Ages ago Wyoming was covered by seas. Through a period of millions of years the land gradually rose, leaving the present landscape of plains, mountains and rolling hills. As the land emerged, erosion began and through eons of time formed Ayres Natural Bridge as it exists today. The bridge is 20 feet high and has a 90 foot span at the base. A trout stream flows beneath it in the center of a high red sandstone-walled amphitheater.