It can be found in his hide-out in the southern Hidden Valley bunker, next to a broken radio.
"This location looks like it might make a good safehouse. Warm, dry, and some sort of crazy natural phenomenon at night that should keep the predators away. I'd love to start getting set up, but there are a few nearby points of interest I need to gather intel on first. Not sure how long that'll take."
Entry 2 to 4 can be read after the start of Still in the Dark, where the Courier is asked to drive off Dobson from the south bunker.
"Finally got started getting this place in order. Put out enough supplies to last a while, swept up some. Gonna hit the hay and continue tomorrow."
"Found a nice little spot to scout the prison from. Place has been pretty active recently. Those thrice-damned powder gangers have been spreading out, so I need to be careful to avoid them. It doesn't help that I have to get back early each night or risk getting blinded by the sand."
"This godforsaken radio still doesn't work. Damn it, I'm a scout, not an electrician. Must've got some sand in it or something. At least that crazy storm is good for keeping people away. This place wouldn't make much of a safehouse if other people were traipsing in and out all the time. I'd hate to have to find another location again, but if the supplies, and especially the equipment weren't safe, I guess I'd have to."