Beaverhead impact structure
Impact crater
The Beaverhead impact structure is the second largest impact structure within the U.S. It lies within the states of Idaho and Montana. Estimated at 60 kilometers in diameter, it is the ninth largest impact crater on Earth. Wikipedia
Coordinates: 44°36′N 113°0′W / 44.600°N 113.000°W
Age: 600 million years
Diameter: 60 kilometres (37 mi)