Fossils can reveal how animals lived and died, and what their environment was like. Evidence from one of the park's nimravid fossils offers crime-scene clues. The size and location of the holes in the forehead of this fossil match the knife-like . . . — — Map (db m113121) HM
Horses have adapted in North America over millions of years. As woodlands changed to grasslands, the dog-sized, primitive horses gradually evolved into the lineage that led to the modern-day horse.
Mesohippus was the first three-toed . . . — — Map (db m113091) HM
Thirty-seven million years ago, the ancient crystalline core of the Black Hills had already been exposed by erosion. The long blue profile of those mountains, visible to the west, looked much as it does now.
About that time, streams flowing . . . — — Map (db m4404) HM
The fence in front of you once guarded the Delta-09 Launch Facility which held a Minuteman II intercontinental ballistic missile (ICBM). During the Cold War, anyone or anything that crossed this fence was in serious trouble. Standing orders meant . . . — — Map (db m66953) HM
A jungle grew here. Before that, a shallow sea covered the land. Both are gone now, but both left evidence of their passing.
The sea's signature is ammonites, baculites, and clams, pearly fossils entombed in a fossil mud called the Pierre . . . — — Map (db m4399) HM