The Monitor
The first hydraulic mining originated on American Hill near Nevada City, California in 1853. This miners giant known as The Monitor washed hillsides away under high pressure uncovering gold bearing gravel beds. This mining technique flourished profitably until 1884 when the Sawyer decision closed hydraulic mining. Rivers were being filled with mud debris causing flooding of the rich farmlands below.
Marker is on Broad Street near Union Alley.
Courtesy hmdb.org
