"The Utah prairie dog, extinct in more than 90 percent of its former range, is an endangered species protected by law. It now lives in a small area of southern Utah, between the ranges of Gunnison's prairie dog and the white-tailed prairie dog. Like the other species, it is social, living in colonies, and diurnal, spending its days feeding on grasses and herbs. In a captive colony that was excavated in winter, each prairie dog was found hibernating alone in a fairly deep chamber, 100-200 cm beneath the surface. The animals had plugged the entrance to their hibernating chambers with earth."

Links:
Mammal Species of the World
Click here for The American Society of Mammalogists species account