1. Ruminant Diseases and Immunology Research Unit, USDA/Agricultural Research Service/National Animal Disease Center, 1920 Dayton Ave., Ames, Iowa 50010, USA
2. US Fish and Wildlife Service, Wildlife Health Office, 10 E Babcock, Bozeman, Montana 59715, USA
3. Parks Canada Agency, Western College of Veterinary Medicine, Department of Veterinary Pathology, 52 Campus Dr., Saskatoon, Saskatchewan S7N 5B4, Canada
4. Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Dr., Saskatoon, Saskatchewan S7N 5B4, Canada
5. The Nature Conservancy, PO Box 458, Pawhuska, Oklahoma 74056, USA
6. Yellowstone Center for Resources, PO Box 168, Yellowstone National Park, Wyoming 82190, USA
7. North Dakota State University, Dept. 4000, PO Box 6050, Fargo, North Dakota 58108, USA
8. Wildlife Livestock Disease Investigations Team, USDA:APHIS:Veterinary Services, 4101 LaPorte Ave., Fort Collins, Colorado 80521, USA