This Wyoming state park contains a unique natural feature, the Popo Agie River disappears ghost-like through a canyon wall only to re-emerge a quarter-mile downstream as a placid basin teeming with trout. The exact route of the passage through the limestone rock is not known, but testing and exploration continue. A visit to the park's visitor center provides scenic overlooks of the area.

No fishing is allowed at The Rise, where the river bubbles out of the mountain side. The canyon is home to variety of wildlife, including yellow-bellied marmot, porcupine, black bears, elk, mule deer, moose, and golden eagles.