<P> The Rocky Mountains took shape during an intense period of plate tectonic activity that resulted in much of the rugged landscape of the western North America . The Laramide orogeny , about 80 -- 55 million years ago , was the last of the three episodes and was responsible for raising the Rocky Mountains . Subsequent erosion by glaciers has created the current form of the mountains . </P>
<P> The Rocky Mountains took shape during an intense period of plate tectonic activity that resulted in much of the rugged landscape of the western North America . The Laramide orogeny , about 80 -- 55 million years ago , was the last of the three episodes and was responsible for raising the Rocky Mountains . Subsequent erosion by glaciers has created the current form of the mountains . </P>
how did the u.s. rocky mountains come to look the way they do today
how did the u.s. rocky mountains come to look the way they do today
erosion by glaciers
erosion by glaciers