Most people who have fished the Madison River in Montana have heard of Whirling Disease, the cause of a massive decline in Madison River's rainbow trout population in the 1990's. If you are interested in learning more, check out this article on Orvis News by Phil Monahan. It highlights Dave Kumlien, a Bozeman-based fly fishing guru, and his involvement in the Whirling Disease Foundation, which helped spread awareness, fundraise, and re