I would think the eastern 2/3rds of both Oregon and Washington would want to join as well.
Pass a right to work law and build a port somewhere near where the present Oregon and California borders meet and you would have a lot of international shipping move there as well. They could immediately lower costs by hiring non-union workers who don't average $120K annually to type shipping documents and $85K annually to drive fork lifts. The difference would go a long way toward paying off the building and maintenance of this infrastructure. Then add an extraction tax on any water shipped south.
I should have included the caption:
|Darker areas show the State of Jefferson, as proposed by Gilbert Gable in 1941. Modern versions of the movement usually include the lighter areas as well.|