Solano County has several inactive cinnabar mines including the Hastings Mine and St. John's Mine,[REF] both of which are subject to ongoing environmental monitoring; these mines were worked in the first half of the twentieth century.
Solano County has a number of rare and endangered species including the beetle Elaphrus viridis, the wildflower Lasthenia conjugens, commonly known as Contra Costa goldfields and the annual plant Legenere limosa or False Venus' looking glass.