The Reddington site is (or was the last time I checked a few years ago) under control of the US Military. I can't recall if it was a survival camp or something else. Access to the site is either by permission or by great personal risk to yourself!
I believe the SR&RL group may have gotten a tour of the place a few years back. I recall seeing a webpage with the trip recounted.
Dallas may be outside of the military zone, but I'm not really sure.