Free: Contests & Raffles.
Plan on being able to hunt all 9 days if needed.
If it were me I'd contact the guys that own the property on lewis peak (the peak itself)and access from there normally if your not a total *censored* they will usually let the guys with the watershed tags access there if not you can camp at the end of biscuit ridge
If you've never done it before I would get on the Walla Walla County taxsifter and start finding landowners who border the shed closest to where you want to hunt, I honestly think a majority of them would let you camp if all you wanted was to access the shed and not hunt their land