How to unlock: Talk with Blake on the Abernathy Farm (M1,7).
You will receive the quest from Blake Abernathy who can be found on his farm. Your objective is to find the locket that belonged to the daughter of the farmer murdered by the raiders.
You must go northeast to the USAF Satellite Station Olivia. Defeat few thugs and walk inside. Watch out for the traps. You must get through few rooms filled with bandits. Eliminate the waves of enemies. The locket is hidden in a red chest in one of the last rooms. Take it and don't forget to search the whole complex.
Now you must only return to Blake. You will receive some bottlecaps from him and the farm will become your settlement in which you can build and recruit new members.
Quest rewards: Experience points, bottlecaps, possibility to take all items from the farm.