Fish and Aquatic Species

For millennia, humans harvested Yellowstone fish for food. From the park’s inception more than a century ago, fishing has been a major form of visitor recreation. It is this long-standing tradition and integration with the parks’ cultural significance that allows the practice of recreational fishing to continue in Yellowstone National Park today. In some cases, it also contributes to the National Park Service goal of preserving native species. The biological significance of fish to ecosystems makes them an ongoing subject of study and concern. Continue: Native Fish, History, Influences of Some Nonnative Species, and Fishing In Yellowstone

Native Fish

A gray fish with ark spots and dark stripes on fins

Arctic Grayling

Arctic grayling dwell entirely in streams.

A spotted fish with red jaw underwater

Yellowstone Cutthroat Trout

Yellowstone cutthroat trout are the most widespread native fish in the park.

A spotted fish with red belly on a black background

Westslope Cutthroat Trout

Historically the most abundant and widely distributed subspecies of cutthroat trout throughout the West.

A greenish fish in a shallow stream next to a fishing reel

Mountain Whitefish

Lives in rivers and streams with deep pools, clear and clean water.

A gray fish with smooth head held by gloved hands

Other Native Fish

More of the 11 native species in Yellowstone: mottled sculpin, suckers, and minnows.


Aquatic Invasive Species

An aquatic invasive species disrupts ecological processes because it is not indigenous to the ecosystem. Invasive organisms can cause species extinction, with the highest extinction rates occurring in freshwater environments. Continue: Basic Information

Two women in orange waders hold a large fish

Lake Trout

Lake trout prey on Yellowstone cutthroat trout.

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.


Quick Facts

Number in Yellowstone

11 native species

  • 3 sport fish: cutthroat trout (Yellowstone and westslope), Arctic grayling, mountain whitefish
  • 8 non-sport fish: longnose dace, speckled dace, redside shiner, Utah chub, longnose sucker, mountain sucker, Utah sucker, and mottled sculpin

5 nonnative species: brook trout, brown trout, lake trout, lake chub, rainbow trout


  • When the park was established, many of its waters were fishless.
  • Park waters were stocked with native and nonnative fish until the mid-1950s.
  • Stocking changed the ecology of many Yellowstone waters as nonnative fish displaced or interbred with native species.
  • By the 1960s, native trout populations were in poor condition and the angling experience had declined.
  • By the late 1980s, native trout had recovered in some areas due to restrictions in fish harvest.
  • In 2001, fishing regulations changed to require the release of all native fishes caught in park waters.


  • Lake trout were apparently illegally introduced into Yellowstone Lake.
  • Whirling disease is now present in Yellowstone Lake, the Yellowstone and Firehole rivers, and Pelican Creek.
  • New Zealand mud snails, which form dense colonies and compete with native species are also present.
  • Competition and hybridization occurs with nonnative rainbow trout (Slough Creek) and brook trout (Soda Butte Creek).

More Information

Frequently Asked Question: Why is fishing lead-free in Yellowstone?

Birds, such as loons, waterfowl, cranes, and shorebirds, are vulnerable to lead poisoning. While we can do little about natural hazards, we can minimize the effects of lead on these species. Yellowstone National Park bans most lead tackle. (Terminal tackle must be lead-free; large down-rigger weights used to fish for deep-dwelling lake trout are permissible because they are too large to be ingested.)

Contact the Park

Mailing Address:

P.O. Box 168
Yellowstone National Park, WY 82190-0168


(307) 344-7381
Recorded information. For road and weather information, please dial 307-344-2117.

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