Mesa Arch is a pothole arch on the eastern edge of the Island in the Sky mesa in Canyonlands National Park in northern San Juan County, Utah, United States. Mesa Arch is a spectacular natural stone arch perched at the edge of a cliff with vast views of canyons, Monster Tower, Washer Woman Arch, Airport Tower, and the La Sal Mountains in the distanc…Mesa Arch is a pothole arch on the eastern edge of the Island in the Sky mesa in Canyonlands National Park in northern San Juan County, Utah, United States. Mesa Arch is a spectacular natural stone arch perched at the edge of a cliff with vast views of canyons, Monster Tower, Washer Woman Arch, Airport Tower, and the La Sal Mountains in the distance. Access is via a relatively easy hiking trail, just a half-mile long from the park road.