Sierra Madre del Sur
The Sierra Madre del Sur is a mountain range in southern Mexico , which extends over 1000 km from southern Michoacán , east through Guerrero to the isthmus of Tehuantepec in east Oaxaca .
It unites with the trans-Mexican volcanic belt of central Mexico in the north of Oaxaca, but remains separated from it further west by the valley of the Río Balsas and the tributaries of the Río Tepalcatepec .
The highest point at 3703 m is in the center of Guerrero.
Although they are separated from the Sierra Madre del Sur by the deep canyon of the lower Río Balsa, the mountains south of Michoacán around Coalcomán are usually included.
The mountain range is largely made up of Madrean Pine-Oak Woodlands and is known for its great biodiversity and large number of endemic species .