Migration Routes of Mule Deer in Clarks Fork Herd in Wyoming

Mule deer within the Clarks Fork herd make a number of significant westward long-distance migrations. These migrations originate north of Cody, near Heart Mountain and along the foothills of Absaroka Front. There, deer winter in the lower elevation sagebrush valleys, and in spring an estimated 2,700 deer head west into the high elevation mountain valleys of the Absaroka Range and Yellowstone National Park. This herd summers along the Lamar River, Cache Creek, and the Clarks Fork of the Yellowstone. The longest migration is 68 miles and ends just north of Yellowstone Lake along the Yellowstone River in the Hayden Valley. These challenging journeys, an average of 38 miles long, cross rugged terrain and steep mountain passes such as those at the head of Sunlight Creek at 11,400 feet in elevation. Deer must also navigate human-created obstacles such as fences and the Beartooth Highway (US Highway 212). These data provide the location of migration routes for mule deer (Odocoileus hemionus) in the Clarks Fork population in Wyoming. They were developed from Brownian bridge movement models using 79 migration sequences collected from a sample size of 29 animals comprising GPS locations collected every 2-8 hours.