probably outside the area for you to travel, but there is a range complex outside of Benton City, about 15miles west of Richland. That would be around 100 miles from Ellensburg.
I'm sure there are ranges closer, but I don't know them. I do know someone from Selah, and will ask him about ranges closer to Ellensburg when I see him next week.
All else being equal (and it almost never is) bigger bullets tend to work better.