An Aermotor windmill and tilting tower were discovered and dismantled in 1995 in Prairie du Sac, Wisconsin, purchased by the Mars Historical Society in 2006, restored by society members, and erected on the train station grounds in the summer of 2011. The 40-foot tower was built by the Aermotor Co. of Chicago, Illinois, sometime between the late 1800s and 1905, and its top half swivels in the middle so the windmill can be tilted near the ground for maintenance, with a large weight at the bottom of the tilting section serving as a counterweight. The windmill itself was built by the Aermotor Co. in Chicago sometime between 1915 and 1933 as a Model 602 with an 8-foot diameter wheel designed to pump water. This tower and windmill combination is very rare because the tower was originally supplied with an open-gear windmill that had to be lowered weekly for lubrication, but sometime after 1915 it was replaced with an oil bath mill that reduced maintenance to once a year or more. Because tilting the tower would cause the oil to run out, maintenance must be done with an external hoist or crane, unlike the fixed towers on which oil bath mills usually sit. How such maintenance was done before extended boom cranes is unknown, and this may be one of the only combinations of its type ever accomplished. Very few tilting towers survive today, mostly in museums. The mill is mounted offset to its supporting pole so that in very strong winds the wheel can swivel sideways to the wind and protect the internal mechanism from over-revving, then a heavy spring pulls it back as the wind dies down, while the tail keeps the wheel facing into the wind. Patented by Aermotor in the late 1800s, this design helped make the company the dominant windmill supplier in the world. Hundreds of thousands of Aermotor windmills were built and shipped worldwide, many still operate, and as of 2011 the company still existed in San Angelo, Texas, building about 2000 windmills a year and supplying parts for this Model 602 mill.