In Hot Springs, an active dig preserves the bones of dozens of mammoths trapped in a prehistoric spring. In a state that turned a mountain into a monument, few places carry more weight than this one.

More than sixty mammoths have been identified in the ancient sinkhole so far.

What sets it apart

The animals became trapped in a warm spring roughly 140,000 years ago. That detail is easy to overlook, but it helps explain the pull this place has on locals and visitors alike.

Excavation continues inside a climate-controlled building raised over the bonebed.

Why it matters

In the end, the story here is really a story about the northern plains and the people drawn to them. However you come to it, this is a place that stays with you long after the drive home.