I can't remember the quest line exactly but at one point you have to go to Hoover Dam instead! The person is well in the basement and can be a bit hard if you don't know where to look for her/arrow to follow.
If you still can't find it maybe you should try and wait until 2-3pm and see if he is in his offices then? Sometimes the time 'frame' can be so off in the game.
If you still can't find it maybe you should try and wait until 2-3pm and see if he is in his offices then? Sometimes the time 'frame' can be so off in the game.