Gold King Mine (Gold King Extension), Gladstone, Eureka Mining District, San Juan County, Colorado, USAi

Regional Level Types
Gold King Mine (Gold King Extension)	Mine
Gladstone	Village (Historical)
Eureka Mining District	Mining District
San Juan County	County
Colorado	State
USA	Country

Ref.: Rocks & Min.:63:366; Burbank(1951). A gold mine featuring the American tunnel (lower level).

The Gold King Mine was one of the larger producers in the Gladstone – Eureka area. Originally discovered in 1887 the operation didn't really become a substantial one for 10 years. Its peak was in the first few years of the 20th century after which it was staggered by 2 major fires and an avalanche. By the end of the First World War the mine was not doing well and it finally closed in 1923 just after extending the American Tunnel.

American Tunnel was originally part of the Gold King Mine at Gladstone. On USGS topographic maps it is still labeled as such. The actual working Gold King Mine's level 7, the main production adit, is called the “Upper Gold King Mine” on modern topographic maps. The American Tunnel was begun in 1900, some 800 feet beneath level 7, but was only driven in about 700 ft. In 1922-3 the American Tunnel was extended to 6233 feet from the portal, to a point beneath the Gold King's main workings, but the mine closed before any other development work could be done.

The Gold King Mine mined ore shoots in veins associated with faults related to the Eureka graben. The geology and ore deposits of the Gold King and other mines in the area is discussed by Burbank and Luedke (1969) and Ransome (1901).

In recent years the main concern in the area is the acid drainage discharging from the American Tunnel and many other adits in the region. Bulkheads were installed in the American Tunnel to stem the flow but the loss of deep drainage in the area has caused adjustments in the water table over a larger area because of interconnected mine workings or the pervasive fracturing. Although the Gold King Mine was never connected to the American Tunnel by raises or other workings, after the American Tunnel was plugged water drainage from the level 7 adit increased considerably. Remediation efforts led to a large spill of acid water and sludge in 2015. A paper entitled “Technical Evaluation of the Gold King Mine Incident” was produced by the U.S. Department of the Interior, Bureau of Reclamation, Technical Service Center. It contains lots of information including maps of the American Tunnel and other mine workings in the area.

Other Regions, Features and Areas containing this locality

References