Check out Trout Unlimited volunteers working through the cold to help CPW aquatic biologists with their year-old rainbow trout that will be released into the Arkansas River. The fish are resistant to "whirling disease [which] is thought to be a major factor in the declines of wild rainbow trout populations in certain Colorado waters. It's suspected that the outbreak of the disease may be linked to other environmental factors that aren't yet apparent. The parasite has been confirmed in 13 of Colorado's 15 major river drainages, including the Colorado, South Platte, Gunnison, Arkansas and Rio Grande rivers, as well as in a number of state hatcheries." CPW Fact Sheet on Whirling Disease Video via Denver Post.