whirling disease

In the '90s, whirling disease hit trout populations hard in Montana, at one point leading to a 95% decline in rainbow trout in the Madison River. It sparked concern among biologists, anger in tourist towns and even played a role in a murder mystery novel. It also inspired this week's question: What's happening with whirling disease and other threats to trout?

Montana faces twin threats this summer: On land, crews are battling some of the biggest and most destructive fires in the country. In the water, officials…