Few local miners still burrow underground, lured by the rich yellow gleam of gold. Most gold now recovered from California's Rand Mining District is microscopic in size, and so finely dispersed that it is invisible to the naked eye. Rock containing as little as .02 ounces of gold per ton is considered "ore" meaning that it can be mined at a profit. From this vantage point, you can watch the Baltic Mine's excavation of approximately 50,000 total tons per day. When tests reveal that gold content in one area is too low to be mined economically, material is hauled to a waste rock stockpile. Rock classified as ?ore"is added in thin layers to the "heap leach pad" on your right, which was started in July 1993. The leach pad is constructed with an impermeable liner beneath it. Atop the pad, a network of tubes constantly drip a "barren" dilute sodium cyanide solution. Cyanide exhibits a strong affinity for gold and silver, which is dissolves from the ore, one minute particle at a time, as gravity draws the solution downward through the heap leach pad toward waiting collector pipes.