The museum sits on the riverbank just off Main Street and tells the story of John Wesley Powell's 1869 and 1871 expeditions down the Green and Colorado rivers. The exhibits include replicas of Powell's wooden boats, photographs from later expeditions, and material on the geology of the canyons.
It is more substantial than it looks from outside. There is a short film, a gallery dedicated to river runners from Nathaniel Galloway to modern guides, and exhibits on the geology of the Colorado Plateau. If you are about to launch into Labyrinth or Stillwater Canyon, half an hour here will change the way you read the cliffs.