Cave of the Mounds is a popular tourist spot just southwest of Madison.Just beneath the surface are beautiful formations that can help to tell a story of Wisconsin's past and future climate. Cave of the Mounds is 2 million years old, but it went undiscovered until an explosion at a limestone quarry uncovered it."We were a cave without a legend for the longest time. And now that we've been here over 80 years, we have so many stories to tell," said Tate Phillip, the communications director at Cave of the Mounds.Philip explained that the cave has been incredibly well preserved since it was uncovered, and the structures inside are still changing. “Our cave is always growing with the drips of water coming in, depositing calcite, and other minerals down here,” Philip said.And the formations have been growing for millions of years, which means the stalagmites growing in the cave can teach us about the past. "We would collect those and slice them open. And once you look inside, they have these rings similar to tree rings, because as you're getting water into the cave, you're precipitating these layers of calcite on top of one another," said Dr. Cameron Batchelor, who received her Ph.D. at UW-Madison.Batchelor's Ph.D. research inside Cave of the Mounds was groundbreaking. The study used one stalagmite, only about two inches long. Since caves grow slowly, the sample took 40,000 years to grow and gave research 40,000 years' worth of data. From the single stalagmite, Batchelor's team was able to look back on Wisconsin’s climate during the last glacial period, which was more than 12,000 years ago. "We were the first record to actually pick up on abrupt, warm events that were happening around the same time as this Greenland warm events were happening. And so it's the first evidence that our climate is indeed linked and that we are sensitive to these rapid, abrupt, warm changes in the high latitudes," Batchelor said. The cave’s structures provide a glimpse into southern Wisconsin's historic climate, but they could also hold a key to a better understanding of how our climate is changing right now."If Greenland is warming and the high Arctic is warming, then we can expect that our atmosphere, our precipitation patterns are going to change," Batchelor said.Bachelor explained that there are signs that the Artic is warming right now. That means the question isn't if Wisconsin’s climate will change, but how. And the findings from Batchelor's study will help to drive new research that can answer that question. The research being done at Cave of the Mounds isn't over because Cave of the Mounds still has more stories to tell."To learn more about caves, how things have changed when humans weren't present, and how the earth has changed to kind of help us in what's happening for the future," Phillip said.