Letter Re: Robert A. Heinlein Didn’t Just Talk and Write About Preparedness

Dear Jim,
I’m not sure if you have covered Robert A. Heinlein’s shelter that featured in his novel, “Farnham’s Freehold.” This site describes the house that Heinlein built in Colorado Springs before NORAD moved into the area

And here’s an archived link of the shelter underneath, which included both air bottles and ventilation, escape routes, and antenna mounts.- Michael Z. Williamson