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'Beaverhead' is an impact structure in central Idaho in the United States.
Estimated at 50 to 90 miles in diameter (75 to 150 km), it is one of the eight largest impact craters on Earth, and possibly the largest in the US.
Its age is estimated to be about 850 to 900 million years (early Neoproterozoic).
The structure is named after the area in southwest Montana where evidence of an impact was first discovered in 1990.
Other than the original shatter cones found on the perimeter, there is little visible evidence of the structure.

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References

References

★ 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.

★ Beaverhead (only for the map)