The city is named for the Tillamook people, a Native American tribe speaking a Salishan language who lived in this area until the early 19th century. Anthropologist Franz Boas identifies the Tillamook Native Americans as the southernmost branch of the Coast Salish peoples of the Pacific Northwest. This group was separated geographically from the northern branch by tribes of Chinookan peoples who occupied territory between them. The name "Tillamook", he says, is of Chinook origin, and refers to the people of a locality known as "Elim" or "Kelim." They spoke Tillamook, a combination of two dialects. Tillamook culture differed from that of the northern Coast Salish, Boas says, and might have been influenced by tribal cultures to the south, in what is now northern California.