The Hastings Mine is a mineral extraction site approximately 4.5 miles (7.2 km) northeast of the city of Vallejo, Solano County, California.
[1] The Hastings site on Sulfur Springs Mountain was used for extraction of cinnabar until the year 1930.
Miles of underground shafts were driven in the course of working the quicksilver deposits in the area.
[4] Principal ongoing impact is from mercury contamination of spring water flowing beneath the site; moreover, historical analysis has shown that the volume of spring water itself has been greatly reduced from levels of a century ago.
This reduction of spring flow has come about due to the extensive mine shafts driven to achieve the cinnabar extraction.