McKinney Falls State Park

  McKinney Falls State Park is a state park in Austin, Texas, United States at the confluence of Onion Creek and Williamson Creek. It is administered by the Texas Parks and Wildlife Department. The park opened on April 15, 1976 and is named after Thomas F. McKinney, a businessman, race horse breeder and rancher, who owned and lived on the land in the mid-to-late 19th century. The park is part of the El Camino Real de los Tejas National Historic Trail. During the Cretaceous Period through the early Paleogene Period, much of Texas was covered by a shallow subtropical sea. The calcium carbonate sediments deposited during this period lithified into the limestone rock underneath the park's soil and was exposed by erosion around the creek bed. Aquatic reptiles swam in the sea as evidenced by a complete skeleton of a mosasaur found in the rocks of Onion Creek not far from the park. In the park, shells of extinct sea animals such as species of Inoceramus and Exogyra are preserved in the li...