Landscape Arch

Landscape Arch stands in the Devils Garden area of Arches National Park in Utah, carved from the park's Entrada Sandstone, a formation laid down in the Early Jurassic roughly 140 million years ago. A 2004 measurement put its span at 290.1 feet with a height of 77.5 feet, making it the longest natural arch in the park and the fifth longest known in the world; it was named in 1933 or 1934 by an expedition led by Frank Beckwith. Arches in the park form as an underlying salt bed pushes up long sandstone walls called fins, which slightly acidic rainwater then dissolves along their weakest points until the rock beneath collapses and leaves a span standing above. Landscape Arch's span has grown thinner through documented rockfalls, including a large slab that fell in 1991 and two more that fell in 1995, after which the park closed the trail that once passed directly beneath it.