Hill Country State Natural Area is located in Bandera and Medina counties, 45 miles northwest of San Antonio. The 5,369.8-acre site was acquired by gift and purchase in 1976 and was opened to the public in 1984. The bulk of the site was a donation from the Merrick Bar-O Ranch with the stipulation that it "be kept far removed and untouched by modern civilization, where everything is preserved intact, yet put to a useful purpose."