There are shootable numbers between Ritzville, Odessa and Harrington. It's all private land so get permission if you can. There are some ranches south of crab creek that offer a pay to shoot situation but I have never found them. I've heard about them from some of the locals around Othello. There are also some places just north Of I-90 west of Moses lake. If you do a search on their habitat you will find a map of the areas they inhabit in Washington. You can then drive around that area asking for permission to shoot them. There is a canyon south of Wenatchee that has a lot of them. I thinks it's Moses Coulee. Getting permission is the hard part.
Good luck