Pecos River, << PAY kuhs or PAY kohs, >> is the largest branch of the Rio Grande. The Pecos starts near Santa Fe, New Mexico, in the southern Sangre de Cristo Mountains. For most of its 800-mile (1,300-kilometer) course, the Pecos flows southeast. It runs beside the western palisade of Llano Estacado, a great plateau in New Mexico and Texas. It flows into the Rio Grande in Texas, near the town of Del Rio. It drains over 33,000 square miles (85,500 square kilometers). Reservoirs built along the river for irrigation include Lakes Avalon, McMillan, Red Bluff, and Sumner.
