Thanks to one of readers, ANOTHER previously unknown and not advertised military campground has been discovered. I refer to these military campgrounds as "secret" military campgrounds. Usually, these are small campgrounds found at National Guard bases.
Camp Ashland National Guard Base in Nebraska has a small , 12 site campground. When not being used by guard members, the campground is open to all eligible military personnel. Although there's mininal amenities, the price is (currently) free.
You can find maps and other known information here. If you visit this campground, please let me know if you find any missing or incorrect information. I also need some photographs.