1. Montana Cooperative Fishery Research Unit, Department of Ecology, Montana State University, 301 Lewis Hall, Bozeman, Montana 59717, USA
2. U.S. Geological Survey, Montana Cooperative Fishery Research Unit, Department of Ecology, Montana State University, 301 Lewis Hall, Bozeman, Montana 59717, USA
3. U.S. Fish and Wildlife Service, Bozeman Fish Technology Center, 4050 Bridger Canyon Road, Bozeman, Montana 59715, USA
4. Montana Fish, Wildlife and Parks, 1400 South 19th Avenue, Bozeman, Montana 59718, USA
5. Fish and Wildlife Ecology and Management Program, Department of Ecology, Montana State University, Post Office Box 173460, Bozeman, Montana 59717, USA