Sierra Madre map

States in the region

Some part of the Sierra Madre reaches into about twenty of Mexico's 32 states. The ranges are the frame of the country: the Occidental and the Oriental enclose the Mesa Central, the high plateau that carries Zacatecas, San Luis Potosí and Querétaro at 1,800–2,200 m, and the Trans-Mexican Volcanic Belt seals its southern end at about 19° N. South of that line the Sierra Madre del Sur takes over. Elevations above are rounded; sources differ by a few tens of metres.

Geography

The three ranges are made of different rock and behave differently. The Sierra Madre Occidental is volcanic: sheets of ignimbrite erupted between about 34 and 27 million years ago form the largest continuous silicic volcanic field on Earth, roughly 1,250 km long and up to 150 km wide, with a flat summit plateau near 2,500 m. Rivers running to the Pacific have sawn through it, producing the Barrancas del Cobre — six canyons in Chihuahua, the deepest at Urique about 1,879 m — and the gorges the old Durango–Mazatlán road crosses at the Espinazo del Diablo.

The Sierra Madre Oriental is folded and faulted Cretaceous limestone raised in the Laramide orogeny, so it is karst country: caves, sinkholes and springs. The Sótano de las Golondrinas in San Luis Potosí is a 376 m free-fall shaft, and the Huasteca Potosina below it is fed by resurgent rivers. The range rises straight out of the Gulf plain behind Monterrey at Cumbres de Monterrey and narrows to the Sierra Gorda biosphere reserve in Querétaro, which spans desert scrub and cloud forest within 30 km.

The Sierra Madre del Sur is the oldest, built on crystalline and metamorphic basement, and runs about 1,000 km from Michoacán through Guerrero to the Isthmus of Tehuantepec, where the whole cordillera drops to a pass of roughly 250 m — the lowest crossing of the mountain chain in Mexico. Cutting east–west across all of this, the Trans-Mexican Volcanic Belt is the only active part, driven by subduction of the Cocos plate, and carries every Mexican summit above 4,300 m. It is mapped separately on the volcanoes map.

Main cities and sights

Few large cities sit in the mountains themselves; most stand at their foot or in a basin inside them. On the Occidental side, Chihuahua and Durango are the gateways, and Creel and Divisadero are the villages on the Copper Canyon rim. On the Oriental side, Monterrey, Saltillo and Pachuca line the range, with Xalapa on its wet eastern slope at 1,400 m. In the south, Taxco clings to a hillside in the Sierra Madre del Sur, Oaxaca City occupies the valley between the southern and Oaxacan ranges, and San Cristóbal de las Casas sits at 2,200 m in the Chiapas highlands.

The mountains supplied the silver that built colonial Mexico: Zacatecas, Guanajuato, Taxco and Real de Catorce were all cut into Sierra Madre rock. They also hold the country's remaining conifer forest and the Monarch Butterfly Biosphere Reserve on the Michoacán–State of Mexico border, where the butterflies winter in oyamel fir between November and March.

When to go and getting around

October to April is the settled season; the rains come from June to September and the higher passes freeze in midwinter. Four roads cross the Occidental: MX-40D from Durango to Mazatlán over the Baluarte bridge, 403 m above the river; the old MX-40 along the Espinazo del Diablo; MX-16 from Chihuahua to Hermosillo; and MX-24 towards Creel. The Oriental is crossed by MX-57 and MX-85D near Monterrey and by MX-140 from Xalapa to the coast. The one railway across the ranges is the Chihuahua al Pacífico. Airports at Chihuahua (CUU), Durango (DGO), Monterrey (MTY), Oaxaca (OAX) and Tuxtla Gutiérrez (TGZ) are the usual entry points — see the airports map and the road map.

Questions about the Sierra Madre

Where is the Sierra Madre on the map of Mexico?

It is not one range but three, framing the central plateau: the Occidental down the Pacific side from Sonora to Jalisco, the Oriental down the Gulf side from Coahuila to Veracruz, and the Sierra Madre del Sur along the Pacific coast of Michoacán, Guerrero and Oaxaca.

What is the highest peak in the Sierra Madre?

Cerro San Rafael in Coahuila, about 3,700 m, is the high point of the Sierra Madre Oriental and of the three Sierra Madre ranges proper. Mexico's highest summits — Pico de Orizaba at 5,636 m and Popocatépetl at 5,426 m — belong to the Trans-Mexican Volcanic Belt that cuts across them.

How deep is the Copper Canyon?

The deepest of its six gorges, Urique, drops about 1,879 m from rim to river, deeper than the Grand Canyon though not as wide. It lies in the western escarpment of the Sierra Madre Occidental in Chihuahua.

How do you cross the Sierra Madre by train?

The Chihuahua al Pacífico line runs 653 km from Los Mochis to Chihuahua through 86 tunnels and 37 bridges, reaching 2,400 m at Creel. It is the only passenger railway across the Occidental.

When is the best time to visit the Sierra Madre?

October to April. The mountains take most of their rain between June and September, and roads above 2,000 m can hold snow and ice in December and January.