I loved the petroglyphs at Valley of Fire State Park and hearing about the Mouse's Tank.
The Liberace Museum was well worth the visit. My son loved the cars and the costumes are incredible. Costumes are rotated for preservation purposes so you may not see the same ones we did. After the tour, be sure to ask directions to Liberace's former home. It's only a few blocks away, and while you can't go iin, you can at least see it from the outside.