Nothing can prepare divers for the vast corridors—carved more than a century ago and since retired and filled with groundwater—found in the lead mines of Bonne Terre. Much like the caves accessible to qualified tec divers, such as nearby Roubidoux Spring, Bonne Terre Mine reaches miles underground.

Bonne Terre Mine was one of the world’s largest producers of lead ore when it was developed in 1860, and still features numerous untouched artifacts above and below water. In addition to diving, walking tours are available in Bonne Terre. All tours above and below water are guided by experts trained in the history and layout of this immense mine. Without guides, one could become lost in the seemingly endless rooms with hundred-foot-tall ceilings and five levels to explore.

When in operation, up to eight pumps were used to lower the water level for miners. Two pumps now maintain the water level to keep parts of the mine above water, creating the world’s largest subterranean lake at 17 miles long. A boat tour takes guests across the water, while divers begin their experience from a large wooden platform fitted with a fleet of tanks and a compressor. Tours follow assigned paths past artifacts such as hard hats, ore carts, magazines, bowls and tools.

Divers climb down 65 stairs and walk through a path to reach the platform with their scheduled guide. This journey is the only way in or out, which underscores how uniquely remote these dives are. A tremendous lighting system provides illumination but doesn’t overpower the darkness, allowing historic working conditions to be appreciated. Dive lights are not permitted so guides can communicate among each other and divers can see artifacts without distractions.

Unlike Bonne Terre Mine, Roubidoux Spring has no open-water diving; only certified cave/cavern divers can explore this site. Bonne Terre is open year-round on weekends to divers of all certification levels, with its busiest season in winter. The PADI Night Diver specialty or an Advanced Open Water certification might help divers feel more at ease in the darkness.

Need To Know

Conditions: Viz varies from 100 to 200 feet; water temperature is 58°F.

What To Wear: Drysuit or 7 mm wetsuit.

Dive Shops Recommended by PADI: Odyssey Scuba, Waynesville, Missouri; West End Diving, Bridgeton, Missouri.

Dive Sites

Bonne Terre Mine Dive Trails

Recreational dives are planned above 60 feet and organized
in a numbered path system to help visitors build experience with safety at the forefront. Guide availability and whether you visit on Saturday or Sunday determine which trails are open. Some trails are designed to highlight artifacts, mine structure and operations, and some include the option for a few swim-throughs if dive groups are comfortable and eerienced enough. Trail 7 is a shallow-water dive that provides an overview of the lake.

Rebreather Trails

Tec and rebreather group tours can be scheduled with a technical dive guide to lead qualified divers to unique areas of the mine. Schedule dives in advance and follow all guidelines. Ensure your gear is in working condition and bring necessary spares to work within the dive schedule.

Roubidoux Spring

Certified divers can check in at the Pulaski County 911 Center in Waynesville to dive this spring. Fish congregate in the small cavern. A sign marks where the cavern ends and the cave continues for more than 11,000 feet to depths up to 230 feet.

Above-Water
 Mine Tour


Follow the first and second levels of the mine on a walking and boat tour along the “Old Mule Trail,” where you will encounter calcite formations, abandoned mining tools, rail systems and the underground lake. Plan the mine tour on the day before dives to orient to the mine and learn its history.

Elephant Rocks State Park


Continue touring larger-than-life geological features with oversize billion-year-old granite boulders that emerged when the land uplifted and subsequently eroded in the St. Francois Mountains. An easy walking trail that can be completed in 45 minutes takes hikers past the ruins of the railroad engine house.

The Old No. 102 Tap House


This casual partner to the fine-dining restaurant 12
 West Bar and Grill showcases fine food with local brews and unique desserts in Farmington. Fashion boutiques, such as Ophelia, and other eateries are also located in this cultural district.