The mine shaft was most likely used by miners to get deeper into the mountain to mine gold, however, some believe that the mine was used to mine out coal. Mine shafts are not as common in southern California as the northern California area because the Gold Rush was bigger in northern California, which makes the shaft suspicious. Players have found a way to enter the old mining tunnel, to find only that there is a stone wall behind it. The boards are not a solid board door as there is a black interior behind the boards leading people to believe the shaft is has an accessible interior.
In the Next-gen version of GTA V, the shaft can be opened by using any explosive at the door. There are railroads, dead ends and several different mining tools inside the shaft, proving that it was used to mine a lot of things (most likely coal, not gold.)
- On the first track of the road, there is an Easter egg. At a fork in the shaft, there is a dead body of a man wearing a classic 1940s suit. There's also a film reel. The body is of a animated cartoon maker called Isaac, that Solomon Richards killed, because he was beginning to know a secret. The body under the water could be his wife, or a friend, that also had known that secret.
- This also might be a reference to the 2009 slasher film My Bloody Valentine. As the killer in the film, a miner named Harry Warden, killed all seven of his co-workers for breathing room after they became trapped in a mine.
- It is also believed that the dead body is that of Officer Cole Phelps, who drowned in the mine at the end of the story of L.A Noire, also a game made by Rockstar Games, although that may be an Easter egg.
- Footsteps are heard, usually after passing the body. Even when the player is at a dead stop, nor being moved in anyway, certainly confirming the myth of it being haunted. Sometimes they can be fast, or in other times rather slow.