Was there contact between the coastal BC groups and the California groups, and did they think of eachother as more closely related?
You can find a number of assertions that the Haida and Tlingit travelled as far south as California on tribal websites, blogs and even Wikipedia. But I can find no peer reviewed or reputable published data to support it and I have worked at it. The distribution of Athabaskans in North America and how they came to be there is enigmatic. I can find no information that suggests the B.C. Athabaskans were in contact with their California and Southern Oregon counterparts.