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. Read more Which Washington casinos will operate sportsbooks? J. Approval is pending for seven more tribes and expected with the next few days. Department of Interior has granted final approval for sports betting to nine Washington tribes. Read more Washington State Sports Betting Update Septem. Plans include a 70,250-square-foot expansion and a complete renovation. This week Tulalip Resort Casino announced a major two-year project to expand and renovate its property. News Headlines Tulalip Resort Casino's New Renovation, Expansion Project Novem.