The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

Oncorhynchus clarkii pleuriticus
Oncorhynchus clarkii pleuriticus
(Colorado River cutthroat trout)
Native Transplant

Copyright Info
Oncorhynchus clarkii pleuriticus (Cope, 1872)

Common name: Colorado River cutthroat trout

Taxonomy: available through www.itis.govITIS logo

Identification: Colorado River cutthroat trout have a bright yellow-gold body with a brassy-green back and orange belly, medium to large spots concentrated on the caudal peduncle and dorsal region (though spotting varies by region) and absent on the pectoral, pelvic, and anal fins, and 180-200 lateral line scales. Similar species include Yellowstone cutthroat trout (O. c. bouvieri) and Bonneville cutthroat trout (O. c. utah), which can be distinguished from Colorado River cutthroat trout by a lower number of lateral line scales (160-175) and less intense body coloration (Behnke 2002; Page and Burr 2011).

Native Range: High elevation streams and rivers (generally above 6000 ft.) in the upper Colorado River drainage above Lake Powell (includes the Escalante, Green, Colorado, Yampa, White, Eagle, Gunnison, Dolores, and San Juan River drainages); Colorado, New Mexico, Utah, and Wyoming (Behnke 2002; Page and Burr 2011).

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Nonindigenous Occurrences:

Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Oncorhynchus clarkii pleuriticus are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
CA193119311Owens Lake
CO198019861San Luis
WY199420033Medicine Bow; North Platte; Upper North Platte

Table last updated 2/22/2024

† Populations may not be currently present.

Means of Introduction: Stocked for sport.

Status: Established in California (Moyle 2002)

Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.

References: (click for full references)

Behnke, R.J. 2002. Trout and salmon of North America. The Free Press, New York, NY.

Gold, J.R., G.A.E. Gall, and S.J. Nicola. 1978. Taxonomy of the Colorado cutthroat trout (Salmo clarki pleuriticus) of the Williamson Lakes, California. California Fish and Game 64:98-103.

Moyle, P.B. 2002. Inland fishes of California. 2nd edition. University of California Press, Berkeley, CA.

Page, L.M., and B.M. Burr. 2011. Field guide to freshwater fishes of North America north of Mexico. Peterson Field Guides series. Houghton Mifflin Harcourt, Boston, MA.

Other Resources:
FishBase Summary

Author: Neilson, M.E.

Revision Date: 6/29/2023

Peer Review Date: 6/1/2012

Citation Information:
Neilson, M.E., 2024, Oncorhynchus clarkii pleuriticus (Cope, 1872): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=896, Revision Date: 6/29/2023, Peer Review Date: 6/1/2012, Access Date: 2/22/2024

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.


The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. It is the user's responsibility to use these data consistent with their intended purpose and within stated limitations. We highly recommend reviewing metadata files prior to interpreting these data.

Citation information: U.S. Geological Survey. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [2/22/2024].

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For general information and questions about the database, contact Wesley Daniel. For problems and technical issues, contact Matthew Neilson.