In the mid 1800’s the mines in Central City were being flooded so badly that the miners were pumping water at least 1/3 of the time. Samuel Newhouse developed the idea that a drainage tunnel could be dug below the mines rather than hauling the water up and out of the shafts. By 1893 the Newhouse Tunnel was started, and soon it became known as the Argo Tunnel. It provided transportation to the Idaho Springs side where ore could be shipped to Denver by trains. Later a mill was needed to process the ore that was not as rich in gold, so a mill processing plant was built and finished in 1914.
The fully electric mill ran 24 hours a day and required only three to five men to operate. Ten stamps used to crush the ore weighed 1,050lbs each and could be heard for 20 miles in every direction. The mill used mercury amalgamation and cyanide leaching to extract the gold from the ore. The men working in the mill faced difficult working conditions. Three to six days of working next to the stamps caused hearing damage and the chemicals used in the process could result in cyanide poisoning or Mad Hatter’s Disease.
Mining camps had few jobs for women. A very popular one was laundry. These women used pine oil to launder and soon realized that tiny gold flecks stuck to the oil and rose to the top of the tubs. Carrie Everson, a female scientist, determined that if fats or oils are combined with ore, the oils adhere to the metals and not the rock, causing metal fragments to float. This discovery allowed the Argo to process 95% of the ore while most mills processed only 40%-60%.
In 1943, a blast inside the tunnel accidently released millions of gallons of water
that killed 4 men. The tunnel shut down at that time and mining ceased. The Environmental Protection Agency (EPA) and then-owner Jim Maxwell, developed a water treatment plant to purify the water that drained out of the tunnel and nearby mine.
Argo Mill and Tunnel