Brown Trout

Brown trout laying on grass and mud
Brown trout

NPS

 

The brown trout (Salmo trutta) is the only nonnative fish species in Yellowstone that is not native to North America. This European species was introduced to Yellowstone in the later part of the 19th century, and was recorded as two different species—the Von Behr and the Loch Leven brown trout. These are now thought to be two varieties of the same species and most of the populations in Yellowstone are indistinguishable.

Description

  • Dark in color, olive, brown, or yellow.
  • Pale halos around black spots.
  • Vibrant red or orange spots.

Behavior

  • They spawn in fall, between September and January, migrating to small tributaries of large rivers, upstream in small rivers, or to lake inlets.
  • Brown trout eat mostly insects, crustaceans, and mollusks, but have a reputation for eating much larger prey: other fish, crayfish, birds, mice frogs and snakes.

Distribution

  • Widely distributed in Gallatin, Gibbon, Firehole,Madison, Lewis, Snake, Gardner, and Yellowstone rivers.
  • Not present in Yellowstone Lake, or the Bechler or Falls rivers.
 
An underwater view of a spotted fish with a red slash on its neck and side swims above pebbles

Fish and Aquatic Species

Native fish underpin natural food webs and have great local economic significance.

Young cutthroat trout in a shallow creek

Fisheries & Aquatic Sciences Program

Explore the National Park Service science program for fish and aquatic species.

Spawning lake trout

Lake Trout

Lake trout prey on Yellowstone cutthroat trout.

Rainbow trout in the hands of an angler

Rainbow Trout

Rainbow trout are native to North America in waters which drain to the Pacific Ocean from northern Mexico to Alaska.

Eastern brook trout swimming

Eastern Brook Trout

Eastern brook trout was the first nonnative species introduced in Yellowstone—stocked in the (then fishless) Firehole River in 1889.

Lake chub held in hand

Lake Chub

Native to the Missouri and Yellowstone river drainages in Montana and Wyoming, the lake chub is not native to Yellowstone National Park.

Two shells sit on a dime and are about the same height as the coin

New Zealand Mud Snails

New Zealand mudsnails are invasive and have a significant detrimental effect on Yellowstone.

Two speckled fish with black tails swim in a colorful streambed

Whirling Disease

Whirling disease can infect some trout and salmon.

Brightly-clothed people in a river near a steaming thermal feature

Red-rimmed Melania

Red-rimmed melania, a small snail, was discovered in a warm swimming area.

Angler fishing in Yellowstone

Fishing

Cast your line for 16 species of fish.

Zebra mussel infestation

Clean, Drain, & Dry

Learn how you can help prevent damaging aquatic invasive species from reaching Yellowstone.

 

Resources

Bigelow, P.E. 2009. Predicting areas of lake trout spawning habitat within Yellowstone Lake, Wyoming. Doctoral dissertation, University of Wyoming, Laramie, WY.

Gresswell, R.E. 2009. Scientific review panel evaluation of the National Park Service lake trout suppression program in Yellowstone Lake, August 25–29, 2008: Final report, October 2009, Edited by USGS Northern Rocky Mountain Science Center. Bozeman, MT.

Koel, T.M., P.E. Bigelow, P.D. Doepke, B.D. Ertel, and D.L. Mahony. 2005. Nonnative lake trout result in Yellowstone cutthroat trout decline and impacts to bears and anglers. Fisheries 30(11):10–19.

Koel, T.M., P.E. Bigelow, P.D. Doepke, B.D. Ertel, and D.L. Mahony. 2006. Conserving Yellowstone cutthroat trout for the future of the Greater Yellowstone Ecosystem: Yellowstone’s Aquatic Sciences Program. Yellowstone Science 14(2).

Middleton, A.D., T.A. Morrison, J.K. Fortin, M.J. Kauffman, C.T. Robbins, K.M. Proffitt, P.J. White, D.E. McWhirter, T.M. Koel, D. Brimeyer, and W.S. Fairbanks. 2013. Grizzly bears link non-native trout to migratory elk in Yellowstone. Proceedings of the Royal Society B 280:20130870.

Munro, A.R., T.E. McMahon, and J.R. Ruzycki. 2006. Where did they come from?: Natural chemical markers identify source and date of lake trout introduction in Yellowstone Lake. Yellowstone Science 14(2).

Wyoming Water Project. 2014. Science supporting management of Yellowstone Lake fisheries: Responses to frequently asked questions. Trout Unlimited: Lander, WY.

Ruzycki, J.R., D.A. Beauchamp, and D.L. Yule. 2003. Effects of introduced lake trout on native cutthroat trout in Yellowstone Lake. Ecological Applications 13:23–37.

Last updated: April 18, 2017

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Yellowstone National Park, WY 82190-0168

Phone:

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