Migration Routes of Pronghorn in Uinta-Cedar Herd in Wyoming

This study was tailored toward the Wyoming section of Interstate 80 (I-80), and so migrations and habitat use are more representative of pronghorn (Antilocapra americana) along I-80 rather than the entire populations. The Uinta-Cedar populations had the highest prevalence of seasonal migrations. This area primarily occupies checkerboard ownership between Bureau of Land Management and private ownership. Oil and gas drilling as well as sheep ranching are relatively common. Seasonal ranges are characterized by arid to semiarid habitats with sagebrush (Artemisia spp.) as the predominant vegetation type. Seasonal ranges can also include interspersed grasslands, and low-lying areas can also include black greasewood (Sarcobatus vermiculatus) and Gardner’s saltbush (Artiplex gardneri). In the Uinta-Cedar population, south of I-80, pronghorn most often had winter ranges either along I-80 or to the south closer to Manila, Utah (fig. 40). The migration route pronghorn followed to access the southern winter range tended to parallel I80 in the eastern direction, then paralleled State Highway 530 and the Flaming Gorge Reservoir in the southern direction. The spring migrations were direct north movements and either paralleled Highway 530 or were between Cedar Mountain and Black Mountain. Summer ranges were often located along I-80, either to the east of Lyman or near the Blacks Fork, north of the confluence with the Green River. On average, pronghorn migrated 45.5 mi (73.3 km), with a minimum distance of 26.0 mi (41.8 km), and a maximum distance of 72.0 mi (115.9 km). These data provide the location of migration routes for pronghorn in the Uinta-Cedar population in Wyoming. They were developed from 16 migration sequences collected from a sample size of 9 animals comprising GPS locations collected every 2 hours.