The Rocky Mountain system stretching from Canada to New Mexico is a string of mountains running along the western United States. What factors would most likely cause this arrangement of mountains?

The Rocky Mountains are a mountain range that has been formed because of the convergent boundary between the North American and the Pacific plates.

The heavier, denser, and lower Pacific plate is subducting bellow the lighter, less dense, higher North American plate. The subduction has caused the land to lift up in the nearby area of the boundary, thus slowly forming the Rocky Mountains over the coarse of millions of years.

Because of this, the location of the Rocky Mountains is as it is, long, linear, close to the western coast, which is a perfect sign that the plate boundary is in close proximity and is stretching in the similar manner as the mountain range itself.