One of the more interesting contrasts we encounter while riding in Mexico is the relatively quick transition from forest to desert. The east side of the Sierra Madre Oriental mountains gets lots of moisture from the Gulf of Mexico and is, accordingly, full of plant life and trees. In fact, ride a few hundred miles south, to the state of San Luis Potosi, and you will be in a jungle. However, ride west over the mountains and in the space of a surprisingly short distance you will find yourself in a desert.
As you make your way through the mountains, you will often bounce back and forth between forest and desert, which really makes the contrast stand out. In this picture Jeff and I had just ridden through a section of desert and were now headed back into the trees. I marveled, as I often do, how fast the terrain changes while riding in these mountains.