Split Rock Resorts’ indoor water park, H20ooohh!! opened in October 2008 and has a 54,000-square-foot indoor park with a wave pool, indoor Flow Rider, Family Raft Ride, several water slides, an activity pool and a water play structure. The park is open to walk-ins (unlike some in the area which require a stay at the resort), and you can grab snacks at the bar when the kids work up an appetite.