In the 1850's, early miners in Nevada were looking for gold and kept encountering "The Blue Mud". It got into everything and was washed away and discarded as fast as possible. On a hunch, one miner had the mud assayed in San Francisco and it revealed that "The Blue Mud" contained $3,000 of silver per ton of mud. Sworn to secrecy, miners returned to Nevada to stake claims. However, rumors spread through California of a Bonanza in Nevada. This Bonanza evolved into the Comstock Lode. The richest silver deposit in the history the United States.