Tonto Natural Bridge State Park has been in the making for thousands of years. It is believed to be the largest natural travertine bridge in the world. The bridge stands 183 feet high over a 400-foot long tunnel that measures 150 feet at its widest point. The discovery of the small and beautiful valley between Pine and Payson was documented in 1877 by David Gowan, a prospector who stumbled across the bridge as he was chased by Apaches. Gowan hid for two nights and three days in one of several caves that dot the inside of the bridge. On the third day, he left the cave to explore the tunnel and green valley surrounding it. Gowan then claimed squatter's rights.
In 1898 he persuaded his nephew, David Gowan Goodfellow, to bring his family over from Scotland and settle the land permanently. After a week of difficult travel from Flagstaff, the Goodfellows arrived at the edge of the mountain and lowered their possessions down the 500 foot slopes into the valley by ropes and burros.
http://azstateparks.com/Parks/TONA/index.html
