Shaft Drill Core
1935-36
Experimental vertical shaft 5’ in diameter to 1125’ depth thru serpentine and gabbro at Idaho-Maryland Gold Mine, Grass Valley. Machinery invented by J.B. Newsom. Greatest drilled footage – 21’ in three days. Core weight 11-tons. Donated to Nevada City by Kenneth E. Baker.
Marker is at the intersection of Union Alley and Broad Street, on the right when traveling east on Union Alley.
Courtesy hmdb.org
