The History of Montana Sapphires and The El Dorado Bar

“The Eldorado bar has also produced an impressive amount of sapphires.” (Montana Department of Environmental Equity report quoting Brown 1867; Pardee and Schrader 1933). 

Nestled along the eastern bank of the Missouri River, lies a treasure trove full of promise - The El Dorado Bar region. During prehistoric eras gold-bearing gravel deposits were washed down from nearby streams forming mineral rich terraces (bars). In addition to gold deposits, a sapphire-bearing layer from the prehistoric era was discovered. In the 1880s - 1890s sapphire recovery from this area garnered about $2,000 per year. Most of the sapphires were used in industrial applications due to “their inferior green color.” Cheaper synthetic sapphires produced toward the end of World War II significantly reduced interest in natural Montana sapphires for industrial use.

Mining the Deposits

The 1800’s:  As early as 1865 miners were placering  the El Dorado Bar region of the Missouri River just downstream from the mouth of Soup Creek. Along with the gold dust they found small hard stones they believed to be diamonds. Numerous companies from both overseas and American worked the bar and made improvements.In 1873 Dr. J. L. Smith wrote that one or 2 pounds of sapphires could be collected in one day. Hydraulic methods  used in 1895 by the Montana Sapphire and Ruby Company netted large amounts of sapphires.

The Early 1900s:  In 1938 an electric dredge was built and put in service by  the Perry-Schroeder Mining Company. In the early to mid 1940s over 13,000 ounces of gold were sorted out of processed materials.  The dredge also removed around 58,000 troy ounces of sapphires. Small amounts of platinum and osmium were also present which allowed the dredge to operate during World War II when other operations were closed by Federal Order.