A friend and I visited this site a couple years ago. It remains secure. That is, it is padlocked and the water table seems to have invaded somewhat, but other than that it is an interesting site...somewhat out of my range, but we were on a roadtrip.
The Atlas E was a liquid fueled ICBM that needed to be fueled before it left the ground. It was stored horizontally and empty. It was only raised vertically prior to launch. The launch door was about 40 X 100 feet, and about two feet thick. It rolled aside and the missile was raised, fueled, and fired. A thing of beauty.
Feel free to leave a comment or question. I will answer as well as I can.