The Quarry Exhibit Hall is a building constructed around a cliff face with about 1,500 dinosaur bones still embedded in it, left exactly where they were buried in a Jurassic river bar. You can put your hand on them. It is probably the single best place in the world to understand how a bone bed actually forms. LOOK ONLY, and the monument also protects Fremont petroglyphs.
Allosaurus, Stegosaurus, Camarasaurus · Late Jurassic, ~150 mya
See it on the map
Other places on the map within a couple of hours.
