The west coast of the united state has features formed by

West Coast of the United States formed by rupture and Pangaea breakup that occurred about 200 million years ago.

The occurrence of these events resulted in Northern American Plate moving towards the west. This resulted in the creation of an active margin on the western continent. Further motion created an accumulation of terrains where the west coast occurred.

Increase of terrain accumulation and crustal shortening during orogeny in different eras and also faulting are some other occurrences. In another era, crustal extension occurred followed by magmatism which is the character of the area now.