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.

Salvelinus namaycush
Salvelinus namaycush
(Lake Trout)
Native Transplant

Copyright Info
Salvelinus namaycush (Walbaum in Artedi, 1792)

Common name: Lake Trout

Synonyms and Other Names: mackinaw, siscowet

Taxonomy: available through www.itis.govITIS logo

Identification: Scott and Crossman (1973); Becker (1983); Smith (1985); Page and Burr (1991).

Size: 126 cm.

Native Range: Widely distributed from northern Canada and Alaska (missing in southern prairie provinces) south to New England and Great Lakes basin (Page and Burr 1991). In northwestern Montana, Lake Trout are native in Waterton Lake, Glenns Lake, Cosley Lake, and St. Mary Lake. (Snyder and Oswald 2005). In southwestern Montana, glacial relict populations of Lake Trout exist in Elk Lake and Twin Lake (Vincent 1963, Brown 1971, Synder and Oswald 2005).

Native range data for this species provided in part by NatureServe NS logo
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 Salvelinus namaycush are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
AK195419752Admiralty Island; Fox Islands
AR198619974Beaver Reservoir; Bull Shoals Lake; Lake Conway-Point Remove; Little Red
CA1865200310Honey-Eagle Lakes; Lake Tahoe; Lower Sacramento; Middle Fork Feather; Newport Bay; North Fork Feather; Sacramento Headwaters; San Francisco Coastal South; Truckee; Upper Cache
CO1895202221Arkansas Headwaters; Big Thompson; Blue; Cache La Poudre; Clear; Colorado Headwaters; East-Taylor; Fountain; Lower Yampa; North Platte Headwaters; Roaring Fork; San Luis; South Platte; South Platte Headwaters; St. Vrain; Upper Arkansas; Upper Arkansas-Lake Meredith; Upper Green-Flaming Gorge Reservoir; Upper Gunnison; Upper North Platte; Upper White
CT188019925Housatonic; New England Region; Outlet Connecticut River; Quinebaug River; Thames
DE187219861Delaware Bay
ID1910202016Bear Lake; Boise-Mores; Clearwater; Lower Bear; Lower Bear-Malad; Lower Boise; North Fork Payette; Palisades; Pend Oreille Lake; Priest; South Fork Salmon; Teton; Upper Salmon; Upper Snake-Rock; Upper Spokane; Willow
IL198620002Lake Michigan; Lower Rock
IN190119022Ohio Region; St. Joseph
IA189819872Little Sioux; Winnebago
KY197719862Obey; Upper Cumberland-Lake Cumberland
ME199819991Maine Coastal
MD187519864Gunpowder-Patapsco; Mid Atlantic Region; North Branch Potomac; Youghiogheny
MA186820204Blackstone River; Chicopee River; Nashua River; New England Region
MI198019806Au Sable; Betsie-Platte; Cheboygan; Detroit; Kalamazoo; Lake Michigan
MN188520015Kettle; Minnesota; Mississippi Headwaters; Souris-Red-Rainy; St. Croix
MT1890202320Big Horn Lake; Blackfoot; Clarks Fork Yellowstone; Flathead Lake; Flint-Rock; Fort Peck Reservoir; Jefferson; Lower Clark Fork; Madison; Marias; Middle Clark Fork; Middle Fork Flathead; Middle Kootenai; Missouri-Poplar; North Fork Flathead; Prairie Elk-Wolf; Stillwater; Swan; Upper Yellowstone; Willow
NE188619525Lower Elkhorn; Lower North Platte; Middle North Platte-Scotts Bluff; Niobrara Headwaters; Upper White
NV188920013Lake Tahoe; Truckee; Walker Lake
NH193719732Headwaters Connecticut River; New England
NJ192019943Mid-Atlantic Region; Raritan; Upper Delaware
NM188819904Cimarron; Rio Chama; Rio Grande-Albuquerque; Upper Canadian
NY198519863Lower Hudson; Upper Delaware; Upper Susquehanna
OR195819943Little Deschutes; Pacific Northwest Region; Upper Deschutes
PA198319831Upper Susquehanna-Lackawanna
SD199220013Fort Randall Reservoir; Lower Lake Oahe; Missouri Region
TN197719943Obey; Stones; Watauga, North Carolina, Tennessee
UT189420199Bear Lake; Fremont; Lower Green-Diamond; Provo; San Rafael; Spanish Fork; Strawberry; Upper Green-Flaming Gorge Reservoir; Utah Lake
VT199419941St. Francois River
VA188519663Middle New; Upper Dan; Upper New
WA1900202114Colville; Kootenai-Pend Oreille-Spokane; Lake Chelan; Lower Cowlitz; Okanogan; Pacific Northwest; Pacific Northwest Region; Pend Oreille; Puyallup; Skykomish; Upper Columbia; Upper Columbia-Entiat; Upper Yakima; Wenatchee
WV198619861North Branch Potomac
WI198019955Coon-Yellow; Middle Rock; Upper Chippewa; Upper Fox; Upper Wisconsin
WY1890202118Big Horn; Clarks Fork Yellowstone; Greys-Hoback; Gros Ventre; New Fork; North Fork Shoshone; Nowood; Salt; Shoshone; Snake Headwaters; Snake Headwaters; Upper Bighorn; Upper Green; Upper Green; Upper Green-Flaming Gorge Reservoir; Upper Green-Slate; Upper Laramie; Yellowstone Headwaters

Table last updated 7/16/2024

† Populations may not be currently present.

* HUCs are not listed for states where the observation(s) cannot be approximated to a HUC (e.g. state centroids or Canadian provinces).

Means of Introduction: Lake Trout have been intentionally stocked as a sport fish. In the Great Lakes, the species was stocked to restore populations within its native range that had been decimated by the sea lamprey. Kaeding et al. (1996) summarized what is known about the illegal introduction into Yellowstone Lake.

Status: Reported as established locally in California, Colorado, Idaho, Massachusetts, North Dakota, South Dakota, Washington, and Wyoming. Extirpated in Connecticut (Whitworth 1996). Scientists have concluded Lake Trout are established in Yellowstone Lake and are present at such high numbers eradication is probably not possible (Kaeding et al. 1996).

Impact of Introduction: Lake Trout often lead to the demise of other trout species where it is introduced. For instance, introductions into Lake Tahoe led to the elimination of the native Lahontan cutthroat Oncorhynchus clarkii henshawi (McAffee 1966; Moyle 1976; Behnke, personal communication). Cordone and Frantz (1966) reported a drastic decline and eventual extinction of native cutthroat in Lake Tahoe after the introduction of Lake Trout. Lahontan cutthroat were abundant in the lake in 1907, with only an occasional Lake Trout reported. By 1938, the cutthroat has virtually disappeared, and by 1966, Lake Trout comprised 70% of angler catch in the lake (Cordone and Frantz 1966). Stocked Lake Trout have replaced native cutthroats in deep Rocky Mountain lakes (Benson et al. 1961). This trout has also virtually eliminated cutthroat and bull trout in Flathead Lake, Montana, and Pend Orielle Lake, Idaho. The introduction into Yellowstone Lake poses a similar threat to the native Yellowstone cutthroat trout O. c. bouvieri. The introduction of Lake Trout led to the extirpation of three of the four populations of Sunapee trout (Behnke, personal communication). Lake Trout introduced into Flaming Gorge Reservoir were found to prey heavily on the Utah chub Gila atraria (Teuscher and Luecke 1996). Predation by Lake Trout was shown to be a major factor in the decline of kokanee O. nerka in Lake Chelan, Washington (Schoen et al. 2012). Competition with and predation by nonnative species (i.e., Catostomus sp., creek chub Semotilus atromaculatus, redside shiner Richardsonius balteatus, burbot Lota lota, brown trout Salmo trutta, and Lake Trout Salvelinus namaycush) limit populations of the rare bluehead sucker Catostomus discobolus (Wyoming Game and Fish Department 2010).

Remarks: A illegal introduction sometime prior to 1994 in Yellowstone Lake, Wyoming, has been of great concern there. Biologists are worried about effects on native Yellowstone Cutthroat Trout (McCullen 1994; Anonymous 1994; Kaeding et al. 1996). A plan was been devised by the National Park Service to remove the Lake Trout from Yellowstone Lake but scientists are skeptical that eradication efforts will succeed. However, as of early 2021, 3.65 million Lake Trout have been removed since gillnetting began and the Cutthroat Trout is returning (T. Koel, National Park Service, personal communication, 2021). Although it is found in some surrounding states, the Lake Trout has not been stocked in Oklahoma (J. Pigg, Oklahoma DEQ, personal communication). Ng et al. (2016) used life history data and population models to evaluate different different management scenarios, finding that a slight (2x) increase in mortality applied over 20 years could cause population eradication.

References: (click for full references)

Anonymous. 1994. Nature: something's fishy in Yellowstone. Newsweek 29 August 1994.

Baxter, G.T., and J.R. Simon. 1970. Wyoming fishes. Bulletin No. 4, Wyoming Game and Fish Department, Cheyenne, WY.

Becker, G.C. 1983. Fishes of Wisconsin. University of Madison Press, Madison, WI.

Beckman, W.C. 1952. Guide to the fishes of Colorado. Colorado Department of Game and Fish.

Behnke, R.J. and R.M. Wetzel. 1960. A preliminary list of the fishes found in the fresh waters of Connecticut. Copeia 2:141-143.

Benson, N.G., J.R. Greeley, M.I. Huish, and J.H. Kuehn. 1961. Status of management of natural lakes. Transactions of American Fishery Society 90:218-224.

Bond, C.E. 1973. Keys to Oregon freshwater fishes. Oregon State University Agriculture Experimental Station Technical Bulletin 58:1-42, revised.

Bond, C.E. 1994. Keys to Oregon freshwater fishes. Oregon State University Bookstores, Corvallis, OR.

Breukelman, J. 1946. A review of Kansas ichthyology. Transactions of the Kansas Academy of Science 49:51-70.

Brown, C.J.D. 1971. Fishes of Montana. Montana State University, Bozeman, MT.

Burr, B.M., and L.M. Page. 1986. Zoogeography of the fishes of the lower Ohio-upper Mississippi basin. 287-324 in C.H. Hocutt and E.O. Wiley, eds. The zoogeography of North American freshwater fishes. John Wiley and Sons, New York, NY.

Burr, B.M., and M.L. Warren, Jr. 1986. A distributional atlas of Kentucky fishes. Kentucky Nature Preserves Commission Scientific and Technical series Number 4.

Cardoza, J.E., G.S. Jones, T.W. French, and D.B. Halliwell. 1993. Exotic and translocated vertebrates of Massachusetts. Fauna of Massachusetts Series 6. Massachusetts Division of Fisheries and Wildlife, Westborough, MA.

Chapman, W.M. 1942. Alien fishes in the waters of the Pacific Northwest. California Fish and Game 28(1):9-15.

Cooper, E.L. 1983. Fishes of Pennsylvania and the northeastern United States. Pennsylvania State University Press, University Park, PA.

Cordone, A.J., and T.C. Frantz. 1966. The Lake Tahoe sport fishery. California Fish and Game 52(4):240-274.

Cox, B.S., A.M. Dux, M.C. Quist, and C.S. Guy. 2012. Use of a seismic air gun to reduce survival of nonnative lake trout embryos: a tool for conservation? North American Journal of Fisheries Management 32(2):292-298.

Cross, F.B. 1967. Handbook of fishes of Kansas. State Biological Survey and University of Kansas Museum of Natural History Miscellaneous Publication 45, Topeka, KS.

Cross, F.B., R.L. Mayden, and J.D. Stewart. 1986. Fishes in the western Mississippi basin (Missouri, Arkansas, and Red Rivers). 363-412 in C.H. Hocutt and E.O. Wiley, eds. The zoogeography of North American freshwater fishes. John Wiley and Sons, New York, NY.

Deacon, J.E. and J.E. Williams. 1984. Annotated list of the fishes of Nevada. Proceedings of the Biological Society of Washington 97(1):103-118.

Denoncourt, R.F., T.B. Robbins, and R. Hesser. 1975. Recent introductions and reintroductions to the Pennsylvania fish fauna of the Susquehanna River drainage above Conowingo Dam. Proceedings of the Pennsylvania Academy of Science 49:57-58.

Dill, W.A., and A.J. Cordone. 1997. History and status of introduced fishes in California, 1871-1996. California Department of Fish and Game Fish Bulletin, volume 178.

Dunham, J.B., D.S. Pilliod, and M.K. Young. 2004. Assessing the consequences of nonnative trout in headwater ecosystems in western North America. Fisheries 29(6):18-24.

Eddy, S., and J.C. Underhill. 1974. Northern fishes, with special reference to the upper Mississippi Valley. 3rd edition. University of Minnesota Press, Minneapolis, MN.

Etnier, D.A., and W.C. Starnes. 1993. The fishes of Tenneessee. University of Tennessee Press, Knoxville, TN.

Everhart, W.H. and W.R. Seaman. 1971. Fishes of Colorado. Colorado Game, Fish and Parks Division Denver, CO.

Ferguson, T.B. 1876. Report of the Commissioners of Fisheries of Maryland to the General Assembly. January 1, 1876. John F Wiley Annapolis, MD.

Fowler, H.W. 1952. A list of the fishes of New Jersey, with off-shore species. Proceedings of the Academy of Natural Sciences of Philadelphia 104:89-151.

Harlan, J.R., E.B. Speaker, and J. Mayhew. 1987. Iowa fish and fishing. Iowa Department of Natural Resources.

Hartel, K. 1992. Non-native fishes known from Massachusetts freshwaters. Occasional Reports of the MCZ Fish Department 1992(2):1-9.

Hartel, K.E., D.B. Halliwell, and A.E. Launer. 2002. Inland fishes of Massachusetts. Massachusetts Audubon Society, Lincoln, MA. 328 pp.

Hendricks, M.L., J.R. Stauffer, Jr., C.H. Hocutt, and C.R. Gilbert. 1979. A preliminary checklist of the fishes of the Youghiogheny River. Chicago Academy of Sciences 203:1-15.

Holton, G.D. 1990. A field guide to Montana fishes. Montana Department of Fish, Wildlife and Parks Helena, MT.

Hoover, E.E. 1936. Prelimary biological survey of some New Hampshire lakes. Survey Report 1. State of New Hampshire Fish and Game Department, Concord, NH.

Hubbs, C.L., and K.F. Lagler. 1947. Fishes of the Great Lakes region. Cranbrook Institute of Science Bulletin 26. Bloomfield Hills, Michigan.

Hubert, W. 1994. Exotic fishes. 158-174 in T.L. Parish and S.H. Anderson, eds. Exotic species manual. Wyoming Game and Fish Department, Laramie, WY.

Insider Viewpoint. 2001. Fishing Records – Nevada. Insider Viewpoint Magazine. 3 pp.

Jenkins, R.E., and N.M. Burkhead. 1994. Freshwater fishes of Virginia. American Fisheries Society, Bethesda, MD.

Jones, D.J. 1963. A history of Nebraska's fishery resources. Nebraska Game, Forestation and Parks Commission.

Kaeding, L.R., G.D. Boltz, and D.G. Carty. 1996. Lake trout discovered in Yellowstone Lake threaten native cutthroat trout. Fisheries 21(3): 16-20.

La Rivers, I. 1962. Fishes and fisheries of Nevada. Nevada State Print Office, Carson City, NV.

Lee, D.S., C.R. Gilbert, C.H. Hocutt, R.E. Jenkins, D.E. McAllister, and J.R. Stauffer, Jr. 1980. Atlas of North American freshwater fishes. North Carolina State Museum of Natural History, Raleigh, NC.

Linder, A.D. 1963. Idaho's alien fishes. Tebiwa 6(2):12-15.

McAffee, W.R. 1966. Lahontan cutthroat trout. Pages 225-231 in Calhoun, A, ed. Inland fisheries management. California Department of Fish and Game. Sacramento, CA.

McCullen, K. 1994. Alien trout puzzle Yellowstone biologists. Rocky Mountain News (Sept. 22, 1994) 8A.

Morris, J., L. Morris, and L. Witt. 1974. The fishes of Nebraska. Nebraska Game and Parks Commission, Lincoln, NE.

Moyle, P.B. 1976. Inland fishes of California. University of California Press, Berkeley, CA.

Ng, E.L., J.P. Fredericks, and M.C. Quist. 2016. Population dynamics and evaluation of alternative management strategies for nonnative Lake Trout in Priest Lake, Idaho. North American Journal of Fisheries Management 36(1):40-54. http://dx.doi.org/10.1080/02755947.2015.1111279

Page, L.M., and B.M. Burr. 1991. A field guide to freshwater fishes of North America north of Mexico. The Peterson Guide Series, vol. 42. Houghton Mifflin Company, Boston, MA.

Pritchard, D.L., O.D. May, Jr., and L. Rider. 1976. Stocking of predators in the predator-stocking-evaluation reservoirs. Proceedings of the 30th Annual Conference of the Southeastern Association of Game and Fish Commissioners 30(1976):108-113.

Raasch, M.S. and V.L. Altemus, Sr. 1991. Delaware's freshwater and brackish water fishes - a popular account. Delaware State College for the Study of Del-Mar-Va Habitats and the Society of Natural History of Delaware.

Rasmussen, J.L. 1998. Aquatic nuisance species of the Mississippi River basin. 60th Midwest Fish and Wildlife Conference, Aquatic Nuisance Species Symposium, Dec. 7, 1998, Cincinnati, OH.

Robison, H.W., and T.M. Buchanan. 1998. Fishes of Arkansas. University of Arkansas Press, Fayetteville, AR.

Scarola, J.F. 1973. Freshwater fishes of New Hampshire. New Hampshire Fish and Game Department, Division of Inland and Marine Fisheries.

Schmidt, R.E. 1986. Zoogeography of the northern Appalachians. 137-160 in C.H. Hocutt and E.O. Wiley, eds. The zoogeography of North American freshwater fishes. John Wiley and Sons, New York, NY.

Schoen, E.R., D.A. Beauchamp, and N.C. Overman. 2012. Quantifying latent impacts of an introduced piscivore: pulsed predatory inertia of lake trout and decline of kokanee. Transactions of the American Fisheries Society 141:1191-1206.

Scott, W.B., and E.J. Crossman. 1973. Freshwater fishes of Canada. Fisheries Research Board of Canada, Bulletin 184. Ottawa.

Shebley, W.H. 1917. History of introduction of food and game fishes into the waters of California. California Fish and Game 3:3-12.

Sigler, W.F. and R.R. Miller. 1963. Fishes of Utah. Utah Department of Fish and Game, Salt Lake City, UT.

Sigler, W.F., and J.W. Sigler. 1987. Fishes of the Great Basin: a natural history. University of Nevada Press, Reno, NV.

Sigler, W.F., and J.W. Sigler. 1996. Fishes of Utah. University of Utah Press, Salt Lake City, UT.

Simpson, J., and R. Wallace. 1978. Fishes of Idaho. University of Idaho Press, Moscow, ID.

Smith, C.L. 1985. The inland fishes of New York State. New York State Department of Environmental Conservation, Albany, NY.

Smith, H.M. 1896. A review of the history and results of the attempts to acclimatize fish and other water animals in the Pacific states. Bulletin of the U.S. Fish Commission 15:379-472.

Smith, P.W. 1979. The fishes of Illinois. University of Illinois Press Urbana, IL.

Snyder, B. and D. Oswald. 2005. Montana's fish species of special concern: Lake trout. Status of native lake trout in Montana. Montana Fish Wildlife and Parks

State of Oregon. 2000. Warm Water Game Fish Records. 7 pp.

Stiles, E.W. 1978. Vertebrates of New Jersey. Edmund W Stiles Somerset, NJ.

Sublette, J.E., M.D. Hatch, and M. Sublette. 1990. The fishes of New Mexico. University of New Mexico Press, Albuquerque, NM.

Sweeney, Z.T. 1902. Biennial Report of the Commissioner of Fisheries and Game for Indiana. Indianapolis, IN.

Syslo, J.M., C.S. Guy, and B.S. Cox. 2013. Comparison of harvest scenarios for the cost-effective suppression of Lake Trout in Swan Lake, Montana. North American Journal of Fisheries Management 33(6):1079-1090. http://dx.doi.org/10.1080/02755947.2013.824935.

Teuscher, D., and C. Luecke. 1996. Competition between kokanees and Utah chub in Flaming Gorge Reservoir, Utah-Wyoming. Transactions of the American Fisheries Society 125(4):505-511.

Tilmant, J.T. 1999. Management of nonindigenous aquatic fish in the U.S. National Park System. National Park Service. 50 pp.

Tyus, H.M., B.D. Burdick, R.A. Valdez, C.M. Haynes, T.A. Lytle, and C.R. Berry. 1982. Fishes of the upper Colorado River basin: distribution, abundance, and status. 12-70 in W.H. Miller, H.M. Tyus, and C.A. Carlson, eds. Fishes of the upper Colorado River system: present and future. Western Division, American Fisheries Society.

Vincent, R.E. 1963. The native range of lake trout, Salvelinus namaycush, in Montana. Copeia. 1963(1): 188-189.

Webster, D.A. 1942. The life histories of some Connecticut fishes. 122-227 in A fishery survey of important Connecticut lakes. State Geological and Natural History Survey of Connecticut, Department of Environmental Protection, Hartford, CT.

Whitworth, W. R., P. L. Berrien, and W. T. Keller. 1968. Freshwater fishes of Connecticut. State Geological and Natural History Survey of Connecticut, Bulletin 101.

Whitworth, W.R. 1996. Freshwater fishes of Connecticut. State Geological and Natural History Survey of Connecticut, Bulletin 114.

Wiley, R.W. 2003. Planting trout in Wyoming high-elevation wilderness waters. Fisheries 28(1):22-27.

Wiltzius, W.J. 1985. Fish culture and stocking in Colorado, 1872-1978. Division Report 12, Colorado Division of Wildlife.

Wydoski, R.S., and R.R. Whitney. 2003. Inland fishes of Washington. Second edition. University of Washington Press, Seattle, WA.

FishBase Summary

Author: Pam Fuller, and Matt Neilson

Revision Date: 4/15/2021

Peer Review Date: 2/2/2016

Citation Information:
Pam Fuller, and Matt Neilson, 2024, Salvelinus namaycush (Walbaum in Artedi, 1792): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=942, Revision Date: 4/15/2021, Peer Review Date: 2/2/2016, Access Date: 7/16/2024

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 [7/16/2024].

Contact us if you are using data from this site for a publication to make sure the data are being used appropriately and for potential co-authorship if warranted.

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