Royal Rainbow Opal Mine
UPDATE Fall 2010: apparently the mine has been closed
The Royal Rainbow Opal Mine is open most days of the year, 13 miles north of Gerlach Nevada on Highway 34, then 35 miles north on Soldier Meadow road.
(Inquire at Bruno's bar or the Gerlach Museum before heading out)
Accessible by 2wd year-round, but 4x4 is required to drive the ~0.9 miles to the mine site, ~500 feet up