The park lies along the northwestern edge of the Colorado Plateau. It comprises great buttressed cliffs of coloured Navajo sandstone extending for 100 miles (160 km) along the western edge of the Waterpocket Fold. The fold was formed when thick layers of sedimentary rocks were flexed, or bent, during the uplift of the plateau some 65 million years ago. The erosion by wind and water of the uppermost layers of the folded rock formed the cliffs, pinnacles, towers, arches, and domes for which the park is noted. The Fremont River and its tributaries, Sulphur and Pleasant creeks, cross the formations through deep canyons that rise to more than 1,000 feet (300 metres).

Much of the park has sparse desertlike vegetation, including piñon pines and junipers on the talus slopes, but cottonwoods, willows, and a profusion of other vegetation grow along the streams. Wildlife ranges from small lizards to mule deer and bighorn sheep; birdlife includes golden eagles, hawks, and numerous songbirds. Some of the smooth cliff walls of the park are covered with pre-Columbian petroglyphs, created by people who lived in the area from about AD 700 to about 1300. The remnants of the now-deserted Mormon community of Fruita, including a schoolhouse and orchards, also are within the park.