Yampa River

Trout need cool water to survive. But record heat this summer has driven water temperatures to levels that can kill fish. Wildlife officials are responding by banning fishing during certain hours on rivers and streams across the U.S. West.

The invasive rusty crayfish was discovered in Lake Granby, and Colorado Parks and Wildlife is concerned because of its proximity to the Colorado River.

The Yampa River is full of snowmelt on its way to the Colorado River, bringing temporary relief for farms, fish and millions of people in the Southwest.

Finding a river in the West that still behaves like a Western river -- one that rises and falls with the annual rush of melting snow -- is tough. Many...