Colorado Parks and Wildlife staff members Jim White, left, John Livingston, center, and Sarah Gump make their way down the Animas River on Friday, as CPW aquatic biologists take a population estimate of fish species using a mark and recapture method. CPW is looking for species composition and survival of fish the agency has stocked, said Livingston, area spokesman. Healthy numbers of the blue head sucker and rainbow trout were recorded. The count also indicated better fish recovery from the 416 Fire than in 2019, one year after the fire. Fish are not harmed in the process. (Jerry McBride/Durango Herald)

One of the larger brown trout that was shocked, weighed and measured by Colorado Parks and Wildlife staff members on Friday. CPW aquatic biologists were taking a population estimate of fish species on the river through downtown Durango. The brown trout was released back into the river. (Jerry McBride/Durango Herald)

Colorado Parks and Wildlife staff members Jim White, in the water, John Livingston, center, and Sarah Gump make their way down the Animas River on Friday, as CPW aquatic biologists take a population estimate of fish species in the river through downtown Durango. Fish were collected by electric shocking and counted. CPW is looking for species composition and survival of fish the agency has stocked, said Livingston, area spokesman. Healthy numbers of the blue head sucker and rainbow trout were recorded. The count also indicated better fish recovery from the 416 Fire than in 2019, one year after the fire. Fish are not harmed in the process. (Jerry McBride/Durango Herald)