1. Montana Cooperative Fishery Research Unit, Department of Ecology Montana State University Post Office Box 173460 Bozeman Montana 59717 USA
2. U.S. Geological Survey Northern Rocky Mountain Science Center, 2327 University Way Suite 2 Bozeman Montana 59715 USA
3. Department of Ecology Montana State University Post Office Box 173460 Bozeman Montana 59717 USA
4. Montana Fish, Wildlife and Parks 2300 Lake Elmo Drive Billings Montana 59105 USA
5. U.S. Geological Survey Montana Cooperative Fishery Research Unit, Montana State University Post Office Box 173460 Bozeman Montana 59717 USA