Keep going northwest towards a tall billboard sign. Continue east, and you will come to a small shack. Talk to your companions to use melee attacks only, any energy or explosive weapon. You can snipe them pretty good from up on the crater top. Head into the Museum to hear the Boomer's story which will add to your rep, then keep talking to the kid for more rep as long as you pick positive answers.
Skill book detour: Head North from Nipton along the railroad tracks. Kill them for food and experience. You will go over some small hills and see a metal trailer ahead. Not much but basic loot. If he turns hostile, reload and try again.
There are raiders in the nearby mountains along the road so head up there and take them out instead of getting sniped on from the road. Once you kill them all, the Legendary Cazador will spawn. Talk to him, and you'll have a new conversation option to get info from. Also a few harvestable plants. Wipe the gangers out and free Beagle. Kill both of them and take their star caps. .
There are two gun turrets in the room, and the overseer himself is a top tier revenant level ghoul. Ranger Station Alpha: Make a brief stop at Ranger Station Alpha to talk to the Comm Officer and pickpocket Ranger Lineholm's Report. You can't complete both Eyesight to the Blind or Tend to Your Business in the same playthrough. Before we continue we will hit a few spots in the northwest since we are up here. If you do kill Motor-Runner and loot his helmet, you will never be able to drop it as it is a bugged quest item. Its hollow so check it for some loot.
Save your healing Stims for emergencies. When finished, clear and loot the building. Gonna be hard foes, so get your stuff together, Deathclaw prep 101. Right when you enter, there are some dead skeletons and a gun. In the back of the complex you will find a science lab staffed by 2 techs that you have to talk to.
Reporting him will cause him to disappear from the supply room for good. Makes you miss the huge explorable areas of Fallout 3. Talk to him for some basic info, then take out a pistol and shoot the memorial. You do not have to climb up Black Mountain to locate the brotherhood corpse nearby. They are a little tougher than your basic foes you have encountered so far, and much faster. Ringo will come up and give you some caps as a reward. Do not attack anyone who isn't hostile.
Finish selling, gathering and storing your items. Just kill Gibson or steal her key and open it. Take a break, rest up, sell, restock, etc. Either kill him in his room, sleep with him and kill him in his sleep, or sleep with him and let him go. If you haven't talked to Alice lately, you can progress You Can Depend on Me while you're there. Enter the shack, there is much loot to sort through.
And here you are with a couple fatman shells and no fatman to use them with. Keeps the fight to only 1 at a time. Talk to him and you can continue your progress towards his personal quest. Convince her to stay It doesn't matter either way because her choice perks don't work in the game. If you have the Perk you can convince him to tell you where they went. Further south, you'll spot the Reststop which has the most ferocious enemies encountered yet - Radscorpions.