Time Machine Tuesday: Tungsten Mining in Colorado

Colorado mining isn’t just about gold and silver. There are many other metals, minerals, and elements that have been mined in our state; one of these is tungsten. Tungsten has the highest melting point of any known metal – more than 6,000 degrees Fahrenheit! It’s an extremely hard substance, so is frequently used for strengthening metal alloys. It’s also used in electrical products, including as filaments in light bulbs. The name tungsten comes from the Swedish words for “hard stone.” Tungsten is found in the mineral wolframite and is sometimes called wolfram, which is why it is “W” on the periodic table.

Tungsten occurs alongside other metals and minerals, so although it was first discovered in Colorado mines in the 1870s, it wasn’t until the early twentieth century that miners recognized its importance. Boulder County’s Cardinal Mill was one of the nation’s first mills equipped to separate tungsten ore from its rocky shell. Then, when World War I broke out, demand for tungsten increased exponentially. The 1915-16 Biennial Report of the state’s Bureau of Mines discusses the war’s effect on tungsten prices, and provides an overview of the tungsten mines and discoveries in Colorado. After the war ended, industrial developments and another World War caused demand to continue into mid-century.

The vast majority of Colorado’s tungsten mines were located in Boulder County, near Nederland and Caribou. In fact, at one time there was even a town in Boulder County called Tungsten. A few tungsten mines were also found in southwestern Colorado, especially San Juan County, as well as in the central mountains. One of the State Publications Library’s most popular items is Tungsten Mines of Colorado, published by the Colorado Geological Survey in 1960, which lists the locations of the state’s tungsten mines up to that time. In addition, an older Geological Survey publication, from 1908, provides information on some of the earlier discoveries of tungsten in Boulder County.

More about tungsten can also be found in several other publications available for viewing at the State Publications Library, including “Tungsten and the Road to War,” a volume in the University of Colorado Studies series; a 1963 report on Colorado tungsten from the Colorado School of Mines; a 1981 Colorado Geological Survey publication focusing on tungsten deposits in south-central Colorado; and a 1992 Colorado State University study on the chemistry of tungsten. For information on accessing these resources, visit the library’s online catalog.