Keystone Bridge in Petrified Forest National Monument, Arizona
Photo by Jay Wilbur
NABSQNO 12S-613821-3866501. Keystone Bridge is an irregular natural arch formed by very recent surface erosion under a petrified log. Because this is an unusual formation process, Keystone Bridge is classified as irregular. It is located in Petrified Forest National Park, Apache County, Arizona. Access is via a very short trail beginning on the Blue Mesa loop road.
Vreeland listed Keystone Bridge as number 11-21 in his catalog and reported a span of 12 feet.