There is a silicon mine at the bottom of North Table Mountain. There are also several old irrigation mines at the north end of North Table Mountain. There is also an old mine shaft at Phantom Falls, which was used during the Gold Rush. Research sometimes takes place at the mine, although it can be difficult. Hydraulic mining near Cherokee produced a large amount of gold before environmental concerns forced an end to it in the late 1800s. Hundreds of good quality diamonds have been found in the area.