January 2006 Fish and Wildlife Habitat Management Leaflet Number 36

Bull Trout

(Salvelinus confluentus)

© 1988 WHC

WILDLIFE HABITAT COUNCILSM

Introduction

Bull trout are members of the Salmonidae family, as 

are cutthroat and rainbow trout, salmon, whitefish, 

and grayling (fig. 1). Bull trout are not trout, but chars 

— members of the genus Salvelinus, which also includes brook trout, lake trout, arctic char, and Dolly 

Varden. Bull trout have large, broad heads, large 

mouths, and prominent jaws and teeth. Their bodies are slender, rounded, and dark with light-colored 

spots. While the bull trout and the Dolly Varden (S. 

malma) are often mistaken for one another, they are 

separate species. The size of a bull trout at maturity 

depends on its life-history. Some fish (resident forms) 

reside solely in headwater or tributary streams and 

tend to be smaller than migratory forms that spend 

most of their time in lakes or reservoirs (adfluvial), large rivers (fluvial), or the ocean (anadromous). 

Resident adults measure 8 to 14 inches in length, 

while migratory forms commonly exceed 24 inches.

In recent decades, both the distribution and abundance of bull trout have declined, likely due to a combination of degraded or fragmented aquatic habitats 

throughout its historic range and the introduction of 

non-native species. Bull trout habitat degradation is 

primarily due to actions related to land use and instream water use. Detrimental land uses include timber harvest, urbanization, road development, mining, 

and agricultural/livestock production. Such land uses 

often result in increased soil erosion, stream channel instability, and decreased water quality. Instream 

use of water for hydroelectric power generation and 

agricultural irrigation diversions negatively affects 

aquatic habitats by altering the timing and amount of 

instream flows and lowering water quality. Instream 

uses also may block or restrict access to critical habitat. Both types of instream installations can cause 

direct mortality to adult and juvenile fish. Physical 

barriers (dams), as well as environmental barriers 

(poor water quality) that prevent upstream and downstream movement are detrimental to all salmonids. 

Widespread introduction of non-native fish species, 

especially brook trout, lake trout, brown trout, northern pike, and walleye, is a significant threat to bull 

trout populations through direct competition, predation, and hybridization (particularly with brook 

trout). Declines in bull trout populations prompted 

the United States Fish and Wildlife Service to list the 

Klamath and Columbia River distinct population segments as threatened under the Endangered Species 

Act in 1998 and all other populations in the coterminous U.S. in 1999. Bull trout are considered to be a 

species of special concern in Canada.

The purpose of this leaflet is to provide information 

to help landowners recognize opportunities to conserve or improve habitat for bull trout and assist with 

the development, implementation, and monitoring of 

a management plan for the species. The success of 

any fish/wildlife management action plan requires:

• a clear statement of management goals

• awareness of the habitat requirements of the 

target species or fish/wildlife group

• accurate assessment of habitat conditions

Ernest Keeley, Idaho State University

Figure 1 Bull trout
Bull Trout

• effective tools and adequate resources to address habitat limitations

• follow-up monitoring of fish/wildlife responses 

and incorporation of results into the management plan

The leaflet also identifies resources and additional 

sources of information available to carry out management plans.

Range

Bull trout historically occurred in major river drainages in the Pacific Northwest, from the southern 

limits of its range in the McCloud River in northern 

California and the Jarbidge River in Nevada, to the 

northern limits of its range in the headwaters of the 

Yukon River in the Northwest Territories, Canada. 

Today in the U.S., bull trout are distributed throughout coastal and mountainous areas from southern 

Oregon and northern Nevada north to the Canadian 

border. Once common throughout this range, they 

have declined in overall distribution and abundance 

during the last century. For example, bull trout are 

extirpated from California and inhabit only one river system in Nevada. Many populations in Oregon, 

Washington, Montana, and Idaho are at high risk of 

extirpation. Table 1 describes the remaining bull trout 

populations in the coterminous U.S.

Life history

Bull trout exhibit both resident and migratory life-history strategies through much of their current range. 

Resident forms complete their entire life cycle in 

the tributary streams in which they spawn and rear. 

However, most bull trout are migratory and live in 

lakes, reservoirs, rivers, or oceans and return to tributary streams to spawn. Resident and migratory forms 

can be found together; it is believed that both forms 

can produce offspring that exhibit either resident or 

migratory behavior.

Bull trout may spawn every year or in alternate years. 

Migratory forms begin their spawning migration in 

mid- to late spring and enter tributary streams in midPopulation States/Provinces Range

Klamath River 

population

Oregon Bull trout occur only in isolated higher elevation headwater streams within 

the watersheds of Upper Klamath Lake, Sprague River, Wood River, and 

Sycan River

Columbia River 

population

Oregon, Washington, 

Idaho, Montana, 

British Columbia

Bull trout occur throughout most of the Columbia River basin and its 

tributaries, including its headwaters in Montana and British Columbia, 

Canada 

Coastal-Puget 

Sound population

Washington Bull trout occur in all Pacific coast drainages within Washington, including 

Puget Sound

Jarbidge River 

population

Idaho, Nevada Bull trout occur in the East Fork, West Fork, and mainstem Jarbidge River 

and headwater tributaries and primarily in headwater streams above 7,200 

feet elevation within the Jarbidge Wilderness Area (including Slide, Pine, 

Sawmill, Fall, and Cougar Creeks), as well as Dave Creek

St. Mary-Belly 

River population

Montana, Alberta Bull trout east of the continental divide occur in the St. Mary and Belly 

Rivers and their tributaries, as well as in headwater lakes, mostly in Glacier 

National Park 

Table 1 Remaining bull trout populations in the coterminous U.S.
Bull Trout



to late summer. Spawning for both forms occurs from 

August to November, during periods of decreasing 

water temperatures.

Bull trout construct a typical salmonid redd (a pit in 

the stream substrate, excavated by the fish’s tail) in 

which to lay eggs. The female chooses the spawning 

site and excavates the redd while the male defends 

the site. Eggs are deposited as deep as 10 inches below the streambed surface. Migratory adults move 

back downstream soon after spawning. Depending on 

the water temperature, hatching occurs in 100 to 145 

days, usually in January. After hatching, fry remain in 

the substrate while they absorb their yolk sax, emerging from the streambed in April or May. Juvenile migratory bull trout stay in the tributary of their birth 

for 1 to 4 years before moving downstream. Bull trout 

typically reach sexual maturity in 4 to 7 years.

Habitat requirements

General

Bull trout require especially clean, cold water—temperatures above 59 oF are thought to limit the survival of juveniles. They live primarily in cold headwater 

lakes and streams and rivers that drain high mountainous areas, especially where snowfields and glaciers are present. Like all salmonids, bull trout require 

diverse, yet well-connected, habitats with structural 

components that provide good hiding cover (boulders 

and large wood).

Headwater streams provide habitat for resident forms 

of bull trout in all their life stages and for migratory forms only in their spawning and rearing stages. 

Migratory forms can move great distances (up to 150 

miles) between the ocean, lakes, reservoirs, rivers, 

and tributary streams in response to spawning, rearing, and adult life history needs.

Both juvenile and adult bull trout tend to remain near 

stream bottoms or closely associated with the substrate, submerged wood, or undercut banks. Adults 

use large cobble and boulder substrates, larger pools, 

and areas with accumulations of large wood. A complex habitat, characterized by a variety of pools, riffles, and water depths and velocities, is important to 

meet the diverse needs of all life stages of bull trout.

Food

Bull trout are opportunistic feeders, but are primarily 

piscivorous. Adults feed almost exclusively on other 

fish, including various trout and salmon species, minnows, suckers, whitefish, and sculpin. Juveniles feed 

on aquatic invertebrates, including mayflies, stoneflies, caddisflies, and beetles. Larger adults have also 

been known to eat frogs, snakes, mice, and ducklings. 

In coastal marine areas of western Washington, bull 

trout feed on Pacific herring, Pacific sand lance, and 

surf smelt. Declines in prey fish populations (salmon) 

are partly responsible for declines in bull trout populations. Healthy streams provide the variety and abundance of food necessary for all bull trout life-history 

stages.

Cover

All life-history stages of bull trout are associated with 

complex forms of cover, including large wood, overhanging vegetation, undercut banks, boulders, and 

pools (fig. 2). Adults will often conceal themselves in 

deep pools with submerged wood or boulders during 

the day and move away from such cover at night. 

Spawning habitat

Both migratory and resident forms of bull trout spawn 

in headwater or tributary streams. Spawning habitat consists of very cold water and loose, clean gravel from 1⁄2 to 3 inches in diameter, with less than 20 

percent fine sediments around it. Spawning and rearing areas are often associated with areas of upwelling, 

such as cold-water springs or subsurface flows, because these streams are often cooler in summer and 

warmer in winter than other streams. While spawning 

can occur in water up to 46 °F, egg survival during incubation is highest at water temperatures of 35 to 39 

°F. Spawning sites include runs, glides, and tail-outs of 

pools with water 4 to 18 inches deep. Because eggs incubate over the winter, incubation sites are particularly vulnerable to scouring, low flows, or anchor ice accumulations.

NRCS

Figure 2 All life-history stages of bull trout are associated with complex forms of cover.
Bull Trout

Overwintering habitat

In the fall and winter, bull trout seek large, deep pools 

with abundant wood and/or rock cover (fig. 3). During 

this time, activity is generally reduced and survival depends on finding suitable food and shelter from predators, freezing water, and high flows.

Migratory habitat

While resident forms of bull trout live their entire 

lives in small headwater or tributary streams, migratory forms travel long distances. In the fall, migratory 

forms of bull trout move from spawning and rearing 

habitats to foraging and overwintering habitats. In the 

spring, they make the return journey back to spawning and rearing areas of headwaters. Migratory bull 

trout have been observed to move up to 150 miles between the ocean, lakes, reservoirs, or rivers and tributary streams in response to changing habitat needs. 

To complete this journey, migratory forms of bull 

trout require networks of interconnected streams, rivers, lakes, reservoirs, and the ocean, which provide 

them with access to spawning, rearing, foraging, and 

overwintering habitats. Migratory habitat also serves 

as foraging habitat for much of the year, so these networks must provide food and cover for bull trout.

Barrier-free migratory corridors are critical for maintaining bull trout populations. Barriers to fish movement, such as dams, diversions, weirs, culverts, and 

elevated stream temperatures, can obstruct migratory pathways and cause declines in bull trout populations.

Habitat assessment

Interested landowners can inquire of local natural resource professionals whether bull trout presently occur or historically occurred in their area and, if so, in 

what life stages (spawning, rearing, foraging, overwintering, migrating). Landowners can then assess the 

availability of suitable bull trout habitat on their property. Table 2 is an example of an inventory chart for 

assessing bull trout habitat. For planning purposes, 

rate the habitat components for the designated planning area based on the descriptions given. Habitat 

and stream community components that are limited 

or absent are likely limiting bull trout habitat quality. 

Management plans should address the habitat components that are determined to be limiting bull trout 

habitat potential. Table 2 also offers management suggestions to raise the quality or availability of each 

habitat component that is considered limiting. Bull 

trout often exhibit a patchy distribution; therefore, 

they are not likely to occupy all available habitat simultaneously, even if it is of high quality.

Aquatic ecosystems and the processes they support 

are functionally interconnected throughout a watershed. Restoring stream conditions along a relatively 

small stream reach may not necessarily improve bull 

trout habitat if the rest of the watershed continues to 

be degraded. Depending on the size of the property 

in question and the watershed in which it lies, landowners may need to collaborate with neighbors to focus restoration efforts on a watershed scale. The best 

approach to bull trout habitat protection or recovery 

is to sustain a fully functional, well-vegetated (trees, 

shrubs, wetland plants) flood plain within a barrier-free watershed. This includes maintaining natural stream flows, minimizing erosion in uplands, protecting flood plains, wetlands, and riparian areas, and 

managing streamside forests and riparian areas for 

aquatic species.

Habitat management recommendations 

Bull trout inhabit cold, clean water with complex instream cover. They are extremely sensitive to warm 

water temperatures, instream disturbances, and siltation. Protecting and enhancing their aquatic habitat 

is the most effective way to maintain or restore bull 

trout populations. Any management plan should attempt to minimize the physical, chemical, biological, 

and hydrological disturbances that land management 

activities may have on bull trout habitat or surrounding riparian areas. Landowners should also make every effort to maintain instream flows for bull trout 

and their food sources during all seasons of the year. Mike Jakober

Figure 3 During the winter, bull trout seek large, deep 

pools with abundant wood and/or rock cover.
Bull Trout

Habitat Component Optimal Conditions Abundant Limited Absent Management Suggestions to Improve Limited or Absent Habitat ComponentGeneral Clean, cold water (temperatures 

not to exceed 59 oF) in complex, connected habitat

Limit activities in the watershed that may alter stream hydrology, increase fine sediments, alter the flood plain, or remove riparian vegetation, particularly in spawning and rearing streamsAlong streams, protect and restore native trees and shrubs to keep water temperatures below 59 oFMaintain a buffer of woody vegetation at least 80 to 100 feet or two channel widths between streams and agriculture fields to reduce siltation and non-point source pollution from fertilizer and pesticide runoffFence livestock from streamside riparian vegetation

Food Adults: Fish, including various 

trout and salmon species, suckers, minnows, whitefish, yellow perch, sculpin

Increase populations of forage fish and insects by carefully managing riparian buffers of native trees, grasses, forbs and shrubs, and protecting large woody debris in the stream

Juveniles: Aquatic invertebrates, such as mayflies, stoneflies, and caddisflies

Increase populations of aquatic insects by keeping gravel beds from being embedded with fine sediment

Cover Large wood, overhanging 

vegetation, undercut banks, boulders, and pools

Preserve and plant native trees and shrubs along streamsMaintain woody material and/or boulders in the stream reach

Spawning Habitat

Very cold water and loose, clean gravel 1⁄2 to 3 inches in diameter, with less than 20% fine sediments

Protect spawning areas from trampling by livestockReduce sediment inputs to streams.Maintain the streams natural hydrology (flow)Protect springs

Overwintering Habitat

Large, deep pools with abundant wood and/or rock cover; adequate sources of food

Maintain woody material or other habitat elements in the stream to create deeper pools

Migratory Habitat

Connectivity between headwater streams, rivers, lakes, reservoirs, and/or the ocean

Improve or eliminate human-created fish passage barriers by improving road crossings, maintaining or increasing flows, modifying diversion structures, and/or reducing contaminants to allow fish to move upstream and downstream during all times of the year

Table 2 Assessment of habitat components and management suggestions
Bull Trout

However, the construction of instream improvements 

requires technical expertise and experience. Poorly 

designed and constructed improvements usually lead 

to further degradation of habitat or loss of channel 

and watershed stability. Consultation with and assistance from Federal, State, or local fish and wildlife 

or land management agencies is critical in identifying 

appropriate management actions and permit requirements.

Riparian areas

Riparian areas naturally consist of a diverse mix 

of trees, shrubs, and/or grasses and occur next to 

streams, extending laterally from the streamside. 

Moist conditions along stream corridors and their 

flood plains provide the conditions necessary for 

growth of riparian vegetation. In managed areas, 

these riparian areas are often referred to as riparian 

buffers (fig. 4).

Riparian buffers are beneficial to bull trout in a number of ways. The structurally and functionally diverse 

mix of riparian vegetation filters sediment in surface run-off during rains, thereby reducing siltation of 

spawning substrates. The buffer also filters nutrients 

and contaminants in surface runoff, thus protecting 

water quality. Vegetation roots and foliage also serve 

to stabilize streambanks, which is particularly important during high flow events. Trees and shrubs provide shade that maintains cool water temperatures 

and habitat for riparian species, including terrestrial 

insects that serve as food for juvenile bull trout and 

other fish. Lastly, riparian vegetation, especially trees 

and shrubs, provides wood and organic matter to the 

stream for use by fish and other aquatic species. For 

maximum effectiveness, riparian vegetation should 

extend 80 to 100 feet on either side of the stream. The 

wider and more structurally diverse the buffer, the 

more value it will have for bull trout and other species 

that live in the stream and the riparian area.

If riparian areas are degraded or no buffer exists, native grasses, sedges, forbs, shrubs, and trees should 

be planted. The ideal riparian buffer zone incorporates the native plant community appropriate to the 

site. Most bull trout habitats include riparian areas in 

forested watersheds. Managing riparian areas or buffers for mature stands of trees spaced sufficiently to 

allow an understory of grasses and shrubs will improve bull trout habitat over time. Trees should be 

close enough to the stream so that some of the roots 

are exposed to supply cover and allow stable undercut banks to develop. This proximity to the channel 

assures that some trees will fall into the stream, providing habitat complexity to the channel. 

Landowners can take an active role in maintaining and restoring riparian buffers by planting native 

woody species as seedlings or saplings. On the other hand, the landowner may choose to take a passive 

approach to restoration, and simply allow natural recruitment of woody species along the streambank. If 

the landowner takes the more active approach, the 

following guidelines are recommended:

• Seek assistance in determining the appropriate 

mix of locally-adapted, native plant species and 

the current flood regimes of the stream and its 

watershed. Using plants adapted to the area will 

increase their survival and save time, money, 

and frustration. If it is not practical to plant the 

full complement of vegetation desired in the 

riparian area, plant the dominant species for the 

site, such as alder, willow, or conifer species, 

and other species will naturally be recruited 

over time.

• Typically, plant species at the edge of a stream 

are different from those farther away. The topography, aspect, soil, and hydrology of the riparian 

area provide diverse layers of different plant 

species. Landowners should seek the assistance 

of local soil and water resource professionals 

in choosing the species, number of plants, and 

location in the riparian zone for planting.

Large wood

Large woody material in the form of fallen trees, 

limbs, and branches plays a major role in providing 

instream cover for bull trout and channel complexity for stream processes, such as pool formation and 

sediment deposition. In forested streams, logs proNOAA Fisheries

Figure 4 Riparian vegetation can improve stream health 

and bull trout habitat.
Bull Trout

vide cover for bull trout when they fall into the stream 

from adjacent stream banks (fig. 5). In areas where 

logging has removed riparian forests, wood can be 

imported from outside the riparian zone and placed 

in the stream channel. Appropriately placed logs, especially those with intact root wads, will mimic the 

natural recruitment of fallen trees into the stream 

channel and will move and adjust to the stream channel and flood plain during rain events. Occasionally, 

logs are anchored in place, but in most situations it 

is best to simply place logs in streams and allow natural flows to adjust them over time. As with any instream structure, wood placement should be designed 

by technical specialists who understand the dynamics 

of stream systems. Projects should be implemented at 

the appropriate times to avoid impacts to bull trout.

Fishways

Human-created instream structures, such as dams, 

weirs, diversions, and culverts, can hinder the ability of bull trout and other fish to move freely within a 

watershed and to access spawning areas. If possible, 

manmade fish barriers should be removed or modified to facilitate fish passage. If these actions are not 

feasible, fishways can be installed or constructed to 

facilitate the passage of fish through or over a barrier. Fishways can be as simple as developing a series 

of pools and small rock “steps” (fig. 6) over or around 

the barrier, which allow fish to swim into a pool, rest, 

and then swim up another step into the next pool, until they have cleared the barrier. Impassable culverts 

can be retrofitted with baffles, or replaced with new 

culverts that allow fish to pass. For more detailed information regarding fish passage, refer to http://wdfw.

wa.gov/hab/engineer/habeng.htm or http://www.salmonidaho.com/screenshop/.

Livestock fencing

Fencing to exclude livestock from streambanks, riverbanks, and lakes can reduce the collapse of undercut banks and reduce soil erosion and siltation in the 

water resulting from livestock trampling. Fencing livestock from waterways can also reduce the amount of 

livestock waste entering a water body, and thus protect water quality. If fencing is not an option, consider seasonally rotating livestock and grazing patterns 

to avoid impacts on bull trout habitat during critical 

times of the year (spawning season). Providing attractants such as salt blocks and watering tanks at 

some distance from the surface water may also help. 

If livestock use the stream as a water source, a fenced 

chute can be built to allow livestock to access a limited section of the stream or water can be pumped to a 

holding area that is accessible to the livestock rather.

Figure 5 Large wood in streams provides cover for bull 

trout and structural complexity in the channel 

for pool formation and sediment deposition.

U.S. Army Corps of Engineers

Washington Department of Fish and Wildlife

Figure 6 Step fishways can help fish move around a manmade barrier.
Bull Trout

Bull trout in the Little Lost River 

system: an evolving success story

The Little Lost River watershed is located in central 

Idaho, where activities limiting recovery of the bull 

trout include inadequate streamflows and fish barriers associated with irrigation diversions. Landowners 

and local biologists in the Little Lost River drainage 

have made great strides in tackling difficult stream 

flow restoration and tributary reconnect issues to accommodate the habitat needs of bull trout. Trout 

Unlimited (http://www.tu.org) has partnered with 

Federal and State agencies to complete a comprehensive fish barrier and diversion assessment in the area. 

Collaborative relationships have been developed with 

landowners to resolve fish passage problems identified in the assessment. Trout Unlimited is working 

with landowners on nearby creeks to develop stream 

flow restoration and tributary reconnection projects 

to reconnect important bull trout habitats to the mainstem Little Lost River. Many of these tributaries have 

been historically diverted and all or most of the water 

taken for agricultural operations. Working with landowners and the NRCS, Trout Unlimited has developed 

funding and implementation strategies that combine 

efficiency measures and innovative water use plans to 

ensure more water is available in the stream. Because 

of these collaborative efforts, the Little Lost River system is one area where bull trout recovery efforts are 

making a difference.

For more information, visit http://www.tu.org/.

Available assistance

Technical and financial assistance for management 

of fish and wildlife habitat is available to landowners 

through a variety of government agencies and other 

organizations. Landowners and managers should enlist the expertise of State and local natural resource 

professionals to help assess habitat quality and management practices for sustaining bull trout populations and enhancing habitat. Some Federal assistance 

programs available through various sources are listed 

in table 3. State fish and wildlife agencies or groups 

such as Trout Unlimited may have additional assistance programs, publications, or other useful tools 

with a more local focus.
Bull Trout

Program Bull Trout Habitat Improvements Land Eligibility Type of Assistance ContactConservation Reserve Program 

Plant riparian buffers Cropland (including 

field margins), riparian pastureland, highly erodible land

50% cost-share for establishing permanent cover, annual rental payments in return for establishing long-term, resource-conserving covers, additional financial incentives are available for some practice

NRCS or FSA state or local office

Environmental Quality Incentives Program 

Conservation practices to improve water quality, reduce erosion and sedimentation

Cropland, rangeland, grazing land, and other agricultural land in need of treatment

Up to 75% cost-share and incentive payments to implement conservation practices to a maximum term of 10 years

NRCS state or local office

Partners for Fish and Wildlife Program 

Plant riparian vegetation, install fencing and off-stream livestock watering facilities, remove exotic plants, restore instream habitat, reestablish migratory fish passageways

Most degraded fish and/or wildlife habitat, especially for listed species

Up to 100% financial and technical assistance to restore wildlife habitat under minimum 10-year cooperative agreements

U.S. Fish and Wildlife Service local office

Waterways for Wildlife

Develop watershed-level habitat management plan, plant riparian buffers, improve in-stream habitat, improve water quality, reduce erosion and sedimentation

Private land Technical and program development assistance to coalesce 

habitat efforts of corporations and private landowners to meet common watershed level goals

Wildlife Habitat Council

Wildlife at Work Develop habitat management plan, 

plant riparian buffers, remove exotic plants and animals, improve instream habitat

Corporate land Technical assistance on developing habitat projects into a 

program that will allow companies to involve employees and the community

Wildlife Habitat Council 

Wildlife Habitat Incentives Program 

Develop habitat management plan, plant riparian buffers, improve instream habitat

High-priority fish and wildlife habitats

Up to 75% cost-share for conservation practices under 5- to 10-year contracts

NRCS state or local office

Table 3 Assistance programs
Bull Trout

10

References

On-line sources

King County Government, Seattle, WA. 1999. Ecology 

of bull trout. http://www.metrokc.gov/exec/esa/

ecobulltrout.htm [Accessed 4 February 2005].

Montana Fish, Wildlife and Parks. n.d. Bull trout 

detailed information. http://fwp.state.mt.us/

fieldguide/detail_AFCHA05020.aspx [Accessed 

4 February 2005].

Montana Fish, Wildlife and Parks. n.d. Bull trout identification and education program. http://fwp.

state.mt.us/bulltroutid/default.htm [Accessed 

20 July 2005].

Natural Resources Conservation Service. n.d. 

Threatened and endangered species: bull trout 

Salvelinus confluentus factsheet. http://www.

mt.nrcs.usda.gov/news/factsheets/bulltrout.

html [Accessed 4 February 2005].

Salmon Idaho. n.d. Idaho Fish Screen Program. http://

www.salmonidaho.com/screenshop/ [Accessed 

20 July 2005].

Trout Unlimited. 2005. http://www.tu.org [Accessed 

20 July 2005].

U.S. Fish and Wildlife Service. n.d. Bull trout. http://

pacific.fws.gov/bulltrout/ [Accessed 20 July 

2005].

Washington Department of Fish and Wildlife. 2005. 

Fish passage technical assistance. http://wdfw.

wa.gov/hab/engineer/habeng.htm [Accessed 20 

July 2005].

Printed sources

Bellerud, B.L., S. Gunkel, A.R. Hemmingsen, D.V. 

Buchanan, and P.J. Howell. 1997. Bull trout 

life history, genetics, habitat needs, and limiting factors in central and northeast Oregon. 

Environment, Fish, and Wildlife, Bonneville 

Power Administration, U.S. Department of 

Energy, Portland, OR, USA.

Behnke, R. 1992. Native trout of western North 

America. American Fisheries Society, Bethesda, 

MD, USA. 

Bonar, S.A., M.Divens, and B.Bolding. 1997. Methods 

for sampling the distribution and abundance 

of bull trout and Dolly Varden. Inland Fisheries 

Investigation, Resource Assessment Division, 

Washington Department of Fish and Wildlife, 

Olympia, WA, USA.

Brewin, M.K., A.J. Paul, and M. Monita, editors. 2001. 

Bull trout II conference proceedings: ecology 

and management of northwest salmonids. Trout 

Unlimited Canada, Calgary, AB, Canada.

Cavender, T.M. 1978. Taxonomy and distribution of 

the bull trout, Salvelinus confluentus (Suckley), 

from the American Northwest. California Fish 

and Game 64: 139-174.

Fraley, J. and B. Shepard. 1989. Life history, ecology and population status of migratory bull trout 

(Salvelinus confluentus) in the Flathead Lake 

and river system, Montana. Northwest Science 

63: 133-143. 

Howell, P.J. and D.V. Buchanan, editors. 1992. 

Proceedings of the Gearhart Mountain bull trout 

workshop. Oregon Chapter American Fisheries 

Society, Corvallis, OR, USA.

Hunt, R.L. 1993. Trout stream therapy. University of 

Wisconsin Press. Madison, WI, USA. 

Hunter, C.J. 1991. Better trout habitat. Montana Land 

Reliance. Island Press, Washington, DC, USA. 

Knudsen, E.E., D.D. MacDonald, and Y.K. Muirhead, 

editors. 2004. Sustainable management of North 

American fisheries. American Fisheries Society 

Symposium 4, Bethesda, MD, USA.

National Marine Fisheries Service. 1997. Fish screening criteria for anadromous salmonids. National 

Marine Fisheries Service, Southwest Region, 

Santa Rosa, CA, USA. Available at: http://swr.

nmfs.noaa.gov/hcd/fishscrn.pdf. 

Rich, C.F. Jr., T.E. McMahon, B.E. Rieman, and W.L. 

Thompson. 2003. Local-habitat, watershed, and 

biotic features associated with bull trout occurrence in Montana streams. Transactions of the 

American Fisheries Society 132: 1053-1064.

Rieman, B.E. and J.D. McIntyre. 1995. Occurrence 

of bull trout in naturally fragmented habitat 

patches of varied size. Transactions American 

Fisheries Society 124:285-296.
Bull Trout

11

U.S. Fish and Wildlife Service. 2002. Bull trout 

(Salvelinus confluentus) draft recovery plan. 

U.S. Fish and Wildlife Service, Portland, OR, 

USA. Available at: http://pacific.fws.gov/bulltrout/colkla/recovery/.

U.S. Fish and Wildlife Service. 1999. Determination 

of threatened status for bull trout in the coterminous United States. Federal Register 64: 

58910-58933.

U.S. Fish and Wildlife Service. 1999. Determination of 

threatened status for the Jarbidge River population segment of bull trout. Federal Register 64: 

17110-17125.

U.S. Fish and Wildlife Service. 1998. Determination 

of threatened status for the Klamath River and 

Columbia River distinct population segments of 

bull trout. Federal Register 63: 31647-31674.

Waters, T.F. 1995. Sediment in streams: sources, biological effects, and controls. American Fisheries 

Society, Bethesda, MD, USA.

Williams, J.E., C.A. Wood, and M.P. Dombeck, editors. 1997. Watershed restoration: principles and 

practices. American Fisheries Society, Bethesda, 

MD, USA.
Bull Trout

12

Primary authors: Bob Batz and Raissa Marks, Wildlife Habitat Council. Drafts reviewed by: Rob Pauline, 

Wildlife Habitat Council; Bill Hohman, Natural Resources Conservation Service; Kathryn Boyer, Natural 

Resources Conservation Service; Howard Hankin, Natural Resources Conservation Service; Jack Williams, 

Natural Resources Conservation Service; Trout Unlimited; Mark Schuller, Natural Resources Conservation 

Service; Bianca Streif, U.S. Fish and Wildlife Service; Tim Viel, Natural Resources Conservation Service; Jim 

Gregory, Trout Unlimited

www.nrcs.usda.gov

Wildlife Habitat Council

8737 Colesville Road, Suite 800

Silver Spring, Maryland 20910

(301) 588-8994

The mission of the Wildlife Habitat Council 

is to increase the amount of quality wildlife 

habitat on corporate, private, and public land. 

WHC engages corporations, public agencies, 

and private, non-profit organizations on a 

voluntary basis as one team for the recovery, 

development, and preservation of wildlife 

habitat worldwide.

www.wildlifehc.org

© 1988 WHC

WILDLIFE HABITAT COUNCILSM

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the 

basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part 

of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all 

programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and 

TDD). To file a complaint of discrimination write to USDA, Director, Office of Civil Rights, 1400 Independence 

Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an 

equal opportunity provider and employer.

Natural Resources Conservation Service

Mailing address:

P.O. Box 2890

Washington, DC 20013

Street address:

14th and Independence Avenue SW

Washington, DC 20250

The Natural Resources Conservation Service 

provides leadership in a partnership effort to 

help people conserve, maintain, and improve 

our natural resources and environment.