U.S. Fish & Wildlife Service

Dworshak

Fisheries Complex

Dworshak National Fish Hatchery 

Idaho Fishery Resource Office

Idaho Fish Health Center 

Kooskia National Fish Hatchery
USFWS

When we try to pick 

out anything by itself, 

we find it hitched to 

everything else in 

the universe. 

John Muir, My First Summer 

in the Sierra, June 1911

Spring Chinook 

salmon sac fry, 

one week old.
Located within the Clearwater River 

basin in north-central Idaho, the 

Dworshak Fisheries Complex consists 

of Dworshak and Kooskia National 

Fish Hatcheries, the Idaho Fishery 

Resource Office, and the Idaho Fish 

Health Center. 

Dworshak National Fish Hatchery 

(NFH) is funded by the Army Corps 

of Engineers and co-managed by the 

U.S. Fish and Wildlife Service and 

the Nez Perce Tribe of Idaho. Both 

Dworshak and Kooskia hatcheries 

work together closely to ensure 

the return of salmon and steelhead 

from the Pacific Ocean to the 

Clearwater River.

Dworshak NFH is located at the 

confluence of the North Fork and 

the main Clearwater River, just 

below Dworshak Dam. The dam 

blocked migrating steelhead and 

salmon from reaching their natural 

spawning grounds on the North 

Fork of the Clearwater River, and 

its height made it impossible to 

construct a fish ladder. 

Hatchery Operations

Dworshak hatchery raises cold-water 

fish species: Clearwater River ‘B’ 

run steelhead, spring Chinook and 

coho salmon, and rainbow trout. 

The hatchery is one of the world’s 

largest combination producers of 

anadromous fish, meaning they 

hatch in freshwater, spend one to 

four years in the ocean as adults, and 

then return to their freshwater birth 

streams to spawn. All salmon and 

most steelhead die naturally 

after spawning.

Dworshak National Fish Hatchery 

is unique in that water temperatures 

for steelhead-rearing ponds can be 

controlled through recirculation and 

filtration similar to an aquarium.

Depending on the time of year, 

hatchery water can either be heated 

or chilled to the proper temperature 

for each fish species. Water flows 

through biological filtration beds 

where bacteria convert wastes into 

harmless by-products before the 

water reaches settling ponds and, 

eventually, the river.

Steelhead are raised for 

one year in water at or near 

50° F to achieve optimum 

health and quality prior 

to their spring release at 

a size of about 8 inches. 

The hatchery strives for 

increased growth rates in fish 

during the fall, which decreases the 

need for using heated recycled water 

in the winter when fish are more 

susceptible to infections.

Chinook and coho salmon are raised 

in much colder water — 38-44 ̊ F — 

for up to 18 months prior to release. 

Dworshak 

Fisheries Complex

All hatchery ponds 

are protected from 

predatory birds by 

wire netting.

Dworshak 

National Fish 

Hatchery 

lies below 

Dworshak Dam.

Steelhead and 

Chinook smolts 

are released 

in April.

Susan Sawyer/USFWS

Fishing for steelhead 

below Dworshak 

hatchery on the main 

Clearwater River.

Dwoshak NFH 

helps continue 

the return of 

salmon and 

steelhead from 

the Pacific Ocean 

to the Clearwater 

River.

Steelhead smolts 

in Burrows pond.

ACOE/Walla Walla District ©2007 Kim Glennon

©2007 Kim Glennon
Susan Sawyer/USFWS

Unidentified 

parasites 

(myxosporea sp.) 

in fish gills.

The Fishery Resource Office (FRO) 

is located at Dworshak National 

Fish Hatchery. Established in 

1981, the FRO provides evaluation 

and fish management planning 

for the three federal hatcheries 

in Idaho: Dworshak, Kooskia, and 

Hagerman National Fish Hatchery. 

FRO staff assesses how each of 

these hatcheries is meeting their 

established mitigation goals.

The primary goal of the FRO 

is to assist in management and 

evaluation of fishery resources that 

relate to federal issues, such as: 

■ Fishery resources of 

national significance

■ Fishery mitigation for 

federal projects 

■ Assistance to Native 

American Tribes 

■ Other fishery projects as 

called for under federal law

Activities under this goal support 

protection, restoration and 

enhancement of anadromous 

fishery resources in the Lower 

Snake River Basin.

The FRO also helps set up 

and design studies to evaluate 

hatchery effectiveness and various 

management scenarios. This involves 

working with state, Tribal, and 

federal fishery offices to evaluate 

fish management programs 

throughout Idaho.

The Fish Health Center (FHC) was 

originally built in 1969 as part of 

Dworshak National Fish Hatchery. 

The FHC provides fish health 

services within Idaho, eastern 

Washington, and eastern Oregon. 

Federally-funded National Fish 

Hatcheries within Idaho, as well as 

private fish growers, receive health 

diagnostic and inspection services 

from the FHC. In addition, the FHC 

works in cooperation with other 

federal, state, and Tribal agencies to 

survey, sample, and analyze hatchery 

and wild fish populations. 

Along with the Tribes, the FHC 

coordinates with federal agencies 

regarding involvement with species 

listed under the Endangered Species 

Act. Fish Health Center staff are 

active participants in committees and 

technical groups that govern policy 

and develop recommendations 

on salmon and steelhead in the 

Pacific Northwest.

Idaho Fishery 

Resource Office

Idaho Fish 

Health Center

Biologists sample 

wild fish populations 

in area rivers.

Biologists check 

young steelhead 

and salmon 

for implanted tags 

prior to hatchery 

release.

Susan Sawyer/USFWS

Staff also conduct 

wild fish health 

surveys in area 

rivers.

Lab staff monitor 

hatchery steelhead 

for health issues.

©2007 Kim Glennon

Laura Kessel/USFWS

Ken Peters/USFWS

The FHC lab cultures fish 

parasites and bacteria to 

determine disease treatments.

USFWS
All: ©Aron Jackson/McSorley Elementary School

Susan Sawyer/USFWS

Kooskia National Fish Hatchery 

is located 35 miles upriver from 

Dworshak National Fish Hatchery, 

at the mouth of Clear Creek on the 

Clearwater River. The hatchery was 

built in 1969 to enhance sport and 

Tribal fishing and to mitigate spring 

Chinook salmon losses resulting from 

water development projects in the 

Columbia River Basin. 

Kooskia NFH became part of the 

Dworshak National Fish Hatchery 

Complex in 1978. As a result of the 

2007 Snake River Basin Adjudication, 

the Nez Perce Tribe will assume 

management of the hatchery from 

the USFWS in the near future. 

Existing goals for Chinook salmon 

production and coho acclimation 

will remain the same.

Adult spring 

Chinook salmon 

return to the Kooskia 

NFH fish trap in 

May and June, and 

are transported to 

Dworshak NFH for 

late August spawning. Fertilized eggs 

are returned in the fall for hatching, 

rearing, and release 18 months later. 

Abundant clean water from Clear 

Creek and several deep wells is 

critical to the fish production cycle. 

Raceway water can be recycled and 

heated during the winter months, 

helping to conserve the limited 

groundwater supply.

Dworshak’s Information/

Education program provides 

comprehensive visitor services, 

education, and year-round public 

outreach programs at hatcheries 

and in local communities throughout 

Idaho and eastern Washington.

Program goals include:

■ Increasing visibility of hatcheries 

■ Providing information about 

hatchery programs and services 

■ Developing effective public 

awareness and educational activities 

■ Promoting the region’s fish and 

wildlife resources 

■ Fostering support and 

understanding of Fish and Wildlife 

Service activities

Outreach goals are achieved through 

a variety of activities, including 

guided tours, school programs, 

information booths 

and presentations, 

and youth fishing 

days. Information/

Education staff 

partner with federal, 

Tribal, and state 

agencies, nonprofits, 

and special interest 

groups to provide 

quality programs. 

Kooskia National 

Fish Hatchery

Information 

and Education

Nez Perce Tribal staff 

manage fish production 

at Kooskia hatchery.

A self-guided tour is available 

around the hatchery, along with 

informational brochures. A short, 

easy foot path is across from the 

hatchery entrance. The trail tells 

the story of Chief Looking Glass 

and his people during the war of 

1877. An observation deck offers 

views of waterfowl and resident 

wildlife. 

Hands-on outdoor 

lessons provide 

education and fun 

for area students.

The hatchery is 

2 miles east of 

Kooskia on Toll 

Road. Visitors are 

welcome from 

8am - 3pm daily.

Students raise 

steelhead and 

release them in the 

Clearwater River 

each spring.

Susan Sawyer/USFWS
Marked for Life. In early 

summer, young fish, 

called parr, are moved to 

outside rearing ponds. In 

the fall, they are fin-clipped 

or marked in the automated 

trailer. These marks 

are visible on adult 

fish, indicating 

they were raised in 

a hatchery.

On Their Way. Each spring, juvenile 

fish or smolts are released into the 

Clearwater River to begin their 

downstream migration to the 

ocean. To aid the fish in 

their journey, dams on 

the lower Snake and 

Columbia rivers often 

release water to increase 

river flows. Fish passage centers 

at the dams can collect and transport 

the smolts downstream for release 

below Bonneville Dam on the Lower 

Columbia River.

Coming Home. Adult fish enter 

the hatchery by a fish ladder or 

gate into a holding pond. 

The fish are 3 to 5 years 

old and weigh from 12 

to 20 pounds.

Spawning Season.

Steelhead return to 

Dworshak and Kooskia hatcheries 

between October and May and are 

spawned from January through 

April. Chinook salmon return from 

May to August and are spawned from 

late August to early September. The 

Nez Perce Tribe collects and 

spawns coho salmon from 

October to November.

Hatchery Life of 

Steelhead and Salmon

Dworshak Fisheries Complex 

produces steelhead, spring 

Chinook salmon, coho 

salmon, and rainbow trout.

Life Ends, Life Begins. Ripe 

adult fish return to the hatchery 

where they are euthanized 

so that eggs and milt can 

be collected and mixed for 

fertilization. Mature female 

steelhead produce an average 

of 6,500 eggs, while Chinook 

and coho females average 

about 3,000. 

The fertilized eggs are then 

incubated for one to three 

months until they reach the 

“eyed” stage, when black 

eyespots are visible. Eggs are 

then sorted, counted, and moved 

to the larger nursery tanks.

First Food. Steelhead and 

salmon fry hatch with yolk 

sacs attached, providing their 

only source of food for the 

first few weeks. Once the yolk 

is absorbed, the fry are fed 

six to eight times daily for 

several months.

Eyed eggs

Sac fry

Parr

©Aron Jackson

Smolt

©Sheri Erickson

Adult steelhead

BPA

Egg 

jar

Adult salmon and 

steelhead returning from 

the ocean enter holding 

ponds at Dworshak by 

swimming up a fish ladder. 

BPA

©Andrew S. Nisbet
Dworshak and Kooskia fish 

hatcheries have protected Tribal 

fishing grounds adjacent to each 

facility. Only Tribal members 

are allowed to use traditional or 

modern methods to harvest salmon 

and steelhead. When fish returns 

exceed hatchery goals, surplus fish 

are collected by several different 

Tribes for ceremonial and cultural 

purposes. Excess adult fish are often 

transferred to wilderness streams to 

supplement natural populations and 

to provide nutrients after spawning.

Today, Nez Perce Tribal 

members fill a variety of 

fish culture, biologist, and 

maintenance positions within 

Dworshak Fisheries Complex.

Tribal biologists 

raise coho at both 

Dworshak and Kooskia 

hatcheries. 

Present day Ahsahka, ID. 

on the North Fork of the 

Clearwater River below 

Dworshak Dam.

ACOE/Walla Walla District

Susan Sawyer/USFWS

From simple 

bone hooks 

and lines 

made of hair 

to elaborately 

made willow 

nets, the Ni Mii 

Puu employed 

a variety of 

techniques to 

catch fish. 

Illustrations, University of Idaho/

Cultural Anthropology Department

Cultural Connection

Steelhead and salmon have played 

a key role in the cultural past of the 

native peoples who once lived in or 

near the Clearwater River basin. 

That tradition continues to this day.

The Nez Perce people, known 

historically as the “Ni Mii Puu,” lived 

and thrived in this region for ages. 

The small town of Ahsahka, next to 

Dworshak National Fish Hatchery, 

was once the site of the largest inland 

fishing village for Native Americans 

throughout the Pacific Northwest. 

Each season, Tribes would gather 

here and harvest from the abundant 

North Fork runs of Chinook and 

steelhead. They considered the fish 

to be much more than a food source 

or trade item. 

Fish were, and still are, a sacred 

and significant part of many Tribes’ 

spiritual and cultural identity. For 

some, the return of these fish also 

symbolizes the renewal of life.
Q—Why do salmon and steelhead 

travel back and forth from freshwater 

to the ocean?

A—A genetically inherited 

instinct is responsible for the 

urge to migrate to and from 

the ocean. The ocean is a much 

richer feeding ground, allowing 

fish to reach a larger size than 

in freshwater. The same instinct 

urging fish to the ocean also 

signals the time to come home. 

Scientists believe the fish use 

their keen sense of smell to follow 

the unique characteristics of their 

birth streams.

Q—What kind and how much fish 

food do you use at the hatchery?

A—Fish are fed a specially 

formulated diet of fish meal in powder 

or pellet form, complete with oils, 

vitamins, grains, minerals, and in 

some cases, medication. Each year, 

about 450,000 pounds of food is used 

to raise 500,000 pounds of hatchery 

fish to release size.

Q—Do you feed the adult fish after 

they come up the ladder?

A—No, the adult fish have spent 

several years feeding in the ocean and 

are able to live off fats and proteins 

stored in their flesh until they 

are spawned.

Q—What happens with the 

spawned fish?

A—Steelhead carcasses are 

provided to the Nez Perce 

Tribe for cultural purposes, to 

universities for research, or 

to captive endangered species 

feeding programs. Chinook 

carcasses in good condition 

are placed in remote streams 

in the fall to enhance habitat 

nutrients.

The Snake 

River Basin 

Adjudication

Frequently Asked 

Questions

Mobile sprinklers use 

Snake River water to 

irrigate Southern 

Idaho fields.

USFWS/NCTC

S. Sawyer/USFWS

© Aron Jackson

McSorley Elementary School

Because they’ve 

spent years 

feeding in the 

ocean, adult fish are 

not fed once they 

reach the hatchery 

via the fish ladder. 

The Snake River 

Basin Adjudication 

agreement: 

Providing water for 

Idaho’s people, land, 

and wildlife.

Idaho’s Snake 

River is a valuable 

resource for 

recreation and 

agriculture. 

USFWS/NCTC

Young salmon 

and steelhead 

imprint on their 

freshwater birth 

streams for up to 

two years.

Background 

photo shows 

the size of fish 

food changes as 

hatchery fish 

grow during

the year.

Susan Sawyer/USFWS

In 2007, Congress enacted a 

landmark decision that settled a 

20-year legal battle over water rights 

between the Nez Perce Tribe, the 

state of Idaho, and the U.S. Fish 

and Wildlife Service. 

The SRBA defines the rights and 

responsibilities of all Idaho water 

users and provides funding for tribal 

water and fisheries projects. 

The agreement calls for Tribal 

co-management of Dworshak 

National Fish Hatchery and full 

management of Kooskia NFH. Fish 

production goals at both hatcheries 

remain the same. 

A portion of the settlement provides 

a Tribal trust fund to protect and 

restore fish habitat in the Salmon 

and Clearwater River basins. Part 

of the agreement allows for multiagency management of annual water 

releases from Dworshak reservoir to 

benefit fish passage and provide for 

recreational use of the reservoir. 

Sport fishing for

steelhead on the 

Clearwater River

boosts local economies.
Q – Can fish see in color? 

A – YES! Fish see color almost as 

well as people. This is one reason 

that many fishing lures come in 

bright colors.

Q – Which 

of their five 

senses do 

anadromous 

fish use to find 

their way home?

A – Smell! Salmon and 

steelhead use this sense more than 

others to find their river or stream 

of birth or to return to the hatchery. 

They remember the smells of the 

water from when they traveled 

downstream several years before.

Q – How do fish hold onto their food?

A – Teeth! Many fish have teeth on 

their tongues, jaws, the roofs of their 

mouths, and even in their throats. 

These teeth make it much easier to 

hold onto the wet and wiggling food 

they eat in the water.

Q – Can a fish drown?

A – YES! A fish can drown if it’s 

pulled through the water too fast by 

its mouth or tail. To release a fish you 

have caught, keep it in the water and 

remove the hook if possible. (If not, 

cut the line close to the hook so it can 

rust out.) Gently cradle the fish under 

its belly, avoiding the gills, and move 

it back and forth slowly until it swims 

away on its own.

Q – Do fish burp?

A- YES! Fish have a swim bladder 

they can fill by gulping air from the 

water to help them 

float. They can 

release that air to 

make them sink.

Fish Finders

Once salmon and steelhead smolts 

leave the hatchery they swim for the 

ocean, where they can range from 

California to Alaska over their one 

to four years of travel. The hundreds 

of miles they swim may take them 

through various governing jurisdictions 

and fishery management boundaries. 

In order to effectively track these 

migratory fish and determine harvest 

levels, a portion of each hatchery’s 

juvenile fish are marked or tagged 

primarily by two methods: coded wire 

tags and fin clipping. 

Coded Wire Tag (CWT)

This procedure occurs when the fish 

are between 3 and 4 inches long and 

under a light anesthesia. Coded Wire 

Tags are inserted into the cartilage of a 

fish’s snout by an automated machine. 

The CWT is a tiny hair-thin piece 

of magnetized metal with a unique 

numeric code that can be detected 

when the fish returns to the hatchery 

or is caught by fishermen. Data from 

these tags are used to track fish 

movement, survival, and to manage 

populations. Due to tag costs, only 

a sample group of hatchery fish are 

marked in this way.

Fin Clipping

Most hatchery steelhead and Chinook 

salmon smolts receive a fin clip prior 

to release. The adipose fin on the 

fish’s back is removed so they can be 

identified as hatchery-raised when they 

return as adult fish. Only fin-clipped 

fish can be legally harvested during 

sport fishing season or spawned at the 

hatchery. Adult fish returning to the 

hatchery without fin clips or tags are 

returned to the river so they can spawn 

naturally.

Fun Fish Facts

Fish have the 

same five senses 

as people!

Susan Sawyer/USFWS

©Charles Wandag

Juvenile spring

Chinook salmon in 

an aeration jar.

Juvenile steelhead 

are sorted prior 

to marking in an 

automated trailer.
Dworshak Fisheries Complex

4147 Ahsahka Road

Ahsahka, Idaho 83520–0018

208/476 4591, fax 208/476 3252

http://dworshak.fws.gov

Kooskia National Fish Hatchery

208/926 4272

http://kooskia.fws.gov

U.S. Fish & Wildlife Service

1 800/344 WILD

http://www.fws.gov

Washington Relay Service

TTY 1 800/833 6388

Voice 1 800/735 0644

Telebraille 1 800/833 6385

June 2009

Steelhead sac fry 

emerging from egg.

USFWS