Trinidad Mine

The Trinidad Mine is a chromium mine located in San Luis Obispo county, California at an elevation of 1,601 feet.

About the MRDS Data:

All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.

Mine Info

Satelite View

MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.

Site Name

Primary: Trinidad Mine
Secondary: La Trinidad

Commodity

Primary: Chromium

Location

State: California
County: San Luis Obispo

Land Status

Land ownership: Military Reservation
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.

Holdings

Not available

Workings

Type: Surface

Ownership

Owner Name: Camp San Luis Obispo Military Res. Cal. National Guard
Percent: 100.0
Home Office: California
Info Year: 1987

Production

Year: 1954
Description: Concentrates Produced From 1954-1958 9000 Mt @ 47.5% - 2.7:1 Cr:Fe
Year: 1954
Description: Ore Mined From 1954-1958 26200 Mt @ 16%
Year: 1954
Description: Lump Ore Mined From 1954-1958 2600 Mt @ 46% - 2.7:1 Cr:Fe
Year: 1943
Description: Concentrates Produced From 1943-1944 850 Mt @ 45% With 3:1 Cr:Fe
Year: 1917
Description: Lump Ore Mined From 1917-1918 800 Mt
Year: 1880
Description: Lump Ore Mined In 1880'S. 1400 Mt
Year: 1943
Description: Ore Mined From 1943-1944 4200 Mt
Year: 1943
Description: Lump Ore Mined From 1943-1944 50 Mt

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Underground
Mining Method: Unknown
Year First Production: 1880
Discovery Year: 1880
Years of Production:
Organization:
Significant: N

Physiography

General Physiographic Area: Pacific Mountain System
Physiographic Province: Pacific Border Province
Physiographic Section: California Coast Ranges

Mineral Deposit Model

Not available

Orebody

Not available

Structure

Not available

Alterations

Not available

Rocks

Not available

Analytical Data

Not available

Materials

Not available

Comments

Comment (Reserve-Resource): MAT 1 COL 1 TOTAL RESOURCES (C1+C2+C3+C4) MAT 1 COL 2 UPPER ORE BODY MAT 1 COL 3 LOWER ORE BODY MAT 1 COL 4 EAST POD MAT 1 COL 5 WEST POD MATRIX 2 COLUMN 1 REPRESENT 1990 ORE PRODUCTION MATRIX 2 COLUMN 2 REPRESENTS 1990 ORE PRODUCTION FROM TRINIDAD MINE AND INCLUDES DILUTION. MATRIX 2 COLUMN 3 REPRESENTS 1990 ORE PRODUCTION FROM LA PRIMERA MINE AND INCLUDES DILUTION MATRIX 3 COLUMN 1 REPRESENTS 1991 ORE PRODUCTION. ALL PRODUCTION IS FROM THE LA PRIMERA AND INCLUDES DILUTION. MATRIX 4 COLUMN 1 REPRESENTS 1992 ORE PRODUCTION. MATRIX 4 COLUMN 2 REPRESENTS 1992 ORE PRODUCTION FROM LA PRIMERA AND INCLUDES DILUTION. MATRIX 4 COLUMN 3 REPRESENTS 1992 ORE PRODUCTION FROM THE CASTRO MINE AND INCLUDES DILUTION. MATRIX 5 COLUMN 1 REPRESENTS 1993 ORE PRODUCTION. MATRIX 5 COLUMN 2 REPRESENTS 1993 ORE PRODUCTION FROM THE CASTRO MINE AND INCLUDES DILUTION. MATRIX 5 COLUMN 3 REPRESENTS 1993 ORE PRODUCTION FROM THE EUCALYPTUS MINE AND INCLUDES DILUTION. MATRIX 6 COLUMN 1 REPRESENTS 1994 ORE PRODUCTION. MATRIX 6 COLUMN 2 REPRESENTS 1994 ORE PRODUCTION FROM THE EUCALYPTUS MINE AND INCLUDES DILUTION. MATRIX 6 COLUMN 3 REPRESENTS 1994 ORE PRODUCTION FROM THE NORCROSS MINE AND INCLUDES DILUTION. MATRIX 7 COLUMN 1 REPRESENTS 1995-2000 ORE PRODUCTION AT 52,000 TPY. ALL PRODUCTION IS FROM THE NORCROSS MINE AND INCLUDES DILUTION. MATRIX 8 COLUMN 1 REPRESENTS 2001 ORE PRODUCTION. MATRIX 8 COLUMN 2 REPRESENTS 2001 ORE PRODUCTION FROM THE NORCROSS MINE AND INCLUDES DILUTION. MATRIX 8 COLUMN 3 REPRESENTS 2001 ORE PRODUCTION FROM THE SWEETWATER MINE AND INCLUDES DILUTION. MATRIX 9 COLUMN 1 REPRESENTS 2002 ORE PRODUCTION AND INCLUDES DILUTION. ALL 2002 PRODUCTION IS FROM THE SWEETWATER MINE.

Comment (Environmental Factors): CHROMITE DEPOSITS IN THE CHORRO CREEK WATERSHED ARE NOT SULFIDES WITH POTENTIAL TO GENERATE ACID MINE DRAINAGE THOUGH THEY MAY ERODE CHROMIUM, ALUMINUM, MAGNESIUM, IRON, MANGANESE, TITANIUM, CALCIUM, SILICON, AND NICKEL TO THE WATERSHED. METALS WHICH APPEAR TO BE ERODING FROM INACTIVE MINES INCLUDE MAGNESIUM, IRON, NICKEL, AND CHROMIUM. SAN LUISITO CREEK, PENNINGTON CREEK, AND UPPER CHORRO CREEK APPEAR TO BE THE MOST HEAVILY MINE-IMPACTED TRIBUTARIES IN THE CHORRO CREEK WATERSHED.

References

Reference (Deposit): CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD, CENTRAL

Reference (Deposit): COAST REGION. SURFACE WATER DEGRADATION BY INACTIVE

Reference (Deposit): METAL MINES IN NORTHWEST SAN LUIS OBISPO COUNTY, CA,

Reference (Deposit): DECEMBER 1993 (P. 6-8).

Reference (Deposit): CALIF. STATE MINING BUR. BULLETIN 76, 1918, P. 171.

Reference (Deposit): CALIF. JOUR. MINES AND GEOL. V. 37, 1941, P. 163.

Reference (Deposit): U.S. BUREAU OF MINES RI 4783, 1951, P. 5-6.

Reference (Deposit): CALIF. DIV. MINES BULLETIN 134, 1953, PART II, CHAPT. 2,

Reference (Deposit): P. 63-64.

California Gold

"Where to Find Gold in California" looks at the density of modern placer mining claims along with historical gold mining locations and mining district descriptions to determine areas of high gold discovery potential in California. Read more: Where to Find Gold in California.