Adits and Shafts
Brighter Days mine shaft, Mohave County, AZ, with memorial for girl that died in accident September 2, 2007. Fence was added after accident.
Adits and Shafts
Mining played a major role in Arizona history. It’s reported by the State Mine Inspector that there are over 100,000 abandoned mines in the state. Today, old mines are both a joy for history buffs and a danger for curious explorers.
As an exploration geologist, I’ve been around abandoned mines all my working career. I understand the dangers and know how to stay safe. On several occasions I’ve been asked to be safety backup in the event of a problem while others were sampling in underground workings. I’ve also been involved in rescues of people and dogs that have fallen into mine shafts. Some survived, some didn’t.
It’s easy to say, “stay out- stay alive” as signage and bumper stickers tell us. And while this warning makes sense and is heeded by most, there are those that are willing to take the risks to explore an old mine. With this in mind, I’d like to start with properly describing an old mine.
A shaft is a hole in the ground that goes down; an adit is an opening that goes horizontal and doesn’t go all the way through. If it did go all the way through the mountain, it’d be a tunnel. Tailings are the finely ground rocks that were discarded from a mill. A mine dump is the pile of dirt and rock left piled up next to a mine opening. A lot of people call the piles of rock next to a mine opening tailing but this is incorrect. Why does this matter? Tailings have gone through a mill and have had chemicals added to the ground-up rock so there might be environmental considerations. This isn’t the case with a mine dump where the material was dug out and piled up on the ground without adding chemicals.
The first danger most people think of with old mines is a cave-in. If a mine opening has remained for over a hundred years, the chances it’ll cave-in are low. When I enter an old mine, I first look at the entrance - does it look sturdy or are there slabs of rock in the roof that could fall. Next, I look at the mine dump to see what kind of minerals were taken out. If the material looks rusted, has a rust reddish-brown color, it’s probably from the oxide zone and there’s little danger of poisonous gases underground. If the minerals on the dump look whiteish-gray to yellow and I can smell hydrogen sulfide gas, smells like rotten eggs, the chances of poisonous gases underground are a real possibility.
Before going in, I look for signs of animals around the opening, such as rattlesnakes or javelina tracks. Years ago, while working in southern Arizona, I entered an old adit to take samples. When I started banging on the rocks with my rock hammer, I heard snorting and something running toward me. I had just enough time to put my feet on one side of the adit and my hands on the other to make a bridge while a herd of javelina ran under me and out the opening. Javelina have sharp tusks so it wouldn’t have been pretty if I’d stayed standing in their way. Of course, there are nearly always bats in old openings so don’t be frightened and don’t hurt them. They won’t hurt you - they just want to be left alone. Also, they are protected.
Once in a mine opening, I feel for the movement of air. If air is moving, chances are that even if there’s poisonous gas, it’ll be diluted or expelled by the air movement. If there’s no movement of air and there’s a musty foul smell, I get out. I also try not to kick up dust as bat guano can carry spores of histoplasmosis, a fungus that settles in your lungs, similar to Valley Fever. Histoplasmosis is especially prevalent in moist climates.
Be careful if you try climbing a pile of rock and dirt near a mine. The dirt might look loose but because of the oxidizing pyrite putting iron in solution, the dirt will form a crust. This crust won’t allow your feet to dig in and you might be left standing on a steep slope that could turn you into ground meat if you slip.
Secondly, once on top of the mine dump, there could be a shaft with a funnel shaped opening. The opening might not have enough room to stand so there’s a real possibility of someone climbing the pile, getting to the top and falling into a shaft. We had a body recovery of a young man that rode his motorcycle to the top of a pile and fell in because he couldn’t stop in time to avoid the opening.
My most vivid memory of a rescue at a mine opening was of the two young girls that fell into the Brighter Days mine shaft above the town of Chloride in 2007. It was a difficult rescue that made national news and is described in the book we wrote called Call-Out. One survived, one didn’t.
It’s best to leave old mines alone but if you choose to explore, know what you’re doing and don’t become a statistic.