This is a detailed map of a proposed mining operation in Mariposa County, California. It shows topography, towns, mines, and even John C. Frémont’s residence.
The map was originally published in The Mariposa Company, 34 Wall Street, New York. James Hoy, President… Organized 25th June, 1863, an elaborate prospectus for the mining property known as the Mariposa Estate. The Mariposas scheme was the brainchild of Frémont, who saw it as the making of his fortune, but who was ultimately bankrupted by it. In January 1863, Frémont, then a Major-General in the Union Army, sold Rancho Las Mariposas with its mines and infrastructure to Morris Ketchum, a New York City banker, who formed a public corporation, the Mariposa Company, and sold stock. In 1863, Frederick Law Olmsted, noted New York landscape architect, came to Mariposa as superintendent for the Mariposa Company. Olmsted was not a mining expert. Investments were made in stamp mills, tunnels, shafts, and the other infrastructure related to the mining towns. By 1865, the Mariposa Company was bankrupt, Olmsted returned to New York, and mines were sold at a sheriff’s sale.