were: biological impacts upon habitat by park users water quality impacts to creeks draining the watershed visual and drainage impacts of road improvements historical analysis of mine usage See also Shaft mining Surface runoff New Almaden town and quicksilver mines References External links Almaden Quicksilver County Park Official Website Geocities userpage with park history and many pictures (Archived 2009-10-25) Parks in the San Francisco Bay Area Mercury mines in the United States Underground mines in the United States Bay Area Ridge Trail County Parks in Santa Clara County, California