Although there are arches and natural bridges found all over the world, these natural phenomena nowhere are found in such profusion as they are in Arches National Park, located in Grand County, Utah, north of the town of Moab. The Colorado River forms the southern boundary of the park, and the LaSal Mountains are visible from most viewpoints inside the park`s boundaries. The park is situated in the middle of the Colorado Plateau, a vast area of deep canyons and prominent mountain ranges that also includes Canyonlands National Park, Colorado National Monument, Natural Bridges National Monument, and Dinosaur National Monument. The Colorado Plateau is covered with layers of Jurassic-era sandstones; the type most prevalent within the Park is called Entrada Sandstone, a type that lends itself to the arch cutting that gives the park its name.

Arches National Park covers more than 73,000 acres, or about 114 square miles. There are more than 500 arches found inside the park's boundaries, and the possibility exists that even more may be discovered. The concentration of arches within the park is the result of the angular topography, much exposed bare rock, and erosion on a major scale. In such an arid area - annual precipitation is about 8.5 inches per year - it is not surprising that the agent of most erosion is wind and frost.

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 AD 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.

The Arches area was inhabited later by two different historic groups of Native Americans, the Ute and the Navajo. Utes lived and hunted throughout the park area, and were responsible for driving out the first white settlers in the area as late as the 1850s. Arches was on the northern fringe of the Navajo lands, and although they passed through the area there is no evidence that Navajos lived within the park area.

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