A rusted chain link gate leads to a dark, misty tunnel; the sound of rushing water surrounds you and echoes off of the dripping walls. The deeper you go, the darker and louder it gets, until the pathway ends at a spectacular 30-ft. waterfall.

Over 130 years ago miners began excavating the 600-ft. long tunnel by hand, following a quartz vein deep into the mountain. Some say that the miners discovered the falls while drilling, but a more colorful tale says that the miners created the falls when they accidentally blasted a hole in the riverbed of Rapid Creek, which flows above the mine. Either way, the constant presence of “surprise” water pouring out of this hole and into that trench made the mine a very difficult work environment.

All along the underground trail are signs pointing to the evidence of drilling work and other interesting facts about the mine itself, which actually never managed to produce any gold. While sadly it turned out to be a bust during the mining boom, Vera Eklund, who purchased the mine in 1943 after spotting water pouring out of the mountain during a train ride, turned it into cash of another color by transforming it into a tourist stop.

Thunderhead is the oldest mine open to the public in the Black Hills area.

Update May 2017: This place is closed down, out of business. Their website is taken down, their phone number is shut down.