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.
As used in this article, the term "west coast of North America" means a contiguous region of that continent bordering the Pacific Ocean: all or parts of the U.S. states of Alaska, Washington, Oregon, and California; all or parts of British Columbia and the Yukon in Canada; all or part of the Mexican states of Baja California, Baja California Sur, Sonora, Sinaloa, Nayarit, Jalisco, Colima, Michoacán, Guerrero, Oaxaca and Chiapas; and the Central American countries of Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica and Panama. The eastern off the west coast, such as the coastal islands of the Californias, are also important.
The west coast of North America likely saw the first sustained arrival of people to the continent. Although there are other theories, most scientists believe that the first significant groups of people came from Asia, through today's Bering Strait area, then through modern Alaska, and from there spread throughout North America and to South America.
Although the cultures on the west coast of today's Canada and United States are not known to have developed substantial urban centers and sophisticated writing or scientific systems, it is likely that, before European contact, the population density was significantly higher than in the rest of the northern part of the continent. For example, it has been estimated that in 1492, one-third of all Native Americans in the United States were living in what is now California.
The Channel Islands of California provide the earliest evidence for human seafaring in the Americas.