ften after supper, Mr. Ford would head through this tunnel, for a bit of tinkering in his private Experimental Laboratory. Within the Tunnel, electrical, fresh drinking water, central vacuum, hair dryer, refrigeration, phone, pool water, and cistern water filtration conduits run 300 feet underground, connecting the "Residence" with support systems located in the Powerhouse. 

Shortly  after the Lindbergh baby kidnapping in 1932, in response to ever- increasing fear for the Ford family's safety, an old jail gate was installed in the tunnel, just prior to entrance of the residence.