U.S. Forest Service Temporarily Closed Upper Cornelius Creek for Fish Removal

RED FEATHER LAKES, Colo. – Colorado Parks and Wildlife recently conducted the second phase of a project to reintroduce Greenback Cutthroat Trout to George and Cornelius Creeks, located on the Roosevelt National Forest in Larimer County. The removal of non-native species is being done in preparation for the reintroduction of greenback cutthroat trout to the creeks. The greenback cutthroat trout is Colorado’s State Fish and is listed as “Threatened” under the Endangered Species Act.

George Creek and its tributary stream Cornelius Creek were the sites of a previous greenback cutthroat trout reintroduction in the early 1980s. The stream has since been reinvaded by non-native brook trout and brown trout, as well the parasite that causes whirling disease, a deadly disease for trout. For the re-establishment of greenbacks to succeed, all other fish currently in the stream population must be removed. This removal is done using rotenone, an EPA-approved organic compound used for decades to control fish populations. The stream must then be left fishless for several years for whirling disease to vacate the system.

As part of the reintroduction project, the U.S. Forest Service temporarily closed (Aug. 23-26) the area around upper Cornelius Creek for public health and safety during the non-native fish removal activities. The closure included forest system roads 188 from its junction with 219 southwest to the National Forest boundary. Additionally, access was restricted into the Cornelius Creek watershed through CPW’s Upper Cherokee State Wildlife Area.

This second phase of the George Creek reintroduction only involves the eradication of non-native trout from four miles of Cornelius Creek, but 14 miles of stream will be re-stocked with greenbacks when all three project phases are completed, drastically improving the conservation status of the species.