John C. Frémont had a Spanish land grant that gave him ownership of most of the Mariposa mining district, but the possibility of securing his property was nearly impossible due to the huge influx of gold seekers, and little or no enforcement from the few law keepers available. In book #1 of Mariposa county records, originally filed in Aqua Fria, on Page 2, there is a claim known as the Spencer quartz mine and adjacent millsite. This claim was just hundreds of feet from Fremonts grant line, and its owners were Lafayette H. Bunnell, and Champlain Spencer, who became rather wealthy from the placer gold in Whitlock and Sherlocks creek. They later erected a 40' waterwheel and steam mill, along with several arrastras. Mr. Bunnell later published a memoir of his time in Midpines and entry to Yosemite valley, which is still in print today - "The Discovery of the Yosemite". Mr. Spencer has never been acknowledged as having named Half Dome, a prominent feature in Yosemite valley. These educated gentlemen and adventurers eventually sold "Spencers Mill" to a French and English conglomerate for a tidy sum. All is quiet now on Spencers mill, but much evidence of a series of mills and the arrastras remain.