Much like the mythological unicorn, though, Colorado's rainbow trout pulled a disappearing act about 20 years ago. The black magic known as whirling disease decimated the state's rainbow trout population, reducing it to less than 1 percent of the total trout population in former strongholds such as the Colorado River in the mid-1990s. With fish hatcheries and rivers statewide soon testing positive for the parasite responsible for whirling disease, the outlook grew increasingly grim. But the tumultuous story may have finally found its fairy-tale ending. LINK (via: The Denver Post)