Sierra Madre Vault

The Sierra Madre vault is a location in the Sierra Madre Casino. It is the last location the player will go before the end of Dead Money. He or she must proceed through the bowels of the Casino, passing areas filled with the Cloud, speakers and holograms to end up in the main Vault room.

Layout
What's labeled as the 'vault' area on your Pip-Boy is actually three areas of what most people would consider "the basement" and then the vault itself. Forcefields in the doorways from this enclosure prevent you from being able to just walk over to the vault. Elijah is the only one who can deactivate the forcefields, and he's only going to do it for himself when he comes down to confront you.

The first two areas of the basement are spent shooting, out-running, and deactivating the various speakers along the catwalks that wind through these two parts of the basement. From the enclosure where you come into the 2nd catwalk room, there are stairs to your right and another set of stairs on your left that lead up/down to the floor of this room. Also note the bare-metal support beam over these stairs that bridges the gap between the catwalk and the door leading to the next section.

The third area of the basement is a bit more complicated, due to several security holograms patrolling the enclosures and catwalks in this area. There is one speaker here, to the right upon entering. From the doorway where you enter this room, on the opposite side of the room, there's a long enclosure that runs most of the length of the opposite wall, plus a very small enclosure in the right corner. The doorway to exit this room is between these 2 enclosures, and one of the holograms is standing guard next to it. There's also a medium-sized enclosure on the far-right wall that has a terminal that controls the hologram next to the exit. Also, on your right as you come into the room, there's stairs going down to a lower catwalk level. The Cloud is covering this lower catwalk level, and you have to jump from the bottom of the stairs to the next section of this catwalk.

The holograms in this room can be turned off with a high enough Repair skill (or a good aim) and some climbing. As the emitters for them are located on top on the small metal box rooms they patrol. This makes a clear run for later if you try to lock Elijah inside the vault. To do so you have to avoid him seeing you and then make a quick dash back the way you came for the elevator before he notices he's trapped and activates your collar.

As you turn the corner after exiting the hologram room, your collar will start beeping as you run toward a speaker on the wall ahead of you. This terminal lets you deactivate the weapon turrets and the blue force fields around the Vault, allowing you to get into the Vault. But deactivating the security also triggers the entire sequence of events leading up to the confrontation with Elijah, including locking the elevator out until Elijah actually comes down to the Vault. So, switching off the security is basically a point of no return. You'll see 2 folders regarding the Vault's security. Back out of the folder and you'll now see a 3rd option to disable the Vault's security protocols.

At the end of this corridor, you'll come out into another enclosure. You're now on the opposite side of the Vault room you first saw when you came out of the elevator. On the walkway in front of the Vault is a holotape. This is a pretty hostile letter from Sinclair to Vera Keyes, condemning her for lying to him, apparently written after he discovered what Dean and Vera were planning, but hastily ripped out of the computer that's in the Vault. The Cloud is hovering just below this walkway. On the pipes that run below and along the front of the walkway, you'll see a skeleton: this is Frederick Sinclair, who apparently met his end at the hands of his own creation. Next to him is a duffle bag with a copy of 'Nikola Tesla and You' inside it. If you jump down to the pipe to obtain the book from the duffle bag, it is tricky but possible to jump back up to the walkway.

On top of the enclosure in the middle of the room (facing the Vault) is a larger enclosure with some miscellaneous computer equipment inside it, and a pair of weapon turrets on top of it (there's 2 more around the room, for a total of 4 turrets). The weapon turrets will be de-activated at this point, since you switched off the security from the terminal in the corridor just before you got in here.

On the outside of the door to the Vault is a single terminal that releases the lock to the Vault. Just inside the door there is a generator and 2 more terminals (one on either side of the door) to control the weapon turrets outside the Vault and the Vault's security systems. Inside the Vault, which is only a single-room, there is a table with some Sierra Madre Chips, 24 stacks of pre-War money and 37 Gold Bars, that comes to 390,239 Caps value but at 1,295 pounds (as each bar weighs 35 pounds) it makes it almost impossible without console commands to leave with more than a few bars. Lastly there is a first aid box with a wide range of chems and aid, and a locker full of Sierra Madre armor and 1000+ .357 magnum rounds, or a laser pistol and 1000+ energy cell(speculated that this is decided between energy weapons vs guns skill as to what will appear), or both if you have the skills the same level or maxed at 100, plus a suitcase on top of the locker with more pre-War money and chips.

At the far end of the room is another terminal on a round Overseer's-type desk. It has 2 messages for Vera from Sinclair, but the first one says "file not found", it was the holotape out in front of the Vault that Sinclair ripped out of this computer which was to tell Vera that she is now trapped and has become the "heart" of the Sierra Madre but he obviously had changed his mind as to her fate. The second message is also from Sinclair who apparently had a change of heart (that was too late) in spite of knowing what Vera and Dean were planning. There is also one for Dean on the computer (labeled Sinclair's Personal Accounts). There is an actual message here that you can read, but reading this message causes you to be trapped within the vault and ending the game, thus continuing from your last game save.

When you exit out of the terminal, a panel on the wall above opens up, revealing a communication screen and you immediately begin a dialog with Elijah.

Appearances
Sierra Madre vault appears in the Fallout: New Vegas add-on, Dead Money.