On February 2, 1848, far to the south in Mexico, the Treaty of Guadalupe Hidalgo was signed, ceding California to the United States in the aftermath of the Mexican-American War. This strikes me as one of the stranger chronological coincidences ever.
Word spread quickly about the gold in the Sierra foothills, and the rush was on. Sutter's Mill didn't operate for very long. It was essentially abandoned by 1853, and all surface evidence was swept away during a flood in 1862. Many years later, the foundation timbers were excavated, allowing archaeologists to calculate the dimensions of the mill. A replica was constructed on the site in 1967, and the original timbers have been put on display (below).
|The 1967 reconstruction of Sutter's Mill in Coloma|
Gold-bearing gravels could be found on ridge lines where ancestral rivers once flowed prior to the main uplift of the Sierra Nevada. The miners couldn't efficiently work the deposits because of the lack of water. Mining companies put together a system of flumes and canals in the high country to bring water to the gravels, and one of the most destructive kinds of mining ensued: hydraulic mining. A water cannon, called a monitor, was pointed at the cliffs with the gold bearing gravels, and the explosive spray washed away the gravel into a large tunnel. Large riffles filled with mercury trapped the particles of gold, and the waste material was dumped into the nearby rivers.
|A monitor (water cannon) used in hydraulic mining at North Bloomfield.|
And then there were the dredges. It took the mining companies a long time to figure out a way to find the very fine gold particles that filled sediments in the Central Valley. The first successful dredge went into action in the late 1890s, and profitable production continued into the 1970s. The dredges were large factory barges with a system of shovels on one end, a waste conveyor belt on the other, and a series of sieves and mercury coated copper plates in the middle to trap the microscopic particles of gold. The dredges were floated in a pond, where they dug away at one end, and filled in the other. In this way, they "sailed" across parts of the Central Valley, producing huge rock piles where fertile soils once existed. Huge swaths of land were ruined in the chase for the elusive metal.
The mines weren't just damaging to the environment. The miners themselves were subject to constant dangers from explosions, cave-ins, falls down shafts, and the gold miner's equivalent to black lung disease: silicosis, a deadly lung disorder caused by breathing in fine quartz dust.
|Source: Kennedy Mine Foundation|
|The Fricot Nugget, the largest surviving nugget from the Gold Rush era. Thieves attempted to steal the nugget last year, but failed. They still made off with numerous other beautiful specimens.|