An unexplored cave deep in the Black Hills of South Dakota could unlock the mysteries of how the climate of the region has changes in thousands of years, according to an Associated Press report.

The National Park Service has begun to excavate the mouth of this cave after a park service worker found it back in 2004 in Wind Cave National Park in the western part of the state. It has since been named Persistence Cave.

The agency didn’t say anything about their find, however, as they didn’t want amateur spelunkers descending upon the site, which appears to be well-preserved.

A team of scientists from East Tennessee State University will begin digging the entrance of the cave today, pulling out bags of sediment and animal bones that they will examine. Bones that are 11,000 years old have already been found, and three species were found that don’t exist in the region today and have since gone extinct.

Jim Mead, the ETSU professor who is leading the team, said that the finding of a pika, a small animal that is related to rabbits, indicates that this region may have had a much different climate, as the pika is typically found in cold and mountainous climates. Now, the pika can be found in Wyoming, but not in the Black Hills, and scientists want to know why the species moved.

The scientists will take these findings and compare them with fossils found in the Mammoth Site in nearby Hot Springs.

The Park Service continues to decline to indicate where the Persistence Cave is located, giving only a vague position: about a third of a mile from the edge of the Wind Cave tunnel system.

Once the sediment is largely removed from the entrance to the cave, a team of researchers will try to explore it, and the cave could be quite large based on the wind that blows from the entrance. It may even connect with the Wind Cave, although the passage is probably blocked.