California has 47,000 abandoned mines and 154,800 prospecting pits and tunnels, some dating to the Gold Rush of 1849.
Grant Barrett
Linguist, lexicographer, writer, editor, broadcaster
California has 47,000 aban
Linguist, lexicographer, writer, editor, broadcaster
California has 47,000 abandoned mines and 154,800 prospecting pits and tunnels, some dating to the Gold Rush of 1849.