long-term trend; (8) threat 

scope; and (9) threat severity. Thus, each core area rank score can be compared to other core 

areas to gain a relative understanding of the status of that core area, with lower scores 

representing core areas that are less robust and more vulnerable to extirpation. 

The status assessment scores for all bull trout core areas range from 0.36 to 3.83

(USFWS, in litt. 2012). The most robust, least threatened core areas include Hungry Horse 

Reservoir and Lake Koocanusa in Montana (Columbia Headwaters Recovery Unit) and the 

Middle Fork Salmon River and South Fork Salmon River in Idaho (Upper Snake Recovery 

Unit). The least robust, most threatened core areas include the North Fork Payette River and 

Weiser River in Idaho (Upper Snake Recovery Unit) and Asotin Creek in southeast Washington

(Mid-Columbia Recovery Unit). A majority of core areas with low status assessment scores 

include ‘simple’ core areas comprised of only a single local bull trout population. We also 

applied the NatureServe status assessment tool to evaluate the tentative status of the six recovery 

units. The tool rated the Klamath Recovery Unit as the least robust, most vulnerable bull trout

recovery unit and the Upper Snake Recovery Unit the most robust and least vulnerable recovery 

unit, with others at intermediate values (Figure 2). 
9

Figure 2. Distribution of 2008 NatureServe status assessment tool scores for each of the six 

bull trout recovery units (Faber-Langendoen et al. 2009). The Klamath Recovery Unit (RU) is 

considered the least robust and most vulnerable, and the Upper Snake RU the most robust and 

least vulnerable. 

5. Habitat Use and Condition

Information on the complex migratory movements of fluvial, adfluvial, and anadromous 

life history forms (e.g., see USFWS 2002b; 2004a; 2004b, USFWS 2005b, 2005c) has now 

increased our understanding of the extensive habitat use and connectivity requirements of the 

migratory life history form. This information has affirmed that the use of migratory corridors is 

critical to the survival of bull trout (e.g., see Bahr and Shrimpton 2004, Brenkman and Corbett 

2005, Mogen and Kaeding 2005; 2007, Nelson et al. 2002, Neraas and Spruell 2001, Homel and 

Budy 2008, Monnot et al 2008). Additionally, a variety of broader-scale stream habitat 

monitoring programs and predictive models provide information on status and trends in stream 

habitat condition, structure, and water temperature (Isaak et al. 2010; Merritt and Hartman 2012; 

Larson 2012; Isaak and Rieman 2013; USFS 2014; Falke et al. 2015; see also Anlauf et al. 

2011). Much of this new information was useful in our determination of critical habitat for bull 

trout (USFWS 2004a, 2010a) and informed the development of conservation actions in this 

recovery plan for important FMO bull trout habitats.

6. Factors Affecting the Species

Supporting documentation for listing the coterminous United States population of bull 

trout as threatened (USFWS 1999a) included a detailed evaluation of threats to bull trout at a 
10

landscape scale and a tabular analysis describing which threat factors acted on each individual 

subpopulation. However, the analysis did not determine the threat factors that were deemed 

most significant in affecting bull trout at finer scales. 

The 2002 and 2004 draft bull trout recovery plans for the Columbia River, Klamath River 

and Saint Mary-Belly populations (USFWS 2002a), and for the Coastal-Puget and Jarbidge 

populations (USFWS 2004b, 2004c), included detailed information on threats primarily at the 

recovery unit scale, similar to regional watersheds. In developing these draft recovery plans 

(USFWS 2002a, 2004a, 2004b), as well as earlier State restoration planning processes in 

Montana and Idaho (e.g., Montana Bull Trout Restoration Team 2000; Batt 1996), common 

categories were used to describe and evaluate the various threats affecting bull trout. Threat 

factors identified and evaluated for these earlier efforts included: passage barriers including 

dams, forest management practices, livestock grazing, agricultural practices, transportation 

networks, mining, residential development and urbanization, fisheries management activities, as 

well as natural events (e.g., wildfire, drought, flooding) that may contribute to core area isolation 

and habitat fragmentation. These general threat categories to bull trout were also evaluated by an 

expert science panel convened by the Service in March 2005 as part of the 5-year review process 

(USFWS 2008a). 

Since our listing of bull trout, numerous conservation measures have been and continue 

to be implemented across the six recovery units that comprise the coterminous United States

population, to address many of the threats identified in the earlier draft recovery plans. These 

include removal of migration barriers (culvert removal or redesign at stream crossings, fish 

ladder construction, dam removal, etc.) to allow access to spawning or FMO habitat; screening 

of water diversions to prevent entrainment into unsuitable habitat in irrigation systems; nonnative fish suppression efforts; habitat improvement (riparian revegetation or fencing, placement 

of coarse woody debris in streams) to improve spawning suitability, habitat complexity, and 

water temperature; instream flow enhancement to allow effective passage at appropriate seasonal 

times and prevent channel dewatering; and water quality improvement (decommissioning roads, 

implementing best management practices for grazing or logging, setting pesticide use guidelines) 

to minimize impacts from sedimentation, agricultural chemicals, or warm temperatures. A more 

comprehensive overview of conservation successes since 1999 can be found in the individual

recovery unit implementation plan (RUIP) chapters and is summarized in a summary of bull 

trout conservation successes and actions since 1999 document (USFWS 2013). 

More recently, in developing this recovery plan and RUIPs, the Service integrated new 

information regarding life history, ecology, conservation actions, climate change effects, etc., 

learned since 1999 and worked with various partners to revise, update and describe threat factors 

(e.g., primary threats) affecting bull trout at the core area scale in each of the six recovery units. 
11

Today, most of the threats affecting bull trout generally fall into three broad categories: (1) 

habitat threats, (2) demographic threats, and (3) nonnative species threats. Habitat threats are 

those threats that impact bull trout habitats, demographic threats are those threats that impact 

individuals or local populations, and nonnative species threats result from introduced fish species 

or their management that impact bull trout individuals or populations. 

The following discussion briefly summarizes our current understanding of the factors 

affecting the status of bull trout across the species coterminous United States range. A more 

complete and specific description of the primary threat factors affecting bull trout can be found 

in the RUIPs developed for each of the six recovery units that comprise the coterminous United 

States population of bull trout.

Factor A. The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat 

or Range

Many of the factors affecting bull trout fall into the category of destruction, modification, 

or curtailment of habitat (Habitat Threats) and are described and characterized in a wide variety 

of documents, including various State plans (e.g., Montana Bull Trout Restoration Team 2000; 

Batt 1996); earlier draft recovery plans (USFWS 2002a, 2004a, 2004b); bull trout critical habitat 

determinations (USFWS 2004a; 2005a; 2010a); the original and updated Bull Trout Core Area 

Templates (USFWS 2005b, 2009); the Bull Trout Core Area Conservation Status Assessment 

(USFWS 2005c); and most recently the 2014/2015 Technical Partner meetings used to develop 

the six RUIPs. Most of these impacts (e.g., dewatering, sedimentation, thermal modification, 

water quality degradation) are a consequence of specific land and water management activities. 

Today, these types of impacts are normally mitigated or moderated, especially on Federal lands 

and there is often a greater conservation emphasis in headwater areas where suitable bull trout 

spawning and rearing habitat occurs. For example, trends for riparian habitats have been 

generally improving over at least the past 25 years on Federally managed timber lands, due in 

part to recent improvements in management practices, declining timber harvest, and virtual 

cessation of road building on Federal lands (USFS 2013). A multitude of restoration actions 

have been implemented or planned on many National Forests and nearby private timber lands 

within the six recovery units and in several watersheds the most egregious road and sediment 

problems have been addressed.

Core areas where “legacy effects” of past land use practices continue to degrade bull trout 

habitats, or where habitat restoration has not yet occurred or has not yet been demonstrated to be 

effective, are identified in the RUIPs along with core area-specific actions that still need to 

occur. Because the legacy effects from past management may persist for decades it may take 

many years (generations) for bull trout populations to respond to management actions and we 
12

can evaluate the effectiveness of future conservation actions. There are numerous recent 

examples of restoration of degraded habitat, improvement of fish passage, and changes in 

angling regulations, across the range of bull trout (USFWS 2013), including documented 

examples where these actions have benefited bull trout (Pierce et al 2013; Erhardt and 

Scarnecchia 2014).

Drought and wildfire impacts occur across the entire range (USFWS 2002b), and their 

potential magnitude, severity, and intensity remain high for bull trout. Throughout much of the 

range of bull trout, wildfires will likely continue to increase in both scope and magnitude in 

forests, prairie, and arid land ecosystems in the coming decades (Littell et al. 2009). Mote et al. 

(2014) stated that: “The combined impacts of increasing wildfire, insect outbreaks, and tree 

diseases are already causing widespread tree die-off and are virtually certain to cause additional 

forest mortality by the 2040s and long-term transformation of forest landscapes. Under higher 

(greenhouse gas) emissions scenarios, extensive conversion of subalpine forests to other forest 

types is projected by the 2080s”.

Warmer and drier springs and summers, lower soil moisture and prolonged periods of 

elevated fire-danger all contribute to higher vulnerability to fire for forests and non-forests in the 

Northwest (Littell et al. 2009; Abatzoglou and Kolden 2013). Wetter winters are correlated with 

fire in non-forested habitats due to higher fuel availability in the summer in the form of grasses 

and shrubs, while fire in forested areas is highly associated with year-of-fire low precipitation 

(Littell et al. 2009; Abatzoglou and Kolden 2013). Also, snowpack losses and earlier snow melt 

at lower elevation forests (Mote et al. 2005; Pederson et al. 2013) are increasing fire risk in these 

areas (Abatzoglou and Kolden 2013). Wildfire frequency in western forests has increased fourfold during the period 1987 to 2003 as compared to 1970 to 1986, while the total area burned 

increased six-fold (Westerling et al. 2006). This study demonstrated that earlier snowmelt dates 

correspond to increased wildfire frequency. Trouet et al. (2006) confirm that these increases in 

area burned are tied to climate conditions despite forest fire suppression management practices 

such as thinning. Prolonged dry and hot periods are generally required for large fires (Gedalof et 

al. 2005) and future conditions will make these periods, and resultant wildfires, more likely 

(Falke et al. 2015).

Fish passage and impaired connectivity continue to impact bull trout and contribute to 

their decline, and isolation and habitat fragmentation in several core areas within the six recovery 

units. Large and small dams, irrigation diversions, and road crossings occur across the 

coterminous United States range of bull trout and often form impassable barriers to fish 

movement, cause entrainment, change suitable temperature regimes, fragment habitats that 

isolate bull trout local populations and affect the availability of suitable FMO habitat.
13

Water control structures and agricultural diversions have contributed to the decline of 

bull trout in several recovery units. For example, bull trout in all three core areas within the 

Klamath River Recovery Unit are currently impacted from unscreened irrigation diversions 

existing in each of the three core areas. Providing fish screens and fish passage at existing water 

control structures, and ensuring sufficient water quantity for bull trout, has been identified as

necessary for recovery within the Klamath River Recovery Unit.

While the detrimental effects from dams continue across the range of bull trout, there are 

numerous examples of significant conservation benefits to bull trout realized since 1999, 

resulting from FERC relicensing of major hydropower facilities. For example, within the 

Coastal Recovery Unit, fish passage or complete dam removal (Elwha and Glines Canyon dams 

on Elwha River, Conduit Dam on White Salmon River, and Powerdale Dam on Hood River) 

have occurred at a number of formerly impassible sites. 

Factor B. Overutilization for Commercial, Scientific, or Educational Purposes 

At the time of listing in 1999, illegal harvest and ongoing incidental take (hooking 

mortality) of bull trout by anglers catching and releasing fish or pursuing other species were 

identified as factors affecting the species in several areas (USFWS 1998a). Today, angling 

regulations have been adjusted in all States where bull trout occur to minimize angling impacts 

to bull trout, and legal, managed bull trout harvest is permitted in a handful of locations with

relatively robust bull trout populations (USFWS 1998a). Current State fishing regulations have 

generally resolved most pre-listing concerns about overutilization of bull trout by anglers, 

although incidental bycatch mortality may impact bull trout in some core areas (Fredenberg 

2014). Bull trout numbers appear to have responded positively to angling restrictions in some 

areas (USFWS 2005b; Erhardt and Scarnecchia 2014).

In certain core areas, however, there remains concern about the vulnerability of large, 

migratory adult bull trout to the effects of illegal fishing and poaching; and incidental harvest 

from legal fisheries. Incidental bycatch of anadromous bull trout in commercial gill-net fisheries 

occurs on the Olympic Peninsula (Brenkman et al. 2007). Bull trout can be locally vulnerable to 

angling pressure, particularly in late summer, when they stage for spawning in small streams. 

Enhanced enforcement of existing regulations, combined with angler education, is generally the 

best remedy to address this issue, and may include site-specific actions to control access and 

enforce take prohibitions. Thus, while at a range-wide scale we consider angling impacts to be a 

relatively minor threat, some significant localized impacts may remain that should be considered 

in core area management. 

Overutilization for scientific purposes, including collecting, is not considered a threat 

factor for bull trout. For purposes of bull trout population monitoring, we authorize a limited 
14

take of bull trout (usually nonlethal capture by net, trap, angling, or electrofishing; marking or 

PIT [passive integrated transponder] tagging; measurement and tissue sampling; and release) for 

scientific research through issuing section 10(a)(1)(A) recovery permits under the Act with 

appropriate special terms and conditions to minimize impacts to bull trout populations.

Factor C. Disease or Predation

Disease was considered only a minor threat at the time of listing (USFWS 1998a, 1999a). 

Since the time of listing, we are not aware of any confirmed disease effects on bull trout

populations, although whirling disease has some potential to affect bull trout either directly or 

indirectly through its effects on prey.

In watersheds where bull trout populations have been severely reduced or extirpated and 

connectivity impairment is likely to prevent natural recolonization, active reintroduction or 

supplementation of bull trout from appropriate source populations may help reestablish viable 

local populations to improve core area status. Active reintroduction or supplementation has 

some potential to introduce fish pathogens, but there is little information available on specific 

effects to bull trout. Some guidelines and agreements among fisheries managers have been 

developed for salmonids to reduce these risks and identify high- and low-risk transfers based on 

distance of transfer, species susceptibility, life stage, and pathogen findings (J. Evered in litt. 

2014). Future translocation programs should consider appropriate precautions against the 

introduction of fish pathogens to new watersheds.

Nonnative fish were identified as a significant threat in the original listing of bull trout 

(USFWS 1998a, 1999a), and the threat has grown significantly since that time (USFWS 2008a). 

Today, in several core areas across the six recovery units, nonnative fishes constitute the single 

most often cited primary threat. Nonnative fish of primary concern include both lake trout and 

brook trout. Lake trout, a congeneric species whose niche has strong overlap with bull trout, can 

outcompete and prey upon bull trout in lake environments where they co-occur or other large 

predators that may prey upon and/or compete or hybridize with bull trout. The effects from lake 

trout are most pronounced in the Columbia Headwaters recovery unit. For example, lake trout 

have expanded since the time of listing and are cited as the dominant primary threat in 4 of 15 

complex core areas (i.e., Lake Pend Oreille, Priest Lakes, Flathead Lake, and Swan Lake), and 8 

of 20 simple core areas (i.e., Bowman Lake, Quartz Lakes, Lower Quartz Lake, Logging Lake, 

Harrison Lake, Whitefish Lake, Upper Stillwater Lake, Lindbergh Lake, and Holland Lake), 

which together include nearly half of the Columbia Headwaters Recovery Unit landscape

(USFWS, 2010c). The expansion of lake trout shows no signs of abating, though there has been 

some success with gill-net suppression efforts in Lake Pend Oreille, Upper Priest, and Quartz 

lakes (Hansen, et al., 2010) (Fredenberg, 2015) (Ryan, et al., 2014).
15

Brook trout represent another threat to bull trout populations. Brook trout is a congeneric 

species that competes with, and can hybridize with, bull trout. Fluvial bull trout core areas are 

more likely to be influenced by the widespread distribution and abundance of brook trout. Core 

areas with fluvial and/or resident bull trout populations are more likely to be influenced by the 

widespread distribution and abundance of brook trout. Several authors project that brook trout 

will continue increasing their range in several areas (an upward shift in elevation) due to the 

effects from climate change (Wenger et al. 2011, Isaak et al. 2010, 2014; Peterson et al. 2013). 

Negative effects of brook trout on bull trout appear to vary substantially between watersheds, 

being relatively severe in small, low-gradient streams with resident or fluvial populations; while

bull trout in larger or steeper streams, particularly large individuals with migratory life histories, 

can often successfully coexist with brook trout (Peterson et al. 2013, D. Isaak in litt. 2014). 

Additionally, brown trout and northern pike have been documented as predators on 

juvenile and sub-adult bull trout, and can be found in many bull trout core areas. In addition, 

walleye and smallmouth bass are continuing to spread in several large rivers and lakes occupied 

by bull trout. The complex species interactions that lead to bull trout decline are often not well 

understood, but there is widespread concern that predation on bull trout by piscivorous (fisheating) nonnative species may play an increasingly large role. At this time, one of the few 

management options available is direct predator removal through netting, trapping, or angler 

incentives (largely by State and Tribal managers). Due in part to the high costs and social 

constraints, application of these techniques has been limited and broader implementation remains 

problematic. Many of the predator species are also highly sought after sport fish species and 

may be preferred by the public and even promoted. 

The long-term compatibility of brown trout and bull trout is not well understood. In 

some cases brown trout, which generally spawn later in the fall than bull trout, have been shown 

to superimpose their redds on bull trout redds, which may impact bull trout egg survival and 

hatching (Moran 2004). Brown trout are piscivorous at larger sizes and may prey upon juvenile 

bull trout in areas where they co-occur. Because brown trout occur in relatively warm waters, 

coldwater habitats below about 11 degrees Celsius (52 degrees Fahrenheit) appear to be 

protected from brown trout invasion, but climate change is expected to reduce the extent of this 

habitat (Isaak et al. 2015). The niche overlap between brown trout and bull trout is considerable 

and, as a result, brown trout may replace bull trout in certain circumstances.

Factor D. Inadequacy of Existing Regulatory Mechanisms

Existing regulatory mechanisms were considered mostly inadequate to conserving bull 

trout in the original listing rule for bull trout (USFWS 1998a), and changes in those mechanisms 

have been taken into account in our analysis, as described below. Under the Act, Federal 
16

agencies consult with the Service on the effects of their management and operations on bull 

trout. Ongoing land management plans (primarily the Bureau of Land Management and the 

Forest Service) and facility operations (primarily U.S. Army Corps of Engineers, Bonneville 

Power Administration, Bureau of Reclamation, and power producers operating under Federal 

Energy Regulatory Commission permits) include provisions to minimize adverse effects to bull 

trout where possible, and avoid jeopardizing the continued existence of the species. 

Implementation of management measures by Federal agencies directly responsible for adhering 

to the section 7(a)(1) and 7(a)(2) requirements of the Act is likely to result in a progressive 

diminishment of some threats on Federal lands and at Federal facilities (e.g., effects of timber 

harvest, road building, grazing, and other land management actions conducted by the Forest 

Service and the Bureau of Land Management). Section 7(a)(1) directs Federal agencies to utilize 

their authorities in furtherance of the purposes of the Act by carrying out programs for the 

conservation of listed species.

State forest practice rules have been revised and updated in Washington and Oregon, at 

least partly in response to concern for the conservation of sensitive, threatened and endangered 

species, including bull trout. Oregon has adopted various amendments to its Forest Practices 

rules and Washington has developed an entire set of new regulations primarily in response to 

Federal listings of several salmonid species, including bull trout, in the late 1990s. The Nevada 

forest practices remain essentially unchanged since the listing of bull trout in 1998. In Idaho, the 

Snake River Basin Adjudication Idaho Forestry Program is currently in development (e.g., draft 

EIS with no firm date of completion) and would supplement the existing Idaho Forestry Program 

to address aquatic species protected by the Act. The objective of the supplemental forestry 

program is the protection of listed salmon and bull trout, within the Salmon/Clearwater River 

basins, and private landowners will be encouraged to participate. However, since the Program 

has not yet been approved or funded, the future effectiveness of the Snake River Basin 

Adjudication Idaho Forestry Program is undetermined. In 2011 Montana completed a multispecies habitat conservation plan (HCP) that also included bull trout. The Montana HCP 

includes best management practices designed to minimize impacts to bull trout and its associated 

habitat (http://dnrc.mt.gov/HCP/links.asp).

In addition to consultation with other Federal agencies, the Service has engaged several 

private corporations and public agencies in the HCP process to provide for the conservation of 

bull trout. The development and implementation of HCPs has resulted in land management 

practices that generally exceed State regulatory requirements. As is the case with consultation 

with Federal agencies under the Act, the development and implementation of HCPs does not 

eliminate take or the adverse effects of legacy land management practices, but avoids jeopardy to 

bull trout by specifying actions that reduce threats and compensate for the effects of take. 

Habitat conservation plans addressing bull trout cover habitat across Montana, Oregon, 
17

Washington, Nevada, and Idaho. Additional HCPs are under active negotiation in several 

locations. 

Factor E. Other Natural or Manmade Factors Affecting its Continued Existence

Demographic Threats: Demographic threats include actions or conditions that impair 

connectivity or cause direct loss of individuals, potentially resulting in unacceptably small 

population size, which can lead to genetic or demographic bottlenecks and reduce the probability 

of persistence over time. Small population size has been identified as a primary threat in several 

core areas across the six recovery units, including all three remaining core areas in the Klamath 

Recovery Unit.

Competition and Hybridization: As discussed previously in Factor C, many of the same 

invasive predatory fish species that prey on smaller juvenile bull trout can also compete 

effectively with adult bull trout. Lake trout, brown trout, brook trout, and northern pike are large 

piscivorous species that overlap with bull trout in several core areas, and compete for the prey 

base of smaller forage fish. Direct competition for redd sites is also possible with brown and 

brook trout. 

Brook trout are the only species known to commonly hybridize with bull trout throughout 

their range. There are numerous examples where bull trout hybridization with brook trout has 

been documented resulting in bull trout declines or even local extirpations (Leary et al. 1983, 

DeHaan and Godfrey 2009, Ardren et al. 2011). When bull trout hybridize with brook trout, the 

resulting hybrid offspring are often, but not always, sterile (Kanda et al. 2002, DeHaan et al. 

2010), which leads to “wasted” reproductive effort, and likely compete with remaining bull trout 

for food and space.

Climate Change: At the time of the listing in 1999, climate change effects were not 

considered as a factor affecting bull trout. Bull trout are vulnerable to the effects of warming 

climates, changing precipitation and hydrologic regimes, and are considered a useful indicator 

species of the effects climate change will have on the mountainous stream ecosystems where 

they reside. In addition to increased degradation of bull trout habitat and increased competition 

from non-native fish, as described above (see Factors A and C), climate change in the Pacific 

Northwest, as summarized by Mote et al. (2014) includes rising air temperature, changes in the 

timing of streamflow related to changing snowmelt, increases in extreme precipitation events, 

lower summer stream flows, and other changes. Late summer streamflow in Pacific coastal 

ranges and the central Rockies has significantly declined since the mid-20th century (averaging 

about 20 percent decline), in association with warmer and drier climate, smaller snowpacks, and 

earlier melt (Leppi et al. 2012; Sawaske et al. 2014). In Pacific Northwest streams over this 
18

period, high-elevation precipitation has decreased due to a slowing in westerly winds during 

winter, a trend which is projected to continue over the 21st century (Luce et al. 2013). 

Variability in annual streamflow has also increased as drier years result in more extreme 

reductions of streamflow (Luce and Holden 2009). These impacts can affect bull trout habitat in 

a number of ways. Several climate change assessments or studies have been published (Dunham 

et al. 2003; Rieman et al. 2007; Porter and Nelitz. 2009; Rieman and Isaak. 2010; Isaak et al. 

2010, 2011, 2015; Wenger et al. 2011; Leppi et al. 2012; Luce et al. 2013; Eby et al. 2014; 

Sawaske et al. 2014; Falke et al. 2015) or are currently underway (USGS 2011) assessing the 

possible effects of climate change on bull trout. The results of these efforts allow us to better 

understand how climate change may influence bull trout and help to identify suitable 

conservation actions to improve the status of bull trout throughout their range and ensure bull 

trout persist in the face of climate change. Issues include: the effects of rising air temperatures 

and lower summer flows on range contractions; changing stream temperatures, influenced by 

stream characteristics (e.g., amount of groundwater base flow contribution to the stream, stream 

geomorphology, etc.) affecting suitable bull trout spawning and rearing habitat; threats to redds 

and juvenile habitat from stream scouring caused by increased winter precipitation extreme 

events and increased rain in lower elevations (rather than snow); lower summer flows inhibiting 

movement between populations and from spawning and rearing habitat to foraging habitat; and 

increased frequency and extent of wildfires resulting in loss and fragmentation of habitat. 

For example, a study of changing stream temperatures over a 13-year period in the Boise 

River basin estimated an 11 to 20 percent loss of suitable coldwater bull trout spawning and early 

juvenile rearing habitats (Isaak et al. 2010). Across the Pacific Northwest, water temperatures in 

free-flowing streams have increased by about 0.2 degrees Celsius [0.36 degrees Fahrenheit] per 

decade since 1980, due to air temperature increases and flow reduction (Isaak et al. 2011). 

Resurveys of historical bull trout sites in the Bitterroot basin, Montana, indicate that over 20 

years, site extirpations exceeded site colonizations and were more frequent at warm, lowelevation sites (Eby et al. 2014). These results suggest that a warming climate already may be 

affecting some suitable bull trout instream habitats. This is consistent with the conclusions of 

Rieman et al. (2007) and Wenger et al. (2011) that bull trout distribution is strongly influenced 

by climate, and predicted warming effects could result in substantial loss of suitable bull trout 

habitats over the next several decades. Stream isotherms in Idaho are projected to shift upstream 

at a rate of about 0.3 to 3.0 kilometers per decade, depending on stream slope (Isaak and Rieman 

2013). Wenger et al. (2011) also noted that bull trout already seem to inhabit the coldest 

available streams in study areas and in several watersheds bull trout do not have the potential to 

shift upstream with warming stream temperatures at lower elevations. In the Flathead basin, 

Montana, projected losses of thermally suitable spawning and rearing habitat for bull trout in 
19

August ranged from 13 to 82 percent across three plausible climate scenarios for the year 2099; 

losses of FMO habitat in August ranged from 38 to 91 percent (Jones et al. 2014). 

Sensitivity of stream temperature to changes in air temperature is complex and is 

influenced by geological and vegetation factors such as topography, groundwater recharge, 

glaciation history, and riparian vegetation (Isaak et al. 2010, Isaak and Rieman 2013). A new 

stream temperature data collection, modeling and mapping project, NorWeST, provides a much 

improved foundation for assessing bull trout coldwater habitat (USFS 2014). Stream 

temperature data for the northwestern United States have been compiled from hundreds of 

biologists and hydrologists working for dozens of resource agencies and contains more than 

45,000,000 hourly temperature recordings at more than 15,000 unique stream sites. These 

temperature data are being used with spatial statistical stream network models to develop an 

accurate and consistent set of climate scenarios for all streams.

Fine-scale assessments of the current and projected future geographic distribution of 

coldwater streams and suitable bull trout habitat have been recently developed through the 

NorWeST (Isaak et al. 2015) and Bull Trout Vulnerability Assessment (Dunham 2015) 

processes. These assessments model probability of presence using the NorWeST stream 

temperature data and models, and map suitable habitat “patches” using fish presence, local 

threats, migratory connectivity, and climate sensitivity. The climate sensitivity parameters 

affecting bull trout occurrence within patches include flow variability (e.g., frequency of winter 

floods), thermal variability (proportion of very cold streams), fire history (proportion of patch 

area severely burned), and snowpack (snow cover frequency). Other threats factors include 

composite indicators of human impacts and nonnative trout presence. Connectivity parameters 

include data among patches (stream/lake/sea distance to nearest occupied patch), migratory 

connectivity (distance to lake/sea), local barriers (culverts, diversions), and natural geomorphic 

features. The relationship of bull trout occurrence to most of these factors shows substantial 

spatial variability, indicating that threats to bull trout are often specific to particular core areas. 

Products of the Bull Trout Vulnerability Assessment model are being applied to informing 

specific management issues in several core areas, including fire management and climate change 

effects on streams in the Wenatchee basin (Falke et al. 2015) and conservation planning within 

the Klamath and lower Pend Oreille basins. 

All these efforts to address climate change effects to bull trout have informed the 

development of the bull trout recovery plan. They suggest that effective long-term conservation 

and recovery of bull trout will require a decision framework to assess possible climate change 

effects to bull trout. Utilizing the best available information regarding climate change should 

ensure that future conservation resources will be allocated to those areas with the coldest water 
20

temperatures that offer the greatest long-term benefit to sustain bull trout and their required 

coldwater habitats.

7. Bull Trout Genetics and Population Structure

At the time that we determined threatened status for all populations of bull trout in the 

coterminous United States (64 FR 58910), five potential distinct population segments (DPSs) 

were identified: (1) Klamath River, (2) Columbia River, (3) Coastal-Puget Sound, (4) Jarbidge 

River, and (5) Saint Mary-Belly River. The five DPSs were disjunct and geographically isolated 

from one another with no genetic interchange between them due to natural and man-made 

barriers, but were listed collectively since they included the entire distribution of bull trout in the 

coterminous United States.

Since listing, advances in genetics techniques and increased bull trout genetic sampling 

have improved our understanding of the genetic structure and relationships among bull trout 

populations throughout the coterminous United States. This information, useful in the 

identification of appropriate units for conservation of bull trout as part of past and current bull 

trout recovery planning strategies, continues to evolve and inform how we look at bull trout 

conservation needs. For example, Rieman and Allendorf (2001) examined available 

demographic information to evaluate effective population size for bull trout. They determined 

that most bull trout populations were at risk of reduced genetic variation due to small population 

size and recommended that recovery should include maintaining and improving connectivity and 

gene flow between populations. Spruell et al. (2003) described the genetic population structure 

of 65 bull trout populations from the northwestern United States, using 4 microsatellite loci. 

Their study concluded that genetic variation within populations was relatively low; variation 

between populations was relatively high; and the data supported the existence of at least three 

major genetically differentiated groups of bull trout, described as “Coastal,” “Snake,” and 

“Upper Columbia”. An earlier, broader scale analysis, which included western Canada (Taylor 

et al. 1999), reached similar conclusions. Whitesel et al. (2004) further analyzed the available 

scientific information associated with bull trout population structure and size to describe 

appropriate ‘groupings’ of bull trout and identify units of conservation. They concluded that for 

bull trout, “... a Conservation Unit should represent a complete and diverse environmental 

template that allows full expression of genotypic, phenotypic and spatial diversity among bull 

trout populations...” to “...help ensure resilience and persistence when environmental changes 

occur”.

More recently, Ardren et al. (2011) used newly developed and more variable genetic 

markers than previous studies and examined genetic variation among 75 representative bull trout 
21

populations sampled throughout the coterminous United States. They determined that 76 percent

of the populations had an effective number of breeders less than 50 and indicated high 

divergence among populations caused by genetic drift and a high degree of natal fidelity. Their 

results suggested that bull trout conservation efforts should be focused at the core area level and 

affirm the hierarchical conservation strategy for bull trout as described in the recovery strategy 

narrative of this recovery plan.

8. Bull Trout Conservation Successes

Since our listing of bull trout in 1999, numerous conservation measures that contribute to 

the conservation and recovery of bull trout have been and continue to be implemented across its 

range in the coterminous United States These measures are being undertaken by a wide variety 

of local and regional partnerships, including State fish and game agencies, State and Federal land 

management and water resource agencies, Tribal governments, power companies, watershed 

working groups, water users, ranchers, and landowners. In many cases, these bull trout 

conservation measures incorporate or are closely interrelated with work being done for recovery 

of salmon and steelhead, which are limited by many of the same threats. These include removal 

of migration barriers (culvert removal or redesign at stream crossings, fish ladder construction, 

dam removal, etc.) to allow access to spawning or FMO habitat; screening of water diversions to 

prevent entrainment into unsuitable habitat in irrigation systems; habitat improvement (riparian 

revegetation or fencing, placement of coarse woody debris in streams) to improve spawning 

suitability, habitat complexity, and water temperature; instream flow enhancement to allow 

effective passage at appropriate seasonal times and prevent channel dewatering; and water 

quality improvement (decommissioning roads, implementing best management practices for 

grazing or logging, setting pesticide use guidelines) to minimize impacts from sedimentation, 

agricultural chemicals, or warm temperatures. At sites that are vulnerable to development, 

protection of land through fee title acquisition or conservation easements is important to prevent 

adverse impacts or allow conservation actions to be implemented. In several bull trout core 

areas, fisheries management to manage or suppress non-native species (particularly brown trout, 

brook trout, lake trout, and northern pike) is ongoing and has been identified as important in 

addressing effects of non-native fish competition, predation, or hybridization (Fredenberg et al.

2007; DeHaan et al. 2010; DeHaan and Godfrey 2010; Fredericks and Dux 2014; Rosenthal and 

Fredenberg 2014).

A more comprehensive overview of conservation successes since 1999, described for 

each recovery unit, is found in the Summary of Bull Trout Conservation Successes and Actions 

since 1999 (USFWS 2013).
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9. Critical Habitat

We first designated critical habitat for bull trout on October 6, 2004 (USFWS 2004a), 

including 1,748 miles and 61,235 acres of bull trout habitat in the Columbia and Klamath River

basins only. This designation was subsumed within the range-wide designation of critical habitat 

on September 26, 2005 (USFWS 2005a), including 3,828 miles and 143,218 acres of bull trout 

habitat. The 2005 designation was challenged in the U.S. District Court for the District of 

Oregon, in part because of concern over large exclusions of habitat that were made from the final 

rule compared to that which had been proposed. The Court directed the agency to complete a 

proposed revision by December 31, 2009, with a final designation to be delivered to the Federal 

Register by September 30, 2010. Final critical habitat was designated for bull trout and was 

published on October 18, 2010 (USFWS 2010a), including 19,729 miles and 488,252 acres of 

bull trout habitat.

We identified 32 critical habitat units (CHUs) in our 2010 bull trout critical habitat listing 

rule (USFWS 2010a), reflecting single core areas or groups of core areas that are in close 

proximity geographically and that are included in 6 recovery units (see Figure 4). These CHUs

are specific to critical habitat designation and interagency consultation procedures under section 

7 of the Act. The CHUs are generally a level of organization at the major river basin scale that 

are intermediate in size and scope between recovery units and core areas in the hierarchical 

structure, and represent groupings of habitats that facilitate implementation of the rule, generally 

as aggregations of core areas within major river basins.

In designating bull trout critical habitat, we considered the conservation relationship 

between critical habitat and recovery planning (see Appendix G). Recovery plans formulate the 

recovery strategy for a species; however, unlike critical habitat, they are not regulatory 

documents, and there are no specific protections, prohibitions, or requirements afforded a species 

based solely on a recovery plan. While we expect that the 2010 critical habitat designation will 

contribute to the overall recovery strategy for bull trout described in this recovery plan, 

designated critical habitat, by itself, does not achieve recovery plan goals.

C. Previous Recovery Planning Efforts

Three separate draft bull trout recovery plans were completed between 2002 and 2004. 

The 2002 draft recovery plans addressed bull trout populations within the Columbia, Saint MaryBelly, and Klamath River basins (USFWS 2002b). They included individual chapters for 24 

separate recovery units. In 2004, draft recovery plans were developed for the Coastal-Puget 

Sound drainages in western Washington, including two recovery unit chapters (USFWS 2004b), 
23

and a single recovery unit chapter for the Jarbidge River in Nevada (USFWS 2004c). In total, 

the 2002 and 2004 draft recovery plans accounted for 27 separate recovery unit chapters. 

This recovery plan represents an integration of information collected since the 1999 

listing regarding bull trout life history, distribution, demographics, conservation successes, etc., 

and an update of all previous bull trout recovery planning efforts across the range of the single 

DPS currently listed under the Act, including all bull trout populations within the range of the 

species in the coterminous United States. This recovery plan supersedes and replaces previous 

draft recovery plans. The recovery unit structure has been reorganized in this current plan, 

combining the previous 27 recovery units into 6 recovery units: (1) Coastal Recovery Unit; (2)

Klamath Recovery Unit; (3) Mid-Columbia Recovery Unit; (4) Upper Snake Recovery Unit; (5) 

Columbia Headwaters Recovery Unit; and (6) Saint Mary Recovery Unit. Additionally, 

recovery criteria proposed in the 2002 and 2004 draft recovery plans were revised to focus on 

effective management of threats to bull trout at the core area level in each recovery unit, and deemphasized achieving targeted point estimates of abundance of adult bull trout (demographics) 

in each core area.

The major changes between the earlier 2002 and 2004 draft bull trout recovery plans and 

this recovery plan were summarized in the revised draft recovery plan (USFWS 2014).
24

II. Strategic Plan for Recovery

A. Overview 

The primary recovery strategy for recovery of bull trout in the coterminous United States 

is to: (1) conserve bull trout so that they are geographically widespread across representative 

habitats and demographically stable; (2) manage and ameliorate the primary threats in each of six 

recovery units at the core area scale such that bull trout are not likely to become endangered in

the foreseeable future; (3) work cooperatively with partners to develop and implement bull trout 

recovery actions in each of the six recovery units; and (4) account for new information and future 

climate effects, apply adaptive management principles and focus on actions, and potentially 

locations, that provide the greatest resilience to climate-related threats.

Bull trout recovery will require building upon the numerous and ongoing conservation 

actions implemented on behalf of bull trout since their listing in 1999. Recovery will require 

improving our understanding of how various threat factors potentially affect the species, and 

using that information to work cooperatively with our partners to design, fund and implement 

effective conservation actions in areas that offer the greatest long-term benefit to sustain bull 

trout and in areas where recovery can be achieved.

Although bull trout are believed to have undergone a significant reduction in their 

historical range prior to the time of their listing in 1999, the species continues to be found in 

suitable habitats and is geographically widespread across numerous major river basins in five 

western states. The Act does not require a species, in this case bull trout, to be recovered 

throughout its historical range or even in any set proportion of currently suitable habitat. Instead, 

the Act requires that we recover listed species such that they no longer meet the definitions of 

“threatened species” or “endangered species,” i.e., are no longer in danger of extinction now or 

in the foreseeable future.

This recovery plan also includes a Threat Assessment Tool (Appendix E) that will be 

integral to an evaluation of bull trout conservation status at the range-wide and recovery unit 

scales based on analyses of threats at the level of the component core areas. Preliminary corearea assessments can inform the recovery process by highlighting conservation actions that 

should be given locally higher priority, and by aiding managers in assessing how well recovery 

criteria are being met at the recovery unit level, thus allowing managers to target those core areas 

where conservation resources can be most efficiently directed. Furthermore, core area-level 

assessments will be useful in recovery criteria evaluation and status assessments conducted as 
25

part of future 5-year reviews and 5-factor threats analysis in any future delisting evaluation for a 

bull trout distinct population segment. 

B. Recovery Strategy

As described in our recovery planning guidance (NMFS and USFWS 2010), the recovery 

strategy provides “a logical construct that identifies the assumptions and logic underlying the 

selection of one path over another to achieve the objectives and goal”. Thus it constitutes the 

framework linking key facts and assumptions about the species’ biology, threats, and 

environmental constraints with the recommended recovery actions. The major threats and 

constraints affecting bull trout (addressed in detail with specific citations above in sections I.B.2,

Life History and Ecology and I.B.6, Factors Affecting the Species), need to be addressed with 

appropriate management actions as described below to allow survival and recovery of the 

species.

Bull trout have specific requirements for spawning and rearing habitat: appropriate 

spawning substrate (loose, clean gravel with minimal fine sediment); cold water (influenced by 

flow levels, groundwater infiltration, cold springs, riparian shading, solar radiation, valley 

geomorphology, air temperature, temperature of upstream tributaries, and other factors); 

excellent water quality (high dissolved-oxygen concentrations and minimal contamination from 

chemicals and sediment); low-gradient stream segments with stable channel structure; and 

presence of complex cover (woody debris, undercut banks, boulders, and pools). While bull 

trout expressing the resident life history will remain localized to watersheds with spawning and 

rearing habitat, the expression of migratory life history strategies (fluvial, adfluvial, or 

anadromous) is also dependent on the presence of appropriate FMO habitat, suitable flow levels, 

and lack of barriers (physical or thermal) to connectivity. Metapopulation structure, genetic 

exchange, and recolonization of extirpated local populations are dependent on unrestricted 

movement of migratory individuals through downstream FMO habitat. Appropriate timing and 

seasonality of streamflow is important for successful spawning (avoiding redd mortality from 

drying or flood scouring events), adult survival (e.g., preventing stranding in side channels), and 

to provide adequate flow for migratory movement past barriers. A suitable prey base is 

necessary for successful survival and reproduction: smaller bull trout such as juveniles and adult 

residents feed on a diverse array of zooplankton, aquatic insects, and small fish (and are 

themselves vulnerable to predation by larger predatory fish), while larger migratory adults feed 

on a variety of larger forage fish. Most of the threat factors affecting bull trout operate by 

impairing one or more of these biological requirements, which are also reflected in the primary 

constituent elements of bull trout critical habitat (USFWS 2010a). Below, we summarize the 

mechanisms by which these threat factors affect bull trout and the general recovery actions that 
26

are appropriate to effectively respond to these threat factors. Specific details and relative 

emphasis of these conservation measures will vary among different core areas and recovery 

units. Conservation actions described for bull trout recovery are summarized by core area for the 

six recovery units in the Recovery Actions section below, and will be discussed in more detail in 

the associated RUIPs.

When fine sediments enter streams at levels beyond natural background conditions, they 

can accumulate within spawning gravels and reduce survival of eggs and embryos (Pratt 1992) 

by impairing their access to oxygenated water, as well as negatively affecting juveniles and 

adults by interfering with foraging, clogging gills, physically abrading tissues, and disrupting 

orientation and movement patterns. Accumulation of sediment can degrade stream structure by 

filling in pools and changing substrate composition. Sedimentation can result from wildfire; 

erosion or debris flows from unstable slopes; and a variety of management activities, including 

instream construction, excessive grazing, timber harvest, agricultural inputs, urban/residential 

land uses, road maintenance and construction, and mining. Therefore, minimizing this threat 

requires reduction of these activities or implementing best management practices to minimize 

erosion and release of sediment into streams. For example, sediment impacts from roads can be 

addressed by identifying sediment-producing areas; redirecting runoff to downslope areas away 

from stream channels; maintaining bridges, culverts, and crossings; or decommissioning surplus 

roads and removing culverts and bridges on closed roads. Mining impacts can be reduced by 

removing or stabilizing mine tailings and waste rock within stream channels and floodplains. 

Compatible grazing practices include fencing of riparian areas, rotation of grazing, and 

relocating salt and watering facilities away from sensitive riparian areas. Timber harvest and 

other upland management impacts should avoid buffer areas along riparian zones and retain 

forest cover on unstable slopes above spawning streams. Additional research on effectiveness of 

these practices and alternative methods may be useful to adaptively improve management of bull 

trout habitat. 

Other impacts to water quality can negatively affect bull trout, including but not limited 

to: pH changes and heavy metal contamination from mines; runoff of pesticides, fecal coliform, 

or nutrients from agricultural activities or urban development; associated low dissolved oxygen 

concentrations; and oil from roads. Fish exposed to contaminants such as heavy metals and 

pesticides can suffer direct mortality at high levels, or at lower levels can experience chronic 

sublethal impacts to performance, swimming ability, migratory behavior, reproductive success, 

and survival rates. Therefore, water quality in bull trout habitat should be maintained at high 

levels by implementing best management practices and enforcing water quality standards.

Bull trout have extremely low tolerance for warm water temperatures, especially in 

spawning and rearing habitat. Thermal tolerances are narrowest during egg incubation, when 
27

warm water reduces egg survival rates and size at hatching. In juvenile and adult bull trout, 

warm water has sublethal effects such as reducing feeding rate and growth rate, or at sufficiently

high temperatures can directly cause mortality. Because water temperature is affected by 

riparian cover and inputs of cold water from groundwater and springs, management practices to 

promote coldwater habitats include identifying geomorphic zones that act as sources of cold 

water and protecting riparian areas from timber harvest, wildfire, and livestock grazing impacts

(Dunham et al. 2003). Moreover, we expect the geographic distribution of coldwater habitat to 

progressively diminish over the next 50 to 100 years as effects of climate change become more 

intense; as ambient air temperature increases, stream reaches with viable cold water sources will 

become increasingly valuable to bull trout and should be targeted early for protection and 

management (Leppi et al. 2012; Isaak et al. in review). Adult bull trout, particularly the 

migratory life history forms, may use comparatively warm river and stream reaches seasonally, 

moving out of them during warm seasons when water temperatures increase; thus, their ability to 

adaptively respond to changing water temperatures depends on full connectivity for movement 

between headwater and mainstem habitats, as discussed further below.

Streams with complex structure, including deep pools, overhanging banks, riparian 

vegetation, and large woody debris, provide local sites of cool microclimate, pockets of slow 

water, and physical shelter, thus increasing bull trout spawning success and adult and juvenile 

survivorship. Removal of these structural components (e.g., stream channelization; grazing, 

forestry, or other impacts to riparian vegetation; reduction of woody debris in streams, either by 

direct removal from streams or by harvest of riparian trees that could supply woody debris in 

future; sediment accumulation reducing pool depth) may negatively affect bull trout populations. 

Implementing management practices that prevent these impacts or restore complex structural 

components to streams will benefit bull trout reproductive success and survivorship. Most 

management practices discussed above to address sedimentation effects can help to mitigate 

impacts to structural complexity of stream and directly restore structural components and 

compensate for past impacts. 

Connectivity between spawning and rearing habitat and downstream FMO habitat 

sufficient for bull trout to move freely and with minimal risk is necessary for the expression of 

migratory life history patterns. In core areas where multiple local populations exist, interaction 

among local populations through movement of migratory individuals is critical to maintaining 

genetic diversity and recolonizing local populations that become extirpated. Thus, when 

connectivity with FMO habitat is impaired or blocked, bull trout populations tend to become 

restricted to isolated local populations of small resident fish, which may have low genetic 

diversity, are vulnerable to extirpation, and cannot be readily recolonized. Barriers to 

connectivity may consist of natural physical features such as waterfalls; river reaches that create 

mortality risks or prevent movement of adult fish because of entrainment; excessively warm 
28

water, or poor water quality; instream structures such as culverts or weirs; or dams. The severity 

of passage barriers is generally affected by the volume of streamflow, which can vary with 

seasonal precipitation, droughts, and dam operations so that passage is available only at certain 

times of year. 

Thus, removing or minimizing the effects of connectivity barriers is important for 

restoring expression of migratory life history and movement among local populations within core 

areas. Core areas should be assessed for significant passage barriers that impair their 

connectivity. Depending on impacts and cost effectiveness, restoration actions may include 

removal or improvement of culverts, modifying seasonal instream flows, or reconfiguring natural 

passage barriers. However, the potential for facilitating colonization by nonnative fishes should 

also be considered before implementing these projects.

Dams that were designed without fish passage facilities, or with fish passage capability 

inadequate for movement of bull trout, can impair or block connectivity. Some dams can block 

movement by causing seasonal dewatering of downstream reaches; or at the other extreme, high 

volumes of spill can also result in nitrogen supersaturation downstream, which can impair or kill 

bull trout by causing gas bubble disease. Seasonal flow regimes resulting from dam operations 

may differ substantially from the flow patterns needed for bull trout migration, for example by 

release of high flows in summer to supply agricultural uses. Therefore, in each core area where 

dam operations are a significant threat to recovery they should be reviewed to determine whether 

they are impairing bull trout passage, and modified if necessary to minimize impacts. Where 

fish passage facilities are lacking or inadequate, it may be appropriate to construct improved 

facilities, or in some cases consider decommissioning the dam.

Water diversions at dams, ditches, small agricultural intakes, and hydropower facilities

can entrain juvenile or adult bull trout, killing them or permanently removing them from access 

to spawning habitat. Therefore, to prevent this impact in core areas where it is a threat, water 

diversion structures or hydropower facilities within bull trout spawning or FMO habitat should 

be prioritized by their level of impact; screens or other remedial actions that are adequate to 

exclude juvenile bull trout should be installed or implemented.

Lack of suitable habitat within FMO habitat, including shared FMO habitats in mainstem, 

estuarine, and near-shore areas, can increase mortality of migratory individuals or discourage 

movement through these areas, resulting in reduced connectivity among local populations or core 

areas. Therefore, impaired FMO areas should be identified within core areas and in shared FMO

habitats, and habitat improvement measures should be implemented where feasible. Recovery 

actions in mainstem river habitats may include flow and water temperature management, channel 

restoration, and improvement of structural habitat components. In estuarine and near-shore
29

habitats projects may include improving beach nourishment; removing or modifying structures

such as riprap, dikes, and tide gates; contaminant remediation; or restoring eelgrass or kelp beds.

In watersheds where bull trout populations have been severely reduced or extirpated and 

connectivity impairment is likely to prevent natural recolonization, active reintroduction or 

supplementation of bull trout from appropriate source populations may help reestablish viable 

local populations to improve core area status. Such efforts may involve direct translocation from 

more vigorous populations or captive breeding of bull trout in controlled propagation facilities. 

Such translocation programs should consider appropriate precautions against introduction of fish 

pathogens to new watersheds.

Because bull trout depend on the availability of invertebrates and smaller fish as prey, 

they can be vulnerable to the introduction of other species with overlapping diets (lake trout, 

northern pike, brown trout, brook trout, and bass) that can compete effectively for these 

resources and reduce the prey base. Insufficient availability of food or behavioral exclusion 

from foraging habitat due to competition can result in decreased growth and survival of bull 

trout. Brown trout and brook trout may also compete directly for spawning and rearing areas, 

damaging bull trout redds and reducing incubation success. Introduction of nonnative fishes can 

also interact with changes in habitat, so that other species that are better adapted to warmer water 

temperatures might competitively exclude bull trout as water temperatures increase. Moreover, 

larger predatory species (particularly lake trout, northern pike, and brown trout) can prey directly 

on smaller bull trout. Once established, nonnative fish populations can often colonize connected 

watersheds and can be difficult to eradicate. 

Therefore, minimizing or eliminating these negative effects from past introductions and 

preventing new introductions into bull trout habitat is important for recovery of bull trout, and is 

a critical issue in certain recovery units. Because nonnative species issues vary greatly among 

core areas depending on ecosystem characteristics and the particular species involved, 

competitive and predatory interactions within watersheds should be reviewed and the feasibility 

of eradication or suppression (for example through targeted experimental removal or liberal 

harvest regulations) should be assessed. Where these measures will benefit bull trout and are 

cost-effective and feasible, nonnative fish species should be actively controlled. Ongoing public 

and private fish stocking programs should be reviewed and modified if necessary to avoid any 

additional introductions of nonnatives; moreover, the potential for illegal introductions should be 

addressed with a combination of public education and enforcement policies. Removal of barriers 

within streams, while usually beneficial for migratory movement of bull trout, should also be 

evaluated with respect to the potential for facilitating colonization by nonnative fishes.

Introduced brook trout can also hybridize with bull trout. Hybrid individuals do not 

contribute to perpetuation of bull trout populations; they are usually sterile and if not, their 
30

offspring are of mixed genetic composition and could result in introgression of brook trout 

genetics into the population. Thus, hybridization represents wasted reproductive effort for bull 

trout, and should be avoided in order to maintain ecologically viable and genetically pure bull 

trout populations. Many of the same measures discussed above for competitive and predatory 

interactions with nonnative fishes are appropriate for addressing hybridization; however, genetic 

studies of bull trout populations that coexist with brook trout can also be useful to evaluate the 

extent of hybridization and identify introgressed individuals. 

We currently consider disease a minor threat to bull trout. Whirling disease has potential 

to affect bull trout either directly or indirectly through its impacts on prey species or competitors. 

Therefore, research into its effects on fish communities and potential management remedies may 

be important in core areas where this is an issue. 

Impacts to bull trout through fishing include killing by legal harvest (in a few watersheds 

where allowed by State fishing regulations at the time of listing) or illegal poaching; harassment 

and inadvertent injury or hooking mortality, for individuals incidentally caught and released by 

recreational anglers targeting other species; and bycatch in nets. Where bull trout populations 

are healthy and angling pressure is relatively low they may be able to sustain a moderate level of 

harvest or bycatch mortality, so it may be reasonable to establish recreational fisheries under 

State management authority in core areas that are proven to have fully met recovery targets. 

However, excessive harvest has potential to depress population levels and slow or reverse 

progress toward recovery, so existing regulations should be enforced and the development of 

State or Tribal fish management plans should employ a conservative approach based on 

watershed-specific fisheries research on bull trout population status and potential for overharvest. 

Climate change is an independent threat to bull trout that exacerbates many of the other 

threats discussed above, and that we expect to increase in severity over coming decades. Stream 

temperature modeling indicates that increasing air temperatures and other changes to hydrology 

and other factors, modified by local habitat conditions, will tend to result in increased water 

temperatures, reducing the amount of stream habitat with suitable cold water conditions to 

scattered refugia protected by groundwater inputs or other factors. Warm dry conditions are also 

likely to increase the frequency and extent of forest fires, which in addition to their acute effects 

on streams can increase sedimentation and cause longer-term warming of water by eliminating 

riparian shading. Projected lower instream flows and warmer water in FMO habitats will 

exacerbate the lack of connectivity within and between bull trout core areas. Moreover, we 

expect increased water temperatures to alter competitive interactions between bull trout and other

fish species that are better adapted to warm conditions, resulting in increased risk of bull trout 

habitat being colonized by fishes that will outcompete and/or prey upon them. Climatic warming 

will change seasonality of streamflow, as increased spring runoff from rain-on-snow events 
31

causes flooding and scouring of spawning gravels, while glacial retreat and reduction of summer 

snowpack reduces coldwater flows during summer months. Sea-level rise will result in the loss 

of, and changes to, near-shore and estuarine habitat. Although addressing the root causes of 

greenhouse gas emissions and climate change is not within our jurisdiction, management 

planning should account for these increased threats and proactively protect those habitats that are 

expected to best maintain coldwater conditions suitable for bull trout. 

Adequate responses to all of these threats will require cooperative work from a wide 

variety of partners, including Federal and State land and water management agencies, regulatory 

agencies, State fish and game departments, Tribes, and user groups. Enforcement of fisheries 

regulations and habitat protection standards by State, Federal, and Tribal agencies is critical for 

protecting bull trout and their habitat. In a number of core areas local working groups are 

already implementing a wide variety of these recovery actions for bull trout, and they will 

continue to be a crucial resource for working toward recovery (i.e., Yakima Basin Fish and 

Wildlife Recovery Board and Lower Columbia Fish Recovery Board in WA; Avista Native 

Salmonid Restoration Program in MT; Malheur River Bull Trout Technical Advisory Committee 

in OR) (USFWS 2014). See Appendix G for additional information on recovery implementation 

approaches for State, Federal, and Tribal governments.

The Role of Artificial Propagation and Translocation in Bull Trout Recovery 

Bull trout remain widely distributed but have been extirpated from major portions of their 

range within the coterminous United States, particularly in the southern and western portions of 

their range including the McCloud River in California, parts of north-central Washington, and 

substantial portions of the Klamath, Deschutes and Willamette basins in Oregon. In some 

watersheds where bull trout populations have been severely reduced or extirpated and 

connectivity impairment is likely to prevent natural recolonization, active reintroduction or 

supplementation of bull trout from appropriate source populations may help reestablish viable 

local populations to improve core area status. Such efforts may involve direct translocation 

(transplantation) from more vigorous populations or captive breeding of bull trout in controlled 

artificial propagation facilities. Such translocation programs should consider appropriate 

precautions against introduction of fish pathogens to new watersheds.

Artificial propagation refers to the production of individuals, generally within a managed 

environment, for the purpose of augmenting a wild population, or for the purpose of 

reintroduction to the wild (USFWS 2000). Translocation, while broadly defined as the 

intentional release of animals to the wild to establish, reestablish, or augment a population 

(IUCN 1987), is often more narrowly described in the fisheries literature as the capture and 
32

movement of wild fish from one location to another (George et al. 2009; Shively et al. 2007). 

Artificial propagation and translocation are the two primary methods of accomplishing species 

introductions, reintroductions, and augmentations (sometimes referred to as supplementation). 

Introduction refers to the release of fish outside their native range whereas reintroduction is the 

release of fish within their native range (George et al. 2009). Augmentation refers to the 

addition of individuals to an existing wild population.

Although guidance specific to bull trout is limited, there are readily available guidelines 

for translocation and artificial propagation (Williams et al. 1988; Minckley 1995; IUCN 1998; 

George et al. 2009; Seddon et al. 2007). Dunham et al. (2011) provided guidance specific to 

reintroduction feasibility assessments with a framework applied to a recent bull trout 

reintroduction effort in the Clackamas River, Oregon. Guidance on artificial propagation is 

provided in the joint policy of the Service and the National Marine Fisheries Service regarding 

the controlled propagation of listed species (65 FR 56916). 

The Montana Bull Trout Scientific Group (MBTSG) evaluated seven strategies for the 

potential use of artificial propagation in the recovery of bull trout (MBTSG 1996). The report 

evaluated the use of hatcheries in establishing genetic reserves, restoration stocking (i.e., 

reintroductions), research activities, supplementation (i.e., augmentation) programs, 

introductions to expand distribution, and the establishment of “put, grow, and take” fisheries. 

The report concluded that the potential use of hatcheries in bull trout recovery could include the 

establishment of genetic reserves for declining populations, restoration stocking (i.e., 

reintroductions), and some research activities including the evaluation of hybridization. 

However, the report concluded that the use of hatcheries for bull trout supplementation 

programs, “put, grow, and take” stocking, and introductions outside historical range were not 

appropriate. For bull trout recovery planning purposes, the Service generally supports these 

recommendations from the MBTSG (1996).

Relative to other widely distributed native trout in North America, the record of bull trout 

propagation and translocation is sparse (MBTSG 2006, Shively et al. 2007). Propagation and 

translocation programs that have occurred since bull trout were federally listed in 1998 have 

been sporadic and geographically dispersed due in part to an absence of clear bull trout recovery 

goals and objectives to guide these programs and a lack of a large-scale system of prioritization 

that would help assess the biological value of these programs relative to other recovery actions. 

To bridge this gap,, models recently developed through the NorWeST (Isaak et al. 2015) and 

Bull Trout Vulnerability Assessment (Dunham 2015) processes will be valuable to conduct a 

range-wide assessment of current and projected future coldwater habitats and the threats to the 

persistence of bull trout in the coterminous United States. Utilizing existing data, climate and 
33

non-climate threats can be evaluated by the independent or interactive influences of these factors 

on the probability of persistence of local populations. Spatial structuring of bull trout 

populations and habitats across the species’ range can be described by mapping and attributing 

occupied and unoccupied patches of habitat in all designated core areas. The identification of 

suitable but unoccupied habitats, based on probabilistic models of bull trout presence, can prove 

valuable for guiding implementation of recovery tasks such as translocations or passage if such 

areas are found consistent with recovery and do not pose unintended consequences for other 

species (e.g., Dunham et al. 2011). We anticipate that this effort, utilized in combination with 

recovery criteria for individual recovery units, will be a critical tool for evaluating and 

prioritizing areas for reintroduction and for weighing the biological benefits of reintroduction 

against other recovery actions.

C. Recovery Units

Our bull trout recovery strategy is founded on a hierarchical approach (Figure 3) to 

geographic classification. Bull trout are listed as a single DPS within the five-state area of the 

coterminous United States. This single DPS is subdivided into six biologically-based recovery 

units, as described below. Recovery units are population units that have been "...documented as 

necessary to both the survival and recovery of the species in a final recovery plan" (NMFS and 

USFWS 2010). A viable recovery unit should demonstrate that the three primary principles of 

biodiversity have been met: representation (conserving the breadth of the genetic makeup of the 

species to conserve its adaptive capabilities); resilience (ensuring that each population is 

sufficiently large to withstand stochastic events); and redundancy (ensuring a sufficient number 

of populations to provide a margin of safety for the species to withstand catastrophic events). 

Therefore, each recovery unit is “individually necessary to conserve [biological features that are] 

necessary for long-term sustainability of the entire listed entity,” and thus “recovery criteria for 

the listed entity should address each identified recovery unit, and every recovery unit must be 

recovered, before the species can be delisted” (NMFS and USFWS 2010).

A distinct population segment (DPS) differs from a recovery unit in that it is an 

individual listed entity, designated through a rule-making process pursuant to Section 4 of the 

Act, and can be listed or delisted independently of other populations of the same species. Our 

1996 DPS policy (USFWS 1996) defines the elements we consider when deciding whether to list 

a DPS under the Act: (1) discreteness of the population segment in relation to the remainder of 

the species to which it belongs; (2) significance of the population segment to the species to 

which it belongs; and (3) the population segment’s conservation status in relation to the Act’s 
34

Figure 3. Hierarchical relationship of bull trout geographic classification units.

standards for listing. It is possible for a recovery unit to also meet these criteria and qualify as a 

DPS, but because DPSs can be designated only through a federal rule-making process, a 

recovery plan cannot designate a DPS or treat a recovery unit as one (NMFS and USFWS 2010).

Upon completion of our 2008 5-year review, we determined that bull trout should still be 

listed as threatened and that the Service should “develop a number of recovery units for bull trout 

(perhaps 5 to 10 for management purposes) that contain assemblages of core areas that retain 

genetic and ecological integrity, and allow potential future options to pursue regulatory 

relief/delisting on a recovery unit basis”. We then conferred with State and Federal partners to 

determine the best course of action and determined that there was a desire from partners to 

complete a final recovery plan to help ensure that recovery actions would continue to be 

implemented. 

Each of the six recovery units are further organized into multiple bull trout core areas, 

which are mapped as non-overlapping watershed-based polygons, and each core area includes 

one or more local populations. Within the coterminous United States we currently recognize 109

occupied core areas, which comprise 600 or more local populations. In addition, there are six 

core areas where bull trout historically occurred but are now extirpated, and two “research needs 

areas” where bull trout were known to occur historically, but their current presence and historical 

use of the area are uncertain. The core areas are designated based on the best available 

information, and since the publication of the 2002 and 2004 draft recovery plans some core areas 

1

US

DPS

6

Recovery Units

109 Core Areas 
35

have been modified, split, or combined as more specific distribution, migratory patterns, and 

genetic information have been gathered. Core areas are functionally similar to bull trout 

metapopulations, in that bull trout within a core area are much more likely to interact, both 

spatially and temporally, than are bull trout from separate core areas. While bull trout are not 

listed in Canada, some core areas are heavily dependent on upstream or downstream SR or FMO 

habitat in Canada (e.g., Saint Mary River, Kootenai River, and Skagit River).

Each occupied core area is composed of often patchily distributed occupied areas of bull 

trout habitat which include one or more local populations. Core areas can be further described as 

complex or simple core areas. Complex core areas are core areas that contain multiple local bull 

trout populations; typically they are situated in a larger patch of habitat, sometimes occupied by 

bull trout of both the migratory life history form and the resident form, which includes a diverse 

pattern of connected SR and FMO habitats. Simple core areas are those that contain one bull 

trout local population. Simple core areas are almost always small in scope, with a population 

size that is necessarily restricted by the size of the habitat. Typically, simple core areas are 

ecologically if not physically isolated from other core areas by natural, not anthropogenic factors 

(e.g., natural barriers, thermal gradients, or large spatial separation from other core areas) that 

have been operable for thousands of years. However, simple core areas may represent extremes 

of the range or habitat and may contain unique genetic or life history adaptations worthy of 

preservation. If additional local populations are discovered or are colonized within simple core 

areas, it could be reclassified as a complex core area. The relative importance of any core area 

will need to be assessed with regard to the specific recovery unit in which the core area is 

located. If a core area contains a unique phenotype or genotype the relative importance of that 

core area should be assessed in terms of resilience, redundancy, and representation compared to 

all core areas (simple or complex) in a specific recovery unit. 

In the bull trout critical habitat rule (USFWS 2010a) we also identified a number of 

marine or mainstem riverine habitat areas outside of bull trout core areas that provide primary 

constituent elements of critical habitat. These areas do not include SR habitat, but provide FMO 

habitat that is typically shared by bull trout originating from multiple core areas. These shared 

FMO areas thus support the viability of bull trout populations by contributing to successful 

overwintering survival and dispersal among core areas.

Since the early 2000s, new data and reanalysis have suggested that the coterminous 

United States listed entity would be more appropriately divided into 6 recovery units, rather than 

the 5 DPSs identified in the original listing rules or the 27 recovery units identified in the 2002

and 2004 draft recovery plans. We worked with a number of State, Federal, and Tribal partners 

in 2008 and 2009 to evaluate alternatives for organizing core areas into possible recovery units 

that would also be consistent with the “discreteness” and “significance” criteria in the DPS 
36

policy. Ten alternatives were evaluated that explored from 2 to 69 potential recovery units, 

based on mitochondrial and microsatellite DNA analysis, and on biogeographical considerations, 

including geological establishment of major watersheds, isolation of portions of watersheds 

above major waterfalls, co-occurrence with other fish species, and occurrence in different 

ecological zones (Ardren et al. 2011). The six recovery units identified in this plan (Figure 4) 

reflect this most recent information and analysis, and were first described in the 2010 proposed 

critical habitat rule (USFWS 2010a). They include: (1) Coastal Recovery Unit; (2) Klamath 

Recovery Unit; (3) Mid-Columbia Recovery Unit; (4) Upper Snake Recovery Unit; (5) Columbia 

Headwaters Recovery Unit; and (6) Saint Mary Recovery Unit (Figure 4).

Figure 4. Locations of the six bull trout recovery units in the coterminous United States.
37

A brief description of the six recovery units (Figures 5 to 10) identified in this recovery 

strategy is provided below; see Appendix D for a more complete description of each recovery 

unit. Each recovery unit comprises several neighboring core areas that share similar bull trout 

genetic, geographic (hydrographic), and/or habitat characteristics. Conserving bull trout at the 

core area level allows for the maintenance of broad representation of genetic diversity. 

Neighboring core areas will benefit from potential source populations in the event of local 

extirpations and provides a broad array of options among neighboring core areas to contribute 

recovery under uncertain future environmental change. 
38

Figure 5. Map of the Coastal Recovery Unit.

The Coastal Recovery Unit is located within western Oregon and Washington. Major 

drainages include the Olympic Peninsula, Puget Sound, and Lower Columbia River basins, 

Upper Willamette River, Hood River, Lower Deschutes River, Odell Lake, and the Lower 

Mainstem Columbia River. In the Coastal Recovery Unit, we have designated 21 existing bull 

trout core areas (including the Clackamas River core area where bull trout had been extirpated

and were reintroduced in 2011) and identified 4 historically occupied core areas that could be 

reestablished. Core areas within the recovery unit are distributed among three geographic 

regions: Puget Sound (includes one core area that is actually part of the lower Fraser River 

system), Olympic Peninsula, and Lower Columbia River. The only core areas currently 

supporting anadromous local populations of bull trout are located within the Puget Sound and 

Olympic Peninsula geographic regions.
39

Figure 6. Map of the Klamath Recovery Unit.

The Klamath Recovery Unit is located in southern Oregon and comprises three bull trout 

core areas, all within the Klamath River drainage. The Upper Klamath Lake core area is 

comprised of the northern portion of the lake and its immediate major and minor tributaries. The 

Sycan River core area is comprised of Sycan Marsh and its tributaries and the Sycan River and 

its tributaries. The Upper Sprague River core area is comprised of drainages of the North Fork 

and South Fork of the Sprague River. 

Eight local populations presently occur in the Klamath Recovery Unit. In addition to 

these eight, nine other local populations previously existed (i.e., Annie Creek, Cherry Creek, 

Sevenmile Creek, Fort Creek, Calahan Creek, Coyote Creek, Sycan River, North Fork Sprague 

River, and South Fork Sprague River; Arant 1911, Light et al. 1996, Buchanan et al. 1997,

Service 2002a). This recovery unit is the most significantly imperiled, having experienced 

considerable extirpation and geographic contraction of local populations and declining 

demographic condition, and natural recolonization is constrained by dispersal barriers and 

presence of nonnative brook trout. 
40

Figure 7. Map of the Mid-Columbia Recovery Unit.

The Mid-Columbia Recovery Unit is located within eastern Washington, eastern Oregon, 

and portions of Idaho. Major drainages include the Yakima River, John Day River, Umatilla 

River, Walla Walla River, Grande Ronde River, Imnaha River, Powder River, Clearwater River, 

and small drainages along the Snake River and Columbia River. The Mid-Columbia Recovery 

Unit includes 24 occupied core areas in 4 geographic regions: (1) the Lower Mid-Columbia (6

core areas in the John Day, Umatilla, and Walla Walla basins); (2) the Upper Mid-Columbia (5

core areas from the Yakima basin north to the Canadian border); (3) the Lower Snake (11 core 

areas in the Clearwater, Tucannon, Asotin, Grande Ronde, and Imnaha basins); and (4) the MidSnake (2 core areas in the Powder basin and Pine, Indian and Wildhorse Creeks). There are also 

two historically occupied core areas (Eagle Creek and Chelan River) and one Research Needs 

Area (Northeastern Washington) in this recovery unit.
41

Figure 8. Map of the Upper Snake Recovery Unit.

The Upper Snake Recovery Unit occurs within central Idaho, northern Nevada, and 

eastern Oregon. Major drainages include: the Salmon River, Malheur River, Jarbidge River, 

Little Lost River, Boise River, Payette River, and the Weiser River. The Upper Snake Recovery 

Unit contains 22 bull trout core areas found in 7 geographic regions: Boise River, Jarbidge River, 

Little Lost River, Malheur River, Payette River, Salmon River and Weiser River. The only core 

areas currently supporting adfluvial populations of bull trout are located in the Upper Salmon 

River, Deadwood River, Anderson Ranch, Arrowrock, Opal Lake, and Lake Creek core areas. 

All remaining core areas contain resident populations and most have fluvial populations.
42

Figure 9. Map of the Columbia Headwaters Recovery Unit.

The Columbia Headwaters Recovery Unit occurs within western Montana, northern 

Idaho, and a portion of northeastern Washington. Major drainages include the Coeur d’Alene 

Lake Basin, Kootenai River Basin, and the Clark Fork River Basin. There are 35 bull trout core 

areas that occur in 4 geographic regions: Clark Fork River, Flathead Lake, Coeur d’Alene Lake, 

and Kootenai River. Fifteen of the 35 core areas are referred to as “complex” core areas as they 

represent larger interconnected habitats, each containing multiple spawning streams considered 

to host separate and largely genetically identifiable local populations. The other 20 are “simple” 

core areas represented primarily by isolated headwater lakes (most are in Glacier National Park) 

with single local populations.
43

Figure 10. Map of the Saint Mary Recovery Unit.

The Saint Mary Recovery Unit, which is located in Montana but is heavily linked to 

downstream resources in southern Alberta, Canada, comprises four core areas; only one (Saint 

Mary) is a complex core area with multiple (four) local populations. The remaining three core 

areas (Slide Lake, Cracker Lake, and Red Eagle Lake) are simple core areas that occur upstream 

of seasonal or permanent barriers comprised of genetically isolated single local populations in 

Glacier National Park.

D. Recovery Goals, Objectives, and Criteria

The ultimate goal of this recovery strategy is to manage threats and ensure sufficient 

distribution and abundance to improve the status of bull trout throughout their extant range in the 

coterminous United States so that protection under the Act is no longer necessary. When this is 

achieved, we expect that:

• Bull trout will be geographically widespread across representative habitats and 

demographically stable;

• The genetic diversity and diverse life history forms of bull trout will be generally 

conserved; and

• Cold water habitats essential to bull trout will be conserved and connected.
44

Specifically, this recovery plan outlines actions needed to:

• Effectively manage and ameliorate primary threats. We will focus on effectively 

managing and ameliorating the primary threats identified for each recovery unit at the 

core area scale such that bull trout will respond and persist well into the future.

• Work cooperatively with partners to develop and implement bull trout recovery 

actions. This includes: acknowledging and building upon the numerous and ongoing 

conservation actions that have already been implemented throughout much of the range 

of bull trout since the time of listing, and utilizing existing and new information, 

including decision support tools (i.e., Structured Decision Making, climate change 

considerations) in developing and prioritizing conservation actions in each recovery unit

that have been included in their associated RUIPs.

• Adaptively manage the bull trout recovery program. Because the effectiveness of 

many of the recovery actions described in this recovery plan, as well as current and future 

climate effects to all populations, are not completely understood, we will apply adaptive 

management principles to future population monitoring, recovery implementation, and 

other recovery actions, including threat management interactions, for bull trout. Specific 

recovery actions for bull trout in each of the six recovery units are described in greater 

detail in the associated RUIPs and accompanying implementation schedules included in 

this recovery plan.

• Focus recovery efforts on actions, and potentially within recovery units, which 

provide the greatest resilience against difficult-to-manage threats such as climate 

change. Emerging decision support tools such as the NorWeST regional stream 

temperature database, mapping and modeling provide information on prioritizing

recovery investments.

It should be emphasized that although bull trout are believed to have undergone a 

significant reduction in their historical range prior to the time of their listing in 1999, the species 

continues to be found in suitable habitats and is geographically widespread across numerous 

major river basins in five western states. The Act does not require a species, in this case bull 

trout, to be recovered throughout its historical range or even in any set proportion of the 

currently suitable habitat. Instead, the Act requires that we recover listed species such that they 

no longer meet the definitions of “threatened species” or “endangered species”.
45

E. How Much Is Enough?

The goals, objectives and criteria stated above are intended to meet the purposes of the 

Act which include “to provide a means whereby the ecosystems upon which [species] depend 

may be conserved,” and to bring species to the point where the protections of the Act are no 

longer necessary. The threshold of when protections are no longer necessary can vary depending 

on the degree of certainty of conservation sought over time; e.g., minimally viable species (least 

certain over shortest time) (Reed et al. 2003, Trail et al. 2007); ecologically viable species 

(moderately certain into foreseeable future) (Peery et al. 2003), or species with viability of 

evolutionary potential (most certain over longest time) (Lynch and Lande 1998).

Our recovery planning guidance (NMFS and USFWS 2010) recommends that recovery 

criteria be SMART: Specific, Measurable, Achievable, Realistic, and Time-referenced. We 

seek to identify recovery criteria for bull trout that meet these practical directives and are based 

in a sound scientific rationale, reflecting biodiversity principles of resilience (ecological quality 

and ability to persist), redundancy (maintaining multiple replicates of populations/habitats to 

insure against catastrophic loss), and representation (conserving the full range of natural 

variation) (Shaffer and Stein 2000, Tear et al. 2005). We have additionally identified seven 

principles of conservation specific to bull trout (USFWS 2010): (1) conserve the opportunity for 

diverse life history expression; (2) conserve the opportunity for genetic diversity; (3) ensure bull 

trout are distributed across representative habitats; (4) ensure sufficient connectivity among 

populations; (5) ensure sufficient habitat to support population viability (e.g., abundance, trend 

indices); (6) address threats, including climate change; and (7) ensure sufficient redundancy in 

conserving population units. These recovery principles take into account the threats and physical 

or biological needs of the species throughout its range and focus on the range-wide recovery 

needs. 

Bull trout continue to be found in suitable habitats and are geographically widespread, 

and their population status remains strong in some core areas, across numerous major river 

basins within the six recovery units that comprise the coterminous distinct population segment. 

However, we also acknowledge that despite our best conservation efforts identified in this 

recovery plan, it is possible that some existing bull trout core areas may become extirpated due 

to various factors, including the effects of small populations and isolation. Thus, our current

approach to identifying recovery criteria and necessary recovery actions for bull trout is intended

to ensure adequate, long-term conservation of genetic diversity, life history features, and broad 

geographical representation of bull trout populations, while acknowledging a small number of 

local extirpations may occur without preventing recovery if threats are successfully managed in 

most core areas. Specifically, we have developed a recovery approach that: (1) focuses on the 

identification of and effective management of known and remaining threat factors to bull trout in 
46

each core area; (2) acknowledges that some extant bull trout core area habitats will likely change 

(and may be lost) over time; and (3) identifies and focuses recovery actions in those areas where 

success is likely to meet our goal of ensuring the certainty of conservation of genetic diversity, 

life history features, and broad geographical representation of remaining bull trout populations so 

that the protections of the Act are no longer necessary.

F. Bull Trout Recovery Criteria

The recovery criteria represent our best assessment of the conditions that would most 

likely result in a determination that listing under the Act is no longer required. For bull trout,

these conditions will be met when conservation actions have been implemented to ameliorate the 

primary threats in suitable habitats. If the primary threats have been effectively managed in each 

recovery unit, the long-term persistence of bull trout should be ensured. 

The Service may initiate an assessment of whether recovery has been achieved and 

delisting is warranted when the following has been accomplished in each recovery unit:

- For the Coastal, Mid-Columbia, and Upper Snake Recovery Units: Primary threats are 

effectively managed in at least 75 percent of all core areas, representing 75 percent or more 

of bull trout local populations within each of these three recovery units (Table 1). 

- For the Columbia Headwaters Recovery Unit: Primary threats are effectively managed in 75 

percent of simple core areas and 75 percent of complex core areas, representing 75 percent or 

more of bull trout local populations in both simple and complex core areas (Table 1).

- For the Klamath and Saint Mary Recovery Units: All primary threats are effectively 

managed in all existing core areas, representing all existing local populations. In addition, 

because 9 of the 17 known local populations in the Klamath Recovery Unit have been 

extirpated and others are significantly imperiled and require active management, we maintain 

that the geographic distribution of bull trout within this recovery unit needs to be 

substantially expanded before it can be considered to have met recovery goals. To achieve 

recovery, we seek to add seven additional local populations distributed among the three core 

areas (two in the Upper Klamath Lake core area, three in the Sycan core area, and two in the 

Upper Sprague core area) (Table 1).
47

- In recovery units where shared FMO habitat outside core areas has been identified, 

connectivity and habitat in shared FMO areas should be maintained in a condition sufficient 

for regular bull trout use and successful dispersal among the connecting core areas for those 

core areas to meet the criterion. Shared FMO areas that function sufficiently to meet the 

criterion should provide the primary constituent elements of critical habitat specific to 

migration habitat.

Table 1. Recovery (Delisting) Criteria: For each recovery unit, number of core areas (and 

local populations) where threats must be effectively managed; reaching this ‘threshold’ 

would initiate the delisting evaluation process.

Recovery Unit Existing Threshold

Total Number 

of Extant

Core Areas

Total 

Number of 

Local 

Populations 

within 

Extant Core 

Areas

Minimum 

Number of

Core Areas 

with Threats 

Effectively 

Managed

Minimum 

Number of 

Local 

Populations 

within 

Effectively 

Managed 

Core Areas

Coastal RU1 20 84 15 63

Mid-Columbia RU 24 142 18 107

Upper Snake RU 22 207 17 156

Columbia 

Headwaters RU2

(simple core areas)

20 20 15 15

Columbia 

Headwaters RU2

(complex core

areas)

15 143 12 108

Klamath RU3 3 8 3* 8*

Saint Mary RU 4 7 4 7 1

Reintroduced population in Clackamas River core area is considered a potential local population until confirmed as 

established; if successful, it may contribute toward meeting the Coastal RU thresholds.

2 For the Columbia Headwaters RU: primary threats are effectively managed in 75 percent of simple core areas and

75 percent of complex core areas.

3

Klamath RU: effective primary threat management in 100 percent of existing core areas and local populations, plus 

additional reintroductions.
48

Outcome: If threats are effectively managed as described in Table 1 above, we expect that bull 

trout will respond accordingly and reflect the biodiversity principles of resilience, redundancy,

and representation. Specifically, achieving the proposed recovery criteria in each recovery unit

would result in geographically widespread and demographically stable local bull trout 

populations within the range of natural variation, with their essential cold water habitats

conserved and connected to allow their diverse life history forms to persist into the foreseeable 

future; therefore the species would be brought to the point where the protections of the Act are 

no longer necessary. 

In developing this bull trout recovery plan, the recovery criteria and recovery actions are 

intended to ensure that bull trout will be conserved as an ecologically viable species for the 

foreseeable future, and where possible, maintain its evolutionary potential. In this context, 

recovery must include the adequate conservation of genetic diversity, life history features, and 

broad geographical representation of bull trout populations in six recovery units that comprise 

the threatened coterminous United States population of bull trout. When identified threats have 

been sufficiently removed and bull trout populations are secure in an ecologically or 

evolutionarily significant portion of its range, the protections of the Act would no longer be 

warranted. With these goals in mind, the recovery plan acknowledges that, despite our best 

conservation efforts identified in this recovery plan, it is possible that some existing bull trout 

core areas will become extirpated within the foreseeable future due to various factors including 

the effects of small populations, isolation, and climate change. Further, the recovery plan also 

recognizes that a small number of such extirpations could occur without preventing recovery if 

threats are successfully managed in most core areas. 

G. Distinct Population Segment(s) and the Coterminous United States 

Population

In the future we may consider, in coordination with our partners and consistent with 

applicable law at the time, whether pursuing the potential reclassification of the listed 

coterminous United States population of bull trout into multiple distinct population segments

(DPSs) is warranted, and/or whether it is a possible approach to delisting bull trout. Section 3 of 

the Act defines “species” to include “any distinct population segment of any species of vertebrate 

fish or wildlife which interbreeds when mature”. In 1996, the Service and National Marine 

Fisheries Service published a joint policy guiding the recognition of DPSs of vertebrate species 

(61 FR 4722-4725). Under this policy, we consider two factors to determine whether the 

population segment is a valid DPS and thus eligible for listing, reclassification, or delisting: (1) 

discreteness of the population segment in relation to the remainder of the taxon, and (2) the 
49

significance of the population segment to the taxon to which it belongs. If a population meets 

both tests, it can be designated a DPS. The population segment’s conservation status would then 

be evaluated according to the standards in section 4 of the Act for listing, delisting, or 

reclassification (i.e., a determination would be made whether the DPS is endangered or 

threatened).

As previously described, our initial analyses for listing bull trout under the Act divided 

the species into five DPSs (Columbia River, Klamath River, Jarbidge River, Saint Mary-Belly 

River, and Coastal-Puget Sound). Collectively, these five DPSs covered the range of the species 

within the United States, excluding populations in Canada and Alaska. Two of these DPSs 

(Columbia River and Klamath River) were listed separately under the Act as threatened in 1998 

(USFWS 1998a). The Jarbidge River DPS was emergency listed as endangered in 1998 

(USFWS 1998b), and later listed with the Coastal Puget Sound and Saint Mary-Belly River as 

threatened in 1999 (USFWS 1999b). Subsequently, all five DPSs were combined into a single 

DPS, covering the species' range in the coterminous United States, and listed as threatened on 

November 1, 1999 (USFWS 1999a). This listing rule provided efficiency because all five DPSs 

were considered “threatened,” and adhered to contemporary DPS guidance to “use sparingly” 

such designations as directed by Congress. The coterminous United States listing rule 

recognized the five DPSs as useful subdivisions for purposes of section 7 consultation under the 

Act, and they continued to be used in the organization of the 2002 and 2004 draft recovery plans 

(USFWS 2002b, 2004b). 

Since that time, new data and reanalysis have suggested that the coterminous United 

States listed entity would be more appropriately divided into 6 recovery units, rather than the 27 

recovery units identified in the 2002 and 2004 draft recovery plans. We worked with a number 

of State, Federal, and Tribal partners in 2008 and 2009 to evaluate alternatives for organizing 

core areas into possible recovery units that might also be consistent with the “discreteness” and 

“significance” criteria in the DPS policy. Ten alternatives were evaluated that explored from 2 

to 69 potential recovery units, based on mitochondrial and microsatellite DNA analysis, and on 

biogeographical considerations, including geological establishment of major watersheds, 

isolation of portions of watersheds above major waterfalls, co-occurrence with other fish species, 

and occurrence in different ecological zones (Ardren et al. 2011). The six recovery units 

identified in this plan reflect this most recent information and analysis, and were first described 

in the 2010 proposed critical habitat rule (USFWS 2010a). They include: (1) Coastal Recovery 

Unit; (2) Klamath Recovery Unit; (3) Mid-Columbia Recovery Unit; (4) Upper Snake Recovery 

Unit; (5) Columbia Headwaters Recovery Unit; and (6) Saint Mary Recovery Unit. 

The six units delineated have a pattern of significant genetic divergence at the 

microsatellite level; are isolated from other populations (strongly for the Coastal, Klamath, St. 
50

Mary, and Columbia Headwaters, limited for the Mid-Columbia and Upper Snake); and show 

life history differences (primarily for the Coastal and Klamath, limited for the others). Loss of 

any unit may create a significant gap in the range (loss from major drainage basin or major 

portion of Columbia basin), loss of unique ecological setting (especially for Klamath and St. 

Mary, more limited for the others) and marked difference (low potential for shared evolutionary 

future among Klamath, St. Mary, and Columbia Headwaters; and evolutionarily significant 

genetic divergence among Coastal, Klamath, and St. Mary).

It is possible that each of the six recovery units may meet the definition of a DPS under 

our 1996 Policy Regarding Recognition of Distinct Population Segments. All six recovery units 

operate as biologically distinct entities and each face different suites of site-specific threats. For 

that reason, recovering and delisting bull trout simultaneously across all six recovery units rangewide may not be necessary. However, because none of these recovery units has been designated 

as a DPS through a formal federal rule-making process, the DPS discussion in this recovery plan 

does not constitute designation of any recovery unit as a DPS. Thus, bull trout remain listed as a 

single DPS in the coterminous United States. 

We have identified recovery criteria in this recovery plan to be applied at the recovery 

unit scale to facilitate independent management and achievement of recovery goals which when 

achieved may lead to considering whether it is possible to delist at the recovery unit (i.e., DPS

scale). Any future and formal determination of DPS status would still require publication of a 

proposed and final rule in the Federal Register, with full consideration of current biological data, 

applicability of the DPS policy, appropriateness of threatened and/or endangered status for each 

DPS, and legal sufficiency of the rule.

H. Recovery Actions

Recovery of bull trout will entail effectively managing threats to ensure the long-term 

persistence of populations and their habitats, ensuring the security of multiple interacting groups 

of bull trout, and providing habitat conditions and access to them that allow for the expression of 

various life history forms within each of six recovery units. Specifically, recovery actions 

described in the following categories, and when implemented and effective, should:

• Protect, restore, and maintain suitable habitat conditions for bull trout.

• Minimize demographic threats to bull trout by restoring connectivity or populations 

where appropriate to promote diverse life history strategies and conserve genetic 

diversity.
51

• Prevent and reduce negative effects of nonnative fishes and other nonnative taxa on bull 

trout. 

• Work with partners to conduct research and monitoring to implement and evaluate bull 

trout recovery activities, consistent with an adaptive management approach using 

feedback from implemented, site-specific recovery tasks, and considering the effects of 

climate change.

The following recovery action categories have been developed in cooperation with 

Federal, State, Tribal, local, and other partners to be implemented in core areas for each of the 

six recovery units. Six comprehensive RUIPs with implementation schedules that include core 

area-specific recovery actions for each recovery unit are included in the recovery plan. RUIPs 

may be updated individually in the future independently of the Recovery Plan as appropriate to 

reflect new information relevant to recovery actions within a recovery unit.

1. Protect, restore, and maintain suitable habitat conditions for bull trout.

Habitat restoration should be done where necessary to maintain and improve water 

quality, conserve suitable cold water habitat, and restore impaired instream and associated 

riparian habitats. These recovery efforts will be focused on those locations in each recovery unit 

that provide the greatest resilience against difficult-to-manage threats such as climate change. 

Habitat maintenance and restoration may involve implementing appropriate grazing and 

forest management practices, mitigating the effects of past forest harvest and forest road system 

construction, urban and rural development planning to consider development effects to bull trout, 

and considering the effects from future climate change on land management activities. Land 

managers with potential to implement these restoration activities include Federal agencies 

(particularly U.S. Forest Service and Bureau of Land Management), State agencies, Tribes, and 

private landowners. 

Core area-specific measures to protect, restore, and maintain suitable habitat conditions 

for bull trout are included in each of the six RUIPs.

2. Minimize demographic threats to bull trout by restoring connectivity or populations 

where appropriate to promote diverse life history strategies and conserve genetic 

diversity.

Promoting and restoring connectivity, both within core areas and with riverine or coastal 

FMO habitat, should encourage the full expression of known migratory life history strategies 

(fluvial, adfluvial, anadromous), and allow appropriate genetic interaction and demographic 
52

exchanges among core areas. Recovery actions that address migratory connectivity may include 

culvert removal, fish ladder installation, management of dams to provide seasonally appropriate 

instream flows or avoid entrainment or dewatering, decommissioning dams where appropriate 

and feasible, and removal of falls or natural barriers. Connectivity management or interpopulation transfers should be considered where needed to meet recovery goals under the 

guidance of a genetic management plan to maintain genetic diversity and regionally appropriate 

genetic composition. 

Core area-specific measures to address demographic threats to bull trout by restoring 

connectivity or populations are included in each of the six RUIPs.

3. Prevent and reduce negative effects of non-native fishes and other non-native taxa on 

bull trout.

In many core areas, non-native fishes including lake trout (predation and competition), 

brown trout (competition), brook trout (competition and hybridization), and northern pike 

(predation and competition) are impacting bull trout. 

Management options to address non-native fish effects vary among the six recovery units 

and may include angler bounties or liberalized fishing regulations, targeted electrofishing or 

netting, application of piscicides, or creation of passage barriers. However, the feasibility of 

controlling non-native fishes varies widely, depending on the specific species present, physical 

and biological characteristics of the watershed, availability of funding for control actions, and the 

public involvement and perception of control activities. Non-native fish control actions should 

be carefully planned with attention to site-specific conditions and public outreach. 

Core area-specific measures to address effects of nonnative fishes on bull trout are 

included in each of the six RUIPs.

4. Work with partners to conduct research and monitoring to implement and evaluate 

bull trout recovery activities, consistent with an adaptive management approach using 

feedback from implemented, site-specific recovery actions, and considering the effects 

of climate change.

Effective monitoring programs are needed to determine whether recovery actions for bull 

trout are successful and effective, and to help determine where and when recovery criteria have 

been achieved. Monitoring may include assessing distribution, population status, life history, 

migratory movements, and genetic characteristics of bull trout in each recovery unit. In addition

to evaluating monitoring efforts, management practices such as those for water diversion 
53

screening, grazing, timber harvest, and riparian management should be evaluated for their 

effectiveness in reducing impacts on bull trout. 

Future climate change impacts on bull trout will require development of a decision 

framework to help inform where climate change effects are most likely to impact bull trout. The 

identification of core areas and watersheds that are most likely to maintain habitats suitable for 

bull trout over the foreseeable future under probable climate change scenarios will also help 

guide the allocation of bull trout conservation resources to improve the likelihood of success.

Given projected losses of lower-elevation bull trout habitat over the 21st century, it will be 

increasingly important to identify these viable cold-water habitats and work with their land 

managers (particularly National Forests) to incorporate bull trout conservation measures in 

management plans (D. Isaak in litt. 2014). 

Interspecific interactions (particularly with brook trout, brown trout, and lake trout) 

should be further studied under a variety of environmental conditions to identify appropriate and 

cost-effective management methods and assess under what circumstances bull trout may be able 

to coexist with minimal negative effects.

Structured decision making processes (e.g., Structured Decision Making (SDM), 

Bayesian Modelling, etc.) can provide a framework for local working groups to identify 

assumptions and adaptively respond to new monitoring data and outcomes of recovery actions. 

It is also important to develop a decision framework to assess climate change effects to bull trout 

and allocate conservation resources and funding to ensure that future bull trout conservation 

efforts are allocated to those areas with the anticipated future coldest water temperatures that 

offer the greatest long-term benefit to bull trout conservation. As part of any potential delisting 

process the Service will need to review information and data regarding the status of the species, 

including any relevant demographic data.

Significant research and monitoring projects that have been identified as important to bull 

trout recovery in each recovery unit are included in each of the six RUIPs.
54

III. Implementation Framework – Recovery Unit 

Implementation Plans

The bull trout recovery plan describes the principal actions needed to advance the 

recovery of bull trout in the six recovery units within the coterminous United States. These 

conservation actions are included in individual recovery unit implementation plans (RUIPs)

for each recovery unit that provide site-specific detail at the core area scale. The RUIPs describe 

and prioritize core area specific recovery actions. These recovery actions have generally been 

developed through an interagency collaboration of interested and knowledgeable Federal, Tribal, 

State, private and other parties. In many parts of the range, local interagency bull trout working 

groups had previously identified recovery actions necessary for local bull trout core area 

conservation, and are already implementing conservation actions. Many of these conservation 

actions are included in the RUIPs.

Each RUIP includes an implementation schedule that outlines core area specific 

recovery actions and estimated costs for bull trout recovery. An implementation schedule is a 

guide for meeting the recovery goals, objectives, and criteria discussed in Parts I and II of this 

plan. The implementation schedule indicates the listing factor being addressed by each recovery 

action, recovery action descriptions, responsible parties, and estimated costs. The initiation and 

completion of recovery actions for bull trout is subject to the availability of funds, as well as 

other constraints affecting the parties involved. There is often synergy between recovery actions 

needed for bull trout with those required for federally listed salmon and steelhead. Much of the 

overall estimated cost of recovery actions, based on the recovery unit-specific estimates 

identified in the RUIP implementation schedules, is/can be accomplished with ongoing or 

planned recovery actions for salmon/steelhead. The total cost of recovery is only an estimate and 

may change substantially as efforts to recover the species continue. Detailed cost breakdowns 

for each recovery unit, with expected annual costs for the first 5 years of recovery 

implementation, are provided in the implementation schedules of the six RUIPs.

While we have the statutory responsibility for developing and implementing this recovery 

plan for bull trout, recovery of bull trout across the coterminous United States will require the 

involvement of Federal, Tribal, State, private, and local interests. The continued expertise and 

contributions of these, and additional agencies and interested parties, is needed to implement the 

recovery actions identified in this plan. Each recovery action described in the implementation 

schedule for each recovery unit lists the primary agency or responsible party, having the 

authority for implementing recovery actions, along with other groups, such as Tribal, State, 

private, and other organizations, that also may wish to be involved in bull trout recovery 
55

implementation. The listing of a responsible party does not require, nor imply a requirement, 

that the identified party has agreed to implement the recovery action(s) or to secure the funding 

for implementing the action(s). When more than one party is listed, the most logical lead agency 

(based on authorities, mandates, and capabilities) are identified in bold type.

To enhance the effectiveness of this recovery plan, we intend to adopt the RUIPs as 

flexible plans able to be updated and revised as needed, independently of revising the recovery 

plan. Each RUIP should be updated regularly (ideally every 5 years) to reflect current 

information on threats and distribution and lessons learned from recovery implementation.

Each RUIP includes the following components:

Introduction: A brief description of the recovery unit in the overall context of bull trout 

recovery. This includes a list of core areas in the recovery unit, description of overall population 

status and significance of the various threats in each core area, and a summary of current status 

of conservation actions. If additional maps are needed for clarification of recovery actions, 

beyond those presented here in the recovery plan, they are included in this section. Watersheds 

in the recovery unit that are expected to most effectively maintain cold water temperatures in the 

face of climate change may be identified and prioritized for management actions. Any core areas 

where expression of migratory life history is not considered an important element of bull trout 

conservation (e.g. due to potential for connectivity to result in negative effects from invasive 

non-native species) are identified. 

Stepdown Narrative. A list of individual recovery actions needed within the recovery 

unit (specific numbered step-down actions under the general recovery actions 1 [management of 

habitat], 2 [management of demographic threats], 3 [non-native fish management], and 4

[research and monitoring] identified in section II.H above). For each action a brief narrative 

discussion should describe any appropriate details of methods, rationale, scope, and 

implementation considerations
56

Implementation Schedule. The RUIPs also include a recovery unit-specific

implementation schedule, describing the responsible parties and cost estimate breakdown for 

recovery actions.

Each recovery unit specific implementation schedule includes the following components:

- Action Priority: Assigned # 1, 2, or 3 based on the following definitions;

 Priority 1 – An action that must be taken to prevent extinction or prevent the species 

from declining irreversibly in the foreseeable future;

 Priority 2 – An action that must be taken to prevent a significant decline in species 

population or habitat quality;

 Priority 3 - All other actions necessary to meet the recovery objectives.

- Action Number: Number of action from stepdown narrative.

- Action Description: Brief descriptive title of recovery action.

- Threat Factor: Listing factor (A through E) or threat category addressed by the action.

- Core Area: Designated core area(s) where the recovery action should be targeted.

- Action Duration: Indicates the number of years estimated to complete the action, or other 

codes defined as follows:

Continual (C) – An action that will be implemented on a routine basis once begun.

Ongoing (O) – An action that is currently being implemented and will continue until no 

longer necessary.

To be Determined (TBD) – The action duration is not known at this time or 

implementation of the action is dependent on the outcome of other recovery actions.

- Responsible Parties: Agencies and others with responsibility or authority to implement 

proposed recovery actions.

- Estimated Costs: Estimated costs assigned to each action identified in the implementation 

schedule, both for the first 5 years after release of the recovery plan and for the total 

estimated cost of recovery (based on time to recovery, for Continual or Ongoing actions).

- Time to Recovery: Estimated time before this recovery unit could meet recovery criteria, if 

recovery actions are successfully implemented.
57

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on issuance of section 10(a)(1)(A) scientific take permits and section 6(c)(1) exemption 

from take for bull trout (Salvelinus confluentus) (6007.2100). Memorandum from Acting 

Supervisor, Snake River Basin Office, Boise, Idaho, to Regional Director, Region 1, 

Portland, Oregon. February 14, 2000. 22 pages.

[USFWS] U.S. Fish and Wildlife Service. 2012. Nature Serve status assessment scores for 110 

core areas. Information compiled by USFWS. 8 pages.
70

V. APPENDICES

Appendix A. Glossary of Terms

Appendix B. Bull Trout Recovery Unit Maps and Description

Appendix C. Future Bull Trout Status Review or Delisting Process

Appendix D. Summary of the Comments Received on the Revised Draft Recovery Plan for the 

Coterminous United States Population of Bull Trout (Salvelinus confluentus): 

September 4 thru December 3, 2014.

Appendix E. Assessment Tool for Describing Effective Management of Threats in Bull Trout 

Core Areas and Six Recovery Units that Comprise the Coterminous Population of 

Bull Trout

Appendix F. Comparison of Current and Former Core Area and Recovery Unit Classifications

Appendix G. Role of the Bull Trout Recovery Plan in Interagency Consultation, Cooperation 

with States, Coordination with Tribes, Habitat Conservation Planning, Recovery 

Permits, and Protective Regulations
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APPENDIX A. Glossary of Terms

Adfluvial bull trout. Bull trout that migrate from tributary streams to a lake or reservoir to 

mature (one of three commonly recognized bull trout life histories). Adfluvial bull trout return to 

a tributary to spawn.

Alevin. A newly-hatched trout or salmon still attached to the yolk sac.

Allacustrine. A fish that rears in lakes and spawns in outlet tributaries of lakes. 

Alluvial. Pertaining to or composed of silts and clays (usually) deposited by a stream or flowing 

water. Alluvial deposits may occur after a flood event. 

Anadromous (fish). A fish that is born in fresh water, migrates to the ocean to grow and live as 

an adult, and then returns to fresh water to spawn (reproduce). 

Bayesian Modelling. A branch of mathematical probability theory that allows scientists to 

model uncertainty about natural resource issues and possible outcomes of interest by modifying

a priori probabilities in response to observational evidence.

Char. A fish belonging to the genus Salvelinus and related to both the trout and salmon. The 

bull trout, Dolly Varden, and the Mackinaw (or lake trout) are all members of the char family. 

Char live in the icy waters (both fresh and marine) of North America and Europe. 

Complex Core Area. A core area that contains multiple interacting bull trout local populations. 

Complex core areas contribute significantly to the viability of a recovery unit.

Core area. The combination of core habitat (i.e., habitat that could supply all elements for the 

long-term security of bull trout) and a core population (a group of one or more local bull trout 

populations that exist within core habitat) constitutes the basic unit on which to gauge recovery 

within a recovery unit. Core areas require both habitat and bull trout to function, and the number 

(replication) and characteristics of local populations inhabiting a core area provide a relative 

indication of the core area’s likelihood to persist. A core area represents the closest 

approximation of a biologically functioning unit for bull trout. Core areas are presumed to 

reflect the metapopulation structure of bull trout (see metapopulation). 

Core habitat. Habitat that encompasses spawning and rearing (SR) habitat (resident 

populations), with the addition of foraging, migrating, and overwintering (FMO) habitat if the 

population includes migratory fish. Core habitat is defined as habitat that contains, or if restored 

would contain, all of the essential physical elements to provide for the security of and allow for 

the full expression of life history forms of one or more local populations of bull trout. Core 

habitat may include currently unoccupied habitat if that habitat contains essential elements for 

bull trout to persist or is deemed critical to recovery.
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Core population. A group of one or more bull trout local populations that exist within core 

habitat. 

Demographically stable. Term applied to how a ‘recovered’ bull trout population can be 

described in terms of size, age structure, and density. Implies that bull trout populations, at the 

local population, core area or recovery unit scale, interact with their surrounding environment so 

that their population scale status is stable or increasing based on measurements and calculations 

of population size, density, and age structure (i.e., ecologically viable).

Distinct Population Segment (DPS). A listable entity under the Endangered Species Act that 

meets tests of discreteness and significance according to Service policy. 

Embeddedness. The degree to which large particles (boulders, gravel) are surrounded or 

covered by fine sediment, usually measured in classes according to percentage covered.

Effective population size. The number of breeding individuals that would give rise to the same 

amount of random genetic drift as the actual population, if ideal conditions held. 

Entrainment. Process by which aquatic organisms are pulled through a diversion, turbine, 

spillway, or other device.

Extirpation. The elimination of a species from a particular local area.

Fish ladder. A device to help fish swim around a dam.

Floodplain. Adjacent to stream channels, areas that are typified by flat ground and are 

periodically submerged by floodwater.

Fluvial bull trout. Bull trout that migrate from tributary streams to larger rivers to mature (one 

of three bull trout life histories). Fluvial bull trout migrate to tributaries to spawn. 

Foraging, migrating, and overwintering habitat (FMO habitat). Relatively large streams and 

mainstem rivers, including lakes or reservoirs, estuaries, and nearshore environments, where 

subadult and adult migratory bull trout forage, migrate, mature, or overwinter. This habitat is 

typically downstream from spawning and rearing habitat and contains all the physical elements 

to meet critical overwintering, spawning migration, and subadult and adult rearing needs. 

Foreseeable Future. The Act does not define the term “foreseeable future”. However, in a 

general sense, the foreseeable future is the period of time over which events can be reasonably be 

anticipated. For a threatened species, such as bull trout, the Service interprets the foreseeable 

future as the extent of time over which we can reasonably rely on predictions about the future in 

making determinations about the future conservation status of the species. For the bull trout 5-

year review (USFWS 2008a) a manager panel defined a reasonable timeframe for the foreseeable 

future as 4 to 10 bull trout generations (approximately 28 to 70 years).
73

Geographic Region. Comprised of neighboring core areas that share similar bull trout genetic, 

geographic (hydrographic), and/or habitat characteristics. Conserving bull trout in Geographic 

Regions allows for the maintenance of broad representation of genetic diversity; neighboring 

core areas to benefit from potential source populations in the event of local extirpations and 

provides a broad array of options among neighboring core areas to contribute recovery under 

uncertain environmental change. 

Headwaters. The source of a stream. Headwater streams are the small swales, creeks, and 

streams that are the origin of most rivers. These small streams join together to form larger 

streams and rivers or run directly into larger streams and lakes.

Hybridization. Any crossing of individuals of different genetic composition, typically different 

species, that results in hybrid offspring.

Lacustrine. Relating to lake habitat.

Legacy effects. Impacts from past activities (usually a land use) that continue to affect a stream 

or watershed in the present day.

Local population. A group of bull trout that spawn within a particular stream or portion of a 

stream system. Multiple local populations may exist within a core area. A local population is 

considered to be the smallest group of fish that is known to represent an interacting reproductive 

unit. For most waters where specific information is lacking, a local population may be 

represented by a single headwater tributary or complex of headwater tributaries. Gene flow may 

occur between local populations (e.g., those within a core population), but is assumed to be 

infrequent compared with that among individuals within a local population.

Manage Threats. Threats to bull trout are addressed (i.e., managed) so that ecologically viable 

populations of bull trout that have: (1) stable or increasing trends, (2) a distribution within the 

recovery unit that promotes a mosaic pattern in representative habitats across the recovery unit,

(3) diverse life history strategies within populations, and (4) connectivity between populations 

and core areas to the maximum extent possible.

Metapopulation. A population structure where a group of semi-isolated local populations of 

bull trout are interconnected and that probably share genetic material. Core areas represent the 

functional equivalent of a metapopulation structure for bull trout, and the local populations 

within these core areas are interconnected by occasional dispersal between them and therefore 

share some genetic characteristics. 

Migratory corridor (bull trout). Stream reaches used by bull trout to move between habitats. A 

section of river or stream used by fish to access upstream spawning areas or downstream lake 

environments. 
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Migratory life history form (bull trout). Bull trout that migrate from spawning and rearing 

habitat to lakes, reservoirs, or larger rivers to grow and mature.

Nonnative species. Species not indigenous to an area, such as brook trout in the western United 

States. Also referred to as exotic or invasive species. 

Piscicide. A chemical substance poisonous to fish.

Primary Threat. Threat factors known or likely (i.e., non-speculative) to negatively impact bull

trout populations at the core area level, and accordingly require management actions to assure 

bull trout persistence to a degree necessary that bull trout will not be at risk of extirpation within 

that core area in the foreseeable future.

Recovery unit (general). A population unit of a listed entity that is geographically or otherwise 

identifiable and is essential to the recovery of the entire listed entity. Recovery units are 

individually necessary to conserve genetic robustness, demographic robustness, important life 

history stages, or some other feature necessary for long-term sustainability of the entire listed 

entity. Recovery criteria for the listed entity should address each identified recovery unit, and 

every recovery unit must be recovered, before the species can be delisted.

Recovery unit (bull trout). Bull trout recovery units are the major units for managing recovery 

efforts. Detailed description of recovery implementation for each recovery unit is provided in a 

separate recovery unit implementation plan (RUIP). Most recovery units consist of one or more 

major river basins. Several factors have been considered in identifying recovery units (e.g., 

biological and genetic factors, common threats, political and watershed boundaries, ongoing 

conservation efforts, and other logistical concerns. Recovery units may include portions of 

mainstem rivers (e.g., Columbia and Snake rivers) when biological evidence warrants inclusion. 

Biologically, bull trout recovery units are considered groupings of bull trout for which gene flow 

was historically or is currently possible. 

Redd. A nest constructed by female fish of salmonid species in streambed gravels where eggs 

are deposited and fertilization occurs. Redds can usually be distinguished in the streambed 

gravel by a cleared depression, and an associated mound of gravel directly downstream.

Research Needs Area. Those geographic locations (e.g., watershed) where bull trout are known 

to occur historically, but the current status and historical use of the area are uncertain. These 

areas may have been historically occupied or had a few contemporary or historical observations 

to suggest at least some current or potential level of use and there was uncertainty with respect to 

their role in recovery. Generally, this is an area that may be necessary for recovery where there 

is some viable information about bull trout use and has a possibility of importance to recovery 

however, the use is undetermined. 
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Resident life history form. Bull trout that do not migrate, but that reside in tributary streams 

their entire lives (one of three bull trout life cycles). 

Salmonid. Fish of the family Salmonidae, including trout, salmon, chars, grayling, and 

whitefish. In general usage, the term most often refers to salmon, trout, and chars.

Simple Core Area. We define a Simple Core Area as a core area that contains one bull trout 

local population. Simple core areas are almost always small in scope, with a population size that 

is necessarily restricted by the size of the habitat. Typically, simple cores are ecologically if not 

physically isolated from other core areas by natural, not anthropogenic factors (e.g., natural 

barriers, thermal gradients, or large spatial separation from other core areas) that have been 

operable for thousands of years.

Source population. Strong local populations within a metapopulation that contribute emigrating 

individuals to other local populations and reduce the risk of local extinctions (see stronghold).

Spawning and rearing habitat (SR habitat). Stream reaches and the associated watershed 

areas that provide all habitat components necessary for spawning and juvenile rearing for a local 

bull trout population. Spawning and rearing habitat generally supports multiple year classes of 

juveniles of resident or migratory fish and may also support subadults and adults from local 

populations of resident bull trout.

Spillway. That part of a dam that allows high water to flow (spill) over the dam.

Stochastic. The term is used to describe natural events or processes that are subject to random 

or unpredictable variation. Examples include environmental conditions such as rainfall, runoff, 

and storms, or life-cycle events, such as survival or fecundity rates. 

Stronghold. A watershed, multiple watersheds, basin or other defined spatial units (e.g., core 

areas) where bull trout populations are strong and diverse, and the habitat has high intrinsic 

potential to support bull trout or suite of species. Important characteristics of bull trout 

strongholds include intact and well-connected habitat, presence of robust migratory populations, 

presence of the native fish fauna, resilient to perturbations, and retains the genetic and 

phenotypic diversity of the species. Strongholds can act as source populations. 

Structured Decision Making (SDM). SDM is an organized approach to identifying and 

evaluating creative options and making choices in complex natural resource decision situations.

Take. Activities that harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect; or 

attempt to engage in any such conduct to a species listed under the Endangered Species Act.

Water right. Any vested or appropriation right under which a person may lawfully divert and 

use water. It is a real property right appurtenant to and severable from the land on or in 
76

connection with which the water is used; such water right passes as an appurtenance with a 

conveyance of the land by deed, lease, mortgage, will, or inheritance. 

Watershed. The area of land from which rainfall (and/or snow melt) drains into a stream or 

other water body. Watersheds are also sometimes referred to as drainage basins or drainage 

areas. Ridges of higher ground generally form the boundaries between watersheds. At these 

boundaries, rain falling on one side flows toward the low point of one watershed, while rain 

falling on the other side of the boundary flows toward the low point of a different watershed. 

Year class (cohort). Fish in a stock born in the same year. For example, the 1987 year class of 

bull trout includes all bull trout born in 1987, which would be age 1 in 1988. Occasionally, a 

stock produces a very small or very large year class, which can be pivotal in determining stock 

abundance in later years.
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APPENDIX B. Bull Trout Recovery Unit Maps and Description

These maps delineate core areas, major water bodies, and additional 

foraging/migration/overwintering (FMO) habitat outside core areas within each of the six 

recovery units that comprise the coterminous United States population of bull trout.

Map A. Coastal Recovery Unit

Map B. Klamath Recovery Unit

Map C. Mid-Columbia Recovery Unit

Map D. Upper Snake Recovery Unit

Map E. Columbia Headwaters Recovery Unit

Map F. Saint Mary Recovery Unit 
Map A

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79

Coastal Recovery Unit (Map A )

The Coastal Recovery Unit is located within western Oregon and Washington. Major 

drainages include the Olympic Peninsula, Puget Sound, Lower Columbia River basins, Upper 

Willamette River, Hood River, Lower Deschutes River, Odell Lake, and the Lower Mainstem 

Columbia River. In the Coastal Recovery Unit, we have designated 21 existing bull trout core 

areas, including the recently reintroduced Clackamas River population, and identified 4 core 

areas that could be reestablished. Ten shared FMO habitats are also identified outside of core 

areas. Core areas within the recovery unit are distributed among three major geographic regions, 

Puget Sound (includes one core area that is actually part of the lower Fraser River system), 

Olympic Peninsula, and Lower Columbia River. The only core areas currently supporting 

anadromous populations of bull trout are located within the Puget Sound and Olympic Peninsula 

regions. Although bull trout in the Lower Columbia River region share a genetic past with the 

Puget Sound and Olympic Peninsula regions, it is unclear whether Lower Columbia River core 

areas supported the anadromous life history to any significant degree in the past, or could in the 

future. Historically, the Lower Columbia River region is believed to have largely supported the 

fluvial life history form; however, hydroelectric facilities built within a number of the core areas 

have isolated or fragmented watersheds and largely replaced the fluvial life history with the 

adfluvial form.

Two core areas within the Coastal Recovery Unit (Chilliwack River and Upper Skagit 

River) are functionally transboundary with British Columbia, Canada. The boundaries of these 

core areas should extend into British Columbia from a functional standpoint, and our developed 

recovery targets have taken this into consideration. 

There are five core areas within the Coastal Recovery Unit that have been identified as 

current population strongholds. These are the Lower Skagit and Upper Skagit core areas in the 

Puget Sound region, the Quinault River core area in the Olympic Peninsula region, and the 

Lewis River and Lower Deschutes River core areas in the Lower Columbia River region. These 

are the most stable and abundant bull trout populations in the recovery unit. 
Map B

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81

Klamath Recovery Unit (Map B)

In the Klamath Recovery Unit in southern Oregon, we have designated three bull trout 

core areas. The Upper Klamath Lake core area is comprised of the northern portion of the lake 

and its immediate major and minor tributaries. The lake is the collection point for most of 

drainage tributaries, with a surface area of 37,260 hectares (92,000 acres). It is classified as 

hypereutrophic (i.e., high chemical nutrient levels, excessive algal growth, and low oxygen 

availability)(NRC 2004). This core area includes waters draining from Crater Lake National 

Park south of Scott Peak and from the area west of and including the Williamson River below 

Klamath Marsh. Also included is the west side of the Winema National Forest from Crater Lake 

National Park south into the Spencer Creek and Varney Creek drainages on the west side of 

Klamath Lake. This core area includes two existing local bull trout populations: Threemile 

Creek and Sun Creek. Sun Creek, in Crater Lake National Park, currently supports the largest 

local population in the Upper Klamath Lake core area. Major tributaries are the Williamson 

River and Wood River. Numerous small streams that are spring fed and surface water fed 

originate along the rim of the basin.

The Sycan River core area is comprised of Sycan Marsh and its tributaries and the Sycan 

River and its tributaries. The Sycan River originates from springs near 2,133 meters (7,000 feet) 

on the eastern edge of the Klamath River basin. The river flows through high-elevation 

meadows and forest lands for 74 kilometers (46 miles). It flows through Sycan Marsh for 15 

kilometers (9.3 miles), and then flows through a variety of landscapes until it joins the Sprague 

River. This core area is composed of the waters that drain into the Sycan Marsh, including Long, 

Calahan, and Coyote creeks on the west side of the marsh. On the east side of the marsh are the 

upper Sycan River, Chocktoot Creek, Shake Creek, and their tributaries. The only local 

population in the Sycan River core area is Long Creek. Bull trout, including a fluvial life history

form, have been found distributed throughout the most of the length of Long Creek.

The Upper Sprague River core area is comprised of drainages of the North Fork and 

South Fork of the Sprague River. The origins of the North Fork and South Fork of the Sprague 

River are from small, mainly spring fed, streams, near 2,926 meters (6,900 feet) elevation on the 

north and southeast sides of Gearhart Mountain. The upper miles of each creek meander through 

high-elevation meadow and forest lands before being confined by narrow forested canyons 

(ODFW 1997). The lower stretches of the North Fork and South Fork of the Sprague River 

meander through the broad, low-gradient Sprague River valley. The Upper Sprague River core 

area is comprised of the drainages of the North Fork and South Fork of the Sprague River 

upstream of their confluence, including Deming, Boulder, Dixon, Brownsworth, and Leonard 

creeks. Deming Creek is believed to support the largest local population of bull trout in the 

Upper Sprague River core area. Presence/absence surveys in 1998 revealed several fluvial bull 
82

trout in the North Fork Sprague River below the confluence with Boulder Creek. Recent surveys 

have determined bull trout and all other fishes are absent from Sheepy Creek, where a cascade 

barrier at its terminus is believed to prevent colonization.
Map C

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84

Mid-Columbia Recovery Unit (Map C)

In the Mid-Columbia Recovery Unit, we have designated 27 bull trout core areas, along 

with 6 FMO habitats. This recovery unit is located within eastern Washington, eastern Oregon, 

and portions of Idaho. Major drainages include the Yakima River, John Day River, Umatilla 

River, Walla Walla River, Grande Ronde River, Imnaha River, Powder River, Clearwater River, 

and small drainages along the Snake River and Columbia River. These core areas include two 

unoccupied core habitat areas (areas that contain suitable habitat that could potentially support 

reestablished bull trout populations; i.e., the Chelan and Eagle Creek basins), and one 

unoccupied research needs area (Northeastern Washington, above Chief Joseph Dam).

The Mid-Columbia Recovery Unit can be divided into four geographic regions: (1) the 

Lower Mid-Columbia which includes all core areas that flow into the Columbia River below its 

confluence with the Snake River (i.e., the John Day, Umatilla, and Walla Walla basins); (2) the 

Upper Mid-Columbia which includes all core areas that flow into the Columbia River above its 

confluence with the Snake River (i.e., the Yakima and all other basins north to the Canadian 

border); (3) the Lower Snake which includes all core areas that flow into the Snake River 

between its confluence with the Columbia River and Hells Canyon Dam (i.e., the Clearwater, 

Tucannon, Asotin, Grande Ronde, and Imnaha basins); and (4) the Mid-Snake which includes all 

core areas in the Mid-Columbia Recovery Unit that flow into the Snake River above Hells 

Canyon Dam (i.e., the Powder basin; Pine, Indian and Wildhorse Creeks). 

Some changes have been made to core areas since the 2002 Draft Bull Trout Recovery 

Plan. First, within the Lower Snake geographic region, the Grande Ronde River Core Area has 

been divided into three separate core areas, along with the Grande Ronde River FMO. These 

three new core areas include: (1) the Lookingglass Creek – Wenaha River Core Area; (2) the 

Upper Grande Ronde – Catherine Creek – Indian Creek River Core Area; and (3) the Wallowa 

River – Minam River Core Area. The decision to split the Grande Ronde into three separate core 

areas was based on distribution patterns determined from telemetry studies of fish tagged in the 

Wenaha and Lostine Rivers and Lookingglass Creek, differences in the environmental 

characteristics among the subdivisions, and the likelihood for genetic exchange and demographic 

linkage given the size of the Grande Ronde basin. The Little Minam River is still its own core 

area. Within the Clearwater River basin, the Fish Lake (North Fork Clearwater River) Core Area 

was absorbed into the North Fork Clearwater River Core Area, and the Fish Lake (Lochsa River) 

Core Area was absorbed into the Lochsa River Core Area. It was determined that while these 

two Fish Lake populations are adfluvial, they are not isolated from the other two core areas and 

represent a continuation of the headwater populations in both the Lochsa River and North Fork 

Clearwater River core areas. Additionally, the Lower-Middle Clearwater River is no longer a 

core area, but is now considered FMO habitat because it was determined that Lolo Creek is not a 
85

local population, which leaves no local populations in the Lower-Middle Clearwater River. 

However, the mainstem Clearwater still provides access to the other core areas in the Clearwater 

basin, providing essential FMO habitat and connectivity. 

In the Mid-Snake geographic region, the Eagle Creek basin was removed from the 

Powder River Core Area and given its own core area status because it is located some distance 

from the rest of the Powder River bull trout populations and contains somewhat different habitat. 

However, the Eagle Creek Core Area is currently unoccupied and is best described as core 

habitat. Within the Upper-Mid Columbia geographic region, the Chelan basin is now considered 

its own core area; however, like Eagle Creek, it is currently unoccupied and is best described as 

core habitat. FMO habitat is also now recognized in the Okanogan River, and the area east of the 

Okanogan River (upstream from Chief Joseph Dam) is recognized as a research needs area. It is 

also considered a core area in a basic sense, but is unoccupied and more information needs to be 

collected in this area to determine its potential for supporting bull trout in the future.

In the Upper Mid-Columbia geographic region, the South Salmo River core area has been 

added because of recent information documenting spawning and rearing and year-round 

occupancy in the South Fork local population.

In the Lower Snake geographic area, the Granite Creek and Sheep Creek core areas have 

been removed because it has been recently determined that these watersheds do not support 

spawning and rearing and year-round occupancy of bull trout.
Map D

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87

Upper Snake Recovery Unit (Map D)

The Upper Snake Recovery Unit occurs within Idaho, Nevada, and Oregon. Major 

drainages include: the Salmon River, Malheur River, Jarbidge River, Little Lost River, Boise 

River, Payette River, and the Weiser River. In the Upper Snake Recovery Unit, we have 

designated 22 bull trout core areas. The only core areas currently supporting adfluvial 

populations of bull trout are located in the Upper Salmon River, Deadwood River, Anderson 

Ranch, Arrowrock, Opal Lake, and Lake Creek core areas. All remaining core areas contain 

resident populations and most have fluvial populations. Large intact habitat exists primarily in 

the Salmon drainage as this is the only drainage in the Upper Snake Recovery Unit that still 

flows directly into the Snake River; most other drainages no longer have direct connectivity due 

to irrigation uses or instream barriers. Bull trout in the Salmon basin share a genetic past with 

bull trout in the Upper Snake Recovery Unit. Historically, the Upper Snake Recovery Unit is 

believed to have largely supported the fluvial life history form; however, many core areas are 

now isolated or have become fragmented watersheds and replaced the fluvial life history with the 

resident or adfluvial form. The Weiser River, Squaw Creek, and North Fork Payette River core 

areas only contain resident populations of bull trout.

Some changes to core areas have occurred since the 2002 draft recovery plan. The Lucky 

Peak core area that was identified in 2002 has been determined to be a population sink with 

limited reproduction. Based on a review of information, it has been determined through genetic 

testing that these individuals are identical to individuals from Arrowrock and the current 

population in the Lucky Peak core area is sustained artificially through entrainment. Based on 

genetic information, the Malheur Core Area was divided into two separate core areas, the Upper 

Malheur Core Area and the North Fork Malheur Core Area.
Map E

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89

Columbia Headwaters Recovery Unit (Map E)

The Columbia Headwaters Recovery Unit occurs within western Montana, northern 

Idaho, and the northeastern corner of Washington. Major drainages include the Coeur d’Alene 

Lake Basin, Kootenai River Basin, and the Clark Fork River Basin. In this plan for the 

Columbia Headwaters Recovery Unit, we have slightly reorganized the 2002 structure, based on 

latest available science and fish passage improvements that have rejoined previously fragmented 

habitats. We have now identified 35 bull trout core areas (compared to 47 in 2002) for this 

recovery unit. Fifteen of the 35 are referred to as “complex” core areas as they represent larger 

interconnected habitats, each containing multiple spawning streams considered to host separate 

and largely genetically identifiable local populations. As such, the 15 complex core areas 

contain the majority of individual bull trout and the bulk of the designated critical habitat 

(USFWS 2010a, 2010b). 

However, somewhat unique to this recovery unit is the presence of 20 smaller core areas 

that are each represented by a single local population. For the most part, these “simple” core 

areas are found in remote glaciated headwater basins, typically in Glacier National Park or 

federally designated wilderness areas. Many are upstream of waterfalls or other natural barriers 

to fish migration and have persisted for thousands of years despite their small populations and 

isolated existence. As such, they meet the criteria for core area designation and continue to be 

valued for their uniqueness, despite limitations of size and scope. Throughout this recovery plan, 

we often separate our analyses to distinguish between complex and simple core areas with

respect to recovery criteria and targets as well as threats. 
Map F

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91

Saint Mary Recovery Unit (Map F)

This recovery unit contains the Saint Mary, Belly, and Waterton River basins from their 

headwaters to the international boundary with Canada at the 49th parallel. For all of these river 

basins, the majority of the watershed area is in Canada; the United States portion includes 

headwater spawning habitat and the upper reaches of FMO habitat in the mainstem of Saint 

Mary River, Belly River, and in Waterton Lake.

Within the Belly River, spawning is known to occur just south of the international 

boundary; however, no other spawning areas are known within the United States. In the 

Waterton Basin, natural fish barriers occur just above Waterton Lake, limiting bull trout 

distribution. Therefore, although part of the geographically defined recovery unit, neither Belly 

nor Waterton drainages are considered core areas for the purposes of the recovery plan. The 

United States portions of both drainages are wholly within remote areas of Glacier National Park 

and thus, subject to few human-caused threats. Furthermore, management options exist only on 

the Canadian side of the boundary.

Across the International Boundary in Alberta, Canada, the Saint Mary River bull trout 

population is considered at “high risk,” while the Belly River is rated as “at risk” (Alberta 

Sustainable Resource Development and Alberta Conservation Association 2009).
92

APPENDIX C. Future Bull Trout Status Review or Delisting Process

The bull trout recovery criteria provided in Section II.F of the recovery plan represent our 

best assessment of the conditions that would result in a determination that listing under the Act 

is no longer required. For bull trout, these conditions will be met when conservation actions 

have been implemented to ameliorate the primary threats to the species (resulting in 

geographically widespread and demographically stable local bull trout populations within the 

range of natural variation, with their essential cold water habitats conserved and connected to 

allow their diverse life history forms to persist into the foreseeable future).

In accordance with our responsibilities under section 4(c)(2) of the Act, the Service will 

conduct a status review of the coterminous United States population of bull trout at least once 

every five years (5-year review) to evaluate the status of the listed population and gauge 

progress towards delisting. Additionally, the Service may initiate an assessment, or status 

review of whether recovery has been achieved and delisting is warranted when the primary 

threats identified for core areas in the six recovery units are effectively managed at the 

thresholds identified in the recovery plan (i.e., 75 percent for the Coastal, Mid-Columbia, and 

Upper Snake Recovery Units; 75 percent for simple and complex core areas in the Columbia 

Headwaters Recovery Unit; and 100 percent for the Klamath and St. Mary Recovery Units).

All future status review or delisting evaluations for bull trout will evaluate the best 

available scientific and commercial information to ensure that the recovery pathway for bull 

trout in a “recovered” recovery unit achieves representation (i.e., existing occupancy within 

most core areas were maintained and existing life history forms that are present in these core 

areas were mostly preserved); redundancy (i.e., a mosaic of healthy populations are distributed 

across the landscape within the recovery unit); and resilience (i.e., core areas that contain 

migratory life history expressions were prioritized for conservation, and “at risk” core areas 

have been improved). The status reviews will take into account the following:

- Achieving recovery criteria (threat assessment process to evaluate the status of threats 

across the range of bull trout in terms of the five listing factors);

- Demonstration of demographically stable populations of bull trout; and

- Adequacy of existing regulatory mechanisms to provide adequate protection for bull 

trout in the foreseeable future (approximately the next 50 years).

To objectively evaluate the status of threats affecting bull trout across the range of the 

species, the Service has created a structured assessment tool that incorporates the best available 
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data and scientific expert opinion participation. The results from this assessment tool will be 

integral to evaluate the status of bull trout at the range-wide and recovery unit scales based on 

the analysis of threat management effectiveness at the core area level. 

The Threats Assessment Tool developed for bull trout includes the following components 

(along with the participating or responsible participants), and is fully described below.

- Assessment Workshop Process. Convene a workshop or series of workshops to 

assess the status (threat severity, threat management effectiveness, bull trout 

demography) of each core area within the recovery unit. Each workshop will include 

broad representation of fisheries biologists knowledgeable about bull trout issues 

within the recovery unit, including but not limited to biologists from U.S. Geological 

Survey, U.S. Fish and Wildlife Service - Fisheries and Ecological Services field 

offices, Federal land managers (U.S. Forest Service, National Park Service, Bureau of 

Land Management), State land management agencies, State fish and game agencies, 

Tribal fisheries programs, and universities. 

- Threats Assessment Decision Matrix. Participating experts involved in the 

Assessment Workshop Process described above will be asked to evaluate all 

identified primary threats for each respective core area with respect to two 

independent metrics: threat severity and management effectiveness. These two 

metrics are combined into a decision matrix that will be used to assess whether 

current management or conservation actions effectively address the threat. 

- Assessment of Threats Effectively Managed. After the individual threats have been 

assessed in the Threats Assessment Decision Matrix, the Service will make a 

determination of whether threats are being effectively managed for the core area 

being evaluated. This assessment may include a collective evaluation of all threats 

within a core area to ensure that interactions and possible cumulative effects of even 

minor threats are considered.

- Evaluation of Recovery Unit Status. After determining whether threats are 

effectively managed for each respective core area, a tally will be produced for the 

entire recovery unit that shows all core areas in a recovery unit and the number of 

local populations in each core area. For each recovery unit, the recovery criteria 

identified in the bull trout recovery plan will be assessed based on the number of core 

areas where primary threats have been effectively managed or are non-existent. 

Additional information that will help assess the overall status of bull trout within a 
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recovery unit and inform whether recovery criteria have been achieved include: 

evidence of demographically stable populations of bull trout; and an evaluation of the 

adequacy of existing regulatory mechanisms to provide adequate protection for bull 

trout in the foreseeable future (approximately the next 50 years).

If the Service, following the Threat Assessment Tool process, determines that the threats 

to bull trout have been effectively managed and sufficiently reduced, then we may consider 

initiating the status review process. In the case of bull trout, each of the recovery units may meet 

the definition of a distinct population segment (DPS) under our Policy Regarding Recognition of 

Distinct Population Segments (61 FR 4722, Feb. 7, 1996). Consequently we may consider,

consistent with applicable law, whether it is possible to delist at the recovery unit (i.e., DPS) 

scale, if a status review indicates that delisting criteria have been met within a recovery unit. 

Any proposal to delist bull trout would be published in the Federal Register. After analyzing the 

comments received on the proposed rulemaking, the Service would decide whether to complete 

the proposed delisting action or leave the protections of the Act in place. Our final decision 

would be announced in the Federal Register. The comments received and our responses to them 

would be addressed in the final rule.
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APPENDIX D. Summary of the Comments Received on the Revised 

Draft Recovery Plan for the Coterminous United States Population of 

Bull Trout (Salvelinus confluentus): Two Comment Periods: 

September 4 through December 3, 2014; and June 4 through July 20, 

2015.

Background

On September 4, 2014 (79 FR 52741), we released the Revised Draft Recovery Plan for 

the Coterminous United States Population of Bull Trout for a 90-day comment period for Federal 

agencies, Native American Tribes, State and local governments, and members of the public. The 

public comment period ended on December 3, 2014. Four peer reviewers provided comments on 

the revised draft plan.

Subsequently, from June 4 through July 20, 2015 (80 FR 31916), we made available for 

public comment our proposed modifications to the recovery criteria, as well as six draft recovery 

unit implementation plans (RUIPs), supplemental recovery planning documents that describe 

more detailed, site-specific conservation actions and implementation schedules for each of the 

six recovery units (Coastal, Klamath, Mid-Columbia, Columbia Headwaters, Upper Snake, and 

St. Mary).

This section provides a summary of general information about the comments received, 

including the numbers of comments (letters) from various sources. 

Sept 4 through Dec 3, 2014 June 4 through July 20, 2015

Federal Agencies (4) (6)

State Agencies (5) (4)

Native American Tribes (6) (3)

Utilities/Commissions/Counties (9) (13)

Conservation/Other Organizations (20) (13)

Individuals (26) (5)

Peer Reviewers (4) (NA)
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In general, comments received during the September 4 through December 3, 2014,

comment period were centered around: (1) recovery unit boundaries and delineations, with 

several suggested boundary changes or splits in recovery units; (2) lack of support for the 

proposed 75 percent threshold for effective threat management for four of the six recovery units, 

which many maintained does not conserve all remaining bull trout populations; (3) concern that 

the revised recovery plan ‘abandons’ demographic targets proposed in earlier draft recovery 

plans for bull trout; and (4) the role of monitoring in bull trout recovery.

We have considered information we received from public comments and peer reviewers 

in our preparation of the final recovery plan. Updated information has been incorporated into the 

final recovery plan and the six final RUIPs as appropriate, and substantive issues and comments, 

together with our responses, are summarized in appendices. Comments relating to overall 

recovery strategy and criteria are addressed in this appendix to the final recovery plan, while 

those comments specific to individual recovery units are addressed in appendices to each RUIP. 

We welcome continuing public comment on this recovery plan, and we will consider all 

substantive comments on an ongoing basis to inform the implementation of recovery activities 

and future updates to the recovery plan. 

The response to comments on the revised draft recovery plan for bull trout are organized 

as follows: General Comments, Peer Review Comments, Summary of Native American Tribal 

Comments, and Summary of Five State Fish and Wildlife Agency Comments.

General Comments

1. Comment: Suggestion that the revised bull trout recovery plan failed to follow “... the 

Service’s long-standing Interim Recovery Planning Guidance”.

Response: The comment refers to the joint National Marine Fisheries Service and U.S. Fish and 

Wildlife Service’s Interim Endangered and Threatened Species Recovery Planning Guidance 

(NMFS and USFWS 2010), which was first proposed in 2004 and revised/updated in 2006, 2007 

and 2010. Our recovery planning guidance recommends that recovery criteria be SMART: 

Specific, Measurable, Achievable, Realistic, and Time-referenced. Current recovery criteria for 

bull trout were developed with these practical directives in mind, and are based in a sound 

scientific rationale, reflecting biodiversity principles of resilience (ecological quality and ability 

to persist), redundancy (maintaining multiple replicates of populations/habitats to insure against 

catastrophic loss), and representation (conserving the full range of natural variation) (Shaffer and 

Stein 2000, Tear et al. 2005). Moreover, the recovery criteria emphasize conservation actions 

whose effects can be monitored and measured to assure that recovery has occurred or to inform 
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adaptive management. We also considered seven principles of conservation specific to bull trout 

in developing recovery criteria: (1) conserve the opportunity for diverse life history expression; 

(2) conserve the opportunity for genetic diversity; (3) ensure bull trout are distributed across 

representative habitats; (4) ensure sufficient connectivity among populations; (5) ensure 

sufficient habitat to support population viability (e.g., abundance, trend indices); (6) address 

threats, including climate change; and (7) ensure sufficient redundancy in conserving population 

units. These recovery principles take into account both threats and the physical or biological 

needs of the species throughout its range and focus on the range-wide recovery needs. At the 

same time, the seven principles and our approach recognize that given the diverse threats to the 

long-term viability of bull trout throughout its range, the pathways to recovery of the species 

cannot be “one-size fits all”. To that end, the recovery plan addresses these questions through a 

framework of six recovery units within which recovery can be tailored to the needs of 

geographically distinct subpopulations of bull trout.

Addressing threats in recovery criteria (threat-based criteria) is a requirement under the 

Interim Recovery Planning Guidance. This principle guided our recovery approach for bull trout 

with a goal to: (1) conserve bull trout so that they are geographically widespread across 

representative habitats and demographically stable, within six recovery units that comprise the 

coterminous United States population of bull trout; (2) effectively manage and ameliorate the 

primary threats in each of the six recovery units at the core area scale such that bull trout will 

persist in the foreseeable future; (3) build upon the numerous and ongoing conservation actions 

implemented on behalf of bull trout since their listing in 1999, and improve our understanding of 

how various threat factors potentially affect the species; (4) use that information to work 

cooperatively with our partners to design, fund, prioritize, implement and monitor effective 

conservation actions in those areas that offer the greatest long-term benefit to sustain bull trout 

and where recovery can be achieved; and (5) apply adaptive management principles to 

implementing the bull trout recovery program to incorporate new information into management.

In summary, we developed recovery criteria that focus on the identification and effective 

management of known, primary threat factors to bull trout in currently occupied core areas in 

each of six recovery units (Specific, Measurable, Achievable); established recovery criteria 

thresholds that acknowledge, despite our best conservation efforts, some extant bull trout core 

area habitats will likely change (and may be lost) over time (Realistic); and identified and 

focused recovery actions in those areas where success is likely, to meet our goal of ensuring the 

conservation of genetic diversity, life history features, and broad geographical representation of 

remaining bull trout populations (Realistic, Time-referenced).
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2. Comment: The revised bull trout recovery plan failed to account for critical habitat in 

recovery planning.

Response: Critical habitat was designated for the coterminous United States population 

of bull trout on October 18, 2010 (USFWS 2010a). Areas designated as critical habitat included 

occupied habitat with the features essential to the conservation of the species, as well as a few 

currently unoccupied areas also considered essential to bull trout. In total, our 2010 critical 

habitat rule identified 32 critical habitat units (CHUs) within 6 biologically based recovery units, 

representing 19,729 river miles (31,751 km) and 488,252 surface acres (197,589 hectares) of bull 

trout habitat, primarily consisting of occupied core areas or groups of core areas that are in close 

geographic proximity.

In designating critical habitat, we considered the conservation relationship between 

critical habitat and past and present bull trout recovery planning processes. It is important to 

note that, while recovery plans formulate the recovery strategy for a species, unlike critical 

habitat designations they are not regulatory documents. There are no specific protections, 

prohibitions, or requirements afforded a species based solely on a recovery plan. Furthermore, 

although critical habitat designation can contribute to the overall recovery strategy of a species, it 

does not, by itself, achieve recovery plan goals. Information used in the 2010 designation of 

critical habitat for bull trout has informed, and contributed to, the overall recovery strategy 

described in the bull trout recovery plan, especially as it relates to sub-dividing the coterminous 

United States population of bull trout into the six recovery units described in the bull trout 

recovery plan (replacing the 27 recovery units proposed in the earlier 2002 and 2004 draft 

recovery plans). Conserving the six recovery units is considered essential to conserving the 

currently listed coterminous population as a whole.

While core areas are the primary focus of the recovery plan because of the importance of 

adequate spawning and rearing habitat, in a few recovery units areas currently designated as 

critical habitat exist outside of or adjacent to core areas. Most of these areas are bull trout FMO 

habitat shared among bull trout originating from multiple core areas (shared FMO habitat). 

These habitats primarily comprise relatively large streams and mainstem rivers, including lakes 

and reservoirs, and estuaries where sub adult and adult migrating bull trout can forage, migrate, 

mature and overwinter. They are typically downstream from core area spawning and rearing 

habitats and may contain all the physical elements to meet critical overwintering and migration 

needs for subadults and adults. The recovery criteria identified in the revised draft recovery plan 

specifically state that, for “recovery units where shared FMO habitat outside of core areas has 

been identified... connectivity and habitat in shared FMO areas should be maintained in a 

condition sufficient for regular bull trout use and successful dispersal among the connecting core 
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areas”. The specific recovery actions that are needed in particular shared FMO areas are being 

identified through the RUIPs.

3. Comment: Some commenters recommend that bull trout recovery strategies should be 

based on the fact that bull trout mostly occur in habitats that are altered from natural conditions 

and management options should recognize “today’s and tomorrow’s environment”.

Response: Our approach to bull trout recovery and conservation is intended to ensure 

adequate conservation of genetic diversity, life history features, and broad geographical 

representation of remaining bull trout populations. Although bull trout are believed to have 

undergone a significant reduction in their historical range prior to the time of their listing in 

1999, the species continues to be found in suitable habitats and remains geographically 

widespread across numerous major river basins in five western states. Additionally, in several 

currently occupied core areas bull trout population status remains stable or strong. As described 

in this recovery plan, recovery of bull trout: (1) will continue to build upon the numerous and 

ongoing conservation actions implemented on behalf of bull trout since their listing in 1999; (2) 

will be focused on the identification of and effective management of known threat factors to bull 

trout in areas where bull trout currently occur; and (3) will use the available scientific 

information to work cooperatively with our partners to design, fund and implement effective 

conservation actions in areas that offer the greatest long-term benefit to sustain bull trout and 

where recovery can be achieved. 

This approach to achieving recovery for bull trout acknowledges the current status of the 

species in both altered and natural habitats, as well as likely future trends. In a few core areas 

habitat alterations have likely resulted in increased bull trout populations relative to historical

conditions or have created barriers to nonnative fish invasion, and should be maintained. In 

many watersheds management should be prioritized in cold water habitats that are most likely to 

be resistant to habitat loss from climatic warming. Our recovery strategy is focused on achieving 

demographically stable bull trout populations in areas where they currently occur. The recovery 

of bull trout is not dependent upon recovery throughout its “historic” range.

4. Comment: Several comments suggested that bull trout recovery efforts are consistent and 

compatible with existing salmon, steelhead and other multi-species recovery plans. It is 

important to work closely with existing aquatic species partnerships and utilize the existing 

“infrastructure” already in place in several areas within the range of bull trout.
100

Response: Since the listing of bull trout, numerous conservation measures have been and 

continue to be implemented across its range in the coterminous United States These 

conservation measures on behalf of bull trout are being undertaken by a wide variety of local and 

regional partnerships, including State fish and game agencies, State and Federal land 

management and water resource agencies, Tribal governments, power companies, watershed 

working groups, water users, ranchers, and landowners. In areas where the range of bull trout 

overlaps with listed salmon and other listed aquatic species, many of these bull trout 

conservation measures are closely interrelated with work already being done for recovery of 

salmon and steelhead, which are limited by many of the same threats. For example, there are 

numerous examples of interagency partnerships implementing or planning fish habitat restoration 

projects in the Coastal, Mid-Columbia, and Upper Snake Recovery Units targeted at bull trout 

and/or listed salmon or steelhead conservation. While we have the statutory responsibility for 

developing and implementing this recovery plan for bull trout, recovery of bull trout across the 

coterminous United States will require the involvement of Federal, Tribal, State, private, and 

local parties. 

This recovery plan takes into account the expertise and contributions of numerous 

individuals and agencies, and describes the principal actions needed to advance the recovery of 

bull trout found in the six RUIPs. The recovery actions described in the RUIPs were developed 

primarily through an interagency collaboration of interested and knowledgeable Federal, Tribal, 

State, private and other parties. In many parts of the range, local interagency salmon or multispecies working groups have previously identified recovery actions necessary for listed species, 

including bull trout conservation, and have already been implementing conservation actions for 

the past several years. The RUIPs were developed building upon these existing partnership 

efforts and information. 

5. Comment: Concerns about the process and timeline for the assessment of management of 

threats as described in Appendix E: Proposed Threat Assessment Tool (TAT) for effective threat 

management. Specifically, a final recovery plan for bull trout would benefit from completing the 

threat assessment process prior to compiling the RUIPs. Additionally, several commenters had 

concerns that the TAT does not include adequate State and other partner involvement in future 

assessments and excludes workshop participants from final decision making.

Response: In the revised draft recovery plan, the Service made available for public and 

peer review a proposed assessment tool that will be useful to an evaluation of the status of bull 

trout at the range wide, recovery unit and core area scales that is based on an analysis of effective 

management of primary threats in bull trout core areas. The proposed assessment tool was 

developed to establish a structured, consistent, and objective approach to evaluate the status of 
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threats across the range of bull trout that is reliant on the best available information and data. 

The assessment tool includes the following components: Description of an Assessment 

Workshop Process designed to utilize an interagency assessment of the status of bull trout (threat 

severity, threat management effectiveness, bull trout demography) in each core area in a 

recovery unit. The Workshop Process intends to seek broad representation of fisheries biologists 

representing agencies, Tribes, and other interested parties, knowledgeable about bull trout issues 

within the recovery unit being assessed. Our objective is to provide a decision framework that 

characterizes bull trout status objectively as possible through interagency partner involvement, 

and to establish a framework through a decision matrix to assess threat severity and management 

effectiveness for each identified primary threat as described for each core area in the RUIPs.

Applying a threat assessment process prior to completing the final recovery plan for bull 

trout may have provided useful information to inform development of the RUIPs. However, the 

Service maintained that it was important to first develop and propose a structured, consistent, and 

objective threat assessment process that can guide future assessments to evaluate the status of 

threats across the range of bull trout, and then solicit public, peer and agency review and 

feedback prior to implementation. The formal Threat Assessment Process included with this 

recovery plan will be useful in recovery criteria evaluation and status assessments conducted as 

part of future 5-year reviews and five-factor threats analysis in any future delisting evaluation(s).

We acknowledge the concern that partners may be excluded from future decision making. 

While the Service bears the final responsibility under the Act for making determinations of 

listing status, we welcome a full range of input on this decision from interested parties. In future 

status review assessments and listing determinations, the Service will consider the best available 

information in the context of the requirements of the Act to assess the status of threats in terms of 

the five listing factors: (A) The present or threatened destruction, modification, or curtailment of 

its habitat or range; (B) Overutilization for commercial, recreational, scientific or educational 

purposes; (C) Disease or predation; (D) The inadequacy of existing regulatory mechanisms; and 

(E) Other natural or manmade factors affecting its continued existence. For example, under the 

proposed TAT process Service managers will meet to determine whether threats have been 

effectively managed in each core area based on the best available information (recommended 

matrix cell assignments, survey and monitoring data on bull trout population and threats, and 

supporting rationales) that has been provided to the Service by experts (Federal, State, Tribal and 

others) during the recovery unit workshops. We acknowledge that opinions on bull trout status 

may vary greatly, and will seek to make the most appropriate assessment while considering 

available data and identifying underlying assumptions. The outcome of these assessments will 

determine the Service’s recommendation for the listing status of bull trout under the Act.
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6. Comment: There is no crosswalk between threats and the physical and biological features 

essential to bull trout conservation. The recovery plan should include habitat-based standards, 

guidelines or goals to achieve recovery.

Response: The Recovery Strategy section (pages 23-28 of the recovery plan) summarizes the 

causal interrelationships between the biological requirements of bull trout, habitat characteristics, 

threats, and the management actions necessary for recovery. The primary constituent elements 

of bull trout critical habitat correspond closely with the biological requirements described in this 

section, and impairment of these requirements results in threats that need to be addressed through 

management actions.

The purpose of the Act is in part “to provide a means whereby the ecosystems upon 

which [listed species] depend may be conserved,” and to bring species to the point where the 

protections of the Act are no longer necessary. Our primary strategy for achieving recovery of 

bull trout is to effectively manage threats in order to protect, restore, and maintain suitable 

habitat conditions for the species that promote its diverse life history strategies and conserve 

genetic diversity. The primary threats identified in the final recovery plan have been identified 

as problems or factors that are affecting bull trout local populations and their suitable habitats in 

a core area at present or in the foreseeable future. Because the relevant threats can vary greatly 

among core areas, in the RUIPs we are specifically identifying such threats and the particular 

recovery actions necessary to address them at the core area level. Thus in core areas where 

habitat impairment is a significant threat to bull trout, the RUIPs recommend management 

actions to restore habitat. Successful implementation of these actions is likely to benefit bull 

trout. Thus, we expect that successful management of primary threats will result in 

corresponding improvements in demographic parameters. However, the RUIPs also identify 

survey and monitoring needs by core area, and if survey data do not indicate that the bull trout 

population is demographically stable and self-sustaining, the threats may be reassessed through 

additional research and adaptive management. We will ultimately evaluate whether such threats 

are being successfully managed, by assessing the efficacy of habitat restoration actions in 

conjunction with relevant survey and monitoring data on a core area scale. 
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Bull Trout Recovery Plan Content

7. Comment: Some comments suggested that the Service further define what a primary threat 

is. The current definition is ambiguous and is subject to varying interpretations when applied at 

different geographic scales. Others suggested replacing the term “primary threat” with the 

simple term “threat”.

Response: In the revised draft recovery plan, the term Primary Threat was defined as: 

Threat factors known or demonstrated (i.e., non-speculative) to impact or affect bull trout 

survival, growth, reproduction, distribution, migration etc., and their suitable cold water habitat. 

In response to the numerous comments and concerns regarding the proposed definition of a 

primary threat, the Service has revised the term to emphasize the appropriate geographic scale 

(core area) and timescale (foreseeable future). Primary threats are now defined as: Primary 

threats are those factors known or likely (i.e., non-speculative) to negatively impact bull trout 

populations at the core area level, and accordingly require management actions to assure bull 

trout persistence to a degree necessary that bull trout will not be at risk of extirpation within that 

core area in the foreseeable future.

8. Comment: New information was provided to the Service suggesting that bull troutoccupied habitat within the South Salmo River drainage in northeast Washington should be 

included in the recovery plan as a new core area within the Mid-Columbia Recovery Unit.

Response: The referenced South Salmo River drainage was previously discussed as a 

potential core area, pending additional survey work, in the 2002 draft recovery plan for bull trout 

that was never finalized. The South Salmo River core area was inadvertently not included in the 

2014 revised draft recovery plan and we are now including this core area as the 24th core area 

within the Mid-Columbia Recovery Unit.

The Salmo River basin is a transboundary system flowing from the Selkirk Mountains of 

British Columbia and northern Idaho and Washington in the United States. The Salmo River 

drains into the Pend Oreille River approximately 3 miles downstream of the international border. 

Major tributaries of the Salmo River include Apex, Clearwater, Hall, Barrett, Ymir, Porcupine, 

Hidden, Boulder Mill, Erie, and Sheep creeks, and the South Fork of the Salmo River (South 

Fork). Of all the major Salmo River tributaries, only the South Fork originates in the United 

States. The headwaters of the South Fork originate in northern Idaho, with the entire United 

States portion located within the Salmo Priest Wilderness Area. Several small tributaries drain 

into the South Fork, including Watch and Lead Creeks. The core area contains four local 

populations in the upper South Salmo mainstem, Clearwater Creek, Sheep Creek, Stagleap 
104

Creek, and the South Fork. Bull trout in the Salmo River watershed exhibit primarily a fluvial 

migratory life history with FMO habitat occurring from approximately river mile 27 (km 44) to 

the confluence with Pend Oreille River. In Canada, the South Salmo River is identified as one of 

the most threatened populations in British Columbia, with an estimated number of redds per year 

between 38 and 109 (1998 to 2009) and an estimated population size between fewer than 50 to as 

many as 250 adults. 

9. Comment: Suggestion to include in a final recovery plan a section describing the role of 

artificial propagation and transplantation in bull trout recovery.

Response: In watersheds where bull trout populations have been severely reduced or extirpated 

and connectivity impairment is likely to prevent natural recolonization, active reintroduction or 

supplementation of bull trout from appropriate source populations may help reestablish viable 

local populations to improve core area status. The recovery plan includes a discussion on the 

role of artificial propagation and translocation in bull trout recovery, and the RUIPs identify 

where propagation or translocation efforts may be useful to aid recovery efforts. Such efforts 

may involve direct translocation from more vigorous populations or captive breeding of bull 

trout in controlled propagation facilities. Such translocation programs should consider 

appropriate precautions against introduction of fish pathogens to new watersheds. 

Recovery Unit Delineation

10. Comment: Several commenters questioned the proposed recovery unit boundaries and 

suggested the six recovery unit structure for the coterminous United States population of bull 

trout is not consistent with the Service’s Distinct Population Segment (DPS) policy. Some 

commenters suggested the Service has demonstrated a conflict of interest in its rationale 

provided for the recovery unit delineations, specifically that “... it appears that the Service has 

interpreted internal science in development of Recovery Units that are indirectly tied to future 

delisting”. Others suggested the recovery unit delineations should be revised to consider existing 

land and resource management boundaries of agencies that will implement threats-based 

management and to encompass smaller geographic areas that are consistent with existing 

jurisdictional boundaries in resident (non-anadromous) fish management.

Specific recovery unit boundary changes proposed include: 

- Split the Coastal Recovery Unit into two recovery units: Washington Coast and Lower 

Columbia Recovery Units. The commenter expressed the belief that the rule-set used to 
105

designate the six recovery units was applied inconsistently with respect to establishing 

the Coastal Recovery Unit. Specifically, the use of genetic data was not consistently 

evaluated across all areas when “... spatial configuration, ecological setting, and 

management authority...” may have influenced appropriate recovery unit boundaries. 

Additional support for splitting the Coastal Recovery Unit based on spatial separation, 

different ecological settings and different expressions of life history was also provided. 

- Split off the two Malheur River core areas from the Upper Snake Recovery Unit and 

create a separate Malheur River Recovery Unit. Recommendation “... based on 

biological uniqueness, biodiversity principles and Service DPS policy...”. Specific 

examples included information that fluvial bull trout in the Malheur River drainage 

mature at an earlier age than individuals in other areas; the two core areas are comprised 

of all three possible life history forms: resident, fluvial, and adfluvial fish 

(Representation); there is a high potential for the establishment of new populations in 

currently unoccupied habitats (Redundancy); and the probability of persistence would 

likely increase (Resilience). Additionally, the recovery plan should consider existing land 

and resource management boundaries of the agencies asked to manage bull trout habitats 

and encompass smaller geographic areas that are consistent with existing State 

jurisdictional boundaries in resident fish management.

- Reassign the Clearwater River core areas from the Mid-Columbia Recovery Unit to the 

Upper Snake River Recovery Unit. Suggestions that political boundaries may have 

influenced the placement of the Clearwater core areas rather than genetic or other 

biogeographical considerations.

Response: Since the early 2000s, new data and reanalysis have suggested that the 

coterminous United States listed entity would be more appropriately divided into 6 recovery 

units, rather than the 27 recovery units identified in the 2002 and 2004 draft recovery plans. We 

worked with a number of State, Federal, and Tribal partners in 2008 and 2009 to evaluate 

alternatives for organizing core areas into possible recovery units that would also be consistent 

with the “discreteness” and “significance” criteria in the DPS policy. Ten alternatives were 

evaluated that explored from 2 to 69 potential recovery units, based on mitochondrial and 

microsatellite DNA analysis, and on biogeographical considerations, including geological 

establishment of major watersheds, isolation of portions of watersheds above major waterfalls, 

co-occurrence with other fish species, and occurrence in different ecological zones (Ardren et al. 

2011). The six recovery units identified in this plan reflect this most recent information and 

analysis, and were first described in the 2010 proposed critical habitat rule (USFWS 2010a). 

They include: (1) Coastal Recovery Unit, (2) Klamath Recovery Unit, (3) Mid-Columbia 
106

Recovery Unit, (4) Upper Snake Recovery Unit, (5) Columbia Headwaters Recovery Unit, and 

(6) Saint Mary Recovery Unit. 

In this analysis of alternatives, we concluded that the six unit alternative could meet the 

discreteness criterion for a DPS because the six units had a pattern of significant genetic 

divergence at the microsatellite level; were isolated from other populations (strongly for the 

Coastal, Klamath, St. Mary, and Columbia Headwaters, limited for the Mid-Columbia and Upper 

Snake); and showed life history differences (primarily for the Coastal and Klamath, limited for 

the others). We also concluded that this alternative could meet the significance criterion for a 

DPS on the basis that loss of any unit would create a significant gap in the range (loss from 

major drainage basin or major portion of Columbia basin), and possibly on the basis of 

ecological setting (unique species assemblage for Klamath and St. Mary, more limited for the 

others) and marked difference (low potential for shared evolutionary future among Klamath, St. 

Mary, and Columbia Headwaters; and evolutionarily significant genetic divergence among 

Coastal, Klamath, and St. Mary).

The seven unit alternative that we analyzed differed from the six unit alternative in 

splitting the Coastal Recovery Unit between the Washington Coast (including both Puget Sound 

and Olympic Peninsula watersheds) and Lower Columbia regions. We concluded that this 

alternative also could meet the discreteness and significance criteria for a DPS. Differences in 

the discreteness analysis included the degree of isolation from other populations and life history 

differences (both strong for Washington Coast and limited for Lower Columbia watershed). We 

concluded that this alternative met the significance criterion on the basis that loss of any unit 

would create a significant gap in the range (loss from major drainage basin or major portion of 

Columbia basin); however, it was noted that this argument might be weak for the Lower 

Columbia. Other differences in the significance analysis included differences in ecological 

setting (unique species assemblage for Washington Coast) and marked difference (evolutionarily 

significant genetic divergence with low potential for shared evolutionary future for Washington 

Coast, but not for Lower Columbia). 

Thus, our original analysis found that both the six unit and seven unit alternatives could 

legitimately meet the criteria in the DPS policy. Recovery unit delineation considered multiple 

factors, including genetics, life history strategies, ecological setting, and geographical 

connectivity. On review of the commenters’ requests to split the Coastal Recovery Unit, while 

their rationale supports the seven unit structure under the DPS policy, we maintain that no 

substantial new information was provided that was not considered in the original analysis. 

Nonetheless, for effective management we do support the use of bull trout working groups at the 

level of recovery subunits organized along the lines of the Washington Coast and Lower 

Columbia regions. Additionally, if such a portion of the Coastal Recovery Unit appears to be 
107

meeting recovery targets, we would also consider application of tools such as HCPs or an 

expanded 4(d) rule to reduce regulatory burdens in the region or in other recovery units.

The Upper Snake and Mid-Columbia Recovery Units comprise a complex array of life 

history types, ecological zones, management jurisdictions, connectivity patterns, and genetic 

characteristics. We determined the specific boundaries between the Upper Snake and MidColumbia recovery units following Ardren et al. (2011), who analyzed bull trout population 

differentiation at 15 microsatellite loci. In this analysis (see their Figures 6 and 7D), three sites 

in the Clearwater River watershed clustered with nearby populations in northeast Oregon within 

the Mid-Columbia Recovery Unit, while two sites in the Malheur River watershed clustered with 

populations in central Idaho and Nevada within the Upper Snake Recovery Unit. We continue to 

maintain that this is a reasonable basis of delineation between these two recovery units.

We understand the concern that the isolated Malheur River bull trout populations (two 

core areas) in Oregon could be delisted based on recovery of the majority of the Upper Snake 

Recovery Unit in Idaho. However, given that several other recovery units cross State boundaries 

and the Malheur River population groups related genetically with the Upper Snake basin 

populations in Idaho and Nevada, we do not support delineation of a separate recovery unit for 

the Malheur River watershed based on its genetic distinctiveness within Oregon. In this context, 

we note that in our original analysis of alternatives we found that the 69-unit alternative could 

meet the discreteness criterion in the DPS policy (based on patterns of genetic divergence at the 

microsatellite level), but did not meet the significance criterion. The Malheur River watershed 

constitutes a relatively small proportion of the Columbia watershed (approximately 2 percent by 

area) and we maintain that it would be difficult to support a separate Malheur River DPS under 

our policy. 

11. Comment: Some commenters question whether the Service’s proposed intention to 

possibly reclassify the coterminous DPS into six separate recovery units is consistent with our 

joint NMFS and FWS’s 2010 Interim Endangered and Threatened Species Recovery Planning 

Guidance.

Response: Our Interim Recovery Planning Guidance defines a recovery unit as “a special 

unit of the listed entity that is geographically or otherwise identifiable and is essential to the 

recovery of the entire listed entity”. The recovery units that we have defined meet this definition 

by representing suitable cold water habitats across the species’ range of genetic diversity, 

adaptation to diverse geographic and environmental conditions, and expression of the full range 

of life history strategies. The six recovery units are individually necessary to conserve and 

ensure the long-term sustainability of the listed entity as presently defined (bull trout within the 
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coterminous United States). Any designation of distinct population segments would be made on 

a separate basis (assessing discreteness and significance) as described in our DPS policy 

(USFWS 1996). We have not made a formal determination through a listing rule that the current 

listed entity should be separated into multiple DPSs; however, because bull trout are wideranging and occur in environmentally diverse watersheds that are often isolated from one 

another, there may be plausible arguments for making such a determination. Thus, when we 

identified the current six recovery units, we also explicitly considered the DPS policy in defining 

unit boundaries, so that possible future modifications would be less likely to require boundary 

changes. However, any formal determination of DPS status would still require publication of a 

proposed and final rule, with full consideration of current biological data, applicability of the 

DPS policy, appropriateness of threatened and/or endangered status for each DPS, and legal 

sufficiency of the rule.

Recovery Strategy

12. Comment: Suggestion that the recovery plan proposes use of a threats assessment tool 

that “... appears to bias results toward conclusions of successful rather than unsuccessful 

management effectiveness...” that may result in delisting where it is not biologically justified. 

Suggested changes included providing more specific criteria (e.g., population demographic data, 

etc.) for the Service’s assessment of whether threats are being effectively managed since the 

proposed Matrix falls short of the objective and measurable criteria that the Act requires of 

recovery plans; and fails to account for “cumulative threats” or even threat management 

interactions.

Response: The bull trout recovery plan includes a Threat Assessment Tool (Appendix E) 

that will be integral to an evaluation of the conservation status of bull trout at the range-wide and 

recovery unit scales. The recovery plan describes recovery of bull trout as dependent upon 

effectively managing and ameliorating the primary threats affecting the species in each recovery 

unit at the core area level such that bull trout are geographically widespread and demographically 

stable across representative habitats within the six recovery units. Therefore to objectively 

evaluate the status of bull trout (through effective threat management) across the range of bull 

trout, the Threat Assessment Tool will be applied at the core area level. Core area assessments 

can inform the process of recovery plan implementation by highlighting and prioritizing 

management actions that maximize conservation benefits for bull trout. This approach also 

provides a basis for managers to forecast the influence of individual management actions on 

status at the aggregated recovery unit level. These core area assessments will also serve as the 
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primary metric to assess the species status in future 5-year reviews and five-factor threats 

analyses, including any future delisting evaluations. 

The Threats Assessment Tool includes the following components (potential participants 

identified in parentheses):

• Assessment Workshop Process (Service, State, Federal, Tribal, and others)

• Proposed Threats Assessment Decision Matrix (Service, State, Federal, Tribal, and 

others)

• Assessment of Threats Effectively Managed (Service)

• Evaluation of Recovery Unit Status (Service)

In summary, ecologically viable populations of bull trout are necessary to produce stable 

core areas which in turn will result in viable recovery units. These recovery principles take into 

account the threats and physical or biological needs of bull trout throughout its range and focus 

on the range-wide recovery needs through conservation at the recovery unit scale. This approach 

to achieving recovery should ensure adequate conservation of genetic diversity, life history 

features, and broad geographical representation (i.e., adequate spatial distribution) of bull trout 

populations in the six recovery units that comprise the coterminous population of bull trout.

13. Comment: Suggestion to develop or encourage consistent monitoring approaches and 

metrics (e.g., population demographic data) for assessing effective threat management. In 

addition, possible threat management interactions should be considered when assessing effective 

threat management.

Response: Effective monitoring programs are needed to reliably assess whether recovery 

actions for bull trout are successful and to help determine where and when recovery criteria have 

been achieved. Bull trout monitoring and evaluation protocols to support and evaluate recovery 

will need to be both reliable and cost effective, with a focus on assessing bull trout status (i.e., 

distribution, population status, life history, migratory movements, and genetic characteristics), in 

combination with direct indicators of threats such as physical habitat conditions (reflecting 

effectiveness of management practices such as water diversion screening, grazing, timber 

harvest, and riparian management) and occurrence of nonnative species. 

Across the range of bull trout, Federal, State and Tribal entities are monitoring bull trout 

and their habitats using a wide variety of monitoring protocols and sampling techniques. In 

developing the RUIPs included in the recovery plan, we asked the RUIP working groups to 

evaluate the existing monitoring programs as to their utility in providing information that will 
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inform future effective threat management. For each recovery unit, these working groups should 

identify deficiencies in existing monitoring programs and include in the RUIPs additional 

monitoring protocols needed to monitor bull trout populations and or their habitat to ensure 

adequate monitoring information at the appropriate spatial scale across each recovery unit. 

However, the Service is not requiring that a single, uniform monitoring program be established 

across the range of bull trout.

The Service’s 2008 Monitoring and Evaluation Guidance draft document (USFWS 

2008b) describes and evaluates various bull trout monitoring protocols and procedures, and is a 

useful guide for those responsible for bull trout monitoring programs. The current generation of 

bull trout habitat models, combined with spatial data on habitat, stream temperature, and 

presence of nonnative species, provides valuable tools for targeting monitoring efforts to 

efficiently identify occupied habitat patches and track population trends in response to habitat 

change (USGS 2011; Isaak et al. 2009, 2014; Isaak in litt. 2014). Environmental DNA assays 

(Wilcox et al. 2013, 2014) are another promising new method for inexpensively assessing habitat 

patches for occupancy by bull trout and other species. Appropriate use of these resources is 

being considered by RUIP working groups in the development and future implementation of 

recovery unit level monitoring programs.

In addition, the recovery plan describes an approach that applies adaptive management 

principles to account for new information regarding threat management interactions and future 

climate effects to adjust and focus bull trout recovery actions in each recovery unit.

Recovery Criteria

14. Comment: Numerous commenters did not support the 75 percent threshold for the 

number of core areas with threats effectively managed for four of the six recovery units. They 

believed the threshold is too low and could lead to a determination that recovery is achieved 

while not conserving all remaining bull trout populations. There were specific comments to 

revise the proposed 75 percent threshold to a 100 percent threshold for a number of core areas 

within each recovery unit with threats effectively managed and the maximum number of local 

populations within the range of natural variation. Additionally, at least one commenter 

expressed that: “its (the 75 percent threshold) broad application across geographically large 

recovery areas assumes local bull trout populations and core areas have equal value ...” and may

allow the potential loss of bull trout ‘representation and redundancy’. Other commenters 

suggested that the 75 percent threshold may be too high in those areas where insufficient 

resources or unproven threat management techniques may be lacking.
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Response: Recovery criteria are the values by which it can be determined that an 

objective has been reached. In the case of bull trout, the ‘objective’ is to manage threats and 

ensure sufficient distribution and abundance to improve the status of bull trout throughout their 

extant range in the coterminous United States so that protection under the Act is no longer 

necessary. Additionally, recovery criteria must be “SMART”: specific, measurable, achievable, 

realistic and time-referenced, and address threats in terms of each of the five listing factors. 

The Service takes seriously its obligations under the Act to prevent the extinction of 

species as well as to help species avoid experiencing the risk of extinction. At the same time, the 

Service recognizes that the protections of the Act must be applied only when a species is truly on 

the verge of extinction or could be at risk of extinction in the foreseeable future because the 

protections of the Act impose economic, social, and cultural limitations that can sometimes be 

onerous. As we strive to balance prevention of extinction or the risk of extinction to bull trout 

with our obligation to not unnecessarily impose the limitations on society that protections under 

the Act carry, the Service has established a recovery standard (criteria) for bull trout. The 

current recovery criteria for bull trout were developed based on the practical directives of being 

SMART (specific, measurable, achievable, realistic and time-referenced) and in consideration of 

the differences between portions of its range where bull trout are stable and likely to persist and 

portions of its range where the risk of extirpation is higher.

To that end, the four recovery units where the 75 percent threshold for effective threat 

management (primary threats managed in 75 percent of core areas representing 75 percent or 

more of local populations within each recovery unit) was established are regions (recovery units) 

where, since listing, bull trout continue to persist and something less than addressing 100 percent

of threats to the species can be expected to assure long-term persistence, viability and even an 

improved status for the species. These four recovery units (i.e., Coastal, Mid-Columbia, Upper 

Snake, and Columbia Headwaters) where the 75 percent threshold was established generally 

span large geographic areas comprised of several major river watersheds with multiple extant 

core areas (range: 21 to 35) and numerous local populations (range: 92 to 208). The threshold 

for these recovery units was established to ensure sufficient bull trout distribution, 

representation, resilience, and redundancy across each recovery unit as demonstrated by 

demographically stable or increasing populations, with the understanding that there may be some 

loss of bull trout local populations or even existing core areas in the future. Because of the size 

and landscape diversity of these four recovery units, the Service is confident that a minimum 

threshold of 75 percent is sufficient to achieve recovery. 

For the Columbia Headwaters Recovery Unit, we did make a change in how the 75

percent threshold for effective management would be applied. The Columbia Headwaters 

Recovery Unit is distinguished from other recovery units in that a high percentage of the core 
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areas within the recovery unit (20 of 35) are simple core areas comprising a single local 

population. Most of these simple core areas occur in remote glaciated headwaters and represent 

unique environments and diversity in genetics and life history strategies. In response to concerns 

that the 75 percent threshold could allow many of these simple core areas to become extirpated, 

or alternatively allow many complex core areas in major watersheds comprising a large portion 

of the recovery unit to remain unrecovered, the Service has decided to apply the 75 percent

threshold separately to both the simple and complex core areas within this recovery unit. This 

would mean that for recovery criteria to be met in the Columbia Headwaters Recovery Unit, 

effective threat management would need to be achieved for 15 of 20 simple core areas and 12 of 

15 complex core areas. 

In the two recovery units where the 100 percent threshold is applied (the Klamath and St. 

Mary Recovery Units), the status of bull trout since listing continues to point to the need for a 

higher level of recovery effort before an expectation of recovery can be met. In the Klamath 

Recovery Unit, because 9 of 17 known local populations have already been extirpated and the 

remainder are significantly imperiled and require active management of threats, we maintain that 

effective threat management is necessary in 100 percent of core areas, and the geographic range 

of bull trout within this recovery unit will need to be expanded through reestablishment of 

extirpated local populations before recovery criteria can be met. Recovery of bull trout in the St. 

Mary Recovery Unit is critically dependent on successfully addressing threats in the St. Mary 

River complex core area, while the other three core areas in this recovery unit each comprise a 

single isolated local population with only minor threats. Because a 75 percent threshold would 

not adequately reflect the importance of the St. Mary River core area, we have set the threshold 

to 100 percent in this recovery unit. 

It should be emphasized that although bull trout are believed to have undergone a 

significant reduction in their historical range prior to the time of their listing in 1999, the species

continues to be found in suitable habitats and is geographically widespread across numerous 

major river basins in five western states. The Act does not require a species, in this case bull 

trout, to be recovered throughout its historical range or even in any set proportion of the 

currently suitable habitat. Instead, the Act requires that we recover listed species such that they 

no longer meet the definitions of a “threatened species” or “endangered species”.

In developing this bull trout recovery plan, the recovery criteria and recovery actions are 

intended to ensure that bull trout will be conserved as an ecologically viable species for the 

foreseeable future, and where possible, maintain its evolutionary potential. In this context, 

recovery must include the adequate conservation of genetic diversity, life history features, and 

broad geographical representation of bull trout populations in six recovery units that comprise 

the threatened coterminous United States population of bull trout. When identified threats have 
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been sufficiently removed and bull trout populations are secure in an ecologically or 

evolutionarily significant portion of its range, the protections of the Act would no longer be 

warranted. With these goals in mind, the plan acknowledges that, despite our best conservation 

efforts identified in this recovery plan, it is possible that some existing bull trout core areas will 

become extirpated within the foreseeable future due to various factors; including the effects of 

small populations, isolation, and climate change. Further, the plan also recognizes that a small 

number of such extirpations might occur without preventing recovery if threats are successfully 

managed in most core areas. 

In summary, although the recovery plan recognizes that all 109 existing bull trout core 

areas contribute to the overall conservation of the species and identifies recovery actions to 

address specific threat factors affecting bull trout in these same 109 core areas, meeting the 75

percent threshold for effective threat management in any of the 4 referenced recovery units is the 

minimum established value at which the Service may initiate an assessment of whether recovery 

has been achieved. It is important to note that to achieve viable (recovered) recovery units, 

identified threats affecting the species in core areas must be effectively managed to produce 

demographically stable bull trout populations. In any delisting evaluation, the Service will 

consider all available information to ensure that bull trout in a ‘recovered’ recovery unit achieve 

representation (i.e., existing occupancy within most core areas was maintained and existing life 

history forms that are present in these core areas were mostly preserved); redundancy (i.e., a 

mosaic of healthy populations are distributed across the landscape within the recovery unit); and 

resilience (i.e., core areas that contain several local populations or more than one life history 

expression were prioritized for conservation, and “at risk” core areas have been improved).

15. Comment: If the proposed recovery criteria are not revised, modify the recovery criteria 

to account for the importance of complex core areas. Specifically, separate recovery criteria 

should be established for simple and complex core areas to maximize the opportunity for 

conservation and recognition of the significance of complex core areas in contributing to the 

viability of a recovery unit.

Response: In developing this recovery plan, we established recovery criteria and recovery 

actions that are intended to ensure adequate conservation of genetic diversity, life history

features, and broad geographical representation of bull trout populations in six recovery units 

that comprise the threatened coterminous United States population of bull trout based on the 

existing distribution of bull trout. Therefore, the recovery plan recognizes that all 109 existing 

bull trout core areas contribute to the overall conservation of the species and identifies recovery 

actions to address primary threat factors affecting bull trout in these same 109 core areas. We 

have modified the recovery criteria for the Columbia Headwaters Recovery Unit to consider 

complex and simple core areas separately, as summarized above. However, the recovery plan 
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does not distinguish conservation importance or prioritize conservation actions differently for 

‘complex’ and ‘simple’ core areas. For example, simple core areas are ecologically if not 

physically isolated from other core areas and are comprised of a single local bull trout 

population. While this can increase the risk of extirpation for bull trout in simple core areas due 

to immediate threat factors, simple core areas may also represent extremes of the species’ range 

and may contain unique genetic or life history adaptations worthy of conservation. Complex 

core areas, on the other hand, contain multiple local bull trout populations and are typically 

situated in larger patches of habitat and often occupied by more than one life history form; 

therefore they can have a higher likelihood of persistence. The relative importance of bull trout 

in any core area is assessed through the RUIP process for each of the six recovery units.

We do acknowledge, however, that despite our best conservation efforts identified in this 

recovery plan, it is possible that some existing bull trout core areas may become extirpated 

within the foreseeable future due to various factors, including the effects of small populations, 

isolation, and climate change. 

16. Comment: The revised draft recovery plan provides no rationale for ‘abandoning’ 

‘critically important demographic recovery targets’ proposed in the 2002 and 2004 draft recovery 

plans for bull trout. Specifically, there are significant risks associated with measuring recovery 

based on effective management of threats alone... and that some measure of the species status 

(abundance, distribution, population trends) is required so that demographic threats (inbreeding, 

loss of genetic variation) can be avoided. There is a need to “... supplement the Draft Plan’s 

reliance on qualitative measures of the success of threats-based management”. The RUIPs 

should incorporate current numerical population abundance levels where possible, with clearly 

defined recovery goal targets. Explain why demographics are no longer needed as recovery 

criteria.

Response: In the previous 2002 and 2004 draft recovery plans, adult abundance levels 

(demographics) were proposed as recovery targets for each identified bull trout core area, 

considering theoretical estimates of effective population size, historical census information, and 

the professional judgment of recovery unit team members. The proposed abundance targets for 

bull trout core areas were derived using best professional judgment by informal recovery unit

teams which in most cases considered best estimates of productive capacity for identified local 

populations and potential local populations in each core area. For many core areas, there 

appeared to be a high degree of subjectivity when identifying proposed bull trout abundance 

targets for each core area and a general lack of consistency in applying recovery population 

targets between core areas.
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The current recovery plan integrates, and benefits from, new information regarding life 

history, ecology, conservation actions, climate change effects, etc., learned since bull trout were 

listed as threatened in 1999. We recognize that bull trout continue to be found in suitable 

habitats and generally remain geographically widespread across 109 core areas in numerous 

major river basins in 5 states; and the recovery plan identifies conservation needs for these 109 

core areas where bull trout continue to persist. However, we acknowledge that despite our best 

future conservation efforts identified in this plan, it is possible that some existing bull trout core 

areas may become extirpated within the foreseeable future; due to various factors including 

existing small population size, climate change, and isolation. Moreover, the availability of 

survey data for accurate population estimates is problematic in some regions, and in certain core 

areas the geographic limitations on available habitat may inherently constrain the ability of bull 

trout populations to achieve the demographic targets proposed in the earlier draft recovery plans. 

Therefore, we reconsidered our earlier recovery approach and developed a recovery plan that 

focuses on the identification and effective management of known threat factors to bull trout in 

currently occupied core areas in each of six recovery units to establish ‘demographically stable’ 

populations. The recovery plan establishes recovery criteria thresholds that acknowledge, 

despite our best conservation efforts, some extant bull trout core area habitats will likely change 

(and may be lost) over time coincident with recovery. We identify and focus recovery actions in 

core areas where success is likely to meet our goal of ensuring the conservation of genetic 

diversity, life history features, and broad geographical representation of remaining bull trout 

populations. The recovery plan does identify a number of core areas where small population size 

is a significant threat factor that needs to be addressed since population levels are particularly 

low considering the spatial extent of existing habitat. Achieving a demographically stable 

population in these core areas would most likely require an increasing population trend and a 

measured increase in population size.

In summary, the recovery plan foresees that achieving effective threat management in 

each recovery unit will result in geographically widespread and demographically stable local bull 

trout populations within the range of natural variation (not necessarily at some theoretical level 

of effective population size), with their essential cold water habitats connected to allow their 

diverse life history forms to persist into the foreseeable future. A ‘demographically stable’ 

population would therefore be expected to vary in size, magnitude, and distribution between core 

areas based upon differences in core area habitat availability, and other indicators of carry 

capacity. Demographic data that can include empirical data on the magnitude and trends in bull 

trout population counts or indices, is just one of several evaluation metrics, such as current or 

historical spatial distribution, connectivity, and extent of populations; expression of life history 

strategies; occurrence, magnitude, scope, trends, and severity of threats; and significant 
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conservation measures that are ongoing or have been completed to address primary threats, that 

will be useful to evaluate the status of bull trout in any future status review process.

17. Comment: There were comments suggesting “significant variation” in how the RUIPs 

were drafted, specifically that a single definition of primary threat was not consistently applied 

across the six recovery units. As a result, some commenters suggested that primary threats and 

related conservation actions were characterized inconsistently between RUIPs when primary 

threats were assigned to core areas.

Response: Our primary strategy for achieving recovery of bull trout is to effectively manage 

threats at the core area scale in each of six recovery units in order to protect, restore, and 

maintain suitable habitat conditions for the species that promote its diverse life history strategies 

and conserve genetic diversity. The bull trout recovery plan includes six individual RUIPs 

intended to identify the primary threats affecting bull trout and describe and prioritize core area 

specific ongoing and future recovery actions. The primary threat description and recovery 

actions were mostly developed through an interagency collaboration of interested and 

knowledgeable Federal, Tribal, State, private and other parties. The process was designed to 

acknowledge and build upon the numerous and ongoing conservation actions already being 

implemented throughout much of the range of bull trout since the time of listing, utilizing local 

biological expertise and existing and new information, including decision support tools (i.e., 

Structured Decision Making, climate change considerations) to describe the primary threats 

affecting bull trout and in developing and prioritizing conservation actions in each recovery unit.

We understand the desire for consistency, especially regarding the description of primary 

threats across the wide geographic range of the six bull trout recovery units, on the part of some 

commenters. We did establish a common definition of primary threat so that recovery actions 

would focus on known or demonstrated threat factors across the coterminous range of bull trout 

at the core area scale. Early on during the RUIP development process, in response to some 

interagency partner concerns that the application of primary threat designations was ambiguous 

and subject to varying interpretations when applied at different geographic scales, the primary 

threat definition was further revised to emphasize the appropriate geographic scale (core area) 

and timescale (foreseeable future). Ultimately, the Service has relied on the expertise and 

guidance of the bull trout biologists assigned to oversee the RUIP development process in 

applying their local expertise and familiarity as to what is necessary to achieve recovery in each 

recovery unit. The process recognized that the specific circumstances and relative emphasis of 

factors affecting bull trout and the suite of possible recovery actions varies widely across the 

different recovery units. Additionally, the process acknowledged and attempted to reconcile 
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inherent differences among experts in applying their professional opinion when discussing all 

scientific information used in developing the RUIPs. Any attempt to apply a common and strict 

rule set overseeing the RUIP development process consistently across all six recovery units, 

risked leaving out or overlooking important primary threats in any one recovery unit and instead 

relied on best professional judgement in crafting recovery unit specific RUIPs.

Summary of Peer Review Comments

All four peer reviewers provided additional supporting information and referenced 

documents regarding pertinent recent research on bull trout. Two peer reviewers appreciated the 

description of climate change impacts on bull trout and their habitats, and suggested including 

some specific estimates of rates of change in aquatic habitats where such information exists. 

Much of the information provided by peer reviewers has been incorporated and referenced in the 

final recovery plan where appropriate. 

1. Comment: Uncertainty associated with the ability and accountability in determining 

effective threat management. There were expressed concerns on how threats will be ranked or 

prioritized, and whether the Service has adequately described the process for determining 

effective threat management, with additional concerns that ‘professional judgment’ will replace 

statistical information.

Response: The bull trout recovery plan includes a Threat Assessment Tool (TAT) that 

will be integral to an evaluation of the conservation status of bull trout at the range-wide and 

recovery unit scales. The recovery plan describes recovery of bull trout as dependent upon 

effectively managing and ameliorating the primary threats affecting the species in each recovery 

unit at the core area level such that bull trout are geographically widespread and demographically 

stable across representative habitats within the six recovery units. The TAT establishes a 

structured, consistent, and objective approach to determining whether the identified primary 

threats to bull trout are being effectively managed at the core area level. The framework for 

making these determinations will include a simple, but consistently applied, decision matrix to 

assess threat severity and management effectiveness for each identified primary threat in the core 

area.

Assessment of this decision matrix will be informed by existing empirical data on 

magnitude and trends in bull trout population counts or indices; current or historical spatial 

distribution, connectivity, and extent of populations; expression of life history strategies; 

occurrence, magnitude, scope, trends, and severity of threats; and significant conservation 

measures that are ongoing or have been completed to address primary threats. These data will be 

interpreted with the best professional judgment of biologists familiar with bull trout populations 

in the core areas under review because statistical information is or would be lacking across much 
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of the range of bull trout. We are confident that this structured approach will provide uniform 

and useful information that will allow Service managers to forecast the influence of individual 

management actions on the status of bull trout at the core area and recovery unit level.

In summary, ecologically viable populations of bull trout are necessary to produce stable 

core areas which in turn will result in viable recovery units. These recovery principles take into 

account the threats and physical or biological needs of bull trout throughout its range and focus 

on the range-wide recovery needs through conservation at the recovery unit scale. This approach 

to achieving recovery should ensure adequate conservation of genetic diversity, life history 

features, and broad geographical representation (i.e., adequate spatial distribution) of bull trout 

populations in the six recovery units that comprise the coterminous population of bull trout.

2. Comment: Comments related to climate change and climate resilience. Specifically, will

climate resilience be used to prioritize conservation actions (i.e., focus conservation in those 

areas where cold water necessary for bull trout is expected to occur)? If so, how?

Response: As stated in the recovery plan, climate change effects were not considered as 

factors affecting bull trout at the time of listing in 1999. Since that time, several climate change 

assessments or studies have been published or are currently underway assessing the possible 

effects of climate change on bull trout and their habitats. The results of these efforts will allow 

us to better understand how climate change may influence bull trout and help to identify suitable 

conservation actions to ensure bull trout persist in the foreseeable future in the face of climate 

change. For example, recent publications have cited information showing estimates of both 

summer flow decreases and stream temperature increases due to climate change in several areas 

where bull trout currently reside (e.g., Leppi et al. 2012; Luce et al. 2013; Sawaske and Freyberg 

2014). Both of these metrics demonstrate that discernible long-term trends are having direct 

negative impacts on availability of suitable habitat for bull trout.

Therefore, it is important to develop a decision framework to assess climate change 

effects to bull trout and allocate conservation resources and funding to ensure that future bull 

trout conservation efforts are allocated to those areas with the anticipated future coldest water 

temperatures that offer the greatest long-term benefit to bull trout conservation. Recent tools and 

regional databases that may be useful for informing and prioritizing the bull trout conservation 

and monitoring actions described in the RUIPs include: NorWeST Regional Database and 

Modeled Stream Temperatures (Isaak et al. 2014) (stream temperature data used to develop 

accurate and consistent data on aquatic habitat spatial distribution and responses to climate that 

may help predict future bull trout occupancy); Bayesian Belief Network decision support tools 

(Peterson et al. 2013) (developed to provide spatially-explicit information about the likelihood of 

fish population, including bull trout, persistence under different climate scenarios); and the 
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numerous recent scientific publications describing historical trends in precipitation and stream 

flow observed across the Pacific Northwest. We expect that these, and other, tools will be useful 

in developing and applying conservation actions identified in the RUIPs, and will be used by 

State, Federal, Tribal and other agencies responsible for implementing actions in support of bull 

trout conservation and recovery.

3. Comment: Suggestions that a “clear, concise monitoring plan” be developed to monitor bull 

trout recovery. One peer reviewer provided information describing some of the new 

technologies that may provide “broad-scale, high-resolution, cost-effective monitoring of bull 

trout populations through space and time”. Periodic distributional monitoring was suggested as 

being useful to track bull trout occurrence across many habitats through time and may help 

describe if, how and where bull trout distribution may be shifting.

Response: As previously discussed in the response to public comments above (see 

response # 13 above), the Service maintains that effective monitoring programs are needed to 

reliably inform whether recovery actions for bull trout are successful and to help determine 

where and when recovery criteria have been achieved. Bull trout monitoring and evaluation 

protocols to support (evaluate) recovery will need to be both reliable and cost effective, with a 

focus on assessing bull trout status (i.e., distribution, population status, life history, migratory 

movements, and genetic characteristics), and possibly the physical habitat conditions (i.e., 

management practices such as those for water diversion screening, grazing, timber harvest, and 

riparian management). In addition, monitoring protocols should also provide information that is 

useful to the local management needs of the agencies collecting such information as well as 

providing information that can be incorporated into the Service’s proposed effective threat 

management process and inform whether core area bull trout populations have achieved 

demographic stability.

Across the range of bull trout, Federal, State and Tribal entities are monitoring bull trout 

and their habitats using a wide variety of monitoring protocols and sampling techniques. In 

developing the RUIPs included in the final recovery plan, we asked the RUIP working groups to 

evaluate the existing monitoring programs as to their utility in providing information that will 

inform future effective threat management. For each recovery unit, these working groups should 

identify deficiencies in existing monitoring programs and include in the RUIPs additional 

monitoring protocols needed to monitor bull trout populations and or their habitat to ensure 

adequate monitoring information at the appropriate spatial scale across each recovery unit. 

However, the Service is not requiring that a single, uniform monitoring program be established 

across the range of bull trout.
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Summary of Native American Tribal Comments:

1. Comment: Require RUIPs to contain demographic targets, and provide guidance for 

developing those targets. There is a need to “... supplement the Draft Plan’s reliance on 

qualitative measures of the success of threats-based management”.

Response: The recovery plan integrates, and benefits from, new information regarding 

life history, ecology, conservation actions, climate change effects, etc., learned since bull trout 

were listed as threatened in 1999. We recognize that bull trout continue to be found in suitable 

habitats and generally remain geographically widespread across 109 core areas in numerous 

major river basins in 5 states; and identifies conservation needs for these 109 core areas where 

bull trout continue to persist. We also maintain that despite our best future conservation efforts

identified in this recovery plan, it is possible that some existing bull trout core areas may become 

extirpated within the foreseeable future due to various factors, including the effects of small 

populations, isolation, and climate change. Moreover, the availability of survey data for accurate 

population estimates is problematic in some regions, and in certain core areas the geographic 

limitations on available habitat may inherently constrain the ability of bull trout populations to 

achieve the demographic targets proposed in the earlier draft recovery plans. Therefore, we 

reconsidered our earlier recovery approach and developed a recovery plan that focuses on the 

identification and effective management of known threat factors to bull trout in currently 

occupied core areas in each of six recovery units; establishes recovery criteria thresholds that 

acknowledge some extant bull trout core area habitats will likely change (and may be lost) over 

time; and identifies and focuses recovery actions in core areas where success is likely to meet our 

goal of ensuring the conservation of genetic diversity, life history features, and broad 

geographical representation of remaining bull trout populations. We do identify a number of 

core areas where small population size is a significant threat factor that needs to be addressed, 

because population levels are particularly low considering the spatial extent of existing habitat. 

In summary, we maintain that effectively managing primary threat factors in each 

recovery unit will result in geographically widespread and demographically stable local bull trout 

populations within the range of natural variation (not necessarily at some theoretical level of 

effective population size), within their essential cold water habitats connected to allow their 

diverse life history forms to persist into the foreseeable future.

2. Comment: Revise proposed recovery criteria in the Mid-Columbia, Upper Snake, and 

Columbia Headwaters Recovery Units to be more stringent. Specifically, revise the proposed 75
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percent threshold to a 100 percent threshold for number of core areas with threats effectively 

managed and the maximum number of local populations within the range of natural variation. 

The five Tribes also suggested a less than 100 percent effective threat management threshold as 

another alternative to consider: “Recovery is achieved when 85% of the primary threats are 

effectively managed in 100% of the core areas”.

Response: As previously stated in our response (#14) above, recovery criteria are the 

values by which it can be determined that an objective has been reached. In the case of bull 

trout, the ‘objective’ is to manage threats and ensure sufficient distribution and abundance to 

improve the status of bull trout throughout their extant range in the coterminous United States so 

that protection under the Act is no longer necessary. Additionally, recovery criteria must be 

“SMART”: specific, measurable, achievable, realistic and time-referenced, and address threats in 

terms of each of the five listing factors. 

The Service takes very seriously its obligations under the Act to prevent the extinction of 

species as well as to help species avoid experiencing the risk of extinction. At the same time, the 

Service recognizes that the protections of the Act must be applied only when a species is truly on 

the verge of extinction or could be at risk of extinction in the foreseeable future because the 

protections of the Act impose economic, social, and cultural limitations that can sometimes be 

onerous. As we strive to balance prevention of extinction or the risk of extinction to bull trout 

with our obligation to not unnecessarily impose the limitations on society that protections under 

the Act carry, the Service has established a recovery standard (criteria) for bull trout. The 

current recovery criteria for bull trout were developed based on the practical directives of being 

SMART (specific, measurable, achievable, realistic, and time-referenced) and in consideration of 

the differences between portions of its range where trout are stable and likely to persist and 

portions of its range where the risk of extinction bull is higher. 

To that end, the four recovery units where the 75 percent threshold for effective threat 

management (primary threats managed in 75 percent of core areas representing 75 percent or 

more of local populations within each recovery unit) was established are regions (recovery units) 

where, since listing, bull trout continue to persist and something less than addressing 100 percent

of threats to the species can be expected to assure long-term persistence, viability and even an 

improved status for the species. These four recovery units (i.e., Coastal, Mid-Columbia, Upper 

Snake, and Columbia Headwaters) where the 75 percent threshold was established generally 

span large geographic areas comprised of several major river watersheds with multiple extant 

core areas (range: 21 to 35) and numerous local populations (range: 92 to 208). The threshold 

for these recovery units was established to ensure sufficient bull trout distribution, 

representation, resilience, and redundancy across each recovery unit as demonstrated by 

demographically stable or increasing populations, with the understanding that there may be some 
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loss of bull trout local populations or even existing core areas in the future. Because of the size 

and landscape diversity of these four recovery units, the Service is confident that a minimum 

threshold of 75 percent is sufficient to achieve recovery. 

For the Columbia Headwaters Recovery Unit, we did make a change in how the 75

percent threshold for effective management would be applied. The Columbia Headwaters 

Recovery Unit is distinguished from other recovery units in that a high percentage of the core 

areas within the recovery unit (20 of 35) are simple core areas comprising a single local 

population. Most of these simple core areas occur in remote glaciated headwaters and represent 

unique environments and diversity in genetics and life history strategies. In response to concerns 

that the 75 percent threshold could allow many of these simple core areas to become extirpated, 

or alternatively allow many complex core areas in major watersheds comprising a large portion 

of the recovery unit to remain unrecovered, the Service has decided to apply the 75 percent

threshold separately to both the simple and complex core areas within this recovery unit. This 

would mean that for recovery criteria to be met in the Columbia Headwaters Recovery Unit, 

effective threat management would need to be achieved for 15 of 20 simple core areas and 12 of 

15 complex core areas. 

In the two recovery units where the 100 percent threshold is applied (the Klamath and St. 

Mary Recovery Units), the status of bull trout since listing continues to point to the need for a 

higher level of recovery effort before an expectation of recovery can be met. In the Klamath 

Recovery Unit, because 9 of 17 known local populations have already been extirpated and the 

remainder are significantly imperiled and require active management of threats, we maintain that 

effective threat management is necessary in 100 percent of core areas, and the geographic range 

of bull trout within this recovery unit will need to be expanded through reestablishment of 

extirpated local populations before recovery criteria can be met. Recovery of bull trout in the St. 

Mary Recovery Unit is critically dependent on successfully addressing threats in the St. Mary 

River complex core area, while the other three core areas in this recovery unit each comprise a 

single isolated local population with only minor threats; because a 75 percent threshold would 

not adequately reflect the importance of the St. Mary River core area, we have set the threshold 

to 100 percent in this recovery unit. 

It should be emphasized that although bull trout are believed to have undergone a 

significant reduction in their historical range prior to the time of their listing in 1999, the species

continues to be found in suitable habitats and is geographically widespread across numerous 

major river basins in five western states. The Act does not require a species, in this case bull 

trout, to be recovered throughout its historical range or even in any set proportion of the 

currently suitable habitat. Instead, the Act requires that we recover listed species such that they 

no longer meet the definitions of a “threatened species” or “endangered species”.
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In developing this bull trout recovery plan, the recovery criteria and recovery actions are 

intended to ensure that bull trout will be conserved as an ecologically viable species for the 

foreseeable future, and where possible, maintain its evolutionary potential. In this context, 

recovery must include the adequate conservation of genetic diversity, life history features, and 

broad geographical representation of bull trout populations in six recovery units that comprise 

the threatened coterminous United States population of bull trout. When identified threats have 

been sufficiently removed and bull trout populations are secure in an ecologically or 

evolutionarily significant portion of its range, the protections of the Act would no longer be 

warranted. With these goals in mind, the plan acknowledges that, despite our best conservation 

efforts, it is possible that some existing bull trout core areas will become extirpated within the 

foreseeable future due to various factors; including the effects of small populations, isolation,

and climate change. Further, the plan also recognizes that a small number of such extirpations 

might occur without preventing recovery if threats are successfully managed in most core areas. 

In summary, although the recovery plan recognizes that all 109 existing bull trout core 

areas contribute to the overall conservation of the species and identifies recovery actions to 

address specific threat factors affecting bull trout in these same 109 core areas, meeting the 75

percent threshold for effective threat management in any of the 4 referenced recovery units is the 

minimum established value at which the Service may initiate an assessment of whether recovery 

has been achieved. It is important to note that to achieve viable (recovered) recovery units, 

identified threats affecting the species in core areas must be effectively managed to produce 

demographically stable bull trout populations. In any delisting evaluation, the Service will 

consider all available information to ensure that bull trout in a ‘recovered’ recovery unit achieve 

representation (i.e., existing occupancy within most core areas were maintained and existing life 

history forms that are present in these core areas were mostly preserved); redundancy (i.e., a 

mosaic of healthy populations are distributed across the landscape within the recovery unit); and 

resilience (i.e., core areas that contain several local populations or more than one life history 

expression were prioritized for conservation, and “at risk” core areas have been improved).

3. Comment: If the proposed recovery criteria are not revised, modify the recovery criteria to 

account for the importance of complex core areas. Specifically, separate recovery criteria should 

be established for simple and complex core areas to maximize the opportunity for conservation 

and recognition of the significance of complex core areas in contributing to the viability of a 

recovery unit.

Response: In developing this bull trout recovery plan, we established recovery criteria 

and recovery actions that are intended to ensure adequate conservation of genetic diversity, life 

history features, and broad geographical representation of bull trout populations in six recovery 
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units that comprise the threatened coterminous United States population of bull trout based on 

the existing distribution of bull trout. Therefore, the recovery plan recognizes that all 109 

existing bull trout core areas contribute to the overall conservation of the species and identifies 

recovery actions to address primary threat factors affecting bull trout in these same 109 core 

areas. We have modified the recovery criteria for the Columbia Headwaters Recovery Unit to 

consider complex and simple core areas separately, as summarized above. However, the 

recovery plan does not distinguish conservation importance or prioritize conservation actions 

differently for ‘complex’ and ‘simple’ core areas. For example, simple core areas are 

ecologically if not physically isolated from other core areas and are comprised of a single local 

bull trout population. While this can increase the risk of extirpation for bull trout in simple core 

areas due to immediate threat factors, simple core areas may also represent extremes of the 

species’ range and may contain unique genetic or life history adaptations worthy of conservation. 

Complex core areas, on the other hand, contain multiple local bull trout populations and are 

typically situated in larger patches of habitat and often occupied by more than one life history 

form; therefore they can have a higher likelihood of persistence. The relative importance of bull 

trout in any core area will be assessed through the RUIP process for each of the six recovery 

units.

We do acknowledge, however, that despite our best conservation efforts identified in this 

plan, it is possible that some existing bull trout core areas may become extirpated within the 

foreseeable future due to various factors, including the effects of small populations, isolation,

and climate change; and that a small number of such extirpations could occur without preventing 

recovery if threats are successfully managed in most core areas. 

4. Comment: Revise the Threats Assessment Decision Matrix to offer more protection for 

complex core areas and ensure access to critical habitat. Belief that there is an inherent bias in 

the proposed matrix favoring simple core areas because effective threat management will be 

evaluated in part on the percentage of affected local populations. The matrix should be revised 

“... to ensure that threats area identified and managed to retain and expand complexity” and “...

to ensure that it does not undercut the Service’s 2010 critical habitat designation. Additionally, 

develop more specific criteria for the Service’s assessment of whether threats are being 

effectively managed. The proposed matrix falls short of the objective and measureable criteria 

that the Act requires of recovery plans; and fails to account for “cumulative threats”.

Response: The Service in any future status review or delisting evaluation will evaluate 

the best available scientific and commercial information to ensure that bull trout in a ‘recovered’ 

recovery unit achieve representation (i.e., existing occupancy within most core areas were 
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maintained and existing life history forms that are present in these core areas were mostly 

preserved); redundancy (i.e., a mosaic of healthy populations are distributed across the landscape 

within the recovery unit); and resilience (i.e., core areas that contain several local populations or 

more than one life history expressions were prioritized for conservation, and “at risk” core areas 

have been improved). The recovery plan recognizes that all 109 existing bull trout core areas 

contribute to the overall conservation of the species and identifies recovery actions to address 

specific threat factors affecting bull trout in these same 109 core areas, and does not distinguish 

between simple and complex core areas. We maintain that the Threat Assessment Decision 

Matrix will be equally useful in evaluating whether threats are being effectively managed 

regardless of the total number of local populations in a core area because it allows a collective 

evaluation of all threats within a core area to ensure that interactions and possible cumulative 

effects of even minor threats are considered. Additionally, if the combination of threat severity 

and management effectiveness for any individual threat indicates that the threat is not effectively 

managed to be consistent with bull trout survival and persistence, then the entire core area will 

be identified as such.

In summary, the Service will focus on three primary areas when evaluating the status of 

bull trout in a recovery unit: utilizing all and best available information in the context of the 

requirements of the Act to assess the status of threats in terms of the five listing factors; 

demonstration of demographically stable populations of bull trout across both simple and 

complex core areas; and evaluation of the adequacy of existing regulatory mechanisms to 

provide adequate protection for bull trout in the foreseeable future (approximately the next 50 

years).

5. Comment: Replace the term “primary threat” with “threat”.

Response: The term primary threat is used in the revised recovery plan to assist bull trout 

managers distinguish threat factors known (i.e., non-speculative) or likely to negatively impact 

bull trout populations at the core area level from suggested or hypothetical generic threat factors, 

many of which were identified as threat factors in previous draft recovery plans but have not 

been shown to negatively impact bull trout populations. 

It should be noted that in response to the numerous comments and concerns regarding the 

proposed definition of a primary threat, the Service has further revised the term to emphasize the 

appropriate geographic scale (core area) and timescale (foreseeable future). Primary threats are 

now defined as: Primary threats are those factors known or likely (i.e., non-speculative) to 

negatively impact bull trout populations at the core area level, and accordingly require 
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management actions to assure bull trout persistence to a degree necessary that bull trout will not 

be at risk of extirpation within that core area in the foreseeable future.

6. Comment: Specific comments related to language in the revised draft recovery plan 

related to the ‘primary strategy’, recovery goal, and recovery actions sections. Primary 

recommendations to include and expand recovery of bull trout to “... across the species’ native 

range...”.

Response: A major goal of the recovery plan is to ensure that bull trout are 

geographically widespread across representative habitats and demographically stable. Bull trout 

will be recovered when they no longer meet the definition of threatened under the Act (“likely to 

become an endangered species within the foreseeable future throughout all or a significant 

portion of its range”) as determined by a threats analysis addressing the five listing factors. Thus 

bull trout populations will need to be secure with threats being successfully addressed across a 

broad geographic range; however, successfully meeting this standard does not necessarily require 

that viable bull trout populations be present in every locality where the species historically 

occurred. In the recovery plan we do identify appropriate recovery actions that should be 

implemented in each of the 109 core areas with extant bull trout populations; assessing whether 

overall recovery goals have been met for the species will be done by evaluating the core areas 

within each recovery unit for whether implementation of these actions has resulted in threats 

being successfully managed. 

7. Comment: Suggestion to include in a final recovery plan a section describing the role of

artificial propagation and transplantation in bull trout recovery.

Response: As previously discussed under General Comment # 9, the recovery plan 

includes a discussion on the role of artificial propagation and translocation in bull trout recovery, 

and the RUIPs identify where propagation or translocation efforts may be useful to aid recovery 

efforts. Such efforts may involve direct translocation from more vigorous populations or captive 

breeding of bull trout in controlled propagation facilities. Such translocation programs should 

consider appropriate precautions against introduction of fish pathogens to new watersheds. 

8. Comment: The Service has demonstrated a conflict of interest in its utilization of the 

scientific rationale provided for recovery unit delineation, specifically that “... it appears that the 

Service has interpreted internal science in development of Recovery Units that are indirectly tied 
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to future delisting. Please re-evaluate the RU boundaries with external scientific evidence prior 

to the release of a final Plan”. Others suggested the recovery unit boundaries in the revised draft 

recovery plan should be revised to consider existing land and resource management boundaries 

of agencies that will implement threats-based management and to encompass smaller geographic 

areas that are consistent with existing jurisdictional boundaries in resident (non-anadromous) fish 

management. The recovery units are too large to practicably reach delisting.

Response: Since the original listing decision in 1998, new data and reanalysis have 

suggested that the coterminous United States listed entity would be more appropriately divided 

into 6 recovery units, rather than the 27 recovery units identified in the 2002 and 2004 draft 

recovery plans. We worked with a number of State, Federal, and Tribal partners in 2008 and 

2009 to evaluate alternatives for organizing core areas into possible recovery units that might

also be consistent with the “discreteness” and “significance” criteria in the DPS policy. Ten 

alternatives were evaluated that explored from 2 to 69 potential recovery units, based on 

mitochondrial and microsatellite DNA analysis, and on biogeographical considerations, 

including geological establishment of major watersheds, isolation of portions of watersheds 

above major waterfalls, co-occurrence with other fish species, and occurrence in different 

ecological zones (Ardren et al. 2011). The six recovery units identified in this plan reflect this 

most recent information and analysis, and were first described in the 2010 proposed critical 

habitat rule (USFWS 2010a). They include: (1) Coastal Recovery Unit, (2) Klamath Recovery 

Unit, (3) Mid-Columbia Recovery Unit, (4) Upper Snake Recovery Unit, (5) Columbia 

Headwaters Recovery Unit, and (6) Saint Mary Recovery Unit. 

In this analysis of alternatives, we concluded that the six unit alternative could meet the 

discreteness criterion for a DPS because the six units had a pattern of significant genetic 

divergence at the microsatellite level; were isolated from other populations (strongly for the 

Coastal, Klamath, St. Mary, and Columbia Headwaters, limited for the Mid-Columbia and Upper 

Snake); and showed life history differences (primarily for the Coastal and Klamath, limited for 

the others). We also concluded that this alternative could meet the significance criterion for a 

DPS on the basis that loss of any unit would create a significant gap in the range (loss from 

major drainage basin or major portion of Columbia basin), and possibly on the basis of 

ecological setting (unique species assemblage for Klamath and St. Mary, more limited for the 

others) and marked difference (low potential for shared evolutionary future among Klamath, St. 

Mary, and Columbia Headwaters; and evolutionarily significant genetic divergence among 

Coastal, Klamath, and St. Mary).

The seven unit alternative that we analyzed differed from the six unit alternative in 

splitting the Coastal Recovery Unit between the Washington Coast (including both Puget Sound 

and Olympic Peninsula watersheds) and Lower Columbia regions. We concluded that this 
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alternative also could meet the discreteness and significance criteria for a DPS. Differences in 

the discreteness analysis included the degree of isolation from other populations and life history 

differences (both strong for Washington Coast limited for Lower Columbia watershed). We 

concluded that this alternative met the significance criterion on the basis that loss of any unit 

would create a significant gap in the range (loss from major drainage basin or major portion of 

Columbia basin); however, it was noted that this argument might be weak for the Lower 

Columbia. Other differences in the significance analysis included differences in ecological 

setting (unique species assemblage for Washington Coast) and marked difference (evolutionarily 

significant genetic divergence with low potential for shared evolutionary future for Washington 

Coast, but not for Lower Columbia). Thus, our original analysis found that both the six unit and

seven unit alternatives could legitimately meet the criteria in the DPS policy. Recovery unit 

delineation considered multiple factors, including genetics, life history strategies, ecological 

setting, and geographical connectivity.

9. Comment: The two Malheur River core areas should be removed from the Upper Snake 

Recovery Unit based on biological uniqueness, the biodiversity principles and the Service’s DPS 

policy.

Response: The Upper Snake Recovery Unit, which includes the two Malheur River core areas, 

comprises a complex array of life history types, ecological zones, management jurisdictions, 

connectivity patterns, and genetic characteristics. We determined the specific boundary for the 

Upper Snake Recovery Unit, and distinguished from other recovery units, by following Ardren et 

al. (2011), who analyzed bull trout population differentiation at 15 microsatellite loci. In this 

analysis (see their Figures 6 and 7D), the two sites in the Malheur River watershed clustered with 

populations in central Idaho and Nevada within the Upper Snake Recovery Unit. 

We understand the concern that the isolated Malheur River bull trout populations (two 

core areas) in Oregon could be delisted based on recovery of the majority of the Upper Snake 

Recovery Unit in Idaho. However, given that several other recovery units cross state boundaries 

and the Malheur River population groups genetically with the Upper Snake basin populations in 

Idaho and Nevada, we do not support delineation of a separate recovery unit for the Malheur 

River watershed based on its genetic distinctiveness within Oregon. In this context, we note that 

in our original analysis of alternatives we found that the 69-unit alternative could meet the 

discreteness criterion in the DPS policy (based on patterns of genetic divergence at the 

microsatellite level), but did not meet the significance criterion. The Malheur River watershed 

constitutes a relatively small proportion of the Columbia watershed (approximately 2 percent by 

area) and we maintain that it would be difficult to support a separate Malheur River DPS under 

our policy.
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10. Comment: General concern that if a recovery unit is delisted, then there will be no 

incentive or mechanisms to continue threat management in core areas. Specific example 

highlighted ongoing brook trout control efforts that might be curtailed in some Malheur River 

core areas within the Upper Snake River Recovery Unit after delisting.

Response: If, at some future date, the Upper Snake River Recovery Unit is determined to 

be a distinct population segment (DPS) and that DPS is proposed for reclassification, yet the 

primary threats affecting bull trout or their populations are not meeting the goals established by 

the Burns Paiute Tribe, then the Service, through its Federal trust responsibilities to federallyrecognized Tribes, would be obligated to support the Tribe’s goals outside of the context of the 

Act.

Summary of Five State Fish and Wildlife Agency Comments

1. Comment: One State agency suggested reconsideration of the inclusion of the 

Clearwater Drainage core areas in the Mid-Columbia Recovery Unit, and instead reassignment 

of those core areas to the Upper Snake Recovery Unit.

Response: Since the early 2000s, new data and reanalysis have suggested that the 

coterminous United States listed entity could be more appropriately divided into 6 recovery 

units, rather than the 27 recovery units identified in the 2002 and 2004 draft recovery plans. We 

worked with a number of State, Federal, and Tribal partners in 2008 and 2009 to evaluate 

alternatives for organizing core areas into possible recovery units that might also be consistent 

with the “discreteness” and “significance” criteria in the DPS policy. Ten alternatives were 

evaluated that explored from 2 to 69 potential recovery units, based on mitochondrial and 

microsatellite DNA analysis, and on biogeographical considerations, including geological 

establishment of major watersheds, isolation of portions of watersheds above major waterfalls, 

co-occurrence with other fish species, and occurrence in different ecological zones (Ardren et al. 

2011). The Service selected the six recovery unit alternative identified in this plan, which we 

have concluded best reflects the available genetic, biogeographical, and ecological information, 

and may be consistent with our “discreteness” and “significance” criteria in our DPS policy. The 

six recovery units were first described in the Service’s 2010 proposed critical habitat rule 

(USFWS 2010), and include: (1) Coastal Recovery Unit; (2) Klamath Recovery Unit; (3) MidColumbia Recovery Unit; (4) Upper Snake Recovery Unit; (5) Columbia Headwaters Recovery 

Unit; and (6) Saint Mary Recovery Unit. 

In this analysis of alternatives, we concluded that the six unit alternative could meet the 

discreteness criterion for a DPS because the six units had a pattern of significant genetic 
130

divergence at the microsatellite level; were isolated from other populations (strongly for the 

Coastal, Klamath, St. Mary, and Columbia Headwaters, limited for the Mid-Columbia and Upper 

Snake); and showed life history differences (primarily for the Coastal and Klamath, limited for 

the others). We also concluded that this alternative could meet the significance criterion for a 

DPS on the basis that loss of any unit would create a significant gap in the range (loss from 

major drainage basin or major portion of Columbia basin), and possibly on the basis of 

ecological setting (unique species assemblage for Klamath and St. Mary, more limited for the 

others) and marked difference (low potential for shared evolutionary future among Klamath, St. 

Mary, and Columbia Headwaters; and evolutionarily significant genetic divergence among 

Coastal, Klamath, and St. Mary).

The Upper Snake and Mid-Columbia Recovery Units comprise a complex array of life 

history types, ecological zones, management jurisdictions, connectivity patterns, and genetic 

characteristics. We determined the specific boundaries between the Upper Snake and MidColumbia recovery units following Ardren et al. (2011), who analyzed bull trout population 

differentiation at 15 microsatellite loci. In this analysis (see their Figures 6 and 7D), three sites 

in the Clearwater River watershed clustered with nearby populations in northeast Oregon within 

the Mid-Columbia Recovery Unit, while two sites in the Malheur River watershed clustered with 

populations in central Idaho and Nevada within the Upper Snake Recovery Unit. We continue to 

maintain that this is a reasonable basis of delineation between these two recovery units.

2. Comment: The recovery plan should be more explicit in describing how bull trout 

demographic data will be considered in relation to the threats based assessment process. For 

example, one State agency suggested that the RUIPs should incorporate current numerical 

population abundance levels where possible, with clearly defined recovery goal targets.

Response: In the previous 2002 and 2004 draft recovery plans, adult abundance levels 

(demographics) were proposed as recovery targets for each identified bull trout core area, 

considering theoretical estimates of effective population size, historical census information, and 

the professional judgment of recovery unit team members. In developing our current recovery 

plan, we reconsidered our earlier recovery approach and developed a recovery plan that 

deemphasized specific demographic (population) targets and instead focuses on the identification 

and effective management of known threat factors to bull trout in currently occupied core areas 

to achieve ‘demographically stable’ bull trout populations throughout each of six recovery units. 

To objectively evaluate the status of threats across the range of bull trout, the recovery 

plan has created a structured approach (threat assessment tool) that incorporates the best 

available data. The results from this assessment tool are integral to evaluate the status of bull 
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trout at the range-wide and recovery unit scales based on the analysis of threats at the core area 

level. Core area assessments can inform the process of recovery plan development and 

implementation by highlighting and prioritizing management actions that maximize conservation 

benefits for bull trout. Available demographic data, as well as other empirical data on the 

magnitude and trends in bull trout population counts or indices; current or historical spatial 

distribution, connectivity, and extent of populations; expression of life history strategies; 

occurrence, magnitude, scope, trends, and severity of threats; and significant conservation 

measures that are ongoing or have been completed to address primary threats. These data will be 

interpreted with the best professional judgment of biologists familiar with bull trout populations 

in the core area.

3. Comment: One State agency suggested the sole inclusion of “primary threat” to be 

problematic since the definition is fairly narrow and potentially sets a low bar in a threats based 

recovery approach. They suggested that all substantive threats be identified and classified as 

minor/moderate or severe.

Response: The term primary threat is used in the bull trout recovery plan to assist bull 

trout managers distinguish threat factors known (i.e., non-speculative) or likely to negatively 

impact bull trout populations at the core area level from suggested or hypothetical generic threat 

factors, many of which were identified as threat factors in previous draft recovery plans but have 

not been shown to negatively impact bull trout populations. 

It should be noted that in response to the numerous comments and concerns regarding the 

proposed definition of a primary threat, the Service has further revised the term to emphasize the 

appropriate geographic scale (core area) and timescale (foreseeable future). Primary threats are 

now defined as: Primary threats are those factors known or likely (i.e., non-speculative) to 

negatively impact bull trout populations at the core area level, and accordingly require 

management actions to assure bull trout persistence to a degree necessary that bull trout will not 

be at risk of extirpation within that core area in the foreseeable future.

4. Comment: Concerns regarding the process and timeline for the assessment of threats to 

bull trout as described in the Threat Assessment Tool proposed in Appendix E of the revised 

draft recovery plan.

Response: Applying a threat assessment process prior to completing the final recovery 

plan for bull trout may have provided useful information to inform development of a final 
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recovery plan, including the RUIPs. However, we maintain that it was important to first develop 

and propose a structured, consistent, and objective threat assessment process that can guide 

future assessments to evaluate the status of threats across the range of bull trout, and then solicit 

public, peer and agency review and feedback prior to implementation. The formal Threat 

Assessment Tool process included with this recovery plan will be useful in recovery criteria 

evaluation and status assessments conducted as part of future 5-year reviews and five-factor 

threats analysis in any future delisting evaluation(s).

5. Comment: Concerns related to the State agency’s perceived lack of involvement in the 

process for assessing whether threats have been effectively managed. The recovery plan does 

not adequately define threats or commit to an objective process for determining effective threat 

management.

Response: We acknowledge the concern that partners may be excluded from future 

decision making. While the Service bears the final responsibility under the Act for making 

determinations of listing status, we welcome a full range of input on this decision from interested 

parties. In future status review assessments and listing determinations, the Service will consider 

the best available information in the context of the requirements of the Act. For example, under 

the proposed TAT process Service managers will meet to determine whether threats have been 

effectively managed in each core area based on the best available information (recommended 

matrix cell assignments, survey and monitoring data on bull trout population and threats, and 

supporting rationales) that has been provided to the Service by experts (Federal, State, Tribal and 

others) during the recovery unit workshops. We acknowledge that opinions on bull trout status 

may vary greatly, and will seek to make the most appropriate assessment while considering 

available data and identifying underlying assumptions. The outcome of these assessments will 

determine the Service’s recommendation for the listing status of bull trout under the Act.

6. Comment: Appears that the revised draft recovery plan did not consider one State’s 

scientific information related to bull trout distribution and abundance.

Response: New scientific information referenced by the State has been incorporated in 

the final recovery plan where appropriate. Because these referenced articles also contain 

information that includes possible bull trout population trend data for several core areas within 

the State, they helped inform the interagency RUIP development process.
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7. Comment: Regarding the 75 percent criteria, one State was concerned regarding the lack 

of clarity on how threat severity or threat management would inform the development of the 

RUIPs. Another State suggests that the 75 percent threats managed threshold “is unacceptably 

high” based on the extensive number of non-native threats listed in the Columbia Headwaters 

RUIP and the lack of resources or proven techniques to address these threats.

Response: As previously described in the response to questions #2 and #3 above, the 

Service proposed in the revised draft recovery plan a threats assessment tool that will be useful to 

inform whether threats have been effectively managed in a bull trout core area. Because the 

proposed threat assessment tool was made available for public review and comment, it would 

have been premature for the Service to mandate use of the assessment tool in completing the 

final bull trout recovery plan. We did however, encourage Service staff involved in the RUIP 

process to consider the use of the draft assessment tool as an aid where feasible in informing the 

identification of primary threats as part of the RUIP development process.

8. Comment: Concerned that the proposed recovery criteria may not be consistent with 

other recovery plans for other ESA-listed western trout.

Response: Recovery criteria developed for species listed as threatened or endangered 

represent our best assessment of the conditions that would most likely result in a determination 

that listing under the Act is no longer required. Recovery criteria are ‘specific’ or unique to a 

respective listed species and can be expected to vary between species. While we cannot speak to 

the adequacy of recovery criteria proposed for other ESA-listed western trout, we developed 

recovery criteria for bull trout that we maintain are specific to the species and justified in the 

context of the species ecology; are technically feasible and grounded in good science, and meet 

the standard of being objective and measurable. For bull trout, these conditions (i.e., recovery 

criteria) will be met when conservation actions have been implemented to ameliorate the primary 

threats in suitable habitats. If the primary threats have been effectively managed in each 

recovery unit, the long-term persistence of bull trout should be ensured in the foreseeable future. 

9. Comment: Further revisions of definitions for “foreseeable future” and “primary threat”.

Additionally, some term definitions should be revised to gain better acceptance and more 

informed decision making process. Specifically, better define the terms: primary threat; persist, 

persistence, and long-term persistence).
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Response: Where appropriate, the Service has revised certain terms in the bull trout 

recovery plan to make them more understandable and useful to the process. For example, the 

term “primary threat” is now used in the recovery plan to assist bull trout managers in 

distinguishing threat factors known (i.e., non-speculative) or likely to negatively impact bull 

trout populations at the core area level from suggested or hypothetical generic threat factors, 

many of which were identified as threat factors in previous draft recovery plans but have not 

been shown to negatively impact bull trout populations. In response to the numerous comments 

and concerns regarding the proposed definition of a primary threat, the Service has further 

revised the term to emphasize the appropriate geographic scale (core area) and timescale 

(foreseeable future). Primary threats are now defined as: Primary threats are those factors 

known or likely (i.e., non-speculative) to negatively impact bull trout populations at the core 

area level, and accordingly require management actions to assure bull trout persistence to a 

degree necessary that bull trout will not be at risk of extirpation within that core area in the 

foreseeable future.

Additionally, the term persistence is applicable to the timescale defined as the foreseeable 

future. In the revised draft recovery plan we described that the “foreseeable future” for 

evaluating actions affecting bull trout and their recovery was from 4 to 10 generations, or 

roughly 28 to 70 years. We adopted this figure based on the foreseeable future timeframe used 

in a manager panel for the most recent bull trout 5-year review (FWS 2008a). Several 

commenters suggested this wide range provided insufficient guidance for evaluating effective 

threat management into the “foreseeable future”. In order to provide a “... consistent and 

meaningful time frame...” for use in the completion of a final recovery plan and developing the 

RUIPs, we have specified approximately 50 years as the foreseeable future. 

10. Comment: Threats identified in the revised draft recovery plan are not up to date or 

ranked, etc.

Response: Threats found in the revised draft recovery plan were derived from 

information assembled in the Core Area Templates (USFWS 2008) in coordination with various 

State, Federal, and Tribal partners, and additional assessments developed by the Service in 2010 

and 2011. These threats were identified as problems or factors that may affect bull trout local 

populations in each core area at that time or expected to into the foreseeable future (in 

consideration of present and future climate change). They included a variety of threats that 

ranged in severity from serious imminent threats to documented, but relatively minor issues that 

should nonetheless be evaluated for their potential impact.
135

Because the threats were derived from information assembled from Core Area Templates 

and Assessments developed in 2008, 2010 and 2011, we anticipated that much of the information 

was likely out of date and in need of updating and revision. New information and suggested 

changes in the list of threats has been incorporated and updated in the final recovery plan through 

the interagency RUIP development process.

11. Comment: One State agency suggested that recovery should recognize that bull trout 

management needs should focus “... within today’s and tomorrow’s environment (science based 

yet reasonable)”.

Response: Our approach to bull trout recovery and conservation is intended to ensure 

adequate conservation of genetic diversity, life history features, and broad geographical 

representation of remaining bull trout populations. Although bull trout are believed to have 

undergone a significant reduction in their historical range prior to the time of their listing in 

1999, the species continues to be found in suitable habitats and remains geographically 

widespread across numerous major river basins in five western states. Additionally, in several 

currently occupied core areas bull trout population status remains stable or strong. As described 

in this recovery plan, recovery of bull trout: (1) will continue to build upon the numerous and 

ongoing conservation actions implemented on behalf of bull trout since their listing in 1999; (2) 

will be focused on the identification of and effective management of known threat factors to bull 

trout in areas where bull trout currently occur; and (3) using the available scientific information 

to work cooperatively with our partners to design, fund and implement effective conservation 

actions in areas that offer the greatest long-term benefit to sustain bull trout and where recovery 

can be achieved. 

This approach to achieving recovery for bull trout acknowledges the current status of the 

species in both altered and natural habitats, as well as likely future trends. In a few core areas 

habitat alterations have likely resulted in increased bull trout populations relative to historical

conditions or have created barriers to nonnative fish invasion, and should be maintained. In 

many watersheds management should be prioritized in cold water habitats that are most likely to 

be resistant to habitat loss from climatic warming. Our recovery strategy is focused on achieving 

demographically stable bull trout populations in areas where they currently occur. The recovery 

of bull trout is not dependent upon recovery throughout its historical range.

12. Comment: Concerns with the proposed threats based recovery approach and Threats 

Assessment Tool. Will there be a process to prioritize conservation actions? And are migratory 

bull trout populations more important from a conservation perspective than resident populations? 
136

Response: In developing this bull trout recovery plan, recovery criteria and recovery 

actions were established for bull trout that are intended to ensure adequate conservation of 

genetic diversity, life history features, and broad geographical representation of bull trout 

populations in six recovery units that comprise the threatened coterminous United States 

population of bull trout. Therefore, the recovery plan recognizes that all 109 existing bull trout 

core areas contribute to the overall conservation of the species and identifies recovery actions to 

address primary threat factors affecting bull trout in these same 109 core areas. Although the 

recovery plan does not distinguish conservation importance or prioritize conservation actions for 

‘complex’ and ‘simple’ core areas, we also acknowledge that despite our best conservation 

efforts identified in this plan, it is possible that some existing bull trout core areas may become 

extirpated within the foreseeable future due to various factors; including the effects of small 

populations, isolation, and climate change, coincident with recovery. 

13. Comment: Due to the uncertainty of terminology, it is difficult to comment and respond 

to the RUIP process and fully evaluate whether the proposed recovery criteria and threats 

determination process are viable.

Response: Where applicable, the Service has revised or better defined specific terms to help 

inform completion of the recovery plan. The Service is committed to working with our partners 

to ensure that we have the best recovery plan available for bull trout while meeting our legal 

obligations in completing the recovery plan.

14. Comment: One State agency suggested that for most core areas bull trout demographic 

information can and should be used to determine tangible conservation and recovery objectives, 

and ultimately recovery criteria.

Response: We agree. One demonstration of effective threat management is a 

demographically stable bull trout population as measured at the core area scale. Therefore, 

demographic data, as well as other empirical data on the magnitude and trends in bull trout 

population counts or indices; current or historical spatial distribution, connectivity, and extent of 

populations, will be useful and help inform the effectiveness of primary threat management 

where such information is available. Because such information is not available in all core areas 

across the species’ range, each RUIP will identify additional monitoring and evaluation needs.
137

15. Comment: One State agency does not believe that bull trout in Montana are currently 

threatened or endangered with extirpation in the foreseeable future (35 or 50 years), but 

acknowledged that in some core areas further management efforts may be needed.

Response: As described in the recovery plan our most recent 5-year status review for 

bull trout was completed on April 8, 2008, and concluded that listing the species as “threatened” 

remained warranted range-wide in the coterminous United States. In our most recent recovery 

report to Congress (USFWS 2012) we reported that bull trout were generally “stable” overall 

range-wide (species status neither improved nor declined during the reporting year), with some 

core area populations decreasing, some stable, and some increasing. Since the listing of bull 

trout, there has been very little change in the general distribution of bull trout in the coterminous 

United States, and we are not aware that any known, occupied bull trout core areas have been 

extirpated. We concur that in some parts of their extant range, bull trout experience few or no 

threats and harbor healthy populations throughout most or all available habitat; some bull trout 

core areas experience limited but major threats and have strong populations throughout most 

habitat; and some continue to experience severe and systemic threats and harbor relatively small 

populations that have been reduced to a limited portion of available habitat. 

In summary, today bull trout remain listed as a threatened species throughout its 

coterminous range in the United States. The Service is committed to completing the recovery 

plan so that future conservation actions will be focused in those areas where success is likely.

16. Comment: One State agency was generally supportive of the ‘managed threats’, ‘core 

area’, and possible ‘recovery unit DPS delisting’ approaches in the draft recovery plan.

Response: Thank you for your comments.

17. Comment: One State agency was generally supportive of the thematic changes from 

previous draft recovery plans for bull trout, including:

- Inclusion of adaptive recovery principles and tools that may play a role in threat 

assessments and measuring recovery;

- Recognition that recovery does not mean restoration everywhere or throughout their 

native range;

- Support the concept of recovery units as possible DPSs.
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Response: Although bull trout are believed to have undergone a significant reduction in 

their historical range prior to the time of their listing in 1999, the species continues to be found in 

suitable habitats and is geographically widespread across numerous major river basins in five 

western states.

This recovery plan incorporates and builds upon all the new information found in 

numerous reports and studies regarding bull trout since the draft 2002 and 2004 recovery plans 

and outlines a strategy that: (1) conserves bull trout so that they are geographically widespread 

across representative habitats and demographically stable in six recovery units; (2) effectively 

manage and ameliorate the primary threats in each of six recovery units at the core area scale; (3) 

builds upon the numerous and ongoing conservation actions implemented on behalf of bull trout 

since their listing in 1999, and improves our understanding of how various threat factors 

potentially affect the species; (4) used that information to work cooperatively with our partners 

to design, fund, prioritize, and implement effective conservation actions in those areas that offer 

the greatest long-term benefit to sustain bull trout and where recovery can be achieved; and (5) 

applies adaptive management principles to implementing the bull trout recovery program to 

account for new information. 

18. Comment: One State agency expressed concerns that the recovery pathway was not fully 

developed in the revised draft recovery plan (acknowledges that this will likely be accomplished 

through the RUIP process).

Response: The recovery plan describes recovery of bull trout as dependent upon 

effectively managing and ameliorating the primary threats affecting the species in each recovery 

unit at the core area level such that bull trout are geographically widespread and demographically 

stable across representative habitats within the six recovery units.

The Service may initiate an assessment, or status review, of whether recovery has been 

achieved and delisting is warranted when the primary threats identified for core areas in the six 

recovery units are effectively managed at the thresholds identified in the recovery plan (i.e., 75

percent for the Coastal, Mid-Columbia, Upper Snake and Columbia Headwaters; and 100 percent

for the Klamath and St. Mary Recovery Units).

In any future status review or delisting evaluation, the Service will evaluate the best 

available scientific and commercial information to ensure that the recovery pathway for bull 

trout in a ‘recovered’ recovery unit achieves representation (i.e., existing occupancy within most 

core areas were maintained and existing life history forms that are present in these core areas 
139

were mostly preserved); redundancy (i.e., a mosaic of healthy populations are distributed across 

the landscape within the recovery unit); and resilience (i.e., core areas that contain migratory life 

history expressions were prioritized for conservation, and “at risk” core areas have been 

improved). The Service will focus on three primary areas: utilizing all and best available 

information in the context of the requirements of the Act to assess the status of threats across the 

range of bull trout in terms of the five listing factors; demonstration of demographically stable 

populations of bull trout; and evaluation of the adequacy of existing regulatory mechanisms to 

provide adequate protection for bull trout in the foreseeable future (approximately the next 50 

years).

19. Comment: Two State agencies submitted a proposal to reconfigure the Coastal Recovery 

Unit into two recovery units. Specifically, to split the Coastal Recovery Unit into two recovery 

units: Washington Coast and Lower Columbia Recovery Units. Belief that the rule-set used to 

designate the six recovery units was applied inconsistently with respect to establishing the 

Coastal Recovery Unit. Specifically, the use of genetic data was not consistently evaluated 

across all areas when “... spatial configuration, ecological setting, and management authority...” 

may have influenced appropriate recovery unit boundaries. Additional support for splitting the 

Coastal Recovery Unit based on spatial separation, different ecological settings and different 

expressions of life history also provided. 

Response: Since the original listing decision in 1998, new data and reanalysis have 

suggested that the coterminous United States listed entity would be more appropriately divided 

into 6 recovery units, rather than the 27 recovery units identified in the 2002 and 2004 draft 

recovery plans. We worked with a number of State, Federal, and Tribal partners in 2008 and 

2009 to evaluate alternatives for organizing core areas into possible recovery units that might

also be consistent with the “discreteness” and “significance” criteria in the DPS policy. Ten 

alternatives were evaluated that explored from 2 to 69 potential recovery units, based on 

mitochondrial and microsatellite DNA analysis, and on biogeographical considerations, 

including geological establishment of major watersheds, isolation of portions of watersheds 

above major waterfalls, co-occurrence with other fish species, and occurrence in different 

ecological zones (Ardren et al. 2011). The six recovery units identified in this plan reflect this 

most recent information and analysis, and were first described in the 2010 proposed critical 

habitat rule (USFWS 2010a). They include: (1) Coastal Recovery Unit, (2) Klamath Recovery 

Unit, (3) Mid-Columbia Recovery Unit, (4) Upper Snake Recovery Unit, (5) Columbia 

Headwaters Recovery Unit, and (6) Saint Mary Recovery Unit. 
140

In this analysis of alternatives, we concluded that the six unit alternative could meet the 

discreteness criterion for a DPS because the six units had a pattern of significant genetic 

divergence at the microsatellite level; were isolated from other populations (strongly for the 

Coastal, Klamath, St. Mary, and Columbia Headwaters, limited for the Mid-Columbia and Upper 

Snake); and showed life history differences (primarily for the Coastal and Klamath, limited for 

the others). We also concluded that this alternative could meet the significance criterion for a 

DPS on the basis that loss of any unit would create a significant gap in the range (loss from 

major drainage basin or major portion of Columbia basin), and possibly on the basis of 

ecological setting (unique species assemblage for Klamath and St. Mary, more limited for the 

others) and marked difference (low potential for shared evolutionary future among Klamath, St. 

Mary, and Columbia Headwaters; and evolutionarily significant genetic divergence among 

Coastal, Klamath, and St. Mary).

The seven unit alternative that we analyzed differed from the six unit alternative in 

splitting the Coastal Recovery Unit between the Washington Coast (including both Puget Sound 

and Olympic Peninsula watersheds) and Lower Columbia regions. We concluded that this 

alternative also could meet the discreteness and significance criteria for a DPS. Differences in 

the discreteness analysis included the degree of isolation from other populations and life history 

differences (both strong for Washington Coast, limited for Lower Columbia watershed). We 

concluded that this alternative could meet the significance criterion on the basis that loss of any 

unit would create a significant gap in the range (loss from major drainage basin or major portion 

of Columbia basin); however, it was noted that this argument might be weak for the Lower 

Columbia. Other differences in the significance analysis included differences in ecological 

setting (unique species assemblage for Washington Coast) and marked difference (evolutionarily 

significant genetic divergence with low potential for shared evolutionary future for Washington 

Coast, but not for Lower Columbia). 

Thus, our original analysis found that both the six unit and seven unit alternatives could 

legitimately meet the criteria in the DPS policy. Recovery unit delineation considered multiple 

factors, including genetics, life history strategies, ecological setting, and geographical 

connectivity. On review of the commenters’ requests to split the Coastal Recovery Unit, while 

their rationale supports the seven unit structure under the DPS policy, we did not find that 

substantial new information was provided that was not considered in the original analysis. 

Nonetheless, for effective management we do support the use of bull trout working groups at the 

level of recovery subunits organized along the lines of the Washington Coast and Lower 

Columbia regions. Additionally, if such a portion of the Coastal Recovery Unit appears to be 

meeting recovery targets, we would also consider application of tools such as HCPs or an 

expanded 4(d) rule to reduce regulatory burdens in the region or other recovery units too.
141

20. Comment: One State agency expressed concerns with proposed recovery criteria 

dependent upon effective management alone, and that some measure of status will be needed 

(demographics).

Response: One demonstration of effective threat management is a demographically 

stable population as measured at the core area scale. Therefore, demographic data, as well as 

other empirical data on the magnitude and trends in bull trout population counts or indices; 

current or historical spatial distribution, connectivity, and extent of populations, will be useful 

and help inform the effectiveness of primary threat management where such information is 

available. Because such information is not available in all core areas across the species’ range, 

each RUIP will identify additional monitoring and evaluation needs.

21. Comment: One State agency suggested that the Bull Trout Recovery Plan include a 

Service staff directory for the entire range of the species.

Response: FWS field offices with primary responsibility for bull trout recovery plan 

development and recovery implementation include: 

Oregon Fish and Wildlife Office (Oregon except for Klamath Recovery Unit; current lead 

biologist Chris Allen)

Klamath Falls Fish and Wildlife Office (Klamath Recovery Unit; current lead biologist Nolan 

Banish)

Washington Fish and Wildlife Office (Washington; current lead biologists Jeff Chan, Erin 

Britton-Kuttel [eastern Washington], Judy Neibauer [central Washington])

Montana Fish and Wildlife Office (Montana; current lead biologist Wade Fredenberg)

Idaho Fish and Wildlife Office (Idaho; current lead biologists Benjamin Matibag [southern 

Idaho], Scott Deeds [northern Idaho])

Numerous biologists in our Fisheries and Ecological Services programs support bull trout 

recovery through section 7 consultation, HCP development, policy review, research, and 

monitoring. Although inevitably incomplete, a list of Service staff and other partners who have 

contributed to bull trout recovery is available at this link.
142

22. Comment: Similar to other comments, one State agency expressed concerns that the lack 

of metrics (abundance and distribution) in recovery criteria seems inconsistent with our recovery 

policy.

Response: This comment was addressed previously in General Comment # 1 (page 2). 

In summary, the comment refers to the joint National Marine Fisheries Service and U.S. Fish and 

Wildlife Service’s Interim Endangered and Threatened Species Recovery Planning Guidance 

(NMFS and USFWS 2010), which was first proposed in 2004 and revised/updated in 2006, 2007 

and 2010. Our recovery planning guidance recommends that recovery criteria be SMART: 

Specific, Measurable, Achievable, Realistic, and Time-referenced. Current recovery criteria for 

bull trout were developed with these practical directives in mind, and are based in a sound 

scientific rationale, reflecting biodiversity principles of resilience (ecological quality and ability 

to persist), redundancy (maintaining multiple replicates of populations/habitats to insure against 

catastrophic loss), and representation (conserving the full range of natural variation) (Shaffer and 

Stein 2000, Tear et al. 2005). Moreover, the recovery criteria shift the emphasis on recovery 

from predetermined, but subjective, outcomes to conservation actions whose effects can be 

monitored and measured to assure that recovery has occurred to or inform adaptive management. 

We also considered seven principles of conservation specific to bull trout in developing recovery 

criteria: (1) conserve the opportunity for diverse life history expression; (2) conserve the 

opportunity for genetic diversity; (3) ensure bull trout are distributed across representative 

habitats; (4) ensure sufficient connectivity among populations; (5) ensure sufficient habitat to 

support population viability (e.g., abundance, trend indices); (6) address threats, including 

climate change; and (7) ensure sufficient redundancy in conserving population units. These 

recovery principles take into account threats to and physical or biological needs of the species 

throughout its range and focus on the range-wide recovery needs. At the same time, the seven 

principles and our approach recognize that the nature of threats to, the long-term viability of and 

the pathways to recovery for bull trout cannot be “one-size fits all” across its entire range. To 

that end, the recovery plan addresses these questions through a framework of six recovery units 

within which recovery can be tailored to the needs of geographically distinct subpopulations of 

bull trout.

Addressing threats in recovery criteria (threats-based criteria) is a requirement under the 

Interim Recovery Planning Guidance. This principle guided our recovery approach for bull trout 

with a goal to: (1) conserve bull trout so that they are geographically widespread across 

representative habitats and demographically stable, within six recovery units that comprise the 

coterminous United States population of bull trout; (2) effectively manage and ameliorate the 

primary threats in each of the six recovery units at the core area scale such that bull trout will 

persist in the foreseeable future; (3) build upon the numerous and ongoing conservation actions 
143

implemented on behalf of bull trout since their listing in 1999, and improve our understanding of 

how various threat factors potentially affect the species; (4) use that information to work 

cooperatively with our partners to design, fund, prioritize, implement and monitor effective 

conservation actions in those areas that offer the greatest long-term benefit to sustain bull trout 

and where recovery can be achieved; and (5) apply adaptive management principles to 

implementing the bull trout recovery program to account for new information.

In summary, we developed recovery criteria that focus on the identification and effective 

management of known, primary threat factors to bull trout in currently occupied core areas in 

each of six recovery units (Specific, Measurable, Achievable); establishes recovery criteria 

thresholds that acknowledge, despite our best conservation efforts identified in this plan, some 

extant bull trout core area habitats will likely change (and may be lost) over time (Realistic); and 

identifies and focuses recovery actions in those areas where success is likely to meet our goal of 

ensuring the conservation of genetic diversity, life history features, and broad geographical 

representation of remaining bull trout populations (Realistic, Time-referenced).

23. Defining recovery units: The States believe more documentation is needed to describe 

more clearly why the proposed recovery unit boundaries were chosen. The recovery plan needs 

to especially include more biogeographic justification for several recovery units.

Response: As previously described above, new data and reanalysis since 2000 have 

suggested that the coterminous United States listed entity could be more appropriately divided 

into 6 recovery units, rather than the 27 recovery units identified in the 2002 and 2004 draft 

recovery plans. We worked with a number of State, Federal, and Tribal partners in 2008 and 

2009 to evaluate alternatives for organizing core areas into possible recovery units that would 

also be consistent with the “discreteness” and “significance” criteria in the DPS policy. Ten 

alternatives were evaluated that explored from 2 to 69 potential recovery units, based on 

mitochondrial and microsatellite DNA analysis, and on biogeographical considerations, 

including geological establishment of major watersheds, isolation of portions of watersheds 

above major waterfalls, co-occurrence with other fish species, and occurrence in different 

ecological zones (Ardren et al. 2011). The Service selected the six recovery unit alternative 

identified in this plan that we maintain best reflects the available genetic, biogeographical, and 

ecological information, and is consistent with our “discreteness” and “significance” criteria in 

our DPS policy. The six recovery units were first described in the Service’s 2010 proposed 

critical habitat rule (USFWS 2010), and include: (1) Coastal Recovery Unit, (2) Klamath 

Recovery Unit, (3) Mid-Columbia Recovery Unit, (4) Upper Snake Recovery Unit, (5) Columbia 

Headwaters Recovery Unit, and (6) Saint Mary Recovery Unit.
144

24. Comment: Comments suggesting that reintroduction and supplementation tools be 

included where appropriate to aid in recovery.

Response: As previously discussed under General Comment # 9, the recovery plan 

includes a discussion on the role of artificial propagation and translocation in bull trout recovery, 

and the RUIPs will identify where propagation or translocation efforts may be useful to aid 

recovery efforts. Such efforts may involve direct translocation from more vigorous populations 

or captive breeding of bull trout in controlled propagation facilities. Such translocation programs 

should consider appropriate precautions against introduction of fish pathogens to new 

watersheds. 

25. Comment: Proposed recovery unit list of threats: concerned that the proposed list of

threats was too broad and not necessarily applicable or representative of current threat factors 

affecting bull trout in each core area.

Response: Threats found in the revised draft recovery plan were derived from 

information assembled in the Core Area Templates (USFWS 2008) in coordination with various 

State, Federal, and Tribal partners, and additional assessments developed by the Service in 2010 

and 2011. These threats were identified as problems or factors that may affect bull trout local 

populations in each core area at that time or expected to into the foreseeable future (in 

consideration of present and future climate change). They included a variety of threats that 

ranged in severity from serious imminent threats to documented, but relatively minor issues that 

should nonetheless be evaluated for their potential impact.

Because the threats were derived from information assembled from Core Area Templates 

and Assessments developed in 2008, 2010 and 2011, we anticipated that much of the information 

was likely out of date and in need of updating and revision. New information and suggested 

changes in the list of threats has been incorporated and updated in the final recovery plan through 

the interagency RUIP development process.

26. Comment: Climate Change: future climate change effects should be considered in 

developing conservation actions and appropriating conservation resources. One State agency 

suggested a more programmatic approach to address climate change in the final recovery plan.
145

Response: Climate change effects were not considered as factors affecting bull trout at 

the time of listing in 1999. Since that time, several climate change assessments or studies have 

been published or are currently underway assessing the possible effects of climate change on bull 

trout and their habitats. The results of these efforts will allow us to better understand how 

climate change may influence bull trout and help to identify suitable conservation actions to 

ensure bull trout persist in the foreseeable future in the face of climate change. For example, 

recent publications have cited information showing estimates of both summer flow decreases and 

stream temperature increases due to climate change in several areas where bull trout currently 

reside (e.g., Leppi et al. 2012; Luce et al. 2013; Sawaske and Freyberg 2014). Both of these 

metrics demonstrate that discernible long-term trends are having direct negative impacts on 

availability of suitable habitat for bull trout.

Therefore, it is important to develop a decision framework to assess climate change 

effects to bull trout and allocate conservation resources and funding to ensure that future bull 

trout conservation efforts are allocated to those areas with the anticipated future coldest water 

temperatures that offer the greatest long-term benefit to bull trout conservation. Recent tools 

and regional databases that may be useful for informing and prioritizing the bull trout 

conservation and monitoring actions described in the RUIPs include: NorWeST Regional 

Database and Modeled Stream Temperatures (Isaak et al. 2014) (stream temperature data used to 

develop accurate and consistent data on aquatic habitat spatial distribution and responses to 

climate that may help predict future bull trout occupancy); Bayesian Belief Network decision 

support tools (Peterson et al. 2013) (developed to provide spatially-explicit information about the 

likelihood of fish population, including bull trout, persistence under different climate scenarios); 

and the numerous recent scientific publications describing historical trends in precipitation and 

stream flow observed across the Pacific Northwest. We expect that these, and other, tools will 

be useful in developing and applying conservation actions identified in the bull trout recovery 

plan’s RUIPs, and will be used by State, Federal, Tribal and other agencies responsible for 

implementing actions in support of bull trout conservation and recovery.
146

APPENDIX E. Assessment Tool for Describing Effective Management 

of Threats in Bull Trout Core Areas and Six Recovery Units that 

Comprise the Coterminous Population of Bull Trout. 

EXECUTIVE SUMMARY

The primary recovery strategy for recovery of bull trout in the coterminous United States 

is to: (1) conserve bull trout so that they are geographically widespread across representative 

habitats and demographically stable; (2) managing and ameliorating the primary threats in each 

of six recovery units at the core area scale such that bull trout will persist well into the future; (3) 

work cooperatively with partners to develop and implement bull trout recovery actions in each of 

the six recovery units; and (4) apply adaptive management principles to implementing the bull 

trout recovery program to account for new information. Recovery criteria described in the 

recovery plan represent our best assessment of the conditions that would most likely result in a 

determination that listing under the Act is no longer required.

To objectively evaluate the status of threats affecting bull trout across the range of the 

species, the Service has created a structured assessment tool that incorporates the best available 

data and scientific expert opinion participation. The results from this assessment tool will be 

integral to evaluate the status of bull trout at the range-wide and recovery unit scales based on 

the analysis of threat management effectiveness at the core area level. These core area 

assessments should also serve as a primary metric to assess the species’ status in 5-year reviews 

and five-factor threats analyses that are initiated in the future, including any delisting 

evaluations. Additional ‘metrics’ that will be important in future status reviews include evidence 

of demographically stable populations of bull trout; and an evaluation of the adequacy of existing 

regulatory mechanisms to provide adequate protection for bull trout in the foreseeable future 

(approximately the next 50 years).

In summary, when future status reviews or delisting evaluations are initiated, the Service 

will evaluate the best available scientific and commercial information to ensure that the recovery

pathway for bull trout in a ‘recovered’ recovery unit achieve representation (i.e., existing 

occupancy within most core areas were maintained and existing life history forms that are 

present in these core areas were mostly preserved); redundancy (i.e., a mosaic of healthy 

populations are distributed across the landscape within the recovery unit); and resilience (i.e., 

core areas that contain migratory life history expressions were prioritized for conservation, and 

“at risk” core areas have been improved). Such reviews will focus on three primary areas: threat 

assessment process to evaluate the status of threats across the range of bull trout; demonstration 

of demographically stable populations of bull trout; and evaluation of the adequacy of existing 
147

regulatory mechanisms to provide adequate protection for bull trout in the foreseeable future 

(approximately the next 50 years).

BACKGROUND

Our recovery planning guidance (NMFS and USFWS 2010) calls for the design of 

recovery criteria to address the five statutory listing factors in section 4(a)(1) of the Act, in order 

to measure whether threats to the species have been ameliorated. Thus, recovery criteria should 

be applicable to a five-factor threats analysis in a subsequent delisting rule. Because bull trout 

are geographically widespread and vary substantially within each recovery unit in the nature of 

the threats that populations face, it is necessary to use an appropriate geographic scale to assess 

whether management is effectively ameliorating threats. Because threats to bull trout are 

generally expressed at a metapopulation level and management actions can be effectively 

planned at that scale, we will explicitly assess threats at the core area scale, in terms of the 

statutory listing factors, and aggregate these core area assessments to the recovery unit level to 

determine whether recovery criteria are being met.

Overview of the Threat Assessment Process

To objectively evaluate the status of threats across the range of bull trout, the Service has 

created a structured assessment approach that incorporates the best available data and scientific 

expert opinion participation. The results from this assessment tool will be integral to evaluate 

the status of bull trout at the range-wide and recovery unit scales based on the analysis of threats 

at the core area level. These core area assessments should also serve as a primary metric to 

assess the species’ status in 5-year reviews and five-factor threats analyses that are initiated in 

the future, including any delisting evaluations.. Core area assessments can also inform the 

process of recovery implementation by highlighting and prioritizing management actions that 

maximize conservation benefits for bull trout.

The Threats Assessment Tool developed for bull trout includes the following components 

(along with the participating or responsible participants), and is fully described below.

• Assessment Workshop Process (Service, Federal, State, Tribal, and others)

• Threats Assessment Decision Matrix (Service, Federal, State, Tribal, and others)

• Assessment of Threats Effectively Managed (Service)

• Evaluation of Recovery Unit Status (Service)
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Assessment Workshop Process

When evaluating the status of bull trout at the recovery unit scale, we plan to convene a 

workshop or series of workshops to assess the status (threat severity, threat management 

effectiveness, bull trout demography) of each core area within the recovery unit. Each workshop 

will include broad representation of fisheries biologists knowledgeable about bull trout issues 

within the recovery unit, including but not limited to biologists from U.S. Geological Survey, 

U.S. Fish and Wildlife Service - Fisheries and Ecological Services field offices, Federal land 

managers (U.S. Forest Service, National Park Service, Bureau of Land Management), State land 

management agencies, State fish and game agencies, Tribal fisheries programs, and universities. 

Our objective is to provide a decision framework that characterizes bull trout status as 

objectively as possible, with acknowledgment that there are inherent differences among experts 

in data interpretation and professional opinion. In the workshops we will seek to determine the 

range of professional opinion on the status of each core area (without seeking group consensus), 

soliciting an open discussion of current survey and management information and eliciting the 

rationale and assumptions involved in the status determination and any differences of opinion.

Our goal is to establish a structured, consistent, and objective approach to determining 

whether the identified primary threats to bull trout are being effectively managed at the core area 

level. The framework for making these determinations will include a simple, but consistently 

applied, decision matrix (described below) to assess threat severity and management 

effectiveness for each identified primary threat in the core area.

Assessment of this decision matrix will be informed by existing empirical data on 

magnitude and trends in bull trout population counts or indices; current or historical spatial 

distribution, connectivity, and extent of populations; expression of life history strategies; 

occurrence, magnitude, scope, trends, and severity of threats; and significant conservation 

measures that are ongoing or have been completed to address primary threats. These data will be 

interpreted with the best professional judgment of biologists familiar with bull trout populations 

in the core area. Data sources may include but are not limited to:

• Available bull trout survey and monitoring data (e.g., redd counts, telemetry, creel 

counts) collected by State, Federal, Tribal, university programs, or other researchers, 

providing information on population size or indices, historical trends, distribution, and 

movements for bull trout, forage fish, or non-native predators/competitors in the core 

area.

• Information from section 7 consultations regarding management actions within the core 

area, including characterization of habitat impacts, population trends, and baseline within 

local populations (e.g., analyses under the consultation matrix template [USFWS 1999]). 
149

This information may be compiled using data on bull trout effects from Service databases

or other information in Service files. 

• Compilation of ongoing and completed conservation actions since the time of listing 

which address identified primary and other threats within the core area.

• Threat monitoring information, including land management agency assessment of stream 

habitat conditions, trends, and high priority actions (e.g., USFS 2013), and water quality 

assessments (impaired waters identified under Clean Water Act 303(d), and total 

maximum daily load determinations). 

• Calculation of an integrated conservation metric for each core area, based on 

methodology of the NatureServe Conservation Status Assessment Tool created by the 

International Union for Conservation of Nature (Faber-Langendoen et al. 2012). This 

metric combines available information on bull trout habitat extent, population size, 

trends, and threats to provide a generalized ordinal representation of current core area 

conservation status.

• Available analyses for core area stream temperature data collected and modeled through 

the NorWeST (USFS 2014, Isaak et al. 2015), and Bull Trout Vulnerability Assessment

(Dunham 2015) processes. This information includes modeled probabilities of bull trout 

presence and mapping of suitable habitat patches using data on stream temperature, fish 

presence, local threats, connectivity, and climate sensitivity. These models were 

completed for much of the range of bull trout during 2014. In several core areas local 

applications of these models have been implemented or are in progress, providing

detailed analyses that have also been employed to prioritize management actions in 

RUIPs. Potential climate change impacts, while not specifically assessed as an 

independent threat, are considered in the context of climatic influence on other threats 

when determining what recovery actions are needed in core areas.

The timeframe over which impacts are projected in this threats assessment process is 

based on the foreseeable future for evaluation of threatened status. For bull trout, the foreseeable 

future for bull trout was first described during the 2008 5-year review process (USFWS 2008a as 

being 4 to 10 generations (approximately 28 to 70 years). For consistency, the time frame used 

for assessing core area status and population persistence is set in the middle of that range, at 

approximately 50 years. 
150

Threats Assessment Decision Matrix

For each core area, participating experts will be asked to evaluate all identified primary 

threats with respect to two independent metrics: threat severity and management effectiveness. 

The categories used for these metrics are defined below, with several examples to describe 

circumstances in which these categories could be appropriately applied to particular types of

threats (nonnative fish impacts, impaired connectivity, etc.). These metrics are combined into a 

decision matrix (Table 1 below) that will be used to assess whether current management or 

conservation actions effectively address the threat. 

For this analysis, threats are classified into several major categories: Upland/riparian land 

management (Factor A; including impacts of forestry, grazing, road maintenance, etc. on 

sedimentation, temperature, and stream habitat); instream impacts (Factor A; instream flow, 

entrainment); water quality (Factor A; contaminants, mining impacts); nonnative fishes (Factors 

C and E; including competition, predation, and hybridization effects); connectivity impairment 

(Factor E: dams, culverts, etc.), forage fish availability (Factor E), and angling impacts (Factors 

B and D; poaching and bycatch). Projected impacts related to climate change should be 

incorporated in the analysis in terms of their effects on these threat categories (e.g., through 

water temperature, instream flow, brown trout colonization) over the foreseeable future. This 

aggregation of threats is designed for the purpose of general core area status assessment; data 

arising from section 7 consultations on bull trout are fully applicable to this analysis but the 

framework of pathways of effects and their indicators commonly used in section 7 analyses

(USFWS 1999) uses a slightly different aggregation of threats as appropriate for project-level 

assessments (see Table 2 below). We do not anticipate a need to alter the threats classifications 

currently used in section 7 consultations. See Appendix G for more information regarding the 

relationship between recovery and section 7(a)(2) of the Act.

Small population size can also constitute a primary threat under Factor E (demographic 

stochasticity, loss of genetic diversity), but threats related to population size are addressed 

separately as discussed below. 

Both axes of the matrix will be evaluated for each combination of core area and threat. 

As an ancillary exercise, it may be useful to consider each particular threat (e.g., nonnative 

fishes) at a broader recovery unit level, ranking all core areas in the recovery unit by the relative 

severity of that threat from most to least affected. This relative ranking could provide a crosscheck against core area specific analyses, to improve the consistency of threat evaluations 

throughout the recovery unit. 

Each threat will be individually assessed at the core area level and the Service will make 

an overall determination for each core area of whether threats are being effectively managed. 
151

These core area determinations will then be rolled up to the recovery unit level to assess recovery 

criteria. 

Table 1. Example of Threats Assessment Decision Matrix.

Threats Assessment Decision Matrix

Threat Severity

Management 

Effectiveness

Minor Moderate High Severe

None or Ineffective

Partially Effective

Mostly Effective

Effective
152

Table 2. Interrelation between the bull trout pathways and indicators matrix and threat classifications in this assessment tool. 

Note that section 7 consultations primarily address specific project impacts, while an overall assessment of core area threats generally 

has a broader geographic scope, can aggregate detailed local analyses to a broader level assessment, and involves assessment of core 

area status over the foreseeable future.

Pathways Indicators Assessment Tool Threat Types

Channel Condition and

Dynamics

- Channel bed stability

- Floodplain connectivity

- Streambank condition

- Width/depth ratio

Upland/Riparian Land Management

[in relation to impacts on stream channel 

structure]

Disturbance - Noise disturbance

- Other disturbance

This pathway may relate more to localized 

project impacts than to overall core area 

condition; but is generally covered under 

upland/riparian land management.

Flow and Hydrology - Altered flow patterns

- Change in peak/base/summer low 

flows

- Drainage network increase

- Springs/seeps/groundwater 

connections

Instream Impacts

[e.g. instream flow, entrainment]

Forage Base - Prey availability

- Species composition

Forage Fish Availability
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Pathways Indicators Assessment Tool Threat Types

Habitat Access - Chemical barriers

- Physical barriers

Connectivity Impairment (e.g., dams, culverts)

Habitat Elements - Cover (other)

- Large pools

- Large woody debris

- Off-channel habitat

- Percent fines in gravel

- Pool frequency and quality

- Refugia

- Substrate embeddedness

Upland/Riparian Land Management

[in relation to impacts on structural features of 

stream habitat]

Population Unit Characteristics - Direct take (loss) of individuals

- Growth and survival

- Life history diversity and isolation

- Persistence and genetic integrity

- Population size

Small Population Size

[in relation to genetics and population size]

“Growth and survival” indicator could relate to 

multiple threat types that may affect this. 

Water Quality - Chemical contamination Upland/Riparian Land Management

[primarily direct land management impacts on 
154

Pathways Indicators Assessment Tool Threat Types

- Nutrients

- Other water chemistry

- Sediment

- Temperature

water temperature and sedimentation]

Water Quality [primarily in relation to chemical 

contaminants/nutrients/acidity]

Watershed Conditions - Riparian condition

- Road density and location

- Watershed disturbance regime

- Watershed disturbance history

Upland/Riparian Land Management

[none; significant core area 

level threat, but not a typical 

consultation subject]

Nonnative Fishes

[none; significant core area 

level threat, but not a typical 

consultation subject]

Angling Impacts
155

Threat Severity: The degree to which a specific threat would affect bull trout survival and 

persistence in a core area in the absence of management actions to eliminate or mitigate the 

threat. This assessment considers both the impacts on persistence of bull trout local populations 

and the spatial distribution and extent of threats within a core area. 

To evaluate the severity of a threat within a core area, consider a hypothetical scenario 

where the threat remains unmanaged and other threats do not negatively affect bull trout in the 

core area. Ranking of threat severity should reflect a gradient in the proportion of existing local 

populations that would be expected to persist over 50 years in this scenario, ranging between the 

two extremes of extirpation of all local populations and persistence of all local populations at 

viable levels. Note that if the most probable expected outcome is a major reduction in 

abundance of a local population over 50 years, the inherent uncertainty of such a long-term 

projection will likely include some risk of the population being extirpated. Both core areas 

where some local populations are considered secure and others are expected to be extirpated, and 

core areas where all local populations have a moderate likelihood of persistence, might fall on 

similar intermediate positions on this gradient.

Information on bull trout population trends may be used to inform threat severity 

assessments, but is most clearly applicable in cases where only one primary threat exists in a 

core area and no significant management is being done. Where multiple threats exist, the actual 

population trends may be a function of several of them; thus threats could be individually ranked 

at different severities based on the same population numbers if they are expected to have 

different degrees of impact on population persistence. Moreover, if a threat is being 

counteracted by ongoing management so that the population remains stable or increasing when it 

would otherwise be expected to decline, these population benefits should be reflected on the 

“Management Effectiveness” axis of the matrix rather than “Threat Severity” to avoid doublecounting. Using actual population data as a direct surrogate for threat severity could thus result 

in underestimating the threat severity in absence of management. Other information such as 

models and status assessments should also be considered when assessing threat severity.

Resilience of bull trout populations at the recovery unit level is supported by a well 

distributed expression of migratory life history strategies, which improve population 

connectivity, reproductive success, and recolonization. Because of variations among core areas 

in habitat configuration and threat of invasion by nonnative fishes, each core area should be 

individually assessed for the relative importance of maintaining or reestablishing various 

migratory life history strategies. In core areas where expression of migratory life history is 
156

important for conservation (as determined in RUIPs), assessment of threat severity should 

incorporate impacts on life history diversity.

Minor: If unmanaged, threat is not expected to appreciably reduce persistence of bull 

trout local populations within the core area for the foreseeable future (50 years). If threat occurs 

broadly throughout the core area, its population-level impacts on local populations are expected 

to be minor or transient. If any local populations are expected to be substantially reduced by the 

threat, they are geographically localized (less than approximately 25 percent of local populations 

in the core area) and are not expected to be extirpated in the foreseeable future. The threat is not 

expected to substantially spread without management. 

Examples: 

• Brook trout occur in a core area but are not actively expanding and do not overlap 

with any bull trout local populations; or brook trout overlap but significant 

negative competitive interactions and hybridization are not believed to exist.

• Introduced nonnative fishes occur in mainstem habitat downstream from a bull 

trout local population, but interactions or impacts are not confirmed (e.g., walleye 

in the Saint Mary Recovery Unit).

• Lake trout and northern pike in core areas where they historically co-occurred 

with bull trout fluvial populations (Saint Mary Recovery Unit only) and are not 

known to negatively affect bull trout.

• In core areas where expression of migratory life history has been identified as 

important for conservation, a “minor” severity level for a connectivity-related 

threat would not be expected to result in loss of migratory life history expression. 

Most or all bull trout spawning/rearing habitat in the core area is connected with 

the historically occupied FMO habitat within the core area. Dams or reaches with 

water quality impairment, if present, provide effective two-way passage during 

most or all periods when bull trout are moving between FMO and 

spawning/rearing habitat. Dispersal between local populations in the core area is 

generally active and retains potential for re-colonization and metapopulation 

function. All migratory life history strategies that were historically present within 

the system are present. 

• Habitat impairment from anthropogenic effects has little or no impact on habitat 

suitability and distribution for bull trout.
157

Moderate: If unmanaged, threat is expected to slightly to moderately reduce persistence 

of bull trout local populations within the core area for the foreseeable future (50 years). Impacts 

on bull trout in the core area have been documented and are well supported. Impacts from the 

threat are moderate but geographically widespread within the core area (more than 

approximately 25 percent of the local populations in the core area are expected to be 

substantially reduced but are generally not expected to be extirpated); or else the threat is more 

geographically restricted, but the affected local populations are expected to be severely reduced 

and are at some risk of extirpation in the foreseeable future. There may be risk of the threat 

spreading to currently unaffected local populations in the foreseeable future. Few local 

populations are expected to be extirpated in the foreseeable future by this threat alone, although 

it may substantially contribute to extirpation risk for local populations in combination with other 

threats. 

Examples: 

• Brook trout that co-occur with bull trout local populations, where some negative

competitive interactions are likely or confirmed but hybridization is absent or 

minimal, and local bull trout populations are expected to persist in the foreseeable 

future.

• Nonnative warm-water fishes (bass, walleye, etc.) that occur in lakes or mainstem 

rivers that are used as FMO habitat, and have some negative effects through 

competition or predation that may reduce survival/dispersal success, but do not 

substantially exclude bull trout from using the habitat.

• Lake trout that compete with or prey upon bull trout in large lakes where some 

negative impacts on bull trout adfluvial populations have been observed but are 

not expected to significantly compromise their viability/persistence over the 

foreseeable future. 

• In core areas where expression of migratory life history has been identified as 

important for conservation, a “moderate” severity level for a connectivity related 

threat may result in partial loss of migratory life history expression within the 

core area. Spawning/rearing habitat in the core area retains connection with 

historically occupied FMO habitat, but some local populations may be isolated, or 

there may be partial or seasonal barriers to dispersal that substantially reduce 

connectivity or survivorship during dispersal. Dispersal between local 

populations in the core area may be episodic or seasonally restricted to a few 

watersheds. Migratory life history strategies that were historically present within 
158

the system likely continue to exist but may not be expressed in all local 

populations. 

• Habitat impacts are localized in a few local populations and not throughout the 

core area, or if widespread are at a degree compatible with persistence of most 

bull trout local populations at reduced levels.

High: If unmanaged, threat is expected to substantially reduce persistence of bull trout 

local populations within the core area for the foreseeable future (50 years). Impacts on bull trout 

in the core area are well supported and geographically widespread (affecting most or all local 

populations). Without active management affected local populations are generally expected to 

be severely reduced and are at some risk of extirpation in the foreseeable future. Threat 

substantially contributes to extirpation risk for local populations, alone or in combination with 

other threats.

Examples: 

• Brook trout that co-occur with bull trout local populations, where hybridization or 

competition is occurring and may compromise the long-term survival or genetic 

integrity of local populations. 

• Lake trout competition/predation in large lake/riverine systems where it 

significantly compromises long-term viability/persistence of adfluvial bull trout 

populations (e.g., Priest Lake or Pend Oreille core areas in the Columbia 

Headwaters Recovery Unit).

• In core areas where expression of migratory life history has been identified as 

important for conservation, a “high” severity level for a connectivity related threat 

is likely to result in loss of migratory life history expression within the core area. 

Most or all spawning/rearing habitat in the core area is effectively isolated from 

the historically occupied FMO habitat within or adjacent to the core area, either 

by physical barriers (dams, dewatered reaches, falls, etc.) that do not provide 

effective two-way passage or by reaches with water temperatures or water quality 

unsuitable for bull trout dispersal. Dispersal between local populations in the core 

area is substantially impaired or absent. Migratory life history strategies that were 

historically present within the system are currently absent or unusual, and most or 

all bull trout populations are resident. Connectivity impacts contribute to a 

significant probability of extirpation in the foreseeable future for a substantial 

proportion of local populations. 
159

• The majority of local populations within a core area have negative habitat effects, 

which could result in extirpation of some local populations in the foreseeable 

future without active management.

Severe: If unmanaged, threat is expected to severely reduce persistence of bull trout 

local populations within the core area for the foreseeable future (50 years). Impacts on bull trout 

in the core area are well supported and affect all local populations. Threat substantially 

contributes to extirpation risk for local populations. Without active management all local 

populations are expected to be severely reduced, and most or all local populations are expected 

to be extirpated in the foreseeable future. 

Examples: 

• Brook trout that co-occur with bull trout populations with complete or nearcomplete overlap in distribution, where hybrids are commonly observed and 

remnant bull trout populations are small and declining in abundance.

• Lake trout competition/predation in highly vulnerable core areas (e.g., small 

montane lake systems) where bull trout extirpation is likely or expression of 

adfluvial life history is precluded and bull trout populations are reduced to 

remnant resident patches.

• In core areas where expression of migratory life history has been identified as 

important for conservation, a “severe” severity level for a connectivity related 

threat is consistent with full loss of migratory life history expression within the 

core area. Spawning/rearing habitat in the core area is restricted and effectively 

isolated from the historically occupied FMO habitat within or adjacent to the core 

area, either by physical barriers (dams, dewatered reaches, falls, etc.) that do not 

provide effective two-way passage or by reaches with water temperatures or water 

quality unsuitable for bull trout dispersal. Dispersal between local populations in 

the core area is absent. Migratory life history strategies that were historically 

present within the system are currently absent, and all bull trout populations are 

resident. Connectivity impacts contribute to a high probability of extirpation in 

the foreseeable future for most or all populations. 

• Habitat conditions in the core area are generally not suitable for bull trout, such 

that remaining populations are few, restricted in distribution, and at extreme risk 

of extirpation within the foreseeable future without active management.
160

Management Effectiveness: The extent to which current management of this specific 

threat in a core area is ‘effective’ in reducing the degree of threat or mitigating its impact with 

respect to bull trout. This axis of the matrix reflects a gradient from the baseline of nonexistent 

or ineffective management, which does not alter the degree of threat, to management that entirely 

removes the threat or fully prevents or mitigates its effect on bull trout. Estimates of 

management effectiveness may be based on the best professional judgment of fisheries biologists 

who are familiar with the core area, and should be primarily supported where possible by data 

directly quantifying trends in the threat (e.g., lake trout population indices, fish passage data, 

sediment load measurements) in conjunction with data on historical changes in management. 

Surveys documenting bull trout population trends may also be used to inform this assessment to 

the extent that they can be attributed to particular threats. This association is likely to be most 

clear when only one threat with a relatively high severity is affecting the population; where 

multiple threats exist, attribution of their relative effects on bull trout trends should be made with 

caution. The management actions that are being implemented should be specifically identified 

when a management effectiveness category is assigned so that it is clear what activities are and 

are not being included in this assessment. Generally this axis of the matrix should reflect the 

success of ongoing, active management actions implemented without fundamentally altering 

existing infrastructure or constraints; thus for connectivity-related threats it could include 

mitigation such as fish passage facilities or changes in dam operations, while permanent removal 

of dams or culverts might better be reflected in changes on the “Threat Severity” axis. 

None or Ineffective: No significant management of the threat is taking place in this core 

area, or there is little or no evidence that existing management actions are effectively reducing 

threat severity.

Partially Effective: Management of the threat is being done with moderate effectiveness 

or within a limited portion of the core area, including at least some of the local populations 

affected by the threat. There is evidence that threat severity is being reduced, but this reduction 

is localized or moderate. 

Mostly Effective: Management of the threat is being done in most or all of the core area, 

including most or all local populations affected by the threat. Threat severity is substantially 

reduced throughout the core area, but some lesser negative effects persist; or comparably, the 

core area is divided between a majority of local populations where the threat has been effectively

neutralized and a minority where management remains absent or ineffective. 

Effective: Management of this threat reduces risk to all affected local populations, and 

the threat is largely or completely neutralized, with existing effects on bull trout being minor or 

absent. Ongoing management may or may not be necessary to maintain this condition.
161

Outcome: The recovery unit workshop is designed to allow participating biologists to 

complete both axes of the Threats Assessment Decision Matrix for each core area and threat 

combination, determining the appropriate matrix cell and presenting their assumptions and 

rationale for making that determination in context of the category definitions. Each of the 

participants’ matrix values will collectively be tallied to express the range of expert opinion.

Assessment of Threats Effectively Managed

After the individual threats have been assessed in the Threats Assessment Decision 

Matrix, the Service will make a determination of whether threats are being effectively managed 

for the core area being evaluated. This assessment may include a collective evaluation of all 

threats within a core area to ensure that interactions and possible cumulative effects of even 

minor threats are considered. 

In recovery units where shared FMO habitat outside core areas has been identified, this 

assessment should also evaluate whether connectivity and habitat in shared FMO areas is 

maintained in a condition sufficient for regular bull trout use and successful dispersal among the 

connecting core areas.

Available bull trout population information (e.g., trend, size, index, etc.) for each core 

area should be considered in this assessment. Because small population size may constitute a 

threat under Factor E due to demographic stochasticity and loss of genetic diversity, low 

populations in a core area could be incompatible with a determination that threats are being 

effectively managed. However, this threshold also depends on the geographic extent of available 

habitat within the core area, since geographically smaller core areas inherently have less ability 

to support a large population and less scope for realistic management to increase populations. 

Based on our best information about population size and habitat extent, the recovery plan does 

identify a number of core areas where current population levels appear substantially depressed 

relative to available habitat, and should be increased before determining that threats are 

effectively managed. Above this minimal threshold, population size should be considered in 

combination with other threats; in many core areas there is scope for population improvement in 

response to amelioration of various threats, and trends in population response can be indicative 

of threat management effectiveness.

The Service will consider the best available information during this assessment in the 

context of the requirements of the Act. Service managers will meet to determine whether threats 

are effectively managed in each core area based on the best available information (matrix cell 

assignments, supporting data, and rationales) provided to the Service by experts during the 
162

recovery unit workshops. Service technical staff familiar with the core areas will provide input 

to managers at this meeting. If the combination of threat severity and management effectiveness 

for any individual threat indicates that the threat is not effectively managed to be consistent with 

bull trout survival and persistence, then the entire core area will be identified as such. All threats 

will be assessed, and the cumulative effects of multiple threats that are individually minor or 

moderate could potentially result in a core area not being considered effectively managed. 

Evaluation of Recovery Unit Status

The primary recovery strategy for recovery of bull trout in the coterminous United States 

is to: (1) conserve bull trout so that they are geographically widespread across representative 

habitats and demographically stable; (2) managing and ameliorating the primary threats in each 

of six recovery units at the core area scale such that bull trout will persist well into the future; (3) 

work cooperatively with partners to develop and implement bull trout recovery actions in each of 

the six recovery units; and (4) apply adaptive management principles to implementing the bull 

trout recovery program to account for new information. Recovery criteria described in the bull 

trout recovery plan represent our best assessment of the conditions that would most likely result 

in a determination that listing under the Act is no longer required.

After determining whether threats are effectively managed for a core area, a tally will be 

produced for the entire recovery unit that shows all core areas in a recovery unit and the number 

of local populations in each core area. For each recovery unit, the recovery criteria identified in 

this recovery plan will be assessed based on the number of core areas where primary threats are 

nonexistent or have been effectively managed. Additional information that will help assess the 

overall status of bull trout within a recovery unit and inform whether recovery criteria have been 

achieved include: evidence of demographically stable populations of bull trout; and an 

evaluation of the adequacy of existing regulatory mechanisms to provide adequate protection for 

bull trout in the foreseeable future (approximately the next 50 years).

In order to attain recovered conditions in each of the six recovery units that comprise the 

coterminous population of bull trout, viable local bull trout populations are necessary across the 

existing landscape. To achieve viable recovery units, identified significant threats must be 

effectively managed to produce demographically stable bull trout populations. The recovery 

strategy presented in this plan is founded in principles of conservation biology and biodiversity, 

ensuring representation, redundancy, and resilience. Recovery entails reducing threats to ensure 

the conservation or restoration of bull trout core areas while striving for representation, 

resilience, and redundancy. In order to achieve representation, we have determined the need to 
163

largely maintain existing occupancy within most core areas and preserve existing life history 

forms that are present in these core areas. In order to achieve resilience, core areas that contain 

migratory life history expressions should be prioritized for conservation, and some currently “at 

risk” core areas will need to be improved. Redundancy will be achieved when a mosaic of 

healthy populations are distributed across the landscape within each of the six recovery units. 

Additionally, in some recovery units there are areas that were historically occupied by bull trout 

that are currently unoccupied. While these areas have the potential for recolonization, there may 

be areas where recolonization will not be required for the recovery unit or DPS to be recovered. 

While the recovery plan identifies conservation actions for all occupied core areas, we do 

not intend that meeting the recovery criteria for the listed entity will necessarily require that 

every currently occupied core areas identified in this recovery plan must individually meet its 

recovery targets. We recognize that recovery bull trout at the recovery unit scale will require 

improvement in bull trout local populations and their essential habitats in some core areas 

relative to the time of listing, while bull trout and their habitats in other core areas will only need 

to be ‘sustained’ or ‘maintained’ into the foreseeable future (approximately 50 years). 

In summary, ecologically viable populations of bull trout are necessary to produce stable 

core areas which in turn will result in viable recovery units. These recovery principles take into 

account the threats and physical or biological needs of bull trout throughout its range and focus 

on the range-wide recovery needs. Ultimately, when future evaluations are initiated to determine 

the status of bull trout at either the coterminous or recovery unit scale, they will be dependent 

upon the results from: threat assessment process to evaluate the status of threats across the range 

of bull trout; demonstration of demographically stable populations of bull trout; and evaluation 

of the adequacy of existing regulatory mechanisms to provide adequate protection for bull trout 

in the foreseeable future. This approach to achieving recovery should ensure adequate 

conservation of genetic diversity, life history features, and broad geographical representation 

(i.e., adequate spatial distribution) of bull trout populations in the six recovery units that 

comprise the coterminous population of bull trout.
164

APPENDIX F. Comparison of Current and Former Core Area and Recovery Unit Classifications

This table provides a crosswalk between the structure of core areas and recovery units that was used in the early draft bull trout 

recovery plans (USFWS 2002a, 2004a, 2004b) and 5-year review (USFWS 2008a) and that used in this final recovery plan, with a key 

to the core area maps in Appendix B. Based on the most current available information, several core areas have been split or 

combined, additional core areas that were historically occupied are identified, and those that did not fit our core area definition have 

been removed. Core area changes are discussed in detail in the RUIPs.

Final Recovery Plan (2015) 2002 and 2004 Draft Recovery Plans 

and 5-year Review (2008)

Map Key in 

Appendix B

Current 

Core Area

Current 

Recovery Unit Area Status

Former 

Core Area

Former 

Recovery Unit

1 (Map A) Chilliwack River Coastal Occupied Chilliwack River Puget Sound

2 (Map A) Nooksack River Coastal Occupied Nooksack River Puget Sound

3 (Map A) Upper Skagit River Coastal Occupied Upper Skagit River Puget Sound

4 (Map A) Lower Skagit River Coastal Occupied Lower Skagit River Puget Sound

5 (Map A) Stillaguamish River Coastal Occupied Stillaguamish River Puget Sound

6 (Map A) Snohomish and 

Skykomish Rivers Coastal Occupied Snohomish and Skykomish Rivers Puget Sound

7 (Map A) Chester Morse Lake Coastal Occupied Chester Morse Lake Puget Sound

8 (Map A) Puyallup River Coastal Occupied Puyallup River Puget Sound

9 (Map A) Elwha River Coastal Occupied Elwha River Olympic Peninsula

10 (Map A) Dungeness River Coastal Occupied Dungeness River Olympic Peninsula

11 (Map A) Hoh River Coastal Occupied Hoh River Olympic Peninsula

12 (Map A) Queets River Coastal Occupied Queets River Olympic Peninsula

13 (Map A) Quinault River Coastal Occupied Quinault River Olympic Peninsula

14 (Map A) Skokomish River Coastal Occupied Skokomish River Olympic Peninsula

15 (Map A) Lewis River Coastal Occupied Lewis River Lower Columbia River 

Basin

16 (Map A) Klickitat River Coastal Occupied Klickitat River Lower Columbia River 

Basin

17 (Map A) Hood River Coastal Occupied Hood River Hood River Basin
165

Final Recovery Plan (2015) 2002 and 2004 Draft Recovery Plans 

and 5-year Review (2008)

Map Key in 

Appendix B

Current 

Core Area

Current 

Recovery Unit Area Status

Former 

Core Area

Former 

Recovery Unit

18 (Map A) Lower Deschutes 

River Coastal Occupied Lower Deschutes River Deschutes River Basin

19 (Map A) Upper Willamette 

River Coastal Occupied Upper Willamette River Willamette River Basin

20 (Map A) Odell Lake Coastal Occupied Odell Lake Odell Lake

21 (Map A) White Salmon River Coastal Historic [not identified as core 

area]

Lower Columbia River 

Basin

22 (Map A) Clackamas River Coastal Occupied 

(reintroduced)

[not identified as core 

area] Willamette River Basin

23 (Map A) North Santiam River Coastal Historic [not identified as core 

area] Willamette River Basin

24 (Map A) South Santiam River Coastal Historic [not identified as core 

area] Willamette River Basin

25 (Map A) Upper Deschutes 

River Coastal Historic [not identified as core area] Deschutes River Basin

1 (Map B) Sycan River Klamath Occupied Sycan River Klamath River

2 (Map B) Upper Klamath Lake Klamath Occupied Upper Klamath Lake Klamath River

3 (Map B) Upper Sprague River Klamath Occupied Upper Sprague River Klamath River

1 (Map C) Methow River Mid Columbia Occupied Methow River Upper Columbia River

2 (Map C) Entiat River Mid Columbia Occupied Entiat River Upper Columbia River

3 (Map C) Wenatchee River Mid Columbia Occupied Wenatchee River Upper Columbia River

4 (Map C) Yakima River Mid Columbia Occupied Yakima River Middle Columbia River

5 (Map C) Touchet River Mid Columbia Occupied Touchet River Umatilla-Walla Walla 

River Basins

6 (Map C) Tucannon River Mid Columbia Occupied Tucannon River Snake River Washington

7 (Map C) Asotin Creek Mid Columbia Occupied Asotin Creek Snake River Washington

8 (Map C) Walla Walla River Mid Columbia Occupied Walla Walla River Umatilla-Walla Walla 

River Basins
166

Final Recovery Plan (2015) 2002 and 2004 Draft Recovery Plans 

and 5-year Review (2008)

Map Key in 

Appendix B

Current 

Core Area

Current 

Recovery Unit Area Status

Former 

Core Area

Former 

Recovery Unit

9 (Map C) Lookingglass/Wenaha 

Rivers Mid Columbia Occupied Grande Ronde River (in part) Grande Ronde River Basin

10 (Map C) Umatilla River Mid Columbia Occupied Umatilla River Umatilla-Walla Walla 

River Basins

11 (Map C) North Fork John Day 

River Mid Columbia Occupied North Fork John Day River John Day River

12 (Map C) Middle Fork John Day 

River Mid Columbia Occupied Middle Fork John Day River John Day River

13 (Map C) Upper Mainstem John 

Day River Mid Columbia Occupied Upper Mainstem John Day River John Day River

14 (Map C) Upper Grande Ronde 

River Mid Columbia Occupied Grande Ronde River (in part) Grande Ronde River Basin

15 (Map C) Powder River Mid Columbia Occupied Powder River (in part) Hells Canyon Complex

16 (Map C) Little Minam River Mid Columbia Occupied Little Minam River Grande Ronde River Basin

17 (Map C) Wallowa/Minam 

Rivers Mid Columbia Occupied Grande Ronde River (in part) Grande Ronde River Basin

18 (Map C) Imnaha River Mid Columbia Occupied Imnaha River Imnaha-Snake Rivers

19 (Map C) Pine, Indian, and 

Wildhorse Creeks Mid Columbia Occupied Pine, Indian, and Wildhorse Creeks Hells Canyon Complex

None None Mid Columbia

[Granite Creek 

core area removed 

in final plan – see 

RUIP]

Granite Creek Imnaha-Snake Rivers
167

Final Recovery Plan (2015) 2002 and 2004 Draft Recovery Plans 

and 5-year Review (2008)

Map Key in 

Appendix B

Current 

Core Area

Current 

Recovery Unit Area Status

Former 

Core Area

Former 

Recovery Unit

None None Mid Columbia

[Sheep Creek core 

area removed in 

final plan – see 

RUIP]

Sheep Creek Imnaha-Snake Rivers

20 (Map C) South Fork Clearwater 

River Mid Columbia Occupied South Fork Clearwater River Clearwater River

21 (Map C) Selway River Mid Columbia Occupied Selway River Clearwater River

22 (Map C) Lochsa River (in part) Mid Columbia Occupied Lochsa River Clearwater River

22 (Map C) Lochsa River (in part) Mid Columbia Occupied Fish Lake (Lochsa River) Clearwater River

23 (Map C) North Fork Clearwater 

River (in part) Mid Columbia Occupied North Fork Clearwater River Clearwater River

23 (Map C) North Fork Clearwater 

River (in part) Mid Columbia Occupied Fish Lake (North Fork Clearwater River) Clearwater River

None None [Clearwater 

FMO only] Mid Columbia FMO only Middle-Lower Clearwater River Clearwater River

24 (Map C) South Salmo River Mid Columbia

Occupied [added 

as core area in 

final plan – see 

RUIP]

[not identified as core 

area] Northeast Washington

25 (Map C) Eagle Creek Mid Columbia Historic Powder River (in part) Hells Canyon Complex

26 (Map C) Chelan River Mid Columbia Historic [not identified as core 

area] Upper Columbia River

27 (Map C) Northeastern 

Washington Mid Columbia Research Needs Area

[not identified as core 

area] Northeast Washington
168

Final Recovery Plan (2015) 2002 and 2004 Draft Recovery Plans 

and 5-year Review (2008)

Map Key in 

Appendix B

Current 

Core Area

Current 

Recovery Unit Area Status

Former 

Core Area

Former 

Recovery Unit

None None Mid Columbia

[Burnt River 

Research Needs 

Area removed in 

final plan – see 

RUIP]

[not identified as core 

area] Hells Canyon Complex

1 (Map D) Upper Malheur River Upper Snake Occupied Malheur River (in part) Malheur River Basin

2 (Map D) North Fork Malheur 

River Upper Snake Occupied Malheur River (in part) Malheur River Basin

3 (Map D) Little Lower Salmon 

River Upper Snake Occupied Little Lower Salmon River Salmon River

4 (Map D) Weiser River Upper Snake Occupied Weiser River Southwest Idaho River 

Basins

5 (Map D) Squaw Creek Upper Snake Occupied Squaw Creek Southwest Idaho River 

Basins

6 (Map D) North Fork Payette 

River Upper Snake Occupied North Fork Payette River Southwest Idaho River Basins

7 (Map D) Middle Salmon River 

- Chamberlain Upper Snake Occupied Middle Salmon River -Chamberlain Salmon River

8 (Map D) Middle Salmon River 

- Panther Upper Snake Occupied Middle Salmon River -Panther Salmon River

9 (Map D) Lake Creek Upper Snake Occupied Lake Creek Salmon River

10 (Map D) Opal Lake Upper Snake Occupied Opal Lake Salmon River

11 (Map D) Lemhi River Upper Snake Occupied Lemhi River Salmon River

12 (Map D) Middle Fork Salmon 

River Upper Snake Occupied Middle Fork Salmon River Salmon River

13 (Map D) South Fork Salmon 

River Upper Snake Occupied South Fork Salmon River Salmon River
169

Final Recovery Plan (2015) 2002 and 2004 Draft Recovery Plans 

and 5-year Review (2008)

Map Key in 

Appendix B

Current 

Core Area

Current 

Recovery Unit Area Status

Former 

Core Area

Former 

Recovery Unit

14 (Map D) Middle Fork Payette 

River Upper Snake Occupied Middle Fork Payette River

Southwest Idaho River 

Basins

15 (Map D) Deadwood River Upper Snake Occupied Deadwood River Southwest Idaho River 

Basins

16 (Map D) Upper South Fork 

Payette River Upper Snake Occupied Upper South Fork Payette River

Southwest Idaho River 

Basins

17 (Map D) Upper Salmon River Upper Snake Occupied Upper Salmon River Salmon River

18 (Map D) Pahsimeroi River Upper Snake Occupied Pahsimeroi River Salmon River

19 (Map D) Little Lost River Upper Snake Occupied Little Lost River Little Lost River

20 (Map D) Arrowrock Reservoir Upper Snake Occupied Arrowrock Reservoir Southwest Idaho River 

Basins

None None Upper Snake N/A Lucky Peak Reservoir Southwest Idaho River 

Basins

21 (Map D) Anderson Ranch 

Reservoir Upper Snake Occupied Anderson Ranch Reservoir

Southwest Idaho River 

Basins

22 (Map D) Jarbidge River Upper Snake Occupied Jarbidge River Jarbidge River

1 (Map E) Lake Pend Oreille (in 

part)

Columbia 

Headwaters Occupied Lake Pend Oreille Clark Fork River Basin

1 (Map E) Lake Pend Oreille (in 

part)

Columbia 

Headwaters Occupied Cabinet Gorge Reservoir Clark Fork River Basin

1 (Map E) Lake Pend Oreille (in 

part)

Columbia 

Headwaters Occupied Clark Fork River (Section 3) Clark Fork River Basin

1 (Map E) Lake Pend Oreille (in 

part)

Columbia 

Headwaters Occupied Lower Flathead River Clark Fork River Basin

1 (Map E) Lake Pend Oreille (in 

part)

Columbia 

Headwaters Occupied Noxon Rapids Reservoir Clark Fork River Basin
170

Final Recovery Plan (2015) 2002 and 2004 Draft Recovery Plans 

and 5-year Review (2008)

Map Key in 

Appendix B

Current 

Core Area

Current 

Recovery Unit Area Status

Former 

Core Area

Former 

Recovery Unit

1 (Map E) Lake Pend Oreille (in 

part)

Columbia 

Headwaters Occupied Pend Oreille River Northeast Washington

2 (Map E) Priest Lakes Columbia 

Headwaters Occupied Priest Lakes Clark Fork River Basin

3 (Map E) Kootenai River Columbia 

Headwaters Occupied Kootenai River Kootenai River Basin

4 (Map E) Coeur d'Alene Lake Columbia 

Headwaters Occupied Coeur d'Alene Lake Coeur d'Alene Lake Basin

5 (Map E) Bull Lake Columbia 

Headwaters Occupied Bull Lake Kootenai River Basin

6 (Map E) Lake Koocanusa (in 

part)

Columbia 

Headwaters Occupied Lake Koocanusa Kootenai River Basin

6 (Map E) Lake Koocanusa (in 

part)

Columbia 

Headwaters Occupied Sophie Lake Kootenai River Basin

7 (Map E) Upper Stillwater Lake Columbia 

Headwaters Occupied Upper Stillwater Lake Clark Fork River Basin

8 (Map E) Upper Whitefish Lake Columbia 

Headwaters Occupied Upper Whitefish Lake Clark Fork River Basin

9 (Map E) Cyclone Lake Columbia 

Headwaters Occupied Cyclone Lake Clark Fork River Basin

10 (Map E) Whitefish Lake Columbia 

Headwaters Occupied Whitefish Lake Clark Fork River Basin

11 (Map E) Flathead Lake (in 

part)

Columbia 

Headwaters Occupied Flathead Lake Clark Fork River Basin

11 (Map E) Flathead Lake (in 

part)

Columbia 

Headwaters Occupied Kintla Lake Clark Fork River Basin
171

Final Recovery Plan (2015) 2002 and 2004 Draft Recovery Plans 

and 5-year Review (2008)

Map Key in 

Appendix B

Current 

Core Area

Current 

Recovery Unit Area Status

Former 

Core Area

Former 

Recovery Unit

11 (Map E) Flathead Lake (in 

part)

Columbia 

Headwaters Occupied Lake McDonald Clark Fork River Basin

12 (Map E) Frozen Lake Columbia 

Headwaters Occupied Frozen Lake Clark Fork River Basin

13 (Map E) Upper Kintla Lake Columbia 

Headwaters Occupied Upper Kintla Lake Clark Fork River Basin

14 (Map E) Akokala Lake Columbia 

Headwaters Occupied Akokala Lake Clark Fork River Basin

15 (Map E) Bowman Lake Columbia 

Headwaters Occupied Bowman Lake Clark Fork River Basin

16 (Map E) Quartz Lakes Columbia 

Headwaters Occupied Quartz Lakes Clark Fork River Basin

17 (Map E) Lower Quartz Lake Columbia 

Headwaters Occupied Lower Quartz Lake Clark Fork River Basin

18 (Map E) Logging Lake Columbia 

Headwaters Occupied Logging Lake Clark Fork River Basin

19 (Map E) Trout/Arrow Lakes (in 

part)

Columbia 

Headwaters Occupied Arrow Lake Clark Fork River Basin

19 (Map E) Trout/Arrow Lakes (in 

part)

Columbia 

Headwaters Occupied Trout Lake Clark Fork River Basin

20 (Map E) Lincoln Lake Columbia 

Headwaters Occupied Lincoln Lake Clark Fork River Basin

21 (Map E) Harrison Lake Columbia 

Headwaters Occupied Harrison Lake Clark Fork River Basin

22 (Map E) Isabel Lakes Columbia 

Headwaters Occupied Isabel Lakes Clark Fork River Basin
172

Final Recovery Plan (2015) 2002 and 2004 Draft Recovery Plans 

and 5-year Review (2008)

Map Key in 

Appendix B

Current 

Core Area

Current 

Recovery Unit Area Status

Former 

Core Area

Former 

Recovery Unit

23 (Map E) Hungry Horse 

Reservoir

Columbia 

Headwaters Occupied Hungry Horse Reservoir Clark Fork River Basin

24 (Map E) Swan Lake Columbia 

Headwaters Occupied Swan Lake Clark Fork River Basin

25 (Map E) Big Salmon Lake Columbia 

Headwaters Occupied Big Salmon Lake Clark Fork River Basin

26 (Map E) Holland Lake Columbia 

Headwaters Occupied Holland Lake Clark Fork River Basin

27 (Map E) Doctor Lake Columbia 

Headwaters Occupied Doctor Lake Clark Fork River Basin

28 (Map E) Lindbergh Lake Columbia 

Headwaters Occupied Lindbergh Lake Clark Fork River Basin

29 (Map E) Clearwater River and

Lakes

Columbia 

Headwaters Occupied Clearwater River andLakes Clark Fork River Basin

30 (Map E) Middle Clark Fork 

River

Columbia 

Headwaters Occupied Clark Fork River (Section 2) Clark Fork River Basin

31 (Map E) Blackfoot River Columbia 

Headwaters Occupied Blackfoot River Clark Fork River Basin

32 (Map E) Bitterroot River Columbia 

Headwaters Occupied Bitterroot River Clark Fork River Basin

33 (Map E) Rock Creek Columbia 

Headwaters Occupied Rock Creek Clark Fork River Basin

34 (Map E) Upper Clark Fork 

River

Columbia 

Headwaters Occupied Clark Fork River (Section 1) Clark Fork River Basin

35 (Map E) West Fork Bitterroot 

River

Columbia 

Headwaters Occupied West Fork Bitterroot River Clark Fork River Basin
173

Final Recovery Plan (2015) 2002 and 2004 Draft Recovery Plans 

and 5-year Review (2008)

Map Key in 

Appendix B

Current 

Core Area

Current 

Recovery Unit Area Status

Former 

Core Area

Former 

Recovery Unit

1 (Map F) Saint Mary River (in 

part) Saint Mary Occupied Saint Mary River Saint Mary-Belly River Basins

1 (Map F) Saint Mary River (in 

part) Saint Mary Occupied Lee Creek Saint Mary-Belly River Basins

None None Saint Mary N/A Belly River Saint Mary-Belly River 

Basins

2 (Map F) Slide Lake Saint Mary Occupied Slide Lake Saint Mary-Belly River 

Basins

3 (Map F) Cracker Lake Saint Mary Occupied Cracker Lake Saint Mary-Belly River 

Basins

4 (Map F) Red Eagle Lake Saint Mary Occupied Red Eagle Lake Saint Mary-Belly River 

Basins
174

APPENDIX G. Role of the Bull Trout Recovery Plan in Interagency 

Consultation, Cooperation with States, Coordination with Tribes, Habitat 

Conservation Planning, Recovery Permits, and Protective Regulations

Recovery is both a process, consisting of discrete actions to conserve listed species, and a 

biological condition of listed species such that self-sustaining and self-regulating populations can 

be supported as persistent members of the ecosystems upon which they depend. The Endangered 

Species Act (Act) clearly envisions recovery plans as the central organizing tool for guiding each 

species’ recovery. In that regard, the bull trout recovery plan has utility with respect to the 

implementation of Federal and non-Federal actions carried out under or subject to compliance 

with sections 4, 6, 7, and 10 of the Act, and in meeting our government-to-government 

relationship with Tribes. See section II.H (Recovery Actions) in the Bull Trout Recovery Plan

for more information on cooperation with State, Federal and Tribal Governments.

Interagency Consultation

Under section 7(a)(1) of the Act, all Federal agencies are required to utilize their 

authorities in furtherance of the purposes of this Act by carrying out programs for the 

conservation of endangered and threatened species. In that regard, Federal agencies have a 

greater obligation than do other parties to conserve listed species, and are required to be proactive over and above any requirements that may result pursuant to compliance with section 

7(a)(2) of the Act (discussed below). A recovery plan can provide an implementation roadmap 

to accomplish these requirements. A recovery plan delineates both general management 

approaches and site-specific management actions that the Service has determined are necessary 

to recover and/or protect listed species. Recovery plans also establish objective, measurable 

criteria for downlisting or delisting the species, and estimate the time and cost required to carry

out these actions. A recovery plan is not a regulatory document and does not obligate 

cooperating or other parties to undertake specific tasks or expend funds. It should be noted that 

recovery plans address all areas determined to be important for recovery of listed species and 

identify needed management measures to achieve recovery. Critical habitat designations are not 

necessarily intended to encompass a species’ entire current range. Because critical habitat 

designations may exclude areas based on factors such as economic cost, approved or pending 

management plans, or encouragement of cooperative conservation partnerships with landowners, 

the areas identified in recovery plans as important for recovery of the species may not be 

designated as critical habitat. Areas that are important to the conservation of the species, but are 

outside the critical habitat designation, should be subject to conservation actions implemented 

under section 7(a)(1) of the Act. 

Recovery plans also guide Federal agencies in developing conservation measures as part 

of their proposed actions and in fulfilling their obligations under section 7(a)(2) of the Act to 
175

avoid jeopardizing listed species and adverse modification of designated critical habitat. 

Recovery plans can help to inform revisions to proposed Federal actions to avoid those 

outcomes.

In the context of the section 7(a)(2) compliance process, the Service has developed 

analytical tools to address the sources of positive influences or stressors that expose both the bull 

trout and its designated critical habitat to both positive and negative effects, respectively, of 

Federal agency actions. Currently, we apply an analytical framework for bull trout jeopardy 

analyses that relies heavily on the importance of known core area populations to the survival and 

recovery of the bull trout. This analytical framework will need to be revised and updated to 

reflect the recovery criteria in the bull trout recovery plan. Specifically, the recovery criteria 

state that the Service will initiate an assessment of whether recovery has been achieved and 

delisting is warranted when the following has been accomplished in each recovery unit: 

- For the Coastal, Mid-Columbia, and Upper Snake Recovery Units: Primary threats are 

effectively managed in at least 75 percent of all core areas, representing 75 percent or 

more of bull trout local populations within each of these three recovery units. 

- For the Columbia Headwaters Recovery Unit: Primary threats are effectively managed 

in 75 percent of simple core areas and 75 percent of complex core areas, representing 75 

percent or more of bull trout local populations in both simple and complex core areas. 

- For the Klamath and Saint Mary Recovery Units, all primary threats are effectively 

managed in all existing core areas, representing all existing local populations. In addition, 

in the Klamath Recovery Unit, because 9 of 17 known local populations have already 

been extirpated and the remainder are significantly imperiled and require active 

management of threats, effective threat management is necessary in 100 percent of core 

areas, and the geographic range of bull trout within this recovery unit will need to be 

expanded through reestablishment of extirpated local populations. 

- In recovery units where shared FMO habitat outside core areas has been identified, 

connectivity and habitat in shared FMO areas should be maintained in a condition 

sufficient for regular bull trout use and successful dispersal among the connecting core 

areas for those core areas to meet the criterion. 

Core areas form the building blocks that provide conservation of the bull trout’s 

evolutionary legacy as represented by major genetic groups. The analysis required by section 

7(a)(2) of the Act is focused not only on these populations but also on the habitat conditions 

necessary to support reproduction, numbers and distribution of the bull trout. Generally, the 

jeopardy analysis focuses on the range-wide status of bull trout, the factors responsible for that 

condition (threats), and what is necessary for this species to survive and recover (criteria). An 

emphasis is placed on characterizing the condition of bull trout in the area affected by the 

proposed Federal action and the role of affected populations in the survival and recovery of bull 
176

trout. That context is then used to determine the significance of adverse and beneficial effects of 

the proposed Federal action and any cumulative effects for purposes of making the jeopardy 

determination. 

In the bull trout recovery plan we recognize core areas as the population units that are 

necessary to provide for bull trout biological needs in relation to genetic and phenotypic 

diversity, and spreading the risk of extinction caused by stochastic events. Given the recovery 

criteria above, we also recognize that not all core areas may be essential to either the survival or 

recovery of bull trout. Although we encourage the conservation of all bull trout core areas, we 

also recognize that in some recovery units, recovery (and thus survival) of the species can be 

achieved without requiring threats to be effectively managed in every individual core area. 

Each of the six recovery units identified in the bull trout recovery plan is individually 

necessary to conserve biological features that are necessary for long-term sustainability of the 

listed entity (NMFS and USFWS 2010). Moreover, “when an action appreciably impairs or 

precludes the capability of a recovery unit from providing both the survival and recovery 

function assigned to it, that action may represent jeopardy to the species” (USFWS and NMFS 

1998). Thus, if a proposed Federal action is found to be incompatible with the viability and 

conservation function of an affected core area, and if (in consideration of the recovery criteria for 

its recovery unit and the role of that core area within the recovery unit) we find that particular 

core area must be conserved in order to conserve the recovery unit overall and the listed entity in 

the coterminous United States, then a jeopardy finding may be warranted. Similarly, under a 

section 7(a)(2) adverse modification analysis, a Federal action is analyzed for how it affects the 

primary constituent elements (PCEs) of bull trout critical habitat, and how it will influence the 

recovery support function of affected critical habitat units. Generally, the conservation role of 

bull trout critical habitat is to support viable core area populations. PCEs and critical habitat 

units are analyzed individually and at the range-wide scale. Bull trout critical habitat units are 

equivalent to one or more core areas. 

When consulting under section 7(a)(2) on the effects of a proposed Federal action on 

designated critical habitat, an independent analysis is also conducted for jeopardy to the species 

when effects to the bull trout are predicted (USFWS 2010a). The Service has developed a tool to 

crosswalk the analysis for critical habitat to the jeopardy analysis since it is comparable in many 

cases. Analyses can inform each other; for example, in occupied bull trout habitat, any adverse 

modification determination could result in a jeopardy determination for the species. See 

Appendix E, Table 2 for additional information regarding integration of recovery and section 7 

threats assessment tools and analytical approaches.
177

Habitat Conservation Planning

Because the issuance of incidental take permits under section 10(a)(1)(B) of the Act 

constitutes a Federal action, such actions are subject to the section 7(a)(2) consultation 

requirements as discussed above. Recovery plans can effectively inform, in part, the 

development of these permit actions. See section I.B.6, Factor D (Inadequacy of Existing 

Regulatory Mechanisms) in the bull trout recovery plan for more information on bull trout 

recovery and HCPs.

Tribal Government Consultation

All of our actions involving American Indian Tribal Governments, including our 

consultation and collaboration, will take place on a government-to-government basis and be 

consistent with applicable executive and secretarial orders, memoranda, and policies, including 

Executive Order 13175, “Consultation and Coordination with Indian Tribal Governments” 

(November 6, 2000); Secretarial Order 3206, “American Indian Tribal Rights, Federal-Tribal 

Responsibilities, and the Endangered Species Act” (June 5, 1997); Presidential Memorandum 

(November 5, 2009); the U.S. Fish and Wildlife Service’s Native American Policy (June 28, 

1994), and the Endangered Species Act. 

We recognize the special government-to-government relationship between the Federal 

government of the United States and American Indian Tribal governments derived from the 

Constitution of the United States, treaties, Supreme Court doctrine, and Federal statutes. We 

acknowledge American Indian Tribal governments as sovereign nations with inherent powers of 

self-governance.

We also recognize that American Indian Tribes have long worked to conserve and 

monitor bull trout and other native salmonids on their lands. The efforts of many Tribes have 

contributed to bull trout conservation and maintained the Tribal cultural values of the bull trout 

and its habitat. Many Tribal lands have been managed with a holistic perspective, including 

reserves, modified silvicultural practices, and riparian and aquatic habitat restoration efforts, and 

therefore can be islands of high quality habitat that support many species as well as healthy 

ecosystems. 

We are committed to engaging in regular and meaningful consultation and collaboration 

with American Indian Tribal governments to determine what cooperative and voluntary 

measures Tribes may take to support bull trout recovery actions and address other recovery needs 

and opportunities for bull trout, recognizing the special status of Tribes and Tribal lands. 

Consistent with existing laws and policies, and to honor this spirit of consultation and 

collaboration, we will give deference whenever possible to Tribal recovery plans, habitat and 

modeling data, and other conservation efforts. 
178

Cooperation with States

Section 6 of the Act facilitates collaboration in species conservation through cooperative 

agreements with State fish and wildlife agencies provided such states have adequate and active 

programs for the conservation of species. The Service maintains cooperative agreements with all 

five states that have bull trout. These states are authorized to implement their conservation 

programs to conserve bull trout, and any take of bull trout that may result is authorized through 

an associated section 7 consultation (USFWS 2000). States typically implement recovery-related 

actions that may take bull trout, such as scientific collecting, control of invasive species, and 

habitat restoration efforts. They may also facilitate actions by others that may take bull trout (for 

example, Federal or university fisheries scientists) through their authority to designate others as 

agents of the State. To understand the status of bull trout, the take and effects to bull trout 

populations and their habitat, and modifications or new actions to be covered under the section 7 

consultation for these agreements, reporting and annual coordination may be necessary. New 

information in the form of newly listed species and critical habitat may require the reinitiation of 

section 7 consultation on these cooperative agreements.

Enhancement of Survival Permits

The Service issues permits authorizing take of bull trout associated with actions that may 

enhance the propagation or survival of the species, including scientific collecting or research by 

non-state entities or implementation of other recovery-related activities. These permits are 

issued under the authority of section 10(a)(1)(A) of the Act. For example, active habitat 

restoration projects such as stream bank stabilization, channel reconstruction, or sediment 

abatement projects by the Forest Service or through Federal Energy Regulatory Commission 

(FERC) mitigation programs often involve short-term impacts in order to achieve longer term 

objectives and are frequently permitted under section 10(a)(1)(A) of the Act. Take of bull trout 

in the course of scientific research may also be permitted through this method, including broadscale or site-specific fisheries monitoring such as utilizing electrofishing or other collection 

methods to document the long-term benefits of habitat restoration or other effects of 

management. Section 7(a)(2) consultation is also completed for these Federal actions. 

Protective Regulations

Upon listing of the Klamath Basin and Columbia River Basin DPSs of the bull trout in 

1998 (USFWS 1998), the Service promulgated a special rule under section 4(d) of the Act that 

authorized take of bull trout consistent with State and Tribal fishing regulations existing at the 
179

time of listing. This rule was expanded to the entire range of bull trout in the coterminous U.S. 

in the 1999 listing rule (USFWS 1999a) (50 CFR 17.44 (w)), with the exception of the Jarbidge 

population for which take prohibitions were reinstated in 2001 (50 CFR 17.44 (x)). All five 

States prohibited direct harvest of bull trout through angling wherever they occurred, except for 

one location in Oregon, one in Montana, and several locations in Washington. In the 1999 

listing rule (USFWS 1999a), we identified our intention to continue to work with States and 

Tribes in assessing whether fishing regulations at the time of listing are adequate to protect bull 

trout and in developing management plans and agreements with the objective of recovery. 

Modifications to the bull trout 4(d) rule to offer additional species management authority to 

States or Tribes may be considered in the future, at the discretion of the Service. 
Pacific Region

U.S. Fish & Wildlife Service

Ecological Services

911 N.E. 11th Avenue

Portland, OR 97232-4181

http://www.fws.gov

September 2015