region, southwestern Chiapas state, southeastern Mexico, extending northwest from the border of Guatemala. Much of the fertile area is occupied by the Sierra Madre de Chiapas (also called the Sierra de Soconusco), which parallels the coast and culminates in the Tacaná Volcano, 13,484 feet (4,110 metres) above sea level; the coastal plain is narrow. The province of Chiapas was administered by the captaincy general of Guatemala during the colonial era and was united with Mexico after independence from Spain was won. The Maya who lived in the Soconusco, however, refused to declare their loyalties to either Mexico or Guatemala and maintained their independence until 1842.