Found this info on another website.
http://huntwashingtonstate.com/ hope it helps

GMU 342-UMTANUM
Oak Creek Wildlife area holds big numbers of deer and elk. You will find them in early season along the dozen or so rolling canyons just south of Wenas. Not a lot of road access here, but the boot hunter can get up into some solitary pockets which will hold the animals. Once, the snow starts falling watch for the animals to be moving along Sanford Pasture along HWY 410.
There is also access into the Umtanum Creek Recreation Area. This is located actually in the Wenas wildlife area. North end of the unit around FR1701 (canteen flats) and FR1702 (rock cr) are productive, but, crowded. Sheep Company Road Access: From I-82 take exit 26 and go West approximately 1/4 mile to Hwy 823/Harrison Rd. Turn left (West) onto Harrison Rd., go two miles until it intersects with North Wenas Rd. Take a right onto North Wenas Rd. and go 4.8 miles to Sheep Company Rd. Turn right (North) onto Sheep Company Rd, go approximately 1 mile to access onto the wildlife area. Once you cross the cattle guard you are on the wildlife area.