1. a U.S. Geological Survey, Montana Cooperative Fishery Research Unit , Montana State University , 301 Lewis Hall, Bozeman , Montana , 59717 , USA
2. b Montana Department of Fish , Wildlife and Parks , Post Office Box 938, Lewistown , Montana , 59457 , USA
3. c Montana Department of Fish , Wildlife and Parks , 4600 Giant Springs Road, Great Falls , Montana , 59405 , USA