Malakoff Diggins Section

Hundreds of millions of years ago, a massive chunk of earth, submerged under the sea, was thrust upward as another piece rammed under it. Water was unwittingly trapped in this process, heated to extremes under the intense pressure of the earth. During this process, all sorts of minerals were dissolved into the water: chlorine, fluorine, boron, sulphur, tellurium, silica, and gold. When there was a fissure between the two plates, the pressurized water would be released from the earth, leaving behind a crystallized vein of quartz, marbled with gold, as the minerals were released. Over time, the ancestors of our modern rivers eroded these veins, carrying with them the gold deposits along their riverbeds.
Eventually, immigrants discovered this eroded gold in the streambeds of these ancient river’s descendants—the modern Yuba and American Rivers. A few years later and hundreds of thousands of people more, all this placer gold (or gold deposited in streams by erosion) had been removed from the stream beds using a simple pan or Long Tom. When things stopped “panning out”, the new immigrants turned to more complex sources; they began to seek “pay dirt” in the quartz veins of the mother lode itself as well as the buried, ancient streambeds of the ancestral rivers. To efficiently mine these buried riverbeds, a new mining technique had to be invented: hydraulic mining. Channeling the water of the existing rivers, the immigrants used pressurized monitors to remove the silt of the ancestral rivers. As the silt and gravel was washed away, mercury was added to remove the tiny particles of gold, transforming the earth into toxic mine tailings. These tailings were washed back into the present river systems, chocking the natural flow of water. The short-term removal of millions of years of sedimentation left devastating ecological consequence; little could grow in the newly exposed gravel, and what could grow was forced to exist in toxic levels of mercury.
Between its inception in 1853 and it cessation in 1883, hydraulic mining removed 1.25 billion cubic yards of earth—more than eight times that of the Panama Canal. At Malakoff Diggins alone, around 50 million yards were washed downstream, chocking the Yuba River and creating devastating floods and mercury contamination downstream. This section shows the geological composition of the site. Before hydraulic mining, the ground was over 400’ higher; what you see here is an enormous pit.