 The machine shop is a two-story structure, long and wide, made of coursed mine rock with a hipped gable roof covered in corrugated sheet metal.A clerestory window admits light to the interior, which is floored in concrete.The original machine shop was designed around 1882 by Erasmus D. Leavitt Jr., a consulting engineer with Calumet & Hecla; it was used to repair large equipment, including mining skips and trams.