Read more Visit The Kitchen at the NEW Quil Ceda Creek Casino Febru. This will be the first sports betting authorization in the state. The Washington State Gambling Commission announced a tentative agreement Friday to add sports betting to the Tulalip Tribes' gaming compact. Read more Tulalip Casino will open first sportsbook in Washington Ap. These agreements are amendments to the state-tribe gaming compacts covering 22 casinos. The Washington State Gambling Commission has formally approved sports betting agreements with 15 state tribes. News Headlines Which Washington casinos will operate sportsbooks? J.