Spanish Flat was founded on a stagecoach road that connected Placerville and Georgetown and is now called State Route 193. The town, just 6 miles south of Georgetown, 6 miles north of Placerville, and 4 miles east of Coloma built its first store in 1849, followed by a saloon, several bakeries, two blacksmith shops, a butcher shop, a gambling establishment and lodges built by both the Masons and the Odd Fellows. Near this mining camp the "Frazier Claim" or "Deep Hole," was worked by M. S. Frazier & Co. The owners of this claim were George Hunsucker, John Hunsucker the founders of Rubicon Soda Springs. It was reported that  more than $100,000 (1860 dollars) in gold was taken out of this claim. This successful mine would have given the brothers the money to invest in other business opportunities such as Rubicon Soda Springs.

Virginia City

 In 1859, a rich deposit of silver ore was discovered on the slop of a mountain near the Carson River, on the eastern slope of the Sierra Nevada. The location of Virginia City about 15 miles from the eastern shore of  Lake Tahoe, was found by prospectors taking a seasonal break from the gold fields of California. By the mid 1860s, there were over 20,000 people occupying the Comstock Lode also known as Virginia City, Nevada. The Comstock Lode, located about 39 miles northeast of Rubicon Springs, proved to be one of the richest silver ore deposits ever found in the United States. The rise of Virginia City with its enormous wealth and demands for supplies, equipment and people created a new demand for transportation routes across the Sierra Nevada Mountains. The route around the south side of Lake Tahoe over Johnston Pass and onto Placerville and Sacramento known as the Overland Trail became known as the Placerville-Carson Road. The route over Johnston Pass and Echo Summit is now known as U.S. Highway 50.