Sign at site reads:
The Lagrange Mine
This mine, originally known as the Oregon Mountain group of claims, first operated about 1862. In 1892 the mine was purchased by the Lagrange Hydraulic Gold Mining Company which brought water from Stuart's Fork through 29 miles of ditch, tunnels and flume and delivered it to the mine pit under a 650 foot head. Over 100,000,000 yards of gravel were moved and 3,500,000 dollars in gold produced. Large scale operations ceased in 1918.
California Registered Historical Landmark no. 778