Lone Cone District

The Lone Cone District is a lead, gold, copper, and silver mine located in Dolores county, Colorado at an elevation of 8,839 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: Lone Cone District
Secondary: Dunton District
Secondary: Patented Claims: Little Wounder, MS 1516
Secondary: Great Bear, MS 12930
Secondary: Lion, MS 12930
Secondary: Sirius, MS 12931
Secondary: Little Emma, MS 12951a
Secondary: Dunton Mill Site, MS 12951b
Secondary: Orion, MS 12953a
Secondary: Orion Mill Site, MS 12953b
Secondary: Otsego Estension, MS 15746a
Secondary: Otsego Mill Site, MS 15746b
Secondary: Otsego, MS 15747a
Secondary: Otsego Extension Mill Site, MS 15747b
Secondary: Gold Nugget, MS 16240a
Secondary: Gold Nugget Mill Site, MS 16240b
Secondary: Como, MS 16246a
Secondary: Como Mill Site, MS 16246b
Secondary: Horlick, MS 17235a
Secondary: Almont, MS 17235a
Secondary: Yule, MS 17235a
Secondary: Priest, MS 17235a
Secondary: Heddle, MS 17235a
Secondary: Smuggler, MS 17235a
Secondary: Lombard, MS 17235a
Secondary: Dick, MS 17235a
Secondary: Lombard Mill Site, MS 17235b
Secondary: Columbia, MS 18486a
Secondary: America, MS 18486a
Secondary: Nil Desperandum, MS 18486a
Secondary: Brooklyn MS 18498
Secondary: Mayflower, Ms18499
Secondary: Susie, MS 18519
Secondary: Nettie, MS 18519
Secondary: Little May, MS 18519
Secondary: Mount Pleasant Mill Site, MS 20539

Commodity

Primary: Lead
Primary: Gold
Primary: Copper
Primary: Silver
Secondary: Coal
Tertiary: Antimony
Tertiary: Zinc
Tertiary: Manganese
Tertiary: Sulfur
Tertiary: Tellurium

Location

State: Colorado
County: Dolores
District: Lone Cone (Dunton) District

Land Status

Land ownership: Private
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: Warren E. Wright, Clifton (Rosebud Mine ; Rado Reef Resources, Stoner (Emma Mine
Years: 1981 -

Production

Not available

Deposit

Record Type: District
Operation Category: Producer
Operation Type: Unknown
Year First Production: 1885
Year Last Production: 1980
Discovery Year: 1880
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: Y
Deposit Size: S

Physiography

General Physiographic Area: Intermontane Plateaus
Physiographic Province: Colorado Plateaus
Physiographic Section: Canyon Lands

Mineral Deposit Model

Model Name: Polymetallic veins

Orebody

Not available

Structure

Type: R
Description: San Juan Uplift, Paradox Basin

Type: L
Description: Rico Dome, Dunton Syncline, Calico Peak Anticline, Dunton Fault, Papoose Fault, Emma Fault, Almont Fault, Unnamed Faults

Alterations

Alteration Type: L
Alteration Text: Silicification Of Sandstone Wall Rocks Near Fissures; Some Oxidayion Of Sulfide Ores

Rocks

Name: Gabbro
Role: Associated
Age Type: Associated Rock
Age Young: Pliocene

Analytical Data

Not available

Materials

Ore: Polybasite
Ore: Argentite
Ore: Coal
Ore: Pyrargyrite
Ore: Chalcopyrite
Ore: Galena
Ore: Stibnite
Ore: Tennantite
Ore: Chalcocite
Ore: Sphalerite
Ore: Pyrite
Gangue: Melanterite
Gangue: Barite
Gangue: Sulfur
Gangue: Epsomite
Gangue: Chalcedony
Gangue: Quartz
Gangue: Gypsum
Gangue: Rhodochrosite

Comments

Comment (Location): MIGUEL MTNS AND NAVAJO BASIN AND UPPER WEST DOLORES RIVER VALLEY. DISTRICT ALSO EXTENDS ONTO RICO (1960) QUAD. ELEV AND LAT-LONG GIVEN ARE FOR DUNTON TOWNSITE (W2 SW SEC. 33, T41N, R11W). ; INFO FROM LAND.ST :1975

Comment (Deposit): DISTRICT LIES BETWEEN INTRUSIVE CENTERS OF SAN MIGUEL MTNS AND THOSE OF PIONEER (RICO) DISTRICT. SEDIMENTARY ROCKS DIP GENERALLY NORTH AND NE, WITH PERMIAN CUTLER FM EXPOSED ON LOWER SLOPES ALONG WEST DOLORES RIVER AND CRETACEOUS DAKOTA SANDSTONE CAPPING MESAS. PROMINENT STRUCTURAL FEATURE IS NNW-SSE-TRENDING ASYMMETRICAL GRABEN EXTENDING FROM SOUTH SIDE OF DUNN PEAK-DOLORES PEAK INTRUSIVE CENTER SE TO NW FLANK OF RICO DOME. DUNTON FAULT BOUNDS GRABEN ON NE AND SPLITS INTO PAPOOSE FAULT EAST OF DUNTON. EMMA FAULT BOUNDS GRABEN ON SW. SEVERAL OTHER FAULTS OR ONE OF TWO FAULTS WITH SPLITS LIE WITHIN GRABEN BUT TOWARD SW SIDE. IN LOWEST STRUCTURAL BLOCK, DUNTON SYNCLINE PRESERVES MANCOS SHALE (UPPER CRETACEOUS) AND DAKOTA SANDSTONE INTRUDED BY LAMPROPHYRE SILL. TOWARD SE, FAULTS DIE OUT IN TRIASSIC SEDIMENTS JUST BEYOND AREA OF HORNBLENDE LATITE SILLS OF RICO DISTRICT. CROSS FAULTS TRENDING NEARLY AT RIGHT ANGLES TO GRABEN SLIGHTLY OFFSET GRABEN FAULTS. PORPHYRITIC LATITE DIKE FOLLOWS

Comment (Deposit): CUTTING PRIMARY ORE. STIBNITE FOUND IN FRACTURES AND AS RADIATING CRYSTAL CLUSTERS ON QUARTZ IN VUG LININGS, BUT PARAGENETIC POSITION UNCERTAIN. UNVERIFIED REPORTS CITE NATIVE SULFUR OF POSSIBLE FUMAROLIC ORIGIN OCCURRING AT SOME MINES. BASTIN (1922) OBSERVED HOT MINE WATERS EVOLVING CO2 AND H2S AND DEPOSITING FERRUGINOUS CALCITE AND SULFATES OF CA, MG, AND AL-FE. ALTHOUGH SECONDARY AG ENRICHMENT NOTED, BASTIN BELIEVED MOST OF AG SULFOSALTS TO BE OF PRIMARY ORIGIN. DEPTH OF OXIDATION AND ENRICHMENT MAY NOT BE FAR DUE TO INHIBITING EFFECT OF HOT, ASCENDING, H2S-BEARING SOLUTIONS. EMMA AND SMUGGLER MINES USED COAL FROM DAKOTA FM ON WEST LIMB OF DUNTON SYNCLINE WHERE IT MAY HAVE BEEN LOCALLY UPGRADED BY LAMPROPHYRE SILL.

Comment (Location): (LAND STATUS AND ADMINISTRATIVE AREA LOCATIONS CALCULATED USING GIS OVERLAY ANALYSIS FOR SAN JUAN N. F.). DISTRICT LIES ALONG WEST DOLORES RIVER FROM DUNTON TO ABOUT 2.5 MILES DOWNSTREAM, AND INCLUDES LOWER PARTS OF PAPOOSE, FALL, EAGLE, AND GEYSER CREEKS, AND SEVERAL UNNAMED TRIBUTARY GULCHES. ISOLATED MINE, ROSEBUD, LIES ALONG SILVER CREEK OR JOHNNY BULL CREEK NNW OF CALICO PEAK SEVERAL MILES TO SOUTH. BUT IS INCLUDED IN LONE CONE DISTRICT ON BASIS OF ORE OCCURRENCE, STRUCTURAL AND HOST ROCK SIMILARITY TO LONE CONE PROPER. DISTRICT ACCESSIBLE VIA ROAD UP WEST DOLORES RIVER FROM NEAR STONER AND VIA DUNTON ROAD ALONG MEADOW CREEK FROM DOLORES RIVER VALLEY 6 MILES NORTH OF RICO; VIA TRAIL UP FISH CREEK AND WILLOW CREEK AND DOWN TRIBUTARY OF COAL CREEK NORTH OF DUNTON; VIA ROAD AND TRAIL SOUTH FROM PLACERVILLE AND SAN MIGUEL RIVER, UP FALL CREEK, AND DOWN UPPER WEST DOLORES RIVER VALLEY; VIA ROAD AND TRAIL FROM VANADIUM AND VANCE JUNCTION ON SAN MIGUEL RIVER SOUTH AND SW OVER SAN

Comment (Development): ALTHOUGH PROSPECTORS HAD TRAVERSED ENTIRE AREA DURING TIME OF RICO DISCOVERIES IN 1870S, NO DISCOVERIES WERE MADE AT DUNTON, PROBABLY BECAUSE OF COVER ON HILLSIDES AND LACK OF EXPOSURES. INITIAL DISCOVERY CREDITED TO JOHN A. GILMORE WHO LOCATED EMMA LODE ON 5/15/80 AND ORIGINALLY NAMED IT LITTLE EMMA. CLAIM WAS RELOCATED ON 5/15/98 BY A. F. ADAMS, EMMA JACKSON, MILLARD GILMORE, ABBIE MESERVY,AND ADELLA TOWNSEND. SECOND DISCOVERY WAS SMUGGLER LODE, LOCATED BY P.K. SCOTT ON 4/16/83;LOCATION WAS AMENDED ON 10/20/00 TO INCLUDE INTERESTS OF RICHARD KELLAR, HORATIO AND MARY DUNTON. DISCOVERIES CAUSED RESPECTABLE BOOM IN 1883, WITH EXTABLISHMENT OF TOWN OF BOWEN ACROSS RIVER FROM EMMA AND SMUGGLER MINES. BOOM WAS SHORT LIVED, AND TOWN COLLAPSED. ALMONT EXTENSION LOCATED 6/26/89 BY A.P. ADAMS, S.W. CLEGG, AND J.P. REES, AMENDED 9/6/01 BY RICHARD KELLAR. PRODUCTION, IF ANY, FROM DISTRICT FROM 1880 TO 1895 WAS CONSIDERED SMALL. RECORDED PRODUCTION BEGAN IN 1896. HENDERSON (1926) REPORTS SMELTER

Comment (Development): AND MILL UNDER CONSTRUCTION AT DUNTON IN 1897; MILL IN OPERATION IN 1898. BULK OF AG AND AU PRODUCTION TOOK PLACE FROM 1896 TO 1913, WITH PB AND CU FIRST BEING PRODUCED IN 1908. PRODUCTION DECREASED FROM 1914 THROUGH WW I, BUT REVIVED FROM 1920 TO 1925 AND 1928 TO 1930. EMMA AND SMUGGLER PRODUCED INTERMITTENTLY FROM 1937 TO 1941; GEYSER GROUP RECORDED SMALL PRODUCTION IN 1950. NO FURTHER ACTIVITY REPORTED IN INTERVENING YEARS AND UNTIL 1970S WHEN SOME EXPLORATION AND DEVELOPMENT WAS DONE BY MINING DEVELOPMENT RESOURCES AT SMUGGLER MINE (1974), WARREN WRIGHT AT ROSEBUD MINE (1981), AND RADO REEF RESOURCES AT EMMA MINE (1979-1980), THE LATTER REPORTING SOME PRODUCTION.

Comment (Deposit): PORTION OF PAPOOSE FAULT; MICROGABBRO DIKES TREND GENERALLY PARALLEL TO EMMA FAULT BOTH INSIDE AND OUTSIDE GRABEN. ALMONT FAULT SPLIT FORMS TRIANGLE WITH EMMA AND CROSS FAULT. THERMAL, FE-BEARING, AND H2S-BEARING SPRINGS ARE ASSOCIATED WITH GRABEN AND CROSS FAULTS. KRANTZ AND FREEMAN (1923) DESCRIBE ORE DEPOSITS AS VEINS AVERAGING 2 FT WIDE AND OLLOWING GRABEN FAULTS, DIPPING STEEPLY SW TO VERTICAL. BUSH AND BROMFIELD (1966) SHOW VERTICAL TO SW DIPS ON ALMONT AND OTHER SUBPARALLEL FAULTS TO SW BUT 80 TO 85 NE DIP ON EMMA VEIN. KRANTZ AND FREEMAN IDENTIFIED TWO PERIODS OF PRIMARY ORE DEPOSITION: (1) SPHALERITE, PYRITE, ARGENTITE (AS INCLUSIONS IN SPHALERITE), AND QUARTZ, FOLLOWED BY SHEARING AND FRACTURING, AND (2) GALENA, CHALCOPYRITE, PYRITE, AND QUARTZ, WITH GALENA DEPOSITED IN FRACTURES AND REPLACING SPHALERITE, FOLLOWED BY SECOND PERIOD OF SHATTERING. NEAR-SURFACE AG ENRICHMENT CAUSED BY SECONDARY DEPOSITION OF PYRARGYRITE, PROUSTITE, ARGENTITE, AND CHALCOPYRITE. IN FRACTURES

Comment (Production): PARTIAL PRODUCTION RECORD. FIGURES UNAVAILABLE BUT CONSIDERED SMALL FOR ANY PRODUCTION FROM 1880 TO 1895. AG PRODUCTION FOR 1896 TO 1903 ESTIMATED BASED ON DIFFERENCE BETWEEN REPORTED DOLORES COUNTY TOTALS AND THOSE FOR PIONEER (RICO) DISTRICT TABULATED BY MCKNIGHT (1974). AG PRODUCTION FOR 1904 TO 1930 DERIVED FROM DIFFERENCE BETWEEN REPORTED ANNUAL DOLORES COUNTY TOTALS AND PIONEER DISTRICT TOTALS. ALL ESTIMATED AU FIGURES FOR 1896 TO 1930 CALCULATED FROM REPORTED VALUES USING AVERAGE PRICE OF $20.65/OZ AU AND DIFFERENCE BETWEEN REPORTED VALUES FOR DOLORES COUNTY AND PIONEER DISTRICT; ROUNDED TO NEAREST TENTH OZ. FIRST PB AND CU PRODUCTION REPORTED IN 1908. ALL ESTIMATED PB AND CU FIGURES FOR 1908 TO 1930 CALCULATED FROM DIFFERENCES BETWEEN REPORTED VALUES FOR DOLORES COUNTY AND PIONEER DISTRICT, USING AVERAGE ANNUAL PRICES/LB FOR PB AND CU AS REPORTED BY HENDERSON FOR 1908-1923 OR USING AVERAGE METALS PRICES CALCULATED FROM YOTAL COUNTY PRODUCTION AND VALUE FOR 1924 AND 1928-1930;

Comment (Production): PB ROUNDED TO NEAREST LB, CU ROUNDED TO NEAREST TENTH LB. FIGURE FOR PB IN 1919 ESTIMATED FROM REPORTED ORE TONNAGE AND GRADE FOR ROSEBUD MINE. FIGURES FOR 1937 AND FROM COLORADO DIV. MINES ANNUAL OPERATOR REPTS. FOR EMMA MINE. FIGURES FOR 1950 REPRESENT PRODUCTION FROM GEYSER GROUP. ORE TONNAGES EITHER NOT REPORTED FOR COUNTY OR NOT REPORTED SEPARATELY BY DISTRICT WITHIN COUNTY. ALL OTHER FIGURES FROM USBM MINERAL YEARBOOKS. NO PRODUCTION REPORTED IN IN DISTRICT FOR 1906, 1917, 1926-1927, 1931-1936, 1939, 1942-1949, 1951-1979, AND AFTER 1980.

Comment (Workings): PRINCIPAL PROPERTIES DEVELOPED BY HILLSIDE DRIFT TUNNELS DRIVEN INTO FISSURES AND VEINS OF GRABEN SYSTEM; SOME HILLSIDE CROSSCUT TUNNELS. SMUGGLER AND EMMA MINES DEVELOPED BY AS MANY AS FIVE LEVELS ON VEIN, INTERCONNECTED BY WINZES AND SHAFTS. OPEN CUTS; MILL SITES; AERIAL TRAM FROM SMUGGLER MINE TO EMMA MILL.

Comment (Deposit): DISTRICTKNOWN MOST COMMONLY BY POPULAR NAME OF "DUNTON," BUT BLM CLAIM RECORDS ASSIGN DISTRICT NAME OF "LONE CONE." LITTLE WOUNDER CLAIM (MS 1516) ORIGINALLY ASIGNED TO PIONEER (RICO) DISTRICT, BUT IS INCLUDED IN LONE CONE ON BASIS OF ACTUALLOCATION NEAR DUNTON. OTHER CLAIMS ASSIGNED TO LONE CONE DISTRICT LIE FARTHER NORTH IN NAVAJO BASIN BUT ARE INCLUDED IN MOUNT WILSON DISTRICT ON BASIS OF DIFFERENT ORE OCCURENCES, HOST ROCKS, AND STRUCTURE. INDIVIDUAL RECORDS PREPARED FOR PRINCIPAL MINES AND PROPERTIES FOR WHICH SOME DESCRIPTIONS AVAILABLE: AMERICA, EMMA, FREE COINAGE, GEYSER, ROSEBUD, AND SMUGGLER. OTHER NAMED PROPERTIES (METAL AND THOSE WITH REPORTED OCCURENCES OF NATIVE S) FOR WHICH NO DESCRIPTIONS AVAILABLE AND NO RECORDS PREPARED INCLUDED B AND M, COMO, CORKSCREW, LITTLE SWAN, MOUNT PLEASANT, POOR BOY, SULFUR KING, TROY, AND YELLOW BEE. ; INFO.SRC : 1 PUB LIT; 2 UNPUB REPT

References

Reference (Deposit): BUSH, A.L., AND BROMFIELD, C.S., 1966, GEOLOGIC MAP OF THE DOLORES PEAK QUADRANGLE, DOLORES AND SAN MIGUEL COUNTIES, COLORADO: USGS MAP GQ-536.

Reference (Deposit): PRATT, W.P., AND OTHERS, 1969, GEOLOGIC MAP OF THE RICO QUADRNAGLE, DOLORES AND NONTEZUMA COUNTIES, COLORADO: USGS MAP GQ-797.

Reference (Deposit): BASTIN,E.S., 1922, SILVER ENRICHMENT IN THE SAN JUAN MOUNTAINS, COLORADO: USGS BULL. 735-D, P. 116-129.

Reference (Deposit): KRANTZ, P.R., AND FREEMAN, W.H., 1923, A STUDY OF THE ORES OF DUNTON DOLORES COUNTY, COLORADO: COLORADO SCHOOL OF MINES THESIS T-503.

Reference (Deposit): HENDERSON, C.W., 1926, MINING IN COLORADO, A HISTORY OF DISCOVERY, DEVELOPMENT, AND PRODUCTION: USGS PROF. PAPER 138, P. 114-117.

Reference (Deposit): COLORADO DIV. MINES INF. REPTS. AND ANNUAL OPERATOR REPTS.

Reference (Deposit): BLM MINERAL SURVEYS

Reference (Production): HENDERSON, 1926, P. 117; MCKNIGHT, 1974, P. 6; USGS/USBM MINERAL RESOURCES OF U.S.; USBM MINERAL YEARBOOKS; COLO. DIV. MINES ANN. OPERATOR REPTS.

Reference (Deposit): MCKNIGHT, E.T., 1974, GEOLOGY AND ORE DEPOSITS OF THE RICO DISTRICT, COLORADO: USGS PROF. PAPER 723.

Colorado Mining Photos

Check out this collection of Colorado's best historic mining photos: Incredible Photos of Colorado Mining Scenes.