 The mountain range begins at Pico de Orizaba, and extends in a southeasterly direction for 300 km (190 miles) until reaching the Isthmus of Tehuantepec.Peaks in the Sierra Madre de Oaxaca average 2,500 m (8200 ft) in elevation, with some peaks exceeding 3,000 m (9800 ft).The eastern slopes of the range are wetter, intercepting moisture-laden winds from the Gulf of Mexico.