"western Oregon is essentially California."

Coastal California, yes. I know that this escapes the gaze of most folks outside of California, but we have the same east/west and urban/rural divide that Oregon and Washington have.

Drive along I-5 from California to Oregon and you will see a lot of signs that mysteriously say, simply, JEFFERSON. What is that all about? you may wonder. It's a movement that is somewhat similar to what they are discussing in this article: a desire for several southern Oregon and northern California counties to create their own new state:

https://en.wikipedia.org/wiki/Jefferson_(proposed_Pacific_state)