Located in northwestern Minnesota, Old Mill State Park opened in 1937 on what was once the Larson family farm beginning in 1882. The Larson's operated wind and water windmills and eventually installed a steam powered mill. The state rebuilt the steam engine in 1958 and is run every year during special programs. The park also features a 25 acre historic district of 25 WPA built rustic structures and a bridge. This district is on the National Register of Historic Places (the steam mill is listed on its own).