13/366: New Mexico Sandstone Mountains
In the Mesozoic era, New Mexico saw a drying trend and dinosaurs roamed much of the state. Many of the rocks of the northern part of the state, including the colorful red, green, gray, brown, and white sandstone and shale, were deposited by rivers that flowed toward the seas. Later in the era, the inland sea once again returned and New Mexico was on the western shore of a great shallow ocean covering most of the central United States. North America broke away from the remaining part of the Pangaea landmass and started its drift to the west, eventually colliding with the Farallon plate.