Eastern Mojave Vegetation Rinconada Mine, San Luis Obispo County, California  
 

Edited by Tom Schweich  

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Literature Cited
 Describes the Rinconada Mine of San Luis Obispo County, California
  federal records show production began in 1872
  an inefficient furnace was installed in 1876; and operations occurred intermittently for the following 11 years

Literature Cited:
- California State Mining Bureau, State Mineralogist, 1890.

Other articles: Pozo Road near Rinconada Mine

Locations: Rinconada Mine.  

The Tenth Annual Report of the State Mineralogist (1890) says this about the Rinconada Mine:
This is sometimes canned the San Jose Valley Mine, and it is situated on the eastern slope of the Santa Lucia Mountains, and toward the San Jose Valley on the Salinas River.

The mines, consisting of seven claims, were located in 1872, at the time of the quicksilver excitement. They were held in high esteem. Much was expended on them and much work done, but the usual charge of incompetency and extravagance was made, and thus the closing was accounted for.

  operations were believed to have been conducted in 1897
  operations were believed to have been conducted from 1915 until 1917

Literature Cited:
- Bradley, Walter W., 1918.

Locations: Rinconada Mine.  

Quicksilver Resources of California (1918) describes the Rinconada Mine as follows:
Rinconada Mine (also called San Jose Valley Mine). Mrs. Theresa L. Bell, owner, San Jose; C. B. Claus, lessee, Santa Margartia. This group of 4 patented claims, names San Jose, Rincon, Tres Amigos, and Livermore, is in Secs. 21 and 28, T. 30 S. R 14 E., M. D. M. 11 miles southeast of Santa Margarita. It is, as noted in the introduction to San Luis Obispo, quite apart from the main quicksilver district of this county which is in the northwestern part.
The property was located in 1872 and in 1876 was equipped with a furnace of the old sheet-iron type, with 5 sheet-iron condensors. The designed attempted to keep the mercury vapor separated from the fuel smoke, but the only definite result achieved appears to have been the salivation of the furnace employees. It is said that little if any quicksilver was recovered, and the plant was abandoned in 1883. In 1897, two benches of 10-pipe retorts were put up; some rich ore treated and a small production made, but no definite figures of which are now obtainable. The upper tunnel, said to be 75' long, is now caved and inaccessible. Two intermediate adits were driven 40' and 25' respectively, and there is a lower adit 400' long as well as several shorter ones and open cuts.
The country rock is loargely serpentine, but some shale exposures are found in the bed of a creek about a quarter of a mile west of the main workings. The mine is in a basin formed by a bend of the mountain ridge. Through this basin runs a line of outcrops showing boldly in places. The face of the lowest adit is at the contact of the serpentine and sandstone. The ore thus far worked is stated to habe occurred in small rich bunches, at times nearly solid cionnabar. Pyrite, calcite, dolomite, quartz and organic matter accompany the ore. It is to some extent disseminated, but usually occupies cracks in the rocks, which it often only partly fills. A formet employee at the retort says that some ore gave 5 flasks from 2 1/2 tons and in a few cases as muchas 65 to 80 pounds were obtained from a single charge in one pipe/. Some samples which have been assayed carried a little silver and iron sulphide with $2.60 per ton in gold, besides the quicksilver. A little ore was mined in 1915 and hauled to the retort in a sled. The capacity of the retorts is 3 1/2 tons per day. Fuel is easily obtainable nearby, but timbers for mining are scarce.
Bibl: Cal. State Min. Bur., Reports X, p. 581; XII, p. 366; XIII, p. 531; XV, p 719, Chapter rep. bien. period, 1915-1916, p. 125; Bull. 27, p. 166. U. S. G. S., Mon. XIII, p.381.
  In 1920, the 4-foot by 54-foot rotary furnace was installed, and it operated intermittently for a decade with various entities making improvements to the plant.
  In 1930, a fire destroyed the plant, but it was rebuilt and operations continued

Literature Cited:
- California State Division of Mines, 1939.  

 

Literature Cited:
- Eckel, E.B., Granger, A.E., and Yates, R.G., 1941.  

1943 and 1944, the mine was operated as part of the war effort

Literature Cited:
- Eckel, E.B., Granger, A.E., and Yates, R.G., 1941.  

The Rinconada mine consists of 7000 feet of underground workings (Bureau of Mines, 1965) on at least four levels through serpentine, sandstone, and shale (Eckel et al., 1941).

Literature Cited:
- Yates, R. G., 1943.  

 
  operations were documented from 1951 until 1961

Literature Cited:
- Collier, J.T., and E. H. Pampeyan, 1954.  

 
  from 1965 until 1968
  Although the mill building was consumed by the Las Pilitas wildfire in 1985, the foundation, retort, condenser structure, rotary oven, and related structures remained intact

Literature Cited:
- Olsen, J., and J. J. Rytuba, 2003.
- Rytuba, J.J., 2003.  

 

Literature Cited:
- Ecology & Environment, 2004.
- Lockheed Martin, 2004.  

 

Literature Cited:
- Ecology & Environment, 2005a.  

 

Literature Cited:
- Ecology & Environment, 2005b.  

 

Literature Cited:
- Rytuba, J.J., 2005.  

 

Literature Cited:
- Johnson, T., 2006.  

 

Literature Cited:
- DeGraff, Jerome V., Michele Rogow, and Pat Trainor, 2007.  

 

Full Size ImageView northwest across the Rinconada Mine.  
 

Full Size ImageUpper area, possibly daylighted adit, at the Rinconada Mine  
 

Full Size ImageLargest pit at the Rinconada Mine.  
 

Full Size ImageMill area at Rinconada Mine  
 

Full Size ImageFurnace at Rinconada Mine  
 

Full Size ImageCondensers at Rinconada Mine  
 
 

Literature Cited

  A list of all literature cited by this web site can be found in the Bibliography.
  Bradley, Walter W. 1918. Quicksilver Resources of California. Bulletin No. 78. San Francisco, CA: California State Mining Bureau, 1918. {TAS}
  California State Division of Mines. 1939. California Journal of Mines and Geology. 35(4):445.
  California State Mining Bureau, State Mineralogist. 1890. Tenth Annual Report of the State Mineralogist. Sacramento, CA: State Office, 1890. {TAS-pdf}
  Collier, J.T., and E. H. Pampeyan. 1954. Rinconada Mine, Rinconada District, San Luis Obispo, California. 1954.
  DeGraff, Jerome V., Michele Rogow, and Pat Trainor. 2007. Approaches to contamination at mercury mill sites: Examples from California and Idaho. pp. in DeGraff, J.V., ed. Understanding and Responding to Hazardous Substances at Mine Sites in the Western United Sta. Reviews in Engineering Geology. XVII. Boulder, CO: Geological Society of America, 2007. {TAS-pdf}
  Eckel, E.B., Granger, A.E., and Yates, R.G. 1941. Quicksilver deposits in San Luis Obispo County and southwestern Monterey County California. United States Department of Interior Bulletin 922-R. Washington, D.C.: United States Government Printing Office.
  Ecology & Environment. 2004. Removal assessment report, Rinconada mine, San Luis Obispo County, California. Region 9 START for United States Environmental Protection Agency. San Francisco, California.
  Ecology & Environment. 2005a. Rinconada removal action report. Region 9 START for United States Environmental Protection Agency. Long Beach, California.
  Ecology & Environment. 2005b. Rinconada mine creek restoration, CY5 summary report. Region 9 START for United States Environmental Protection Agency. Long Beach, California.
  Johnson, T. 2006. Rinconada mine creek excavation and restoration. Las Vegas, Nevada: United States Environmental Protection Agency.
  Lockheed Martin. 2004. Sample results (updated), Rinconada mercury mine. New Jersey: Lockheed Martin REAC for United States Environmental Protection Agency.
  Olsen, J., and J. J. Rytuba. 2003. Geochemistry of mine tailings and sediment samples downstream from the Rinconada mercury mine, California. Menlo Park, California: U.S. Geological Survey and U.S. Bureau of Land Management.
  Rytuba, J.J. 2003. Environmental impact of mercury mines in the Coast Ranges, California. U.S. Geological Survey Circular 1248, Geologic studies of mercury by the U.S. Geological Survey.
  Rytuba, J.J. 2005. Summary of chemistry of sediment and waters sampled in mine and Rinconada Creeks. Internal report to Bureau of Land Management. Menlo Park, California: U.S. Geological Survey.
  Yates, R. G. 1943. Notes on the Rinconada mine, San Luis Obispo County, California.
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Date and time this article was prepared: 10/6/2017 5:58:59 PM