Oasis Waterpark, a non-profit started by the Better Billings Foundation and Harvest Church, gives locals a place to cool their heels when the summer sun strikes. There toddlers and younger kids scamper in their own specially designed aquatic playground, complete with mini slides, a shade canopy, and water cannons. Older siblings, meanwhile, go for the gusto, taking on tiny tsunamis in the wave pool or giggling as they rush headlong into the darkness of a totally enclosed water-slide tunnel. Kids looking to splash a bit more purposefully can enlist the center's swimming lessons, which teach kids to respect the water and recognize when it's teeming with krakens.