Thunderhead Underground Falls
If you are looking for something truly unique and truly awe-inspiring during your trip you should certainly make time to stop at Thunderhead Underground Falls, the ‘roaring spectacle’ sitting 600 feet within a mountain. The fall itself sitting at 30 feet tall, the water flowing out the wall and then back along the cave passageway, through all the quartz and stalactites along the way.
The history of this spot can be traced back 130 years when miners excavating a tunnel of 600 feet within the mountain ‘discovered’ the falls. Local legend has it that the miners blasted a hole right below the Rapid Creek riverbed, causing the sudden rapid flow of water seen today, though this is not a proven fact. What is a proven fact, however, is that the falls were left forgotten until 1949 when Vera Eklunds found and followed the water path after spotting it on a train ride. It was soon turned into a tourist attraction, one that folks on the way to Rapid City and the Black Hills always love to visit!
Note** This attraction is only open during daylight hours in May, June, July, August, September, and October.