Once a Garrahan Mining Company mineshaft, now the caves are filled with makeshift buildings alongside contraptions such as automated turrets and a machine-powered shotgun. Such constructs were built by Lou in an attempt to end his life, as he could not bring himself to pull the trigger himself.
It can be found directly under the butterfly on the world map. The mine is accessible by a cave entrance leading to a long narrow tunnel. This abruptly stops at a large metal door locked by a terminal. There is a short tunnel to the right that leads to a dead-end, though the path is cleared during the quest Cheating Death. During the quest, a deep, intricate series of caves and tunnels are revealed, consisting of radscorpions and mole miners.
- Lou's log: Cave-in - Note, in the room where Lou is found.
- Lou's log: Chamber - Note, on a desk near the crusher room.
- Lou's log: Engine room - Note, on a desk near the shotgun contraption.
- Lou's log: New plan - Note, on a desk near the shotgun contraption.
- Lou's log: Turret repair - Note, on top of a machine in a side room while walking down the tracks past the engine room.
- Potential Vault-Tec bobblehead - On the shelves in the control room near the turret trap and fog crawler.
- About two dozen radscorpion eggs can be found in the deepest part of the mine.
- A respawning super sledge can be found on the back of a fallen dump truck just past the section with the radscorpions and frogs.
Carleton Mine is internally referred to as "Carnegie Mine" in the location editor ID.