DENVER – A 20-year government effort to restore the population of an endangered native trout in Colorado has made little progress because biologists have been stocking some of the waterways with the wrong fish, a new study says.

Biologists called the finding a setback and a potential black eye but said there is still hope for restoring the greenback cutthroat trout because at least four pure populations of the fish have been identified.

The three-year study was led by University of Colorado researchers and published online in Molecular Ecology on Aug. 28. […]