The $175 million hotel is set on the south side of the casino outside Rohnert Park and will feature a 10,000-square-foot spa, a fitness center, a 20,000-square-foot event space and an expansive outdoor pool. “We took the first one about a month ago,” said Joe Hasson, Graton Resort & Casino’s vice president and general manager. 15, and casino officials said they’ve already taken hundreds of reservations. The 200-room hotel under construction at Graton Resort & Casino since September will officially open to the public on Nov.