The North Fork Red River is a tributary of the Red River about 271 mi (436 km) long, heading along the eastern Caprock Escarpment of the Llano Estacado about 11.4 mi (18.3 km) southwest of Pampa, Texas. From its source, it flows eastward from western Gray County, Texas, passing through Wheeler County, Texas, into Oklahoma. Just west of the Wheeler county line, it is joined by McClellan Creek, its chief tributary.