How The Earth Was Made: The Rockies
As shown on the History Channel. From Alaska to New Mexico, the Rockies are one of the great mountain belts of the world--caused by tectonic forces of the Pacific Plate pushing against the North American continent. They have formed as the earth's continental crust has been shortened under pressure, by around one inch a year. What's more, they are still rising and they are still young in geologic terms: when the dinosaurs roamed the Earth they had not even started to form.