The Pedernales River is a tributary of the Colorado River, approximately 106 miles (171 km) long, in central Texas in the United States. It drains an area of the Edwards Plateau, flowing west to east across the Texas Hill Country west of Austin. The river rises from springs in southeastern Kimble County, approximately 25 miles (40 km) southeast of Junction. It flows generally east into Gillespie County, past Fredericksburg, and into Blanco County, passing north of Johnson City. It joins the Colorado from the southwest in Lake Travis, approximately 10 miles (16 km) west of Austin.