Mt. Bullion, CA

Mt. Bullion is a Mariposa County census-designated place about five miles northwest of Mariposa, in the foothill country where old Mother Lode roads and mining districts shape the map. The community began in the early 1850s as La Mineta, a rich placer camp; after the Princeton Mine opened in 1852, the settlement was also called Princeton. Mt. Bullion first referred to the local post office, and the name became established after the Princeton Mine closed sometime after 1862. The modern CDP is small—154 people in 2020—but its name carries the memory of a much busier gold landscape.

The wider Mt. Bullion District reaches back to mining by people of Spanish descent beginning in 1848 and sits largely within the former Las Mariposas land grant. Gold work continued through the 1850s and 1870s, returned in a major way around 1900–1920, and left nearby traces such as the ghost town of Mount Ophir and the ruins of its early mint. Today Mt. Bullion is a small foothill community tied to Mariposa for services, with ranch roads, wooded parcels, and historic mine country supplying the everyday setting. It is less a conventional town center than a living address inside a layered mining district, where La Mineta, Princeton, and Mt. Bullion remain three names for the same long local story.