They said, “there’s gold in them thar ‘ills” and they say 80% of it is still there! Go get it if you want, but it’s not just lying around on the surface. Gold was discovered in 1859 in what is now Idaho Springs, Colorado, beginning a gold rush into the Rocky Mountains, and also beginning many of the Colorado towns now more famous for snow, the “white gold” of the ski industry.
In the Idaho Springs area at first there was plenty of gold (if there is such a thing as “plenty” of gold) near the surface, but as miners dug deeper, it was harder and harder to get the gold out of the pits, and there were more and more problems with water flooding the mines. The solution was the Argo Tunnel. The tunnel was to drain water out of the major gold mines in the area, including the Glory Hole mine workings which were dug into the “richest square mile on earth”. The tunnel would also create a generally horizontal direction for bringing gold ore out, much easier than lifting the ore thousands of feet vertically.
Begun in 1893 and finished in 1910, the tunnel ran from 1300 feet below the corner of Central City through the hills and down about 700 more feet to the canyon side beside Idaho Springs. From Idaho Springs the gold could be taken into Denver to be smelted. Over 4 miles long, the tunnel was the longest in the world at the time.
To handle the ore coming out of this tunnel and reduce the cost of sending raw ore to Denver, the Argo Gold Mine and Mill was built at the mouth of the tunnel. The mill started the process of gold extraction, and over the years it sent $200,000,000 of rich ore to Denver, saving $100,000,000 that would otherwise have been spent in shipping unprocessed ore.
The mill shut down after an accident with water in the tunnel in 1943; it wasn’t worth starting up again after the accident due to the lack of men and money in the middle of World War II. After the war, the price of gold was no longer worth the cost of getting it out of the depths of the mountains. The Argo Gold Mine and Mill is now a museum and also a major landmark along I-70 going up into the mountains.