Nail chronology as an aid to dating old buildings
In this same year, the work force reached 200 men and the mine had been sunk to a depth of 400 feet.
The mine shaft, identified as Feature 81, reached a depth of 600 feet in 1892.
In 1887, Waterman became Governor when the incumbent governor died.
Subsequent archaeological studies by SSC Archaeologists have defined an additional 18 historic features at the Stonewall Mine site.According to a 1963 California Division of Mines & Geology report, Stonewall Mine was the most productive gold mine in current San Diego County with a total yield of approximately two million dollars over its entire span of operation.[Note: San Diego County was much larger than today up to 1907.] During the operation of Stonewall Mine, a lively community for the mine workers and families was located nearby in the present-day State Park.Archaeologists from the Southern Service Center (SSC) of California State Parks conducted test-level archaeological excavations at potential locations of new park visitor facilities in April-June 2006 and October-November 2007 to identify the presence or absence of significant cultural remains.The latter fieldwork represents the first subsurface archaeological explorations ever conducted at the Stonewall Mine site.