Wolverine-
The Tributaries are probaly your best bet...
The Walla Walla, lower Yakima, Touchet, and possibly Umatilla (Oregon- need a lisc.) Rivers all offer an opportunity to get a line wet.
Also, below the dams on the Snake (Ice Harbor) might be another spot to try- be ready to plunk!
Not sure of the regs ...so ya better check up on em before you throw in.
Good luck and enjoy the Sun!

Mac