Patsy is a narrow-gauge steam engine that did quarry work at the South Dakota Cement Plant in Rapid City for 38 years and before that hauled logs and timber at the Homestake Mine in Lead, S.D. The 18-foot engine was brought to Huron from the cement plant on a lowboy truck in a nine-hour trip from Rapid City. The National Guard dug a hole next to the cement slab and lowered the lowboy into it with a 20-ton crane, and when Patsy was level with the rails mounted on the foundation, an Army wrecker pulled her into place. Patsy was donated by the S.D. Cement Plant. Also at the museum is a compressed air locomotive built in 1913 that worked in the Homestake Gold Mine in Lead, S.D., until 1982, where it pulled ore cars inside the mine using 1500 PSI compressed air and weighs 14,500 pounds. It was donated by the Homestake Mining Company.