Arches National Park - Utah

Established November 12, 1971

76,519 acres

This park contains more than 2,000 natural arches—the greatest concentration in the world. But numbers have no significance beside the grandeur of the landscape—the arches, the giant balanced rocks, spires, pinnacles, and slickrock domes against the enormous sky.

Perched high above the Colorado River, the park is part of southern Utah's extended area of canyon country, carved and shaped by eons of weathering and erosion. Most of the formations at Arches are made of soft red sandstone deposited 150 million years ago in a vast desert. As underlying salt deposits dissolved, the sandstone collapsed and weathered into a maze of vertical rock slabs called "fins." Sections of these slender walls eventually wore through, creating the spectacular rock sculptures you see today.

The land has a timeless, indestructible look that is misleading. Almost a million visitors each year threaten the fragile high desert ecosystem. One concern is a dark crust called crypto-biotic soil composed of algae, fungi, and lichens that grow in sandy areas in the park. Footprints tracked across this living community may remain visible for years. In fact, the aridity helps preserve traces of past activity for centuries.

Well-preserved petroglyphs carved into a low cliff near a pioneer cabin offer evidence that Indians roamed this land. Pictures of riders on horseback date the carvings to historic times, after the Spaniards introduced horses to the Southwest.