The Salish language family is found on the Northwest Coast and in the Columbia Plateau. Salish is generally felt to have great antiquity in the Northwest Coast. Salish-speakers were the earliest settlers in the Fraser River area of British Columbia. Linguists estimate that this language family may be 6,000 years old, although some feel it may be as young as 3,000 years old.
The Athabaskan (also spelled Athapaskan and Athabascan) language family is found in the western American Indian culture areas. Linguists feel that the Athabaskan language family is one branch of a larger genetic grouping called Athabaskan-Eyak. Eyak is a single language which was spoken on the south coast of Alaska and which is nearly extinct. Proto-Athabaskan and Proto-Eyak became differentiated from each other by 1500 BCE. Michael Krauss and Victor Golla, in their entry on the Northern Athapaskan languages in the Handbook of North American Indians, report:
“Whenever it occurred, the linguistic split between Proto-Athapaskan and Proto-Eyak was apparently followed by a total cessation of communication between the two groups, for there is no evidence of subsequent linguistic interinfluence.”
In North America, linguists generally recognize 58 language families and isolates. Understanding language families is one of the keys to understanding the historical relationships between the Indian groups. The Algonquian language family is a large American Indian language which is found in the Eastern Woodlands, the Plains, and California.
Linguists studying and comparing languages throughout the world have noted that some languages are similar to each other in terms of vocabulary, sound patterns, and grammatical structure. Using these comparisons, they group languages into language families. According to linguists Laurence C. Thompson and M. Dale Kinkade, in their chapter on languages in the Handbook of North American Indians:
“Language families are groups of languages that can be shown to be genetically related, using techniques developed by comparative linguistics.”