Mapimi, a desert in N. Mexico, extending from the great bend of the Rio Grande, in hit. 30°, southward to the vicinity of Parras, in lat. 25° 30', and averaging 2£ degrees in width. It embraces two thirds of the state of Coahuila and parts of Chihuahua and Durango, and consists chiefly of a vast basin called the Bol-son, or pocket, bounded N. by the Sierra del Carmen, E. by a portion of the Sierra Madre, and W. by low ranges of mountains. From the mountains to the northeast the rivers Es-condido, Alamos, and Nadadores take their rise, but in the central basin there is no water except the brackish lagoons called Jaco, Agua Verde, Cayman, and El Muerto. Nomadic Apaches are the only inhabitants, but well preserved mummies have been found in caves near the S. border. There is rarely any vegetation. Meteoric iron and coal abound, and the precious metals are believed to exist. Only the S. portions, called the Canon de San Marcos, and the plains of La Paila and La Ban-durria, have been explored with any care. The Ivickapoo Indians established themselves in 1804 near the N. border of this desert, and remained there till 1873, when they wire removed to their former reservation in the Indian territory. At the W. entrance to the Poison is situated the mining town of Mapimi, with 5,000 inhabitants.

The emperor Maximilian erected a department under this name, with limits differing from those of the desert.