Rich mines of the Rancho las Mariposas

The Great Trees by Albert Bierstadt

In 1863 John Fremont sold the Rancho las Mariposas and all the mine holdings to Morris Ketchum, a New York Banker who formed the Mariposa Mining Corporation. The company was so poorly managed that by 1865 it was bankrupt and the mines had to be sold at a sheriff’s auction. The final resolution of the rancho ran from the Merced River to Bridgeport. At it’s widest it lay about seventeen miles across and averaged five from east to west. The other towns there included Guadalupe, Arkansas Flat, Agua Fria, Princeton, and Mount Ophir.

In the southeast corner was Mariposa, eighty miles southeast of Stockton. Here there was a quartz lode that was extraordinarily rich with massive pockets of gold. Thirteen miles northwest of Mariposa were the Pine Tree Mine and the Josephine Mine sitting on the southern end of the mother lode. Halfway between them was the Princeton Mine, one of the most productive in California. The Mount Ophir Mine was also on the mother lode but Bear Valley and a number of other operations were on separate veins or on branches of the mother lode so remote as to be seen as independent.

Stamp Mill at the Mount Ophir Mine



  1. Evan Rahilly says

    Does anyone have any photos of the Princeton Mine? I would appreciate your sharing. Thank You, Evan

Speak Your Mind


This site uses Akismet to reduce spam. Learn how your comment data is processed.