The western range of Mexico's sierra madre mountains found in Mexico?
the answer is ( occidental )
There are many mountains in Mexico, such as the Popocatepetl, Iztaccihuatl, Cofre de Perote or Pico de Orizaba. If you mean "mountain ranges", there are three in Mexico. One is the Sierra Madre Oriental on eastern Mexico; the other is the Sierra Madre Occidental on western Mexico and the Sierra Madre del Sur on southern Mexico.