Wall Arch was a natural sandstone arch in the Arches National Park in the U.S. state of Utah. Before its collapse in 2008, it was ranked 12th in size among the park's over 2,000 arches. At its largest, the opening underneath the span was 71 feet (22 m) wide by 33.5 feet (10 m) high. It consisted of Entrada Sandstone, specifically the member known as Slick Rock. Wall Arch was first reported and named in 1948 by Lewis T. McKinney.
Wall Arch collapsed sometime between the night of Monday, August 4, 2008, and the morning of August 5, temporarily blocking Devil's Garden Trail. No one observed the fall. It was the first collapse of a major arch in the park since sections of Landscape Arch fell in 1991. Officials from the National Park Service and Utah Geological Survey visited the site of the collapsed sandstone arch on Thursday, August 7, and noted stress fractures in the remaining formation which may cause additional collapse in the future.