Big Bend Ranch State Park is a 311,000-acre (126,000 ha) state park located on the Rio Grande in Brewster and Presidio counties, Texas. It is the largest state park in Texas. The closest major town is Presidio, Texas. The state park's head office is located in Lajitas, Texas at the Barton Warnock Visitor Center. It includes Colorado Canyon.

Farm to Market Road 170 is a 114.6-mile (184.4 km) highway maintained by the Texas Department of Transportation (TxDOT) in Presidio and Brewster counties in Texas. The route, known locally as the River Road, runs along the United States side of the Rio Grande which in Texas forms the international boundary between the U.S. and Mexico. The road runs from Candelaria through the city of Presidio as well as several smaller communities and former settlements to State Highway 118 in Study Butte near Big Bend National Park. The road also passes through the southern portion of Big Bend Ranch State Park.