The geology of the Little Snake River Valley spans 1.2 billion years and the features we see today were formed by volcanic action, plate tectonics, erosion, and the ebb and flow of an ancient inland sea. Beginning about 14 million years ago, volcanic activity shook the Valley, forming the peaks that are a familiar sight in the valley. The western edge of the region is rich with fossil deposits which speak to a very different environment, one where the area was inhabited by large mammals, turtles and crocodiles living in a warm and humid climate. Other areas hold fossilized remains of mammals suited to much colder climates, woolly mammoths, camels, bison, and rhinos. Over time, rivers have changed direction; mountains have grown and disappeared; sand dunes have formed and blown away; and certainly, the landscape of today will also change, becoming unrecognizable to those in millennia to come.

In the region, the land rises to the aspen and evergreen forests near the Continental Divide and descends through rolling hills to the salt-sage deserts in the west. The Little Snake River and its tributaries flow through the landscape supplying much needed water to the arid landscape.

The area is rich with wildlife, from big-game like moose and elk to predators like wolves, mountain lions and bears—they can all be found roaming the habitat. Wild horses have made the Red Desert their home for over 100 years and can be seen along with coyotes, rattlesnakes, pronghorn and other desert inhabitants in the western part of the region.