The human history of the west coast of North America is believed to stretch back to the arrival of the earliest people over the Bering Strait, or alternately along a now-submerged coastal plain, through the development of significant pre-Columbian cultures and population densities, to the arrival of the European explorers and colonizers. The west coast of North America today is home to some of the largest and most important companies in the world, as well as being a center of world culture.