In December 1863, Indians showed James Daley and R.V. Craig the location of silver in the Paradise Range, and the following year the Mammoth Mining District was organized. A townsite called Mammoth was laid out in February 1864, but it was soon renamed Weston. Nearby two other camps developed, known as Upper Weston/Summit City and Ellsworth. Before long, the three camps were consolidated to form one larger town, called Ellsworth.

The town grew slowly throuth the 1860s, though it did gain a post office in 1866. The boom finally came in 1870, when a new ten-stamp mill was placed into operation. The population quickly grew to over 200, and over thirty permanent buildings had been constructed. Camels hauled ore, and a stage and freight line made trips to and from Wadsworth.

By 1872, ore quality decreased and the mill only operated sporadically before closing in 1874. It reopened briefly in 1877 to process tailings and ore from the Alexander mine in Grantsville, but once they completed their own mill that November Ellsworth fell silent. The post office closed in 1884, and in April 1895 the mill was dismantled and moved to Union.

For the next several decades, Ellsworth saw only intermittent activity, but none lasted. In 1906, Oliver Boyd made a small strike to the east and a camp of thirty called Corrine was formed, but it disappeared by the end of the year. In 1910, the Return mine was reopened, followed by the reopening of the Mexican mine by the Bluebird Consolidated Mining Co. in 1916. By 1919, $57,000 was recovered and in the early 1920s the mill was moved from Liberty. It proved to be a failure, and the Company folded. The last activity began in 1924, when the New Return Mining Company operated a 12-stamp mill and cyanide plant until 1926. With the exception of minor, inconsistent work until 1944, Ellsworth was abandoned.