Silver Reef Group

The Silver Reef Group is a silver, copper, and lead mine located in La Plata county, Colorado at an elevation of 10,971 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

Name: Silver Reef Group  

State:  Colorado

County:  La Plata

Elevation: 10,971 Feet (3,344 Meters)

Primary Mineral: Silver, Copper, Lead

Lat, Long: 37.48111, -107.47694

Map: View on Google Maps

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.


Satelite image of the Silver Reef Group

Silver Reef Group MRDS details

Site Name

Primary: Silver Reef Group
Secondary: Three Jacks Group
Secondary: Red Bird Group
Secondary: Shy Claims
Secondary: Chance Group
Secondary: Silverreef Mine
Secondary: Mary Murphy Mine


Commodity

Primary: Silver
Primary: Copper
Primary: Lead
Secondary: Gold
Tertiary: Zinc


Location

State: Colorado
County: La Plata
District: Runlett Peak-Cave Basin Area


Land Status

Land ownership: National Forest
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.
Administrative Organization: San Juan N. F.


Holdings

Not available


Workings

Not available


Ownership

Owner Name: Hinsdale Mining, Milling, And Smelting Co.
Home Office: Bayfield, Co.
Years: 1929 -


Production

Not available


Deposit

Record Type: Site
Operation Category: Past Producer
Deposit Type: Replacement
Operation Type: Unknown
Year First Production: 1913
Year Last Production: 1928
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: S


Physiography

General Physiographic Area: Intermontane Plateaus
Physiographic Province: Colorado Plateaus
Physiographic Section: Navajo Section


Mineral Deposit Model

Model Name: Polymetallic replacement


Orebody

Not available


Structure

Type: R
Description: San Juan Uplift, San Juan Basin

Type: L
Description: Unnamed Faults


Alterations

Alteration Type: L
Alteration Text: Oxidation Of Fe And Base-Metal Sulfide Minerals


Rocks

Name: Limestone
Role: Host
Age Type: Host Rock
Age Young: Late Devonian


Analytical Data

Analytical Data: 576-LB ORE SHIPMENT CONTAINED 0.2 OZ/TON AU, 38.2 OZ/TON AG, 24% CU, 4% PB
Analytical Data: STEVEN AND OTHERS' (1969) SAMPLE FROM 5-TON STOCKPILE CONTAINED 0.01 OZ/TON AU, 0.64 OZ/TON AG, 2.84% CU, 0.46% PB, 5.88% ZN. FOUR ORE ASSAYS FROM SILVER REEF GROUP: 1478-LB SHIPMENT CONTAINED 0.4 OZ/TON AU, 48.9 OZ/TON AG, 30% CU, 4.8% PB
Analytical Data: 4298-LB ORE SHIPMENT CONTAINED 0.01 OZ/TON AU, 75 OZ/TON AG, 3% CU.
Analytical Data: 19140-LB ORE SHIPMENT CONTAINED 0.01 OZ/TON AU, 75 OZ/TON AG, 3% CU
Analytical Data: 2478-LB ORE SHIPMENT CONTAINED 0.01 OZ/TON AU, 125 OZ/TON AG, 4% CU
Analytical Data: SELECTED ORE SAMPLE CONTAINED 25% CU AND 592 TO 1103 OZ/TON AG. FOUR ORE ASSAYS FROM THREE JACKS GROUP: 704-LB ORE SHIPMENT CONTAINED 0.02 OZ/TON AU, 620 OZ/TON AG, 28% CU
Analytical Data: 9332-LB ORE SHIPMENT CONTAINED 0.02 OZ/TON AU, 10.4 OZ/TON AG, 12% CU, 3.4% PB


Materials

Ore: Galena
Ore: Malachite
Ore: Sphalerite
Ore: Smithsonite
Ore: Chalcocite
Gangue: Limonite
Gangue: Siderite
Gangue: Hematite
Gangue: Calcite


Comments

Comment (Workings): SILVER REEF WORKINGS: 100-FT NW-HEADING CROSSCUT TUNNEL; 25 FT HIGHER IS DRIFT DRIVEN 50 FT WEST, THENCE 50 FT SOUTH; 25 FT HIGHER IS SECOND DRIFT DRIVEN 50 FT WEST, AT 25 FT FROM PORTAL IS 25-FT-HIGH GLORY HOLE CONNECTING WITH 40-FT CROSSCUT TUNNEL TO SURFACE. CHANCE GROUP WORKINGS: 40-FT VERTICAL SHAFT. SHY CLAIMS WORKINGS: UNKNOWN. RED BIRD GROUP WORKINGS: TRENCH, OPEN CUT, 137 FT OF DRILLING. THREE JACKS GROUP WORKINGS: 225-FT CROSSCUT TUNNEL DRIVEN EASTWARD WITH 30-FT NORTH DRIFT AT 150 FT, 10-FT NORTH AND 10-FT SOUTH DRIFTS AT 190 FT; 75 FT WEST OF PORTAL IS 50-FT VERTICAL SHAFT.

Comment (Commodity): PB AND ZN SULFIDES UNVERIFIED; CDM CITES PB-ZN CARBONATE ORE ON CHANCE GROUP DUMP

Comment (Production): PARTIAL PRODUCTION RECORD. FIRST SET OF ANNUAL ORE FIGURES IS FOR SILVER REEF GROUP, YEAR OR YEARS UNKNOWN; SECOND SET IS FOR THREE JACKS GROUP, YEAR OR YEARS UNKNOWN. STEVEN AND OTHERS CITE CUMULATIVE PRODUCTION FOR 1913-1916, 1921, 1924, AND 1928.

Comment (Location): (LAND STATUS AND ADMINISTRATIVE AREA LOCATIONS CALCULATED USING GIS OVERLAY ANALYSIS FOR SAN JUAN N. F.). FROM SOUTH SIDE OF CAVE BASIN CREEK SOUTHWARD TO RUNLETT PEAK, WEST ACROSS COUNTY LINE AND ACROSS UPPER REACHES OF INDIAN CREE, INCLUDING TUCKERVILLE. ELEV AND LAT-LONG GIVEN ARE FOR COMMON CORNER OF SECS. 07, 18, 12, AND 13 (HINSDALE CO.). ; INFO FROM LAND.ST :1974

Comment (Deposit): CAMBRIAN-PERMIAN SEDIMENTARY SECTION DIPS SW AND OVERLIES PRECAMBRIAN SEQUENCE OF IRVING FM AND VALLECITO CONGLOMERATE. REPLACEMENT TYPE SULFIDES FOUND IN LOWER PART OF SECTION IN 50-FT-THICK HEMATITIC SANDY LIMESTONE IN EITHER ELBERT FM OR OURAY LIMESTONE LESS THAN 100 FT STRATIGRAPHICALLY ABOVE PRECAMBRIAN UNCONFORMITY. BED CONTAINS RELATIVELY SMALL FAULT-CONTROLLED DEPOSITS. GENERALLY N 15 E-TRENDING FAULT LIES NORTH OF AREA AND WEST OF EMERALD LAKE; N 65 TO 80 E-TRENDING FAULT DISPLACES PALEOZOIC SEDIMENTS AGAINST PRECAMBRIAN ON RUNLETT PEAK.


References

Reference (Deposit): STEVEN, T.A., AND OTHERS, 1969, MINERAL RESOURCES OF THE SAN JUAN PRIMITIVE AREA, COLORADO: USGS BULL. 1261-F, P. 53, 110, 113.

Reference (Deposit): COLORADO DIV. MINES INF. REPTS.

Reference (Production): COLORADO DIV. MINES INF. REPTS. (ANNUALS); STEVEN AND OTHERS, 1969, P. 113 (CUMULATIVE)