Menomonee Falls, WI
The Harley‑Davidson Powertrain Operations plant in Menomonee Falls, Wisconsin, spans 849,000 square feet and produces engines and transmissions for touring, softail, and dyna models. It supplies components to final assembly sites in York, Pennsylvania, and Kansas City, Missouri, and also manufactures parts for the Genuine Motor Parts and Accessories line. The standard tour allows visitors to see the assembly line and designated machining areas.
http://www.harley-davidson.com/en_US/Content/Pages/Factory_Tours/factory_tours.html