 It was one of the most culturally and linguistically diverse areas in pre-Columbian North America.After contact with , most of the Native Americans died out from European diseases.After the Portolá expedition of 1769–70, Spanish missionaries began setting up 21 California Missions on or near the coast of Alta (Upper) California, beginning with the Mission San Diego de Alcala near the location of the modern day city of San Diego, California.