Enter NCR and return to Stark

After completing Sergeant Stark's previous quest, you can then ask him for another job. He tasks you with finding a route to NCR along with entering the town to scope it out. He also conviently marks the location on your map.

Travel there and enter. You can explore if you like, but all that's required is that you go in but once. Head back to Vault City and report in to the Sarge.

Reward:
 * 750 Experience points
 * $500
 * 1 Motion Sensor