To understand the formation of the Rockies, we need to understand
Plate Tectonics. According to this theory, the surface of the Earth is made up of a series of plates, each of which move relative to the others. At one time, all the continents were joined into one large land mass known as Pangea. Slowly, this supercontinent began to break apart and the continents began to drift. Inevitably, the plates eventually began to collide with one another -- with mountainous consequences.
Indeed. Sedimentary rock formed over millions of years high above the tectonic plates, and when what is now known as British Columbia (cannabis heaven) collided and became part of North America, it pushed this sedimentary rock eastward, where it rose out of the ground (and ocean), and layered upon itself at an angle.
At close glance, the mountains are actually sheets of this rock piled upon itself, and it is all angled. It's pretty cool.
For my southern neighbours (there's that damned 'u' again) in Montana, you house the southern end of the Rockies. Your part of the mountains contain much more granite than ours do, as your tectonic plates actually shed some weight in the process. Up north, our mountains are primarily made of shale and limestone (sediment).
Despite all of this, the plant and animal life is pretty well the same along the entire stretch, differing between the east and west side of the Rockies.
There. Did something today. Spread some of my knowledge to help further
@Commander Strax's educational session
-spek