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.
Native Fish Species
Yellowstone’s native fish underpin natural food webs, have great local economic significance, and provide exceptional visitor experiences. Though policies of the National Park Service provide substantial protection from pollution and land-use practices that often degrade habitat, historic management efforts by the park service subjected native species to the effects of nonnative fish introductions, egg-taking operations, commercial fishing, and intensive sport-fishery harvest into the middle of the twentieth century.
To reverse declining native fish populations and loss of ecosystem integrity, the National Park Service now takes action to ensure their recovery. A Native Fish Conservation Plan/Environmental Assessment was completed in 2010. The National Park Service aims to reduce long-term extinction risk and restore the ecological role of native species, including fluvial Arctic grayling, westslope cutthroat trout, and Yellowstone cutthroat trout, while ensuring sustainable native fish angling and viewing opportunities for visitors. Scientific peer review continues to provide guidance for future efforts on Yellowstone fisheries. The National Park Service strives to use the best methods available for addressing threats, with a focus on direct, aggressive intervention, and welcomed assistance by visiting anglers.
Yellowstone Cutthroat Trout
Yellowstone cutthroat trout are the most widespread native fish in the park.
Mottled sculpin live in shallow, cold water throughout Yellowstone except the Yellowstone River above Lower Falls and in Yellowstone Lake.
Yellowstone’s minnows are small fish living in a variety of habitats and eating a variety of foods.
Suckers are bottom-dwelling fish that use ridges on their jaws to scrape flora and fauna from rocks.
About 8,000-10,000 years ago twelve species (or subspecies) of native fish, including Arctic grayling, mountain whitefish, and cutthroat trout, dispersed to this region following glacier melt. These native fish species provided food for both wildlife and human inhabitants. The distribution of native fish species was originally constrained by natural waterfalls and watershed divides. These landscape features provided a natural variation of species distributed across the landscape and vast areas of fishless water. At the time Yellowstone National Park was established in 1872, approximately 40% of its waters were barren of fish—including Lewis Lake, Shoshone Lake, and the Firehole River above Firehole Falls.
Park inhabitants and visitors fished for sustenance and survival in this wild, remote place. While most hunting was curtailed by early park management, fishing was not only allowed but encouraged. Driven by the desire to establish recreational fishing in more park waters and new technology that enabled the long-distance transport of exotic fish; Early park managers stocked fish into fishless waters, produced fish in hatcheries, and introduced several nonnative species. The majority of the non-native fish introductions were trout species (lake trout, brook trout, brown trout, and rainbow trout), but other species were also introduced.
Constrained by geography, the native fish within the stocked waters were forced to live together with the nonnatives, be displaced to downstream habitats, or die out. The ranges and densities of Yellowstone’s native trout and grayling were substantially altered. Nonnative species contributed to the decline in the park’s native fish population by competing for food and habitat, preying on native fish, and degrading the genetic integrity of native fish through hybridization. By the 1930s, managers realized the destructive impact caused by nonnative fish. As a result, the National Park Service (NPS) created a formal stocking policy to discontinue these efforts.
Even though the stocking of non-natives stopped, stocking of Yellowstone cutthroat trout from Yellowstone Lake continued both within and outside the species’ native range. Overall, from the early 1880s to the mid-1950s, more than 300 million fish were stocked throughout Yellowstone. Today, about 40 lakes have fish; the others were either not stocked or have reverted to their original fishless condition.
Influences of Some Nonnative Species
Aquatic nuisance species disrupt ecological processes because they are not indigenous to the ecosystem. Invasive organisms can cause species extinction, with the highest extinction rates occurring in freshwater environments. Aquatic nonnative species that are having a significant detrimental effect on the park’s aquatic ecology include lake trout in Yellowstone Lake; brook, brown, and rainbow trout in the park’s streams and rivers; and the parasite that causes whirling disease. Though there are other aquatic nonnative species in the park, their effects are less dramatic.
The Yellowstone Resources and Issues Handbook, updated annually, is the book our rangers use to answer many basic park questions.
Bartholomew, J.L. and P.W. Reno. 2002. The history and dissemination of whirling disease. In J.L. Bartholomew and J. C. Wilson, ed., Whirling disease: Reviews and current topics. Vol. Symposium 29. Bethesda, MD: American Fisheries Society.
Franke, M.A. 1997. A grand experiment: The tide turns in the 1950s: Part II. Yellowstone Science 5(1).
Franke, M.A. 1996. A grand experiment: 100 years of fisheries management in Yellowstone: Part I. Yellowstone Science 4(4).
Kerans, B.L. and A.V. Zale. 2002. The ecology of Myxobolus cerebralis. In J.L. Bartholomew and J.C. Wilson, ed., Whirling disease: Reviews and current topics, 145–166. Vol. Symposium 29. Bethesda, MD: American Fisheries Society.
Koel, T.M., D.L. Mahony, K.L. Kinnan, C. Rasmussen, C.J. Hudson, S. Murcia, and B.L. Kerans. 2007. Whirling disease and native cutthroat trout of the Yellowstone Lake ecosystem. Yellowstone Science 15(2).
Koel, T. et al. 2014. Yellowstone Fisheries and Aquatic Sciences Report 2012–2013. National Park Service: Yellowstone National Park.
Lilly, B. and P. Schullery. 2000. Bud Lilly's Guide to Fly Fishing the New West. Portland, OR: Frank Amato Publications.
MacConnell, E. et al. 1997. Susceptibility of grayling, rainbow, and cutthroat trout to whirling disease by natural exposure to Myxobolus cerebralis. Whirling Disease Symposium, Logan, UT.
Murcia, S., B.L. Kerans, E. MacConnell, and T.M. Koel. 2006. Myxobolus cerebralis infection patterns in Yellowstone cutthroat trout after natural exposure. Diseases of Aquatic Organisms 71(3):191–199.
National Park Service. 2011. Native Fish Conservation Plan /Environmental Assessment for Yellowstone National Park. Yellowstone Center for Resources.
Parks, R. 1998. Fishing Yellowstone National Park. Helena, MT: Falcon.
Schullery, P. 2008. Vaguely disquieting scenes: Fishing bridge and the evolution of American sport fishing. Yellowstone Science 16(3): 24–33.
Varley, J.D. and P. Schullery. 1998. Yellowstone fishes: Ecology, history, and angling in the park. Mechanicsburg, PA: Stackpole Books.
Last updated: May 30, 2019