The location consists of several buildings on the surface and a complex of underground rooms. It is occupied by a large group of bandits you need to take care of.
Watch out for an enemy who will run to the train car and try to enter the armor. Try to kill him before he does it. If you prevent it, you'll be able to use it.
You can get rid of the enemies on the surface with a sniper rifle. Watch out for the turrets.
Federal Ration Stockpile basement is impressively large. You will encounter many enemies and find numerous valuable items here. This location connects two places on the surface - Federal Ration Stockpile on one side, and Lonely Chapel from the Sanctuary on the other.
1. Stealth-Boy that makes you invisible for a period of time. It is located on the higher level of the tunnels. To reach the room, you need to get across the footbridge.
2. A room locked with terminals on both sides (Master level) Inside you can find large quantities of food, some bottlecaps, ammo and one mini-nuke.
3. A room with a Novice lock. You'll find a fusion core inside.
4. A wall safe (Expert level). Inside you can find ammo.
5. You have to jump into the room. Inside you'll find some food and U.S. Covert Operations Manual that increases your stealth level.