Native Trout of the Contiguous Western States

The contiguous western United States is home to a diverse array of native trout and other non-anadromous salmonids. Isolated watersheds, glacial history, volcanic activity, and long-term hydrologic separation have produced distinct evolutionary lineages across the region.

This series examines non-anadromous trout, char, grayling, and whitefish found in western drainages, with emphasis on taxonomy, subspecies distinctions, watershed distribution, and conservation context. Each article explores species identity within its broader evolutionary and geographic framework.

Species of the West

Trout (Genus Oncorhynchus)

• Cutthroat trout (species group)

  • Coastal cutthroat trout  － O. clarkii

  • Lahontan cutthroat trout － O. henshawi

  • Rocky Mountain cutthroat trout － O. virginalis

  • Westslope cutthroat trout － O. lewisi

• Gila and Apache trout － O. gilea and O. apache

• Golden trout － O. aquabonita

• Rainbow trout － O. mykiss

  • Coastal rainbow trout － O.m. irideus

  • Eagle Lake rainbow trout － O.m. aquilarum

  • Redband trout－ Interior or inland forms of rainbow trout

    • Columbia River redband trout － O.m. gairdneri

    • Great Basin redband trout － O.m. newberrii

    • Sacramento River redband trout － O.m. stonei

Char (Genus Salvelinus)

• Bull trout － Salvelinus confluentus

• Dolly Varden － S. malma

Grayling (Genus Thymallus)

• Arctic Grayling － Thymallus arcticus

Whitefish (Genus Prosopium)

• Mountain whitefish － Prosopium williamsoni

Relationship to Regional Guides

While regional guides such as Nevada Native Trout and California Native Trout introduce species within a state context, this series focuses on broader taxonomic relationships and watershed-level distribution across the western United States.

Understanding these distinctions supports informed recreation and reinforces conservation priorities for native salmonids throughout the region.

Conservation Context

Many western native trout populations persist in limited habitats shaped by historic isolation and modern watershed pressures. Increased familiarity with species identity, subspecies diversity, and drainage boundaries strengthens public understanding of conservation priorities and long-term stewardship.

Scientific Names and Taxonomy

Scientific names used in this series follow the American Fisheries Society’s Common and Scientific Names of Fishes of the United States, Canada, and Mexico (8th Edition, 2022) at the species level.

Where subspecies are relevant to conservation, management, or regional identification, trinomial names commonly used in fisheries and conservation literature — including those recognized by NatureServe — are included for clarity.

The classification of western trout continues to evolve as genetic and phylogenetic research advances. Readers may encounter alternative treatments in other sources.

Additional Reading

• Native Trout of California and Native Trout of Nevada by Kurt Zeilenga (Trout Adventures)

• Native Trout Fly Fishing (nativetroutflyfishing.com) by Gary Marston

• Identifying Cutthroat Trout by Hayden Cook, Utah Trout Unlimited

• What Are Western Native Trout and Char by Western Native Trout Initiative

• Oregon Native Fish Status Report by Oregon Division of Fish and Wildlife

• Fish Species of Special Concern in California by Peter M. Moyle, et. al.

• Trout and Salmon of North America by Robert Behnke