The Twin Sisters Mine is a 1-hour drive from Grass Valley-Nevada City, the county seat of Nevada County, CA in the northern Sierra Nevada Mountains.
It is located off a well-maintained US Forest Service Road (German Bar Road) , roughly 5 miles from Graniteville Road, one of the major east-west roads on San Juan Ridge. The mine is between 3800-5200 feet in elevation.

The Twin Sisters Mine is one of a small number of mine in the famous Alleghany MD that produce highly-prized gold/quartz slabs-identical in quality to the 16to1 Mine’s gold/quartz slabs. Specifically, the pure white matrix and bright yellow gold specimens which are typically found in “lode pocket deposits” of several ounces to hundreds of ounces and are considered the highest quality in the world for cutting into slabs. The gold slabs were sold by previous owners to jewelers and lapidarists to create one-of-a-kind cabochon jewelry pendants and earrings at a significantly higher gold price because of their unique nature as natural gold specimens and use in precious metal jewelry. Sale Price $2,000,000. Price subject to negotiation.

The lode gold pockets are found along the Twin Sisters Vein System, which exists on the western margin of the Melones Fault Zone, the producer of California’s “world-class gold specimens”.

The Twin Sisters Mine operated intermittently from the mid-1860's until the 1990’s. During its long exploration and production history, high-grade gold pockets exceeding 2,000 ounces have been discovered and extracted.

The current Twin Sisters Mine USFS Plan of Operations and Reclamation Plan document awaits final approval in 2024 by the USFS and Nevada County. The mine is in good standing with CA-SMARA requirements. The Central Valley Water Control Board – Storm Water Plan has been submitted for exploration-phase operations by the current operators.