Beautiful Rushmore Cave is located at:

13622 Highway 40
Keystone, SD 57751-6604
Voice: 605-255-4384 or 605-255-4467
Website: www.beautifulrushmorecave.com
E-mail: info@beautifulrushmorecave.com

The Black Hills region is home to some of the most unique caves in the world. They are among the world's most interesting because of their age, evolutionary history, rare formations and complexity.

Sharing the common bonds of their origin, each is unique in its own way. Located in a band of limestone rock, the caves encircle the central granite core of the Black Hills. This limestone was created during the Mississippian Period, approximately 360 to 330 million years ago on the bottom of an ancient sea.

Generally speaking, caves are a young and short-lived geological phenomenon. The very solutional and erosional processes that create them will eventually destroy them. Therefore their age is usually in mere millions and tens of millions of years. The Black Hills region is an exception. Many area caves intersect and contain portions of the 320+ million year old Mississippian cave systems, and there is evidence that the present day cracking planes were partially inherited from older rock structures. Part of the reason that these caves are so old is that the rock (pahasapa limestone) is sandwiched between other layers of sedimentary rock and thus partially protected from the forces of erosion.