Jerry from the Washington state Legislature web site.

"A charter boat licensed in Oregon may fish without a Washington charter license under the same rules as Washington charter boat operators in ocean waters within the jurisdiction of Washington state from the southern border of the state of Washington to Leadbetter Point, as long as the Oregon vessel does not take on or discharge passengers for any purpose from any Washington port, the Washington shore, or a dock, landing, or other point in Washington. The provisions of this subsection shall be in effect as long as the state of Oregon has reciprocal laws and regulations."

So I would say no a Washington boat can't pick up passengers in Oregon...
but to CYA... I will say I found very little info on Oregon Charter Laws. it seems to still be open entry and the cost looks like around $1000 in fee's to get a License. there are equipment and registration laws that may cost you some money but I bet you would need those things to be a guide in this state also. I did find a Washington salmon charter license for sale for $25,000 so that shows the difference in entry between the 2 states, and explains why you would guide out of Oregon rather then hope to find a Washington License. I had a slow day so I did some internet digging... I am likely to have missed something so I wouldn't use my research to fill out a business plan... but it should give some basic answers to the discussion.