Hosta

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 (37 mi) in diameter, it is the ninth largest impact crater on Earth.

With an estimated age of 600 million years (Neoproterozoic), the impact's original shatter cones along the impact structure's perimeter provide some of the structure's only remaining visible evidence.

It is named for the Beaverhead region of southwestern Montana in which it was first discovered.

See also

• Chesapeake Bay impact crater
• List of impact craters in North America

References

Further reading

• Carr, J and Link, PK, 1999, Neoproterozoic conglomerate and breccia in the formation of Leaton Gulch, Grouse Peak, northern Lost River Range, Idaho: Relation to Beaverhead Impact Structure, in Hughes, S.S., and Thackray, G.D., eds., Guidebook to the Geology of Eastern Idaho: Pocatello, Idaho Museum of natural History, p. 21-29.
• Aerial Exploration of the Beaverhead crater