The Story of Sprockets

The small town of Keystone, South Dakota,  just down the hill from Mount Rushmore National Memorial in the Black Hills, has a rich mining history, which inspired the design of the Sprockets Fun Foundry building.

Formerly known as the Holy Terror building, the structure was built in 2005 by Robert Hanson and a partner to look like an old mine. Rusty metal, old barn wood and artifacts from Homestake Gold Mine, were sought far and wide to complete the building’s unconventional character. Robert and his wife, Heidi Hofer, added various attractions over the years and operated the venue until 2021.

The building, with its unique exterior and multi-level design, drew the interest of the current owners.  Their vision combines the aesthetic of the building with updated renovations and today’s advanced technology to bring a new multi-sensory experience to the area.

Introducing state-of-the-art attractions to South Dakota is nothing new for the Sprockets’ founders, who as owners of Rush Mountain Adventure Park, Home of Rushmore Cave, recently received the Peter Norbeck Excellence in Tourism Innovation Award from the South Dakota Department of Tourism.  From guided cave tours to a mountain coaster and a zipline ride, they are no strangers to creative thinking and delivering memory making fun for guests.  The addition of Sprockets Fun Foundry continues their goal of bringing high quality, family-friendly activities to the Black Hills.