Flooded

Alhambra Mine, in California's Sierra Nevada above Hope Valley to the west. That's actually still, clear water--the little light-colored spots are bits of floating vegetation. The Alhambra was originally worked for gold in the 1860s, but had a new lease on life in the 20th century as a tungsten mine. It closed in the mid-1950s, presumably when the "strategic metal" subsidies went away, and the run-up in gold prices in the late 20th century didn't lead to any new activity.