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?
John Wetherill was already the Superintendant of Navajo National Monument when he was also given the same task for Rainbow Bridge National Monument. He operated both monuments, provided tours and supplies, and lived at his Kayenta, AZ trading post.