On the map of North America, Mexico’s state of Oaxaca (wah-HAH-kah) makes up the southern bulge of Mexico, the region where the Mexican coastline thrusts into the Pacific like the belly of a frolicking Pacific dolphin. Oaxaca is a sizable place—with about 36,800 square miles (95,400 sq. km)—and Mexico’s fifth-largest state, as big as a midsize U.S. state, such as Indiana, or an entire small European country, such as Portugal.

As in Mexico as a whole, mountains rule Oaxaca’s landscape. From the U.S. border, Mexico’s grand pair of mother ranges, the Sierra Madre Oriental in the east and Sierra Madre Occidental in the west, sweep southward a thousand miles until they reach Oaxaca, where they bend eastward and practically merge. In Oaxaca, the ranges, respectively called the Sierra Madre de Oaxaca and the Sierra Madre del Sur, form a broad, rumpled, pine-tufted landscape, dotted with 20 peaks in excess of 10,000 feet (3,000 meters). Only the mostly narrow southern coastal plain, one large valley, and a few scattered lesser vales provide enough level cropland to support large towns. From those few valleys, a handful of streams, blocked and forced by the mountains to twist through deep canyons, make their way to the sea.