The Berkeley Pit

The Berkeley Pit is a 1700 foot deep hole in the ground, nearly 3 miles around the outside, and as you stand on the viewing area, the far side is about a mile away. The Pit was created over a 30 year period, beginning with block caving of some of the underground mines after WWII. By the mid-’50s because of the availability of huge trucks and loaders, the ore was mined from the surface. The ore, containing about 1.5% copper, was milled at a concentrator southeast of the Pit. When ARCO closed all the mines in 1982, the underground pumps were shut off and the abandoned Pit has slowly filled with extremely acidic water. Eventually, the water will be cleaned at the water treatment plant, but in the meantime, the Pit gives Butte a lake like none other, as well as giving researchers a unique challenge. Open late May through September. Admission Fee charged.