Which mountain range in eastern Mexico runs parallel to the Gulf of Mexico?

The Sierra Madre Oriental is the mountain range in eastern Mexico that runs roughly parallel to the Gulf of Mexico. It stretches for about 1,000 kilometers from the Rio Grande near the Texas border southward to northern Puebla, where it meets Mexico’s Trans-Mexican Volcanic Belt.

The range lies west of Mexico’s Gulf Coastal Plain and east of the Mexican Plateau. Its name means “Eastern Mother Mountain Range,” distinguishing it from the Sierra Madre Occidental, which follows Mexico’s Pacific side. The two ranges help form Mexico’s major mountainous backbone.

The Sierra Madre Oriental contains steep ridges, limestone formations, canyons, and biologically rich pine-oak and cloud forests. Cerro El Potosí, rising to about 3,721 meters in Nuevo León, is commonly identified as its highest summit. Protected landscapes include Cumbres de Monterrey National Park and the El Cielo Biosphere Reserve.

A common mix-up is confusing this range with the Sierra Madre Occidental. “Oriental” means eastern, while “Occidental” means western; the latter runs generally parallel to the Pacific coast rather than the Gulf.