The Rio Puerco is a tributary of the Rio Grande in the U.S. state of New Mexico. From its source on the west side of the Nacimiento Mountains, it flows about , generally south to join the Rio Grande about south of Belen and about south of Albuquerque. Its drainage basin is about large, of which probably about are noncontributing. The Rio Puerco is ephemeral, with no streamflow for part of the year. Its discharge averages . The maximum officially recorded discharge was , in 1941. The greatest flood since about 1880 occurred on September 23, 1929, with an estimated discharge of . Another flood, on August 12, 1929, reached an estimated . Name Although Rio Puerco means River of Pigs in Spanish, this usage in the southwestern United States is better translated as Muddy River. Course The Rio Puerco arises in the San Pedro Peaks area of the Nacimiento Mountains, in the San Pedro Parks Wilderness area of the Santa Fe National Forest. It flows generally south and southwest, leaving the mountains and national forest near the village of Cuba. From there the river flows generally south. It flows along the west side of the Jemez Indian Reservation. Arroyo Chico joins from the west, between Mesa San Luis and Mesa Chivato. The Rio Puerco continues south, passing west of Mesa Prieta, then through the Laguna Indian Reservation and the Tohajiilee Indian Reservation. Near the Bernalillo–Valencia county line and the Isleta Indian Reservation the river is joined by the Rio San Jose, which flows from the west near Grants through the Laguna Reservation. The Rio Puerco continues south through the Albuquerque Basin to the Rio Grande about south of Belen and about south of Albuquerque. History The Rio Puerco Valley is notable for once hosting a significant numbers of ancestral Puebloan (descendants of the Basketmaker II) people, many of them fleeing the collapse of the Chacoan civilization. In the 1860s the US Army moved strongly against Native American raiding west of the Rio Grande. By the late 1860s the Navajo were no longer a chronic threat and the Apache had been pushed back into the high mountains. The Hispanos living along the Rio Grande were able to move west with some security for the first time. Hispano colonists from Albuquerque and Bernalillo quickly occupied every irrigable patch of land along the Rio Puerco. By the middle of the 20th century