By 1853 placer mining had recovered over 10 million ounces of gold worth roughly $200 million, but this was only the start. The immediate financial boom of the gold rush caused the continued expansion in terms of both population and technological advance. With gold becoming harder and harder to come by and miners pouring in from across the globe at an increased rate with the completion of the Panama Rail Road connecting the east and west coasts of the Americas in 1855 the need to devise new methods of gold extraction were ripe, and both miners and companies were ready to pick the shiny fruit. Perhaps more than the value of gold itself the ingenuity of the miners and the engineering advances made during the gold rush provided its most dynamic worth.
For the first year or so a gold pan and a keen eye were all that was necessary to come by nearly an once of gold per day. Claims along numerous rivers and creeks throughout the gold region yielded multiple flakes in every pan. Once this gold was gone the industrialization of gold mining was ready to begin. It started small with single miners or small groups utilizing sluices, long toms, and "rocker boxes" - a device where gravel was poured through a sieve allowing only smaller materials to fall onto a 'baffle' (a sheet often made of canvas that would sag and allow small flakes to settle) and finally run down a small 'sluice' (a wooden funnel with bars to catch the gold). This entire contraption was placed on a set of rockers to rock the device back and forth while water was poured through it in order to settle the heavier gold.
Soon even these methods became obsolete and the introduction of hard rock gold mining spread through the California goldfields. Initially the process was a grueling endeavor using black powder and hand powered tools to crush the extremely resistant host rock quartz into a fine powder. The entire process may have gone under if it hadn't been for the introduction of steam powered drills and invention of dynamite in 1867. With these two forces hard rock mining became a calling card of the gold rush. Mines like the Kennedy Mine dug over a mile a deep, and the total gold production from hard rock mining accounted for close to %60 of the total gold rush yield. This method of crushing ore still encountered the problem of extraction and the solution to this problem would be one of the later downfalls of the gold rush. Quicksilver (mercury) was used to form an amalgam which was extracted and heated to finally isolate the gold. The release of mercury into the environment had consequences Californians are still dealing with today.
Quicksilver wasn't the only downfall to the gold rush, equally devastating, if not more so, was the the process of hydraulic mining. Similar to the transition to hard rock mining, miners realized that the majority of gold was still held buried in the hills and it would take little less than an avalanche to set it free. Hydraulic mining, invented in 1853 by three miners; Eli Miller, Edward Matteson, and Anthony Chabot (also famous for his engineering work in the bay area) would soon create that man made avalanche. Hydraulicking, as it was called, forced pressured water out of a nozzle at an extreme force, blasting the hillside into sludge. The tailings (runoff) were passed through long sluices to settle the gold. Once settled the final process also utilized quicksilver for its extraction process.
The state's largest hydraulic mine, the Malakoff Mine, located in the foothills of Grass Valley utilized 40 miles of pen-stocks (pipes) dropping 1000 ft in elevation creating a jet stream of water shot out of the monitor (water cannon) at 500psi. This devastating blasting carved out a pit over one mile long, over half a mile wide, and 600 ft deep. It removed 41 million cubic yards of earth and garnered $3.5 million dollars worth of gold alone (the modern day equivalent of over $251 million). The mine, run by the North Bloomfield Mining and Gravel Company, operated around the clock causing need for the installation of the first ever long distance phone line in 1878 and electric lights in 1880. To process the giant quantities of gravel the company also constructed a 7,800ft drain tunnel out of solid bedrock, an engineering feat that took almost two years of day and night work to complete.
The very same power that brought gold mining in California to the forefront of engineering and profits also led to its rapid demise. The tailings produced by hydraulic mining and the release of mercury brought ruin and court cases to the state of California waging a war between the miners, farmers, and environmentalists that would shape California legislature and end put a final end to the gold rush era. Check back to our blog again for the downfall of the gold rush.