Fish known to be native to the area that became Rocky Mountain National Park were cutthroat trout, suckers and sculpins. These fish were only historically found in the lower reaches of what would become the park due to waterfalls and cascades which served as fish migration barriers. Cold water temperatures make it probable that many of the waters in the park were originally fishless.
There are seven native fish and four exotic fish that now inhabit the aquatic systems of the park. One native fish, the greenback cutthroat trout is federally listed as endangered. A long-range recovery program for Greenback and Colorado River cutthroat trout has been ongoing since 1975 in cooperation with the U.S. Fish and Wildlife Service.
Go to IRMA Portal NPSpecies site to see a working list of the fish species in Rocky Mountain National Park.
History of Fisheries in Rocky Mountain National Park
Fish stocking in the area began in 1886 and continued with the State of Colorado stocking tens of thousands of fish on an annual basis. In the early 1900's, fish hatcheries were constructed in the gateway communities of Estes Park and Grand Lake. These hatcheries produced hundreds of thousands of fish annually. The majority of these fish were non-native trout species which were stocked into historically fishless waters. This extensive stocking of fish for recreational fishing altered aquatic landscapes and nearly extirpated native species.
The first formal guidance on management of fish resources provided by the National Park Service came in 1936 and encouraged the stocking of native fish, discouraged stocking non-native fish and prohibited stocking of fishless waters. In 1968, fisheries management shifted from an emphasis on recreational fishing to that of the recovery of native fish species. Stocking ceased, but not before over 20 million fish had been stocked into Rocky's waters between 1886 and 1968. By this time almost all the park's waters were inhabited by non-native fish species. Under the new management policy, 17 native trout reclamation projects have been conducted thus far.
(Text provided by Chris Kennedy / U.S. Fish and Wildlife Service)
Go to the park's Fishing page for more information about recreational fishing in the park.