Diving at Bonne Terre Mine

bonne terre mine diving
Bonne Terre Mines were the largest lead ore mining site in North America operating from 1860 until 1962.

Bonne Terre Mine Tours offer tourists and divers one of the most unique opportunities to step back in time that can be found in North America. The Bonne Terre Mines were founded in the1860’s in Bonne Terre Missouri about an hour’s drive south of St. Louis. Bonne Terre which means good soil in French had the largest deposit of lead ore in North America. For just over a century the mines produced the majority of the lead ore used in the United States, if not the world.

The Bonne Terre Mines cover an area bigger than the town located above it. The mines are five stories deep into the ground and remain in exactly the same condition today as the day back in 1962 when the mines closed. Over the years of operation untold millions of tons of ore and dirt were excavated from the mine shafts. Many of the techniques and tools of modern mining were invented or perfected at the Bonne Terre mines, including the technique of pumping out ground water to gain access to the precious ore.

bonne terre mine diving
Ground water that was originally pumped out seeped back into the mine shafts creating the Billion Gallon Lake.

As miners dug deeper and deeper into the ground, ground water which occurs naturally under ground and is the source of water in wells would seep back into the mine shafts. To prevent the shafts from filling up, the miners would run pumps which pumped out thousands of gallons of water per hour. This allowed for the construction of massive tunnels underground so big that locomotives could be used to haul train loads of ore up to the surface to be processed.

Once mining operations ceased in 1962 the ground water began to seep back into the Bonne Terre shafts filling them up, creating what is now known as the Billion Gallon Lake. The crystal clear water filled the shafts to a depth of over 100’ in some places. The waters are so still and calm that they appear to be only a few feet deep, but are actually much deeper. The bottom three floors of the mine shafts are filled with water but the upper two are still accessible for walking tours. The bottom three floors are now home to North America’s largest inland diving resort.

Tours can be arranged for certified SCUBA divers to explore the shafts and see what life in a mine would have been like over a hundred years ago. Mining tools and vehicles left abandoned are perfectly preserved by the cold water that covers them, resting exactly where they were left by the miners. The cold underground waters prevent air from corroding the metals and bacteria from rotting the woods that were commonly used to build the mining equipment, making for an exciting under water tour unlike any other on Earth.

outdoors at the Bonnee Terre Mine
The cold ground water preserves artifacts left behind when the mine closed, keeping them in practically the same condition as when they were abandoned.

Boat rentals are also available at the Billion Gallon Lake in the Bonne Terre Mines for those who may no be experienced divers. The clear waters give boaters an amazing view of the sunken tools, rooms and equipment beneath them without the need to swim waters with a cool 62° Fahrenheit (16.7 °Celsius) temperature.

visiting bonne terre mines
This locomotive left behind in the mines has hardly deteriorated despite being covered in water for close to 70 years.

Guided walking tours are available on the upper two floors of the mine shafts for a nominal fee and are accessible for families who do not wish to SCUBA dive.

On your next trip through Missouri, make plans to visit the Bonne Terre Mines and Billion Gallon Lake historic sites for an unparalleled historical tour with some of the best preserved artifacts to be found anywhere from the 18th century.

Copyright 2019 Mike Wilson