Mountain Country from Cajon Pass to Oak Glen Two Centuries of Changing UseThe imposing San Bernardino Mountains overlook the San Bernardino Valley on the south, the Mojave Desert on the north, and the Joshua Tree country to the east. These mountains, because of their proximity to the population centers of Southern California, have a rich heritage. Few mountain ranges anywhere have been as swarmed over, dug into, deforested, and built upon as have the San Bernardinos. Primitive peoples once sought food, clothing, and shelter