Thunderhead Falls is a 30-foot underground waterfall in a former gold-mine tunnel on Rapid Creek in Pennington County, South Dakota, west of Rapid City near Pactola Dam. For decades it was a roadside attraction, but the business has closed and the tunnel is not open to visitors.
The falls
The water pours down inside the mountain, about 600 feet into the old mine tunnel, linked to Rapid Creek above the mine. Roaring water, cool air and damp rock — not mining relics — were the main impression. The drop is about 30 feet, still unconfirmed on the ground; earlier surveys listed 40 feet.
Getting there
There is no public access. The attraction sat on Highway 44 west of Rapid City on privately owned land. By 2017 the business had shut down and its website and phone line were gone; it is now permanently closed.
On site
When it operated, visitors walked a self-guided route through a lit tunnel to the falls, a visit of about half an hour.
History and name
The Ft. Meade Hydraulic Gold Mining Company filed a claim here in 1881, though mining in the area predates the filing. One account credits Vera Eklund with rediscovering the tunnel in 1949 after she noticed water pouring from the mountainside while riding a sightseeing railway; she and her husband Albert bought the land and opened it to the public in 1950. Another dates her discovery to 1943 and records a competing story that the waterfall was created by blasting.
Nearby
Grizzly Bear Falls is about 13.6 miles away, Remington Falls about 15.9 miles and Sylvan Lake Falls about 16.3 miles.
Distances are straight-line.