The Gugel farm was sold to the University of Wisconsin in 1947 and operated as an experimental farm until 1975. It is located within Hill Farms University neighborhood, which you can read about here:
http://content.wisconsinhistory.org/cdm4/document.php?CISORO...On page 23 of that article, you can see the white house and outbuildings of the Gugel farmstead in the lower left corner of the photo. The outbuildings have been destroyed but the farmhouse still stands among 1970's era homes at 5321 Manitowoc Parkway, Madison, WI 53705. As of July 2015, the home is for sale.
https://www.redfin.com/WI/Madison/5321-Manitowoc-Pkwy-53705/... http://www.wisconsinhistory.org/Content.aspx?dsNav=N:4294963...