With an official state dinosaur, the triceratops, and a state fossil, Wyoming has one of the richest fossil records in the United States. Take the kids to watch paleontologists unearth and examine delicate dinosaur bones.
Start at the Wyoming Dinosaur Center where you can see 20 full-size skeletons and learn from 200 interpretive exhibits. In addition, the center operates several active dig sites.
While you are in the area, make sure to visit Glenrock Paleontological Museum too. More information about both attractions is here.