Malakoff Diggins State Park is the remains of an old hydraulic soft rock surface mining operation in the Sierra foothills north of Grass Valley and Nevada City. The "diggins" are the pits that remain when the aggregate rock that was ancient river bottom was blasted away with hydraulic nozzles, aka "monitors", silting up the San Francisco Bay and all the rivers in between.
And in the process, between the deforestation and the various mud dams, causing tremendous flooding problems in the interventing paths.
When a process was stopped in the 1800s because of environmental damage, you know it was bad.
And, no, "soft rock mining" doesn't involve digging James Taylor looking for gold.
The remaining pits are gradually filling back in, the ranger said it was about half a foot a year, but even with the filling in and the new growth the manmade scenery is bizarre and worth a visit.
The park also contains the remnants of North Bloomfield, California, formerly Humbug, California. Two families still live there, but the rest of the buildings are in various states of decay or restoration.
And the park is also slated for shutdown in the current California state budget slashing. Sigh.