The first U.S. gold rush began in the early 1800s in Georgia, North Carolina and Alabama. In the first documented discovery of gold in Montgomery County, in 1849, Samuel Ellicott invited a geologist to inspect rock outcroppings on his Brooke Meadow farm. The Maryland Journal published the findings positively identifying gold. Samples indicated that a mine could provide a valuable yield. Ellicott constructed a 60-foot mine shaft and contracted to sell the property to a New York gold company, but the deal fell through. A total yield of $2000 was reported recovered from the Ellicott Mine.  

National and local newspapers spread gold fever and Montgomery County, located at the northernmost end of the Appalachian Gold Belt, became the scene of extensive gold mining operations. The gold rush in Montgomery County began in earnest after the Civil War. Historian Walter Goetz identified 22 gold mines in the county, and more than half of them were located in the Potomac area.  

There were 12 gold mines in the Potomac area, five in the Rockville area, three in Cabin John-Bethesda, one near Brookeville (Ellicott) and one near Boyds in Black Hills Park. The Montgomery Mine was in the Heritage Farm Neighborhood Park near River and Falls Roads in Potomac.  

During the civil war, a Union soldier unintentionally panning for gold while cleaning pots and pans in a nearby stream made the first discovery of gold in the area of Maryland outside of Washington, D.C. 

The first county gold mine to be commercially exploited was the Maryland Mine, near Great Falls. A former California prospector discovered the site in 1861 and opened it in 1867. It was destroyed in a 1906 explosion and rebuilt. Reputed to be one of the largest gold mines in the Eastern United States, the Maryland Mine was long-lived, operating intermittently until 1951. 

The county is home to the Great Falls region, which was surrounded by several mines, most of which produced gold. The major gold mine near the Great Falls is the Great Falls Gold Mine that produced both gold and Tetradymite. 

Although trace amounts of gold can still be found in the region, there was never enough gold discovered for the mining operations here to be profitable.