Saturday, March 16, 2013

Such a Peaceful Scene...and the Birth of Horrific Destruction

A beautiful serene stretch of river on a sunny spring evening. How could anything like this be associated with the extermination of not just a culture, but of many cultures? How could this be linked to one of the most environmentally destructive periods in our state's history? Yet it is...
In late January of 1848, James Marshall had a contract with John Sutter to construct a sawmill on this stretch of the American River near Coloma in the Sierra Nevada foothills of California, and on January 24th, he was realigning the millrace to get the sawmill working properly. They let the river do some of the work by letting water flow through the culvert all night, and in the morning he and his workers found yellow flakes of metal in the bottom of the millrace ...

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 village at Coloma is now a state park that commemorates the discovery of gold and the rush that followed. There is a fundamental fascination with the yellow metal that caused hundreds of thousands of people to abandon their homes to seek a fortune in the gold fields of California. Legends abound of miners who found giant nuggets and rich pockets that made them instantly rich. Other legends tell the story of bandits and desperadoes. Few stories are ever told of the people whose culture disappeared into the mists of history without ever being recorded. The Native Americans of California, who may once have numbered over a million people, had already been decimated by European diseases, but for some cultures the Gold Rush was the last nail in the coffin.
The 1967 reconstruction of Sutter's Mill in Coloma
The Gold Rush did not last for very long. By 1853, the rivers had been overturned in the quest for the yellow metal, and the miners were beginning to disperse in hopes of finding ores in eastern California and across Nevada. The attention of the mine owners and investors shifted to methods of gold extraction that were more efficient and even more destructive.

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.
Millions upon millions of cubic yards were washed away. In the scene below near Interstate 80, the landscape was once level with the white cliff in the far distance. The valleys downstream were choked with debris, and silt filled the floor of the Central Valley. Floods became commonplace as river channels filled with silt and overflowed. Mud filled parts of San Francisco Bay to the extent that it is only about 70% of its original extent. Mercury that escaped from the mines contaminated the sediments, and continues to be a problem today. Hydraulic mining was so destructive to the environment that it was essentially outlawed in 1884.

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 hard rock mines of the Mother Lode had their own problems. The first mines were dug in 1849, and they were active until 1942, when presidential orders shut down the mines for strategic reasons. A few tried to start up again after the war, but were ultimately unsuccessful. The miners brought huge amounts of ore to the surface, where the rock was crushed to a powder in stamp mills and treated with mercury or arsenic to tease out the gold (cyanide is used today). The mine dumps are toxic, not only with the mercury and arsenic, but also the acids produced by exposure of the sulfide minerals in the gold veins to oxygen in the atmosphere. Clean up efforts are still ongoing today, 70 years after the mines closed.

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
Today the Mother Lode is a tourist destination, and the miners have achieved a sort of legendary status. The heritage of the Gold Rush is more equivocal: the destruction of cultures, and the environmental devastation of a wide swath of the Sierra Nevada foothills, the Central Valley, and San Francisco Bay. And yet, every time I take a field trip through the Mother Lode, I can't help but look through the mine dumps for the bright yellow gleam of the strange metal.
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.

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