Which National Park Service park contains more than 2,000 natural sandstone arches, the world’s highest density?

Arches National Park contains more than 2,000 natural sandstone arches, the world’s highest density.

The park lies north of Moab, Utah, on the Colorado Plateau. Its arches formed mainly in Entrada Sandstone after erosion widened fractures and weakened layers of rock. Water, ice, wind, and gravity gradually shaped the openings.

Delicate Arch is the park’s best-known formation and has become a symbol of Utah. Other notable features include Landscape Arch, Double Arch, Balanced Rock, and the narrow sandstone passages of Fiery Furnace.

Arches began as a national monument in 1929 and became a national park in 1971. Natural arches are not permanent: Wall Arch collapsed in 2008, illustrating that erosion continues even in protected landscapes.