Location and history
Clearinghouse is in central Mariposa County a few miles west of El Portal and Yosemite National Park. It was named for the Clearinghouse mine, the largest source of gold in the district. The Merced River, which Rows through the area, was extensively placer-mined during the gold rush. The Clearinghouse mine was discovered in 1860 and worked on a fairly large scale until about 1880. There was mining activity again during the early 1900s and 1930s, and there has been intermirtent prospecting and development work since. Substantial quantities of limestone and barite and some tungsten are found here. At one time the Yosemite Valley Railroad extended through the area to El Portal, the line's eastern terminus. From El Portal, passengers were taken by stage to Yosemite Valley.
Geology and ore deposits
The principal rocks underlying the district are graphitic schist, slate, quartzite, and hornfels of the Calaveras Formation (Carboniferous to Permian). There are some granitic dikes, and the main mass of the Sierra Nevada granitic batholith is a few miles to the east. The gold deposits occur in north-striking quartz veins that usually range from one to five feet in thickness. The ore contains free gold and often abundant sulfides. Appreciable amounts of high-grade ore have been found here, and milling-grade ore commonly contained one ounce or more of gold per ton. Several of the veins have been developed to inclined depths of about 1200 feet.
Mines
Clearinghouse $3.35 million, Gold Star, Old Timer, Rutheford and Cranberry, South Cranberry, Uncle Jim, West Rutherford.
Bibliography
Bowen. O. E., Jr., 1957, Mariposa County, lode mines: California Jour. Mines and Geology, vo1. 53, pp. 72-187.
Laizure, C. McK, 1928, Mariposa County, gold lode mines: California Div. Mines ond Mining Rept 24, pp. 79-122.
