San Juan Cutthroat

Artwork by Casey Underwood and Property of 5RTU

Cutthroats are the native trout for the region and until the mid-1800s were the only trout in Colorado. Once widespread throughout the state, their populations have been significantly impacted by human actions such as logging, mining, and water infrastructure, as well as natural stressors such as competition from non-native trout, aquatic invasive species, and habitat fragmentation. They are now found in only about 11% of their original range.

For more than 30 years, aquatic biologists surveyed remote creeks in SW Colorado looking for isolated populations of native cutthroat trout with the belief that remnant populations of unique species might be present. In 1989, likely candidates were identified and transported to the most secure and isolated headwaters that could be found with the hope that the fish might carry traits and adaptations that could be revealed through genetic testing at some point in the future.

Artwork by Garrison Doctor and Property of 5RTU

In 2018, researchers from the University of Colorado used advanced DNA testing to link cutthroat found in the San Juan River Basin to fish samples collected and preserved in 1874 by naturalist Charles E. Aiken, who had donated two trout to the Smithsonian National Museum of Natural History.

Several small populations of these trout have been found in isolated habitats on streams of the San Juan River Basin, within the San Juan National Forest and on private property. Fish were salvaged from those habitats to preserve their unique genetic stocks and are now being bred in CPW’s Durango fish hatchery with the intention of re-establishing self-sustaining populations in additional streams.

The Five Rivers Trout Unlimited Chapter located in Durango, CO, in conjunction with partners at Colorado Trout Unlimited, Colorado Parks and Wildlife and the U.S. Forest Service, has initiated a multi-year project designed to reintroduce the species into streams once habitat restoration is completed. The focus will be on habitat most likely to survive future climate change.

Did You Know …

six distinct lineages of cutthroat appear to have evolved in Colorado, with native ranges that roughly correspond to major drainage basins in the state.