1994 Mining History Association Field Trip



Georgetown Tour, June 7, 1994

Option A: Idaho Springs Tour

with the Edgar Mine


In January 7, 1859, placer gold was discovered by George A. Jackson near the mouth of Chicago Creek where it joins Clear Creek. Today this is the location of the town of Idaho Springs.  He returned to Golden where news of his discovery leaked out.  In the spring, 400 prospectors rushed to the area. In May of that year, John Gregory made his hard rock gold discovery in Gregory Gulch between Central City and Black Hawk.  These two discoveries set the stage for nearly a century of metals production.


The Idaho Springs mining district is approximately 9 square miles in area extending from below Clear Creek on the south to above the Clear Creek-Gilpin County line on the north and about 3 miles in an east-west direction.  The town of Idaho Springs is at the southeast corner.  The Central City district bounds it on the north. The district is criss-crossed with faults and veins.  The estimated value of production from the district is $60 million from gold, silver, and lead, and smaller values of copper and zinc.  In the 1950s, the district was prospected for uranium but no production came from these efforts. Like most mining districts, a few mines accounted for most of the production.  The early million dollar mines included the Stanley, Specie Payment, Sun and Moon, Frontenac, and Gem, plus the French Flag-Silver Age-Franklin group.  Production peaked in the 1890s, fell after the 1893 Silver Panic, rose during World War I, hit a low point in 1928, rose again after the gold price was raised in 1933, rose further during World War II, and then went into permanent decline.


A series of mine haulage and drainage tunnels were developed in hopes of tapping deep extensions of the district’s richer veins.  The longest of these was the 4.5 mile long Argo Tunnel which passed under Central City.  Ore was hauled to Idaho Springs for treatment in the Argo Mill or shipped by rail to other destinations.  The Argo Mill, now a museum, is the most prominent of the mining heritage structures in the district. In the 1990s, a Superfund clean-up included construction of a mine water treatment plant at the mouth of the Argo Tunnel.


Many homes and commercial buildings in Idaho Springs have been restored to their Victorian appearance.  Miner Street is now populated with restaurants, bars, and shops catering to tourists and locals alike.  One of the town’s most unique features is the Edgar Mine which is owned by the Colorado School of Mines.  In the 1870s, it was an active mine producing gold, silver, lead, and copper from the Edgar Vein which runs along the hill above the town.  Today it serves as an underground classroom for students and a laboratory for mining research.  It was visited on the 1994 Mining History Association tour and is open seasonally for public tours that give visitors a glimpse of what underground mining is like.


Unfortunately, no photographs remain from the 1994 MHA tours.  Using historic and more recent photographs, the Photo Galleries attempt to reconstruct what attendees saw as they visited the various Colorado mining towns.


A view of Idaho Springs looking west, ca1908. (After Spurr, Garrey, and Hall, Professional Paper 68, USGS)


A view of George Jackson’s April 1, 1859 gold placer discovery site on Chicago Creek just above Clear Creek in Idaho Springs, ca1908. (After Spurr, Garrey, and Hall, Professional Paper 68, USGS

Many of the historic buildings along Miner Street in Idaho Springs have been repurposed as restaurants and shops.

More historic buildings along Miner Street in Idaho Springs.

The Argo Mill was built in at the end of the 4.5 mile long Argo Tunnel to process ore from the mines in Central City.  The tunnel was intended to provide drainage, ventilation, and ore transport.

Cribbing and ore bins at the end of the Argo Tunnel, ca 1941. (Courtesy Library of Congress)

Water pollution was caused by acid mine drainage from the Clear Creek and Gilpin County mines.  In the late 1990s, the Argo Tunnel was rehabilitated to convey polluted water to a new treatment plant.

This treatment plant was constructed to neutralize and remove contaminants in the water from the Argo Tunnel. Clean water is released into Clear Creek.



Photo Credits Mike and Pat Kaas (unless otherwise attributed)


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