Colorado Parks and Wildlife will conduct treatment, as part of an initiative to restore native Colorado River cutthroat trout populations in the Hermosa Creek area, Tuesday and Wednesday to eliminate non-native fish in main stem sections of Hermosa Creek and East Hermosa Creek.
Two areas will be treated: Hermosa Creek, below Hotel Draw Creek to below the confluence with East Hermosa Creek, and East Hermosa Creek, from the barrier below the waterfall to below the confluence. Rotenone, an organic chemical used for fish-management projects, will be applied to the water, with a second chemical added at the terminus of the treatment area to neutralize the Rotenone.
The two areas are not expected to support fish populations until next summer. After the 2019 spring runoff, CPW biologists will evaluate streams to ensure non-native trout are eliminated. If none is found, the two areas will be stocked with Colorado River cutthroats. Native cutthroat trout are restored in pristine headwater streams free of whirling disease. Pure native cutthroat trout are not stocked in major rivers because they are unable to compete with established rainbow and brown trout populations.
As part of the restoration project, the U.S. Forest Service also constructed three barriers to prevent non-native fish from migrating upstream and has conducted extensive habitat work along Hermosa Creek.
While the restoration project is underway on Tuesday and Wednesday, anglers can fish above Hotel Draw and above the waterfall on East Hermosa Creek. The Hermosa Creek Trail is closed because of the 416 Fire, which has made the creek below the confluence inaccessible. Fishing is also available in the area at Lime Creek and Cascade Creek.
CPW and San Juan National Forest conducted the restoration project, with assistance from the Five Rivers Chapter of Trout Unlimited. The native trout that were introduced to reclaimed sections are thriving. A 2017 survey showed that more than 400 fish per mile inhabit Hermosa Creek. Cutthroat fishing in mentioned areas is fly-and-lure, catch-and-release only.
For more information, visit cpw.state.co.us/learn/pages/researchcutthroattrout.aspx.