A significant landmark of Comstock history The Donovan Mill in Silver City is an internationally significant site, representing the location where cyanide/zinc processing was perfected in a way that set the stage for the subsequent 115+ years of precious metal mining throughout the world. Some historians claim that the original part of the Donovan Mill, the Dazet Mill, and the adjacent Jackson Cyanide Plant is the location on the Comstock where the cyanide process discovered in Scotland (1887) was revolutionized for processing ore. The use of cyanide and zinc for the retrieval of precious metals was conceived in Scotland in 1887. Limited testing in New Zealand and elsewhere proved the value of the process. In 1896, Professor Richard D. Jackson of the University of Nevada adapted the idea and perfected the process, especially for Comstock ore. He conducted tests on Comstock mill tailings, and then at the turn of the century, he set up a more formal operation at the industrial complex now known as the Donovan Mill today and the Dazet Mill or Jackson Cyanide Plant. The success of his experiment opened the door for the industry to cease using mercury for processing gold and silver ore, arriving at an approach to milling that was more efficient and better for the environment.
After the tour and lunch, brave soles will head to El Dorado Canyon to try it in the opposite direction from what we normally do. El Dorado Canyon is sandy, rocky, brushy and has steep drop offs and climbs - it is not suitable for stock vehicles.