Sierra Madre

Miner's bridge near the city of Durango, capital of Durango state, north-central Mexico. Situated in the volcanic Sierra Madre Occidental, the state of Durango is abundant in silver, gold, sulphur, tin, mercury, antimony, and copper. One of the world's largest deposits of iron ore lies just north of the city.

Mountain top, Mexico. Mexico's complicated topography is a result of its position at the junction of two converging tectonic plates. Tectonic activity has caused the volcanism of the Sierra Madre Occidental and Neo-Volcanica Cordillera, as well as the folding and lifting of the plateaux and Sierra Madre Oriental. The northern part of the country is relatively dry, with sparse, desert vegetation.

Chief mountain system of Mexico, consisting of three ranges, the Sierra Madre Oriental, the Sierra Madre del Sur, and the Sierra Madre Occidental, enclosing the central plateau of the country; the highest peak is Citlaltepetl at 5,700 m/18,700 ft. The Sierra Madre del Sur (‘of the south’) runs along the southwest Pacific coast.

Sierra Madre

City in southwestern California, in the foothills of the San Gabriel Mountains, immediately east of Pasadena and 21 km/13 mi northeast of central Los Angeles; population (1990) 10,800. A residential community in an area noted for its orange groves, it has some light high-tech manufacturing.