Herd of elk running across the dunes, Great Sand Dunes National Park and Preserve, 2015.

Rocky Mountain elk (Cervus canadensis nelsoni), along with other large animals like pronghorn, sandhill cranes and golden eagles, are often seen by visitors in the fall to spring. Elk prefer open grasslands and avoid forests when possible. In the San Luis Valley, they may seasonally migrate up to montane meadows or alpine tundra. However, some herds stay on the valley floor all year round. Unfortunately, encroachment onto grasslands by humans as well as maturing closed-canopy forests have affeected their distribution. There is an estimated 4,000 elk in the eastern part of the San Luis Valley.