A number of small lode mines and prospects occur in the general area of Spring Garden and Argentine Rock in south-central Plumas County. A patch of Tertiary auriferous gravel was mined by hydraulicking years ago and the area has been intermittently prospected in recent years. The country rock is greenstone, slate, and quartzite that is overlain to the south by andesite.
Turner, H.W., 1897, Downieville folio: U. S. Geol. Survey Geol. Atlas of the U.S., folio 37, 8 pp.