Flora and fauna in the park and its immediate surrounding area are mainly desert adaptations, except in the canyon bottoms and along the Colorado River, where a riverine or riparian environment is found. Where the landscape is not just bare rock, sage and other low shrubs are common; pinyon and juniper trees are also present. Cottonwoods, willows, and tamarisk predominate in the wetter areas within the park. The largest mammals are bighorn sheep, deer, coyotes, and bobcats; other animals include porcupines, jackrabbits, cottontail rabbits, foxes, mice, and squirrels. Lizards and snakes that have adapted to an arid environment are common, as are birds, both local and migratory, including canyon wrens, ravens, eagles, hawks, and waterfowl along the river.

The first known inhabitants of the area that is now Arches National Park were the archaic groups found throughout the West between 3,000 and 8,000 years ago. (A Folsom projectile point, up to 11,000 years old, was found just west of the Park in 1959.) The first to leave a distinct trace were the Anasazi and Fremont peoples, similar cultures that inhabited the Colorado Plateau from about A.D. 200 to about A.D. 1300. Arches National Park is just outside the Fremont cultural area, so the most common vestiges of ancient society are Anasazi. Within the park are many superb examples of rock art left in hidden canyons by prehistoric artists; dwelling sites and associated artifacts are also found.