From the Loveland Reporter-Herald (Pamela Johnson):
Specialists with the Larimer County Department of Natural Resources and Colorado Parks and Wildlife carried 269 greenback cutthroat trout in backpacks — protected in small plastic bags filled with water — about 2.5 miles to a section of Sand Creek.
There, they placed the fish in the waters and let them swim free — an effort to reintroduce Colorado’s state fish into its native region, the Platte River Basin, and to study whether they will thrive in a unique stream versus non-native brook trout…
The greenbacks made their way onto the endangered species list until, several decades ago, researchers discovered what they thought were a population of this species. Efforts to revive and reintroduce the species led to the fish being downgraded to a threatened species by 1978.
But genetics, which have improved in the past 15 years, proved experts wrong. These fish were not genetically pure greenback cutthroat trout.
A colony of fish in Bear Creek near Colorado Springs, however, was discovered within the past five years and is believed to be the only one left in the state.
Genetic testing by researchers from Colorado Parks and Wildlife, University of Colorado and Colorado State University compared these fish to samples that were collected in the 1860s and preserved at the Smithsonian Institution and Harvard Museum and proved that they were in fact, pure greenback cutthroat trout, Kehmeier explained.
Fish biologists have since been conserving and growing the population of this fish to put them back into their native habitat.
Populations have been introduced into Zimmerman Lake on top of Cameron Pass and Rock Creek in South Park and now into Sand Creek on Larimer County’s Red Mountain Open Space. This fall, more will go into Sand Creek, a small 3-mile stretch that is sustained by spring inputs and rainfall, as well as into Herman Gulch in Clear Creek.
Larimer County had hoped to reintroduce the greenback cutthroat trout into Sand Creek and included that as a goal in its plan for the open space.
And recently, the timing was right because there were extra fish available at the Colorado Parks and Wildlife hatchery near Salida.
So, together, the county and state agencies put fish into the middle third of Sand Creek.
But first, they delivered an electrical shock to the one-mile middle section of the stream and removed all the nonnative brook trout to create a setting in which to study the fish. (The 875 trout they removed were donated to the Rocky Mountain Raptor Center for lunches and dinners.)
The first release, on July 21, involved putting yearlings that were about 5 inches long into one section of the water.
The second release, in September, will put fish into a section of the river in which brook trout still exist as well as the stretch that was recently stocked. These 1,000 fish will be 1-month old.
Then, biologists will study the population for years to come and see how the greenback cutthroat trout survive. And in about three years, time will reveal whether the fish not only survive but also are able to reproduce and thrive.