Mule deer - Arches National Park, UT. Mule deer are named for their large mule-like ears and are common in the park. Adult deer can weigh 150-200 pounds, reaching a height of 4 feet and a length of 6 feet. Bucks are larger than females, and have an antler spread of up to 4 feet.Photo: Russ Finleywildlife, mammal Film Size 35mm