Unexploded military ordnance turns up in parks from time to time, and a recent find in Badlands National Park was handled cautiously. That proved to be the right call.
According to a park report,
On the morning of Thursday, July 23rd, rangers learned of the discovery of unexploded military ordnance near the heavily-visited Fossil Exhibit Activity and Trail area along Norbeck table. The ordnance—a belt of unexploded 20 mm shells—was found by park paleontologists who were conducting surveys in the rugged formations east of the visitor use area.
A military EOD team from Ellsworth AFB was contacted and came to the park. Team members inspected the shells, determined that they were too unstable to move, and exploded them on site.
Caution proved to be the correct decision in this case.
The detonation was heard at the park visitor center more than three miles away. It’s believed that the rounds were dropped by a military aircraft during training exercises in the 1940's.
Could the shells have detonated if they had simply been moved by unsuspecting visitors or employees? It's impossible to say with certainty, but this incident is a good reminder that the only safe rule for unexploded ordnance is simply to leave it alone, and notify the proper authorities.