The Isthmus territory of the Huave people encompasses the shoreline of the big tidal Lagunas Superior, Inferior, and the Mar Muerto. About 15,000 Huave-speaking people live there, notably around the villages of San Mateo del Mar, Santa María del Mar, San Dionisio del Mar, and San Francisco del Mar.

The Huave language, not clearly identified with any other language family, is generally classified in a family of its own. This is supported by studies by colonial historians, indicating that the Huave may have migrated from the Nicaraguan Pacific coast and settled around present-day Jalapa del Marqués on the Isthmus. The more-numerous Zapotecs, invading around 1375, forced them to the edges of the lagoons, where they now live.

Generally ignored and neglected by everyone, the Huaves hold on to many pre-conquest beliefs. In the absence of Catholic priests, native curanderos practice thinly veiled pagan rites in some village churches.

Although they subsist mainly on corn, beans, chilies, vegetables, and occasional meat, Huave-speaking people earn cash from their fish catches. Men sell fresh fish to wholesalers who arrive afternoons at the shoreline villages, while women sell the surplus as dried fish at Salina Cruz, Tehuántepec, and Juchitán markets.