Western North America is the western edge of theNorth American continent that borders thePacific Ocean. It consists ofAlaska at the farthest north, down through the westernCanadian province ofBritish Columbia, the western U.S. states ofWashington,Oregon, andCalifornia, and thenMexico farthest south. The region consists of one long continuousmountain range formed over the last 350 million years through the movement oftectonic plates, as the largePacific plate submerged under theNorth American plate through the process calledsubduction.[1]