Louisa Wetherill was told of Rainbow Bridge by a Navajo trader, and she convinced her husband to lead the Cummings-Douglass expedition.
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?
Neighboring Indian tribes believe Rainbow Bridge is a sacred religious site. They travel to Rainbow Bridge to pray and make offerings near and under its lofty span. Special prayers are said before passing beneath the Bridge: neglect to say appropriate prayers might bring misfortune or hardship.