The Solitario is a large geologic formation in Big Bend Ranch State Park in West Texas. When viewed from above, it suggests an impact crater; though it is actually the eroded remains of a laccolith. The approximate center of the Solitario is located 56.8 km (35.3 mi) east southeast of Presidio, Texas, just west of the line dividing Brewster County, Texas and Presidio County, Texas. The formation covers a circular area of approximately 135 km2 (52 sq mi). The geology of the Solitario is complex. In 1988 the state of Texas purchased the property containing the Solitario and created Big Bend Ranch State Park. The formation lies in the Chihuahuan Desert ecoregion of the United States.