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. The event began with a ribbon cutting ceremony following by a first bet celebration. The Emerald Queen Casino in Tacoma Monday opened the largest sports betting venue in the northwest. News Headlines EQC opens largest sportsbook in NW Decem.