Ayres Natural Bridge State Park

Ayres Natural Bridge Park is a county park in Converse County, Wyoming in the United States. It occupies 150 acres between the towns Glenrock and Douglas about 6 kilometers south of Interstate 25 exit 151. The park's name is derived from the rock formation of the same name. Ayres is the surname of the family who donated the land which had been part of their ranch.

Over the course of millions of years, a bend in LaPrele Creek wore away at a wall of solid rock, creating a natural opening. The creek eventually shifted course through the opening, forming a 30-foot high and 50-foot wide arch, today known as Ayres Natural Bridge, from sandstones of the Casper Formation.