The Washita River (/ˈwɑːʃitə/) is a river in the states of Texas and Oklahoma in the United States. The river is 295 miles (475 km) long and terminates at its confluence with the Red River, which is now part of Lake Texoma (33°55′N 96°35′W / 33.917°N 96.583°W) on the Texas–Oklahoma border.