The surrounding mountains are home to pine-oak forests: the Trans-Mexican Volcanic Belt pine-oak forests to the north and northwest, the Sierra Madre del Sur pine-oak forests to the south, and the Sierra Madre de Oaxaca pine-oak forests to the east. The xeric Tehuacán Valley matorral lies to the northeast. The Balsas dry forests meet the coastal Southern Pacific dry forests where the Balsas breaks through the Sierra Madre del Sur on its way to the Pacific Ocean.