This is actually an abandoned air force radar station, dating back to the 1960's. The folks at radomes.org have a lot of details about it here:
http://radomes.org...22Brookfield%2BAFS,%2BOH%22&key=BrookfieldAFSOH&doc=BrookfieldAFSOH
Long story short: the site was home to the 662nd AC&W squadron, which operated air-defense radar stations during the Cold War. The latest operational date I could find was 1968, but they operated GATR there until probably the 1980s, based on documents I found there.
http://radomes.org...22Brookfield%2BAFS,%2BOH%22&key=BrookfieldAFSOH&doc=BrookfieldAFSOH
Long story short: the site was home to the 662nd AC&W squadron, which operated air-defense radar stations during the Cold War. The latest operational date I could find was 1968, but they operated GATR there until probably the 1980s, based on documents I found there.