May Rose Mine

The May Rose Mine is a gold and silver mine located in La Plata county, Colorado at an elevation of 10,600 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: May Rose Mine
Secondary: Uncle Sam Mine, Saxon Mine
Secondary: Unpatented Claims: Acropolis
Secondary: Acropolis Extension
Secondary: Big Bertha
Secondary: Cresson
Secondary: Ideal
Secondary: Protection
Secondary: Mayflower
Secondary: Mayflower No. 1
Secondary: May Rose
Secondary: Mammoth
Secondary: Model
Secondary: Silver King
Secondary: Tennie
Secondary: Uncle Sam
Secondary: Uncle Sam No. 1
Secondary: Yuletide

Commodity

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

Location

State: Colorado
County: La Plata
District: California (La Plata) District

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: Amparo Mining Co.
Home Office: Philadelphia, Pa.
Years: 1937 -

Production

Year: 1921
Description: Ap_Grade: ^1.1 Oz/Ton Au, 2823.08 Oz/Ton Ag
Year: 1921
Description: Ap_Grade: ^1.59 Oz/Ton Au, 2.2 Oz/Ton Ag
Year: 1917
Description: Ap_Grade: ^12.1 Oz/Ton Au, 14.4 Oz/Ton Ag
Year: 1917
Description: Ap_Grade: ^0.84 Oz/Ton Au
Year: 1911
Description: Ap_Grade: ^3.10 Oz/Ton Au, 1.5 Oz/Ton Ag

Deposit

Record Type: Site
Operation Category: Past Producer
Deposit Type: Vein
Operation Type: Unknown
Year First Production: 1887
Year Last Production: 1921
Discovery Year: 1885
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 veins

Orebody

Not available

Structure

Type: R
Description: San Juan Uplift, Four Corners Platform

Type: L
Description: La Plata Dome

Alterations

Alteration Type: L
Alteration Text: Oxidation Of Pyrite To Limonite

Rocks

Name: Syenite
Role: Associated
Age Type: Host Rock Unit
Age Young: Late Permian

Name: Syenite
Role: Associated
Age Type: Host Rock
Age Young: Late Permian

Name: Syenite
Role: Associated
Age Type: Associated Rock
Age Young: Eocene

Analytical Data

Analytical Data: OTHER MAY ROSE ASSAYS RANGED FROM 0.04 TO 0.76 OZ/TON AU WITH HIGHS OF 3.7 AND 681 OZ/TON AU, AND TRACE TO 7 OZ/TON AG WITH HIGHS OF 69 AND 88.8 OZ/TON AG, 1.5% CU, AND SOME PB
Analytical Data: WINZE CONTAINED 0.28 TO 4.8 OZ/TON AU WITH HIGHS OF 18.00, 61.72, AND 106.78 OZ/TON AU, AND 1.0 TO 7.0 OZ/TON AG WITH HIGHS OF 95.24 AND 312.3 OZ/TON AG
Analytical Data: CARAMOUZIS TABULATED ASSAYS FROM VARIOUS PROPERTIES. MAY ROSE VEIN ALONG TUNNEL AND RAISE CONTAINED 0.3 TO 1.2 OZ/TON AU WITH HIGHS OF 6.24 TO 6.80 OZ/TON AU, AND 0.2 TO 0.4 OZ/TON AG WITH HIGH OF 2.2 OZ/TON AG
Analytical Data: MAY ROSE DUMP SAMPLES CONTAINED 2.04 TO 2.08 OZ/TON AU. UNCLE SAM VEIN ASSAYED 0.4 TO 5.75 OZ/TON AU AND 0.02 TO 1.9 OZ/TON AG. SILVER KING VEIN ASSAYED 0.16 TO 1.0 OZ/TON AU AND TRACE TO 0.12 OZ/TON AG. ACROPOLIS VEIN ASSAYED 0.66 TO 4.92 OZ/TON AU, 0.09 TO 15.3 OZ/TON AG, 2.6 TO 2.8% CU, 8.5% PB. SMELTER RETURNS FROM ACROPOLIS ORE GAVE 0.44 TO 0.56 OZ/TON AU, 5.8 TO 6.2 OZ/TON AG, 0.07 TO 1.2% CU, 0.06 TO 0.08% PB, 2.4 TO 3.2% ZN.

Materials

Ore: Chalcopyrite
Ore: Sphalerite
Ore: Galena
Gangue: Quartz

Comments

Comment (Workings): PROPERTIES DEVELOPED BY NUMEROUS OPEN CUTS, SHORT TUNNELS, AND SEVERAL SHAFTS. ACROPOLIS CLAIM: 25-, 30-, 40-, 40-, AND 75-FT TUNNELS; ACROPOLIS EXTENSION CLAIM: 20-, 35-, AND 75-FT TUNNELS AND SHAFT OF UNKNOWN DEPTH; CRESSON CLAIM: 130-FT TUNNEL; IDEAL CLAIM: 65- AND 90-FT TUNNELS; MAYFLOWER CLAIM: 25-FT TUNNEL; MAYFLOWER NO. 1 CLAIM: 10-, 15-, AND 15-FT TUNNELS; MAY ROSE CLAIM: 40- AND 150-FT TUNNELS, 60-FT SHAFT, ONE SHAFT OF UNKOWN DEPTH; MAMMOTH CLAIM: 200-FT TUNNEL; MODEL CLAIM: 40-FT TUNNEL; SILVER KING CLAIM: 15-FT TUNNEL; TENNIE CLAIM: 50-FT TUNNEL; UNCLE SAM CLAIM: 154- AND 237-FT TUNNELS AND 175-FT TUNNEL WITH 280FT OF DRIFT; YLETIDE CLAIM: 15-FT TUNNEL, AMPARO ADIT DRIVEN GENERALLY S 30 W FOR 700 FT TO FACE, WITH WINZES AT 160 AND 360 FT FROM PORTAL.

Comment (Deposit): Discovery Year: 1880S

Comment (Deposit): COUNTRY ROCK CONSISTS OF METAMORPHOSED CUTLER FM RED BEDS INTRUDED BY DIORITE-MONZONITE PORPHYRY SILLS GRADING INTO SYENITE. STEEPLY DIPPING VEINS STRIKE PREDOMINANTLY NW WITH A FEW AT NE AND CONSIST OF FRACTURE ZONES 0.5 TO 5 FT WIDE IN THOROUGHLY BRECCIATED AND SILICIFIED ROCK. ABUNDANT PYRITE FILLS BRECCIA-FRAGMENT INTERSTICES AND FORMS VEINLETS. ORE OXIDIZED TO LIMONITE NEAR SURFACE.

Comment (Location): (LAND STATUS AND ADMINISTRATIVE AREA LOCATIONS CALCULATED USING GIS OVERLAY ANALYSIS FOR SAN JUAN N. F.). CLAIMS LIE ALONG NEPTUNE CREEK FROM LA PLATA RIVER CONFLUENCE SE ONTO BRAGDON RIDGE AND INTO BURNT CREEK DRAINAGE, 0.5 TO 1.7 MILES SOUTH OF LA PLATA TOWNSITE (UNSURVEYED SECTION). ; INFO FROM LAND.ST :1974

Comment (Production): PARTIAL PRODUCTION RECORD. FIGURES UNAVAILABLE FOR EARLY PRODUCTION FROM UNCLE SAM MINE. FIGURES ABOVE ARE INDIVIDUAL SMELTER SHIPMENTS FOR MAY ROSE ORE.

Comment (Development): UNCLE SAM CLAIM PRODUCED AU ORE FROM 1887 TO 1890 AND 1912-1917. PRODUCTION IN OTHER YEARS FROM OTHER CLAIMS UNKNOWN. LAST REPORTED PRODUCTION IN 1921. EXPLORATORY WORK DONE IN 1936-1937 BY AMPARO MINING CO, BUT NO ORE PRODUCED.

References

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

Reference (Production): CARAMOUZIS (UNPUB ENG. REPT.)

Reference (Deposit): CARAMOUZIS, BASIL, (N.D.), REPORT ON THE MAY ROSE MINES, LA PLATA COUNTY, COLORADO: UNPUB. ENG. REPT., 4 P.

Reference (Deposit): ECKEL, E.B., AND OTHERS, 1949, GEOLOGY AND ORE DEPOSITS OF THE LA PLATA DISTRICT, COLORADO: USGS PROF. PAPER 219, P. 67-68, 149-151.

Colorado Mining Photos

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