Though its "discovery" by the outside world was only a hundred years ago, American Indians have known about Rainbow Bridge for centuries. It is also quite likely that prospectors, ranchers, and others happened across the bridge in their wanderings.
The story of the official recorded discovery of Rainbow Bridge is an interesting one. Click on the link above to read about this modern day exploration party.
Did You Know?
Rainbow Bridge spans 275 feet across Bridge Creek in an almost perfect parobolic arch. The top of the arch is 42 feet thick and 33 feet wide.