Chinook salmon are anadromous fish, which means they can live in both fresh and saltwater. Chinook salmon have a relatively complex life history.
Chinook Salmon (Protected)
Oncorhynchus tshawytscha
Protected Status
ESA Endangered
Sacramento River winter-run
Upper Columbia River spring-run
ESA Threatened
California coastal
Central Valley spring-run
Lower Columbia River
Puget Sound
Snake River fall-run
Snake River spring/summer-run
Upper Willamette River
ESA Experimental Population
Central Valley spring-run in the San Joaquin River XN
Upper Columbia River spring-run in the Okanogan River subbasin XN
Central Valley spring-run XN Shasta
Sacramento winter-run XN Shasta
Central Valley spring-run XN Yuba
ESA Candidate
Upper Klamath-Trinity Rivers
Gulf of Alaska
Washington Coast
Quick Facts
Weight
40 pounds but can be up to 120 pounds
Length
3 feet
Lifespan
Up to 7 years, typically 3 to 4 years
Threats
Climate change,
Commercial and recreational fishing,
Habitat degradation,
Habitat impediments (dams),
Habitat loss
Region
West Coast
Spring Chinook Salmon. Credit: Michael Humling, U.S. Fish & Wildlife Service
Spring Chinook Salmon. Credit: Michael Humling, U.S. Fish & Wildlife Service
About the Species
Spring Chinook Salmon. Credit: Michael Humling, U.S. Fish & Wildlife Service
Spring Chinook Salmon. Credit: Michael Humling, U.S. Fish & Wildlife Service
Chinook salmon are anadromous fish, which means they can live in both fresh and saltwater. Chinook salmon have a relatively complex life history that includes spawning and juvenile rearing in rivers, estuaries, and wetlands followed by migrating to saltwater to feed, grow, and mature before returning to freshwater to spawn. They are vulnerable to many stressors and threats including blocked or impeded access to spawning grounds and habitat degradation caused by dams and culverts. In addition, downstream migration or movement of juveniles and smolts (i.e., fish entering the ocean) can be impeded or blocked. Populations of Chinook salmon that have juvenile life stages that remain in freshwater habitat through their first summer or remain in freshwater for a full year are at particular risk from degraded freshwater habitats and passage. Two species of Chinook salmon are listed as endangered under the Endangered Species Act, seven species are listed as threatened under the ESA, and one species is a candidate for listing under the ESA.
NOAA Fisheries is committed to conserving and protecting Chinook salmon. Our scientists and partners use a variety of innovative techniques to study, learn more about, and protect this species.
Scientific Classification
Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Salmoniformes
Family
Salmonidae
Genus
Oncorhynchus
Species
tshawytscha
Last updated by NOAA Fisheries on 03/16/2026
Featured News
An excavator breaches the Bateman Island causeway, allowing water to flow freely through the river channel for the first time in 85 years. Credit: Michael-David A. Bushman/Yakama Nation Fisheries
Biologists hold a fall Chinook salmon with a tracking tag attached like a backpack before returning it to the ocean. Photo courtesy Miles Daniels/NOAA Fisheries/UCSC
New research may help scientists and fisheries managers reduce bycatch of chum salmon (above) and Chinook salmon in the eastern Bering Sea pollock fishery. Credit: Roger Tabor/U.S. Fish and Wildlife Service
The Sacramento River winter-run evolutionarily significant unit (called an "ESU") of Chinook salmon is one of NOAA Fisheries' Species in the Spotlight. This initiative is a strategic approach to endangered species recovery that focuses on highly at-risk species for which immediate, targeted actions can halt their decline and stabilize their populations.
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Chinook salmon are an iconic part of California's natural heritage that must be preserved in order to ensure the economic and recreational wellbeing of future generations. Millions of wild salmon once returned to spawn in the foothills and mountains of California's Central Valley. Streams fed by rainfall, snowmelt, and cold water springs encircled the valley, fostering a diversity and abundance of Chinook salmon. The endangered Sacramento River winter-run Chinook salmon are particularly important among California's salmon runs because they exhibit a life-history strategy found nowhere else on the West Coast. These Chinook salmon are unique in that they spawn during the summer months when air temperatures usually approach their warmest.
As a result, winter-run Chinook salmon require stream reaches with cold water sources that will protect their incubating eggs from the warm ambient conditions. Because of this need for cold water during the summer, winter-run Chinook salmon historically occurred only in rivers and creeks fed by cold water springs, such as the Little Sacramento, McCloud, and Pit rivers, and Battle Creek.
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Juvenile Sacramento River winter-run chinook salmon. Credit: NOAA Fisheries
The construction of Shasta and Keswick dams eliminated access to the Little Sacramento, McCloud, and Pit rivers, effectively causing the extirpation of the winter-run Chinook salmon populations that spawned and reared there. The fish from these different populations were forced to mix and spawn as one population downstream of Keswick Dam on the Sacramento River. The construction and operation of hydropower facilities in Battle Creek made the creek inhospitable to winter-run Chinook salmon, and that population also was extirpated.
The one remaining winter-run Chinook salmon population has persisted in large part due to agency-managed cold water releases from Shasta Reservoir during the summer and artificial propagation from Livingston Stone National Fish Hatchery's winter-run Chinook salmon conservation program. Thus, winter-run Chinook salmon are dependent on sufficient cold water storage in Shasta Reservoir, and it has long been recognized that a prolonged drought could have devastating impacts, possibly leading to the species' extinction.
Threats
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Credit: NOAA Fisheries
Currently, Shasta and Keswick dams block winter-run Chinook salmon from nearly all of their historical spawning habitat. The spawning habitat that is accessible is subject to water temperatures that are too warm to support egg and fry survival, particularly during droughts, some of which have been very severe in recent years.
In addition to lost and degraded spawning habitat, 98 percent of riparian and floodplain habitat along the Sacramento River is no longer available to support juvenile rearing. Other threats to winter-run Chinook salmon include water withdrawals, predation by non-native species, lack of quality rearing habitat in the Sacramento-San Joaquin Delta, and commercial and recreational fisheries.
State and federal agencies, public organizations, non-profit groups and others in California's Central Valley have formed strong partnerships to save Sacramento River winter-run Chinook salmon. Efforts to protect winter-run Chinook salmon include restoring habitat, utilizing conservation hatchery programs, closely monitoring the population, and carefully managing scarce cold water. Additional key actions needed to safeguard winter-run Chinook salmon from further declines include:
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Juvenile winter-run chinook salmon being reintroduced to Battle Creek.
Improving management of Shasta Reservoir's storage in order to provide cold water for spawning adults, eggs, and fry, stable summer flows to avoid dewatering redds, and winter/spring pulse flows to improve smolt survival through the delta.
Improving Yolo Bypass fish habitat and passage so juveniles can more frequently utilize the bypass for rearing and adults can freely pass from the bypass back to the Sacramento River.
Managing winter and early spring delta conditions for improved juvenile survival.
Conducting landscape-scale restoration throughout the delta to improve the ecosystem's health and support native species.
Expanding the Livingston Stone National Fish Hatchery's facilities to support both the captive broodstock and conservation hatchery programs; and
Evaluating alternative control rules used to limit incidental take of winter-run Chinook salmon in ocean fisheries.
Species in the Spotlight Priority Actions
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We developed a Species in the Spotlight Priority Action Plan that builds on the recovery plan and details the focused efforts that are needed in the near term. The plan lists key actions NOAA Fisheries and its partners can take to help recover the species. These actions include:
Improve management of Shasta Reservoir cold water storage
Restore and reintroduce winter-run Chinook to Battle Creek habitat
Reintroduce winter-run Chinook salmon into historical habitats above Shasta Dam
Improve Yolo Bypass fish habitat and passage
Manage winter and early spring delta conditions to improve juvenile survival
Collaborative science and fostering partnerships
In our first five years of the Species in the Spotlight, we have:
Improved Shasta Reservoir cold water management (good survival from egg to juvenile stages since 2016).
Reintroduced 567,000+ winter-run Chinook salmon into Battle Creek.
Documented successful spawning and natural production of juveniles in Battle Creek in 2020.
Improved fish passage conditions with projects completed at the Knights Landing Outfall Gates, Wallace Weir, and Fremont Weir.
Acoustically tagged winter-run Chinook salmon juveniles annually to get real-time information on distribution to inform water management decisions.
While we still have much to do, these are important steps towards recovery for Sacramento River winter-run chinook salmon.
2017 Species in the Spotlight Hero Award
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Lewis Bair at Wallace Weir.
Lewis Bair, General Manager of Reclamation District 108, has been a leader in northern California water and salmon issues for many years. As part of the Sacramento Valley Salmon Recovery Program, Lewis has helped implement numerous actions to benefit Sacramento River winter-run Chinook salmon. Most notably, Lewis' efforts led to the funding of two major projects. Both projects were included in the 5-year action plan: a fish barrier at the Knights Landing Outfall Gates and the Wallace Weir Fish Rescue Project.
Randi Field with the U.S. Bureau of Reclamation's MidPacific Region is responsible for operation of the largest reservoir in California, the Shasta Reservoir. Shasta Reservoir stores up to 4.5 million acre-feet of water that meets critical water supply needs for farms and cities. It must also maintain conditions for drinking water and fish protection throughout California. Winter-run Chinook salmon eggs and fry are vulnerable to summer heat. They persist because of the careful operations of the limited cold-water pool deep in Shasta Reservoir.
John Hannon, U.S. Bureau of Reclamation, has motivated the restoration community in the Central Valley of California and formed strong partnerships among the local communities, farmers, environmental groups, and federal and state agencies. John leads the Sacramento River restoration effort. He has moved projects from conception to construction at an unmatched pace—since 2017, 13 projects were completed, resulting in new spawning areas and approximately 26 new acres of much needed rearing habitat.
Matt Johnson, California Department of Fish and Wildlife, along the McCloud River, California. Credit: Travis VanZant, CDFW.
Matt Johnson, California Department of Fish and Wildlife, worked tirelessly to turn initial ideas into on-the-ground actions, resulting in winter-run Chinook salmon being reintroduced to the McCloud River in 2022 for the first time in over 80 years. He fostered a trustful and effective partnership with the Winnemem Wintu Tribe, NOAA Fisheries, and other project partners, and sacrificed the creature comforts of home to camp along the McCloud River throughout the summer and fall to protect remote incubators containing 40,000 endangered salmon eggs from fires, bears, humans, mud, and algae. 2022 was a historic year in the conservation of winter-run Chinook because of Matt’s efforts.
NOAA Fisheries has adopted three recovery plans for the four ESA-listed Snake River basin species: steelhead, spring/summer Chinook salmon, fall Chinook salmon and sockeye salmon. The Snake River Sockeye Recovery Plan was adopted in June 2015. The Snake River Fall Chinook Recovery Plan and Snake River Spring/Summer Chinook Salmon and Snake River Basin Steelhead Recovery Plans were adopted in November 2017.
It is our intent to optimize Recovery Plan implementation through stakeholder involvement to prioritize and implement recovery actions; particularly through NOAA Fisheries’ Snake River Coordination Group.
In 2017, the Karuk Tribe and Salmon River Restoration Council petitioned NOAA to list the Upper Klamath-Trinity Rivers (UKTR) Chinook salmon ESU or, alternatively, create a new ESU to describe Klamath Spring Chinook salmon and list it as threatened or endangered under the ESA.
Upon completion of the status review for Oregon Coast spring-run and Southern Oregon and Northern California Coastal spring-run Chinook, NOAA Fisheries announced a joint 12-month finding on these petitions to list populations of spring-run Chinook salmon as threatened or endangered ESUs under the ESA and to designate critical habitat concurrently with the listings. Based on the best scientific and commercial data available, including the ESU configuration report, NOAA Fisheries determined that listing the Oregon Coast and Southern Oregon and Northern California Coastal spring-run Chinook salmon populations as threatened or endangered ESUs is not warranted. NOAA Fisheries determined that the Oregon Coast and Southern Oregon and Northern California Coastal spring-run Chinook salmon populations do not meet the ESU policy criteria to be considered ESUs separate from the Oregon Coast and Southern Oregon and Northern California Coastal fall-run Chinook salmon populations.
In December 2023, we, NOAA Fisheries, announced a 90-day finding on a petition to list spring-run Chinook salmon on the Washington Coast (WC) or, alternatively, list the existing WC Chinook salmon Evolutionarily Significant Unit (ESU) as threatened or…
On August 4, 2022, we received a petition to list the Oregon Coast (OC) and Southern Oregon and Northern California Coastal (SONCC) Chinook salmon Evolutionarily Significant Units (ESUs) as threatened or endangered under the Endangered Species Act (ESA)…
NOAA Fisheries announces a 90-day finding on a petition to list Gulf of Alaska (GOA) Chinook salmon (Oncorhynchus tshawytscha), or any evolutionarily significant unit (ESU) that may exist in the petitioned area, as a threatened or endangered species…
NOAA Fisheries is adopting a final rule designating Central Valley winter-run and spring-run Chinook salmon reintroduced to the upper Sacramento and McCloud rivers as experimental populations under Endangered Species Act Section 10(j) to promote their…
NOAA Fisheries is notifying the public of the availability for public review and comment of an environmental assessment, and a proposed evaluation and pending determination under limit 6 of the salmon and steelhead 4(d) rule, for the Yankee Fork and Panther Creek spring/summer Chinook hatchery programs.
NOAA Fisheries announces the Final Calaveras River Habitat Conservation Plan (HCP) and Environmental Assessment (EA) availability and subsequent issuance of the Incidental Take Permit under Section 10(a)(1)(B) of the Endangered Species Act (ESA).
Juveniles of the five Pacific salmon species. Credit: NOAA Fisheries/Alaska Fisheries Science Center
NOAA Fisheries conducts various research activities on the biology, behavior, and ecology of chinook salmon. The results of this research are used to inform management decisions for this species.
Dive Deeper Into Our Research
Chinook Salmon in Alaska
Our work to forecast salmon harvests, assess the impact of commercial fisheries on salmon, and evaluate how salmon populations respond to environmental changes enable us to estimate abundance and trends for chinook salmon in Alaska.
Our research on Pacific salmon covers several topics including bycatch, salmon harvest forecasts, ecotoxicology, genetics, marine survival and responses to climate change.
