Mule deer can be found throughout the Upper Rio Grande’s diverse and rich landscapes. Named for their large mule-like ears, mule deer migrate seasonally across vast distances between Colorado and New Mexico. Spending summers in the mountains and winters at lower elevations, some mule deer herds have been known to migrate more than 90 miles.
The mule deer migration paths are increasingly under threat from the expansion of roads and highways. About 4,000 mule deer are killed in vehicle collisions in Colorado every year. Fences, railroads and energy extraction also disrupt their habitat and migration trails, which is why it is so critical to protect these corridors.