Pitch Mine

Site Name

Primary: Pitch Mine
Secondary: Pinnacle Mine
Secondary: Erie No. 28 Claim
Secondary: Pitch Tunnel

---

Commodity

Primary: Uranium
Secondary: Vanadium
Tertiary: Lead
Tertiary: Zinc
Tertiary: Copper

---

Location

State: Colorado
County: Saguache
District: Marshall Pass 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.

---

Holdings

Type: Located Claim

---

Workings

Type: Surface/Underground

---

Ownership

Owner Name: Pinnacle Exploration
Info Year: 1975

Owner Name: Homestake Mining Co.
Home Office: Gunnison, Co.
Years: 1980 -

---

Production

Year: 1978
Time Period: 1958-1971
Mined: 102868.580 mt
Material type: uranium ore

---

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Surface-Underground
Mining Method: Caving Methods - Top Slicing
Year First Production: 1958
Year Last Production: 1981
Discovery Year: 1955
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: M

---

Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Southern Rocky Mountains

---

Mineral Deposit Model

Not available

---

Orebody

Form: intermediate dipping breccia zone

---

Structure

Type: R
Description: Sawatch Range

Type: L
Structure: Chester Fault
Description: Chester Fault, Unnamed Syncline

---

Alterations

Alteration Type: L
Alteration: Weathering of sulfides
Alteration Text: Oxidation Of U And Fe Minerals

---

Rocks

Not available

---

Analytical Data

Analytical Data: ORE GRADE AT LITTLE INDIAN NO. 36 IN 1957-59 WAS 0.48 % U3O8. RESERVES ESTIMATE HAS ORE GRADE 0.17 % U3O8. AVERAGE ANALYSES OF LEADVILLE AND BELDEN CARBONATES ARE 1.79 % AL2O3, 2.54 % FE2O3, 13.28 % MGO, 23.92 % CAO, 22.67 % SIO2, 0.03 % NA2O, 0.38 % K2O, 1.37 % H2O, 0.088 % TIO2, 0.038 % P2O5, 0.074 % MNO, 0.032 % F, 33.15 % CO2, 0.36 % S, 143.6 PPM CL, 116.8 PPM BA, 91.9 PPM SR, 20.9 PPM PB, 112.6 PPM ZN, 6.94 PPM MO, 0.187 PPM HG. MEAN VALUES OF OTHER METALS FROM SEMIQUANTITATIVE EMISSION SPECTROGRAPHIC ANALYSIS OF ORE SAMPLES WITH 0.01 TO 0.05 % U ARE 13 PPM CR, 5 PPM CU, 13 PPM NI, 14 PPM V, 36 PPM ZR. FOR ORE SAMPLES WITH G.T. 0.05 % U, 13 PPM CR, 3.5 PPM CU, 10 PPM NI, 12 PPM V, 24 PPM ZR.

---

Materials

Ore: Uranophane
Ore: Pitchblende
Ore: Uraninite
Gangue: Hematite
Gangue: Galena
Gangue: Chalcocite
Gangue: Pyrite
Gangue: Limonite
Gangue: Jasper
Gangue: Marcasite
Gangue: Covellite

---

Comments

Comment (Workings): ORIGINAL WORKINGS WERE SURFACE PROSPECT PITS ON FAULT TRACE AND UNDERGROUND TUNNELS DRIVEN SE ABOUT 1000 FT TO FAULT ZONE. PITCH TUNNEL FACE WAS ABOUT 250 TO 300 FT BELOW SURFACE. OVER 3000 FT TOTAL TUNNEL AND DRIFTS. STRIPPING FOR OPEN PIT DEVELOPMENT BEGAN 1970, PIT SIZE AS OF 1978 GIVEN ABOVE. ULTIMATE PIT DIMENSIONS TO BE 5000 FT LONG (ALONG FAULT TRACE), 2000 FT WIDE, 400 FT DEEP.

Comment (Production): PRODUCTION FOR 1957 UNDER NAME OF LITTLE INDIAN 36. PRODUCTION FOR 1958-59 UNDER NAME OF LITTLE INDIAN 36 AND PITCH TUNNEL; 1959 PRODUCTION BREAKDOWN WAS 8684 ST ORE AND 83931 LB U308 FOR PITCH TUNNEL AND 765 ST ORE AND 5429 LB U308 FOR LITTLE INDIAN. NO PRODUCTION 1963-67. PRODUCTION IN 1968-72 BY SOLUTION MINING AND ION-EXCHANGE RECOVERY. PRODUCTION SINCE 1976 FROM OPEN PIT. U308 FIGURE FOR 1979 CALCULATED FROM ORE GRADE. MINE REPORTEDLY PRODUCED IN 1981 BUT FIGURE UNAVAILABLE. CUMULATIVE FIGURE FOR 1957-80 EXCLUDES 1968-72 PRODUCTION BY SOLUTION MINING AS NO "ORE" WAS ACTUALLY REMOVED.

Comment (Location): AT HEADWATERS OF INDIAN CREEK 3 MILES NW OF MARSHALL PASS ; INFO FROM LAND.ST :(1976)

Comment (Development): URANIUM WAS DISCOVERED ON THESE CLAIMS IN 1955. SITE WAS ORIGINALLY OPERATED BY PINNACLE EXPLORATION CO. AS PINNACLE MINE ON THE LITTLE INDIAN, ERIE, AND OTHER CLAIMS. PITCH TUNNEL WAS DEVELOPED IN 1958 AND PRODUCED ORE THRU 1962 WHEN MINE CLOSED DUE TO EXPIRATION OF AEC LEASE. PRODUCTION FROM PITCH MINE PROPER FROM 1968-72 WAS BY SOLUTION MINING OR RECIRCULATION OF WATER THRU UNDERGROUND WORKINGS AND RECOVERY OF U3O8 VALUES BY ION-EXCHANGE PROCESS IN SURFACE PLANT. HOMESTAKE MINING CO. ACQUIRED LEASES IN 1972 AND BEGAN EXPLORATION AND DEVELOPMENT FOR OPEN PIT PRODUCTION.

Comment (Deposit): MINERALIZATION OCCURS MOSTLY IN LEADVILLE AND BELDEN FMS AS FRACTURE COATINGS, AND POSSIBLY DISSEMINATED IN BRECCIA MATRIX, ALL IN FOOTWALL OF CHESTER FAULT ZONE (ATTITUDE GIVEN ABOVE). OXIDATION OCCURS TO DEPTHS OF ABOUT 330 FT. SOME ORE FOUND IN HANGING WALL IN PRECAMBRIAN BIOTITE SCHIST AND PEGMATITE. MINERALIZATION AT LITTLE INDIAN 36 FOUND IN LIMONITIC HARDING QUARTZITE (ORDOVICIAN). HIGH URANIUM CONCENTRATIONS FOUND IN COLLUVIUM OR REGOLITH OVERLYING PRECAMBRIAN ROCKS. CHESTER FAULT IS CUT BY 6 SMALLER REVERSE FAULTS OF AVERAGE ATTITUDE N70E. MINERALIZATION DECREASES BELOW AND AWAY FROM FAULT ZONE.

Comment (Orebody): Copied from deleted duplicate record 10167205: Length: 396 M Thickness: 15 M Type of Orebody #1 : SHEAR ZONE Shape of Orebody #1 : UNKNOWN Type of Orebody #2 : FISSURE VEIN Type of Orebody #3 : DISSEMINATED Primary mode of Origin : OXIDATION Secondary mode of Origin : RESIDUAL CONCENT Primary Ore Control : FAULTING Secondary Ore Control : FRACTURING Degree of Wallrock Alter. : INTENSE Date of Last Modification : 780615

Comment (Workings): Copied from deleted duplicate record 10167205: Type of Workings: Underground MAS Development Schedule #: 1 Mining Record # : 1 Status of Mining Method : ESTIMATE Mining Method : TOP SLICING 10-70 Hardness of Rock : HARDROCK FISSURED WITH MODERATE WATER Rock Characteristics : MULTIPLE SYSTEMS OF WEAKNESS PLANES Rock Support Chars. : UNSUPPORTING MAY SLOUGH Mine Support Chars. : STEEL W/LAGGING CONCRETE REINFOR Avg. Length of Adits (m) : 265 Number of Adits : 1 Capacity Units : MT ORE/DAY Units of Production : $/MT ORE Year of Information : 1975

Comment (Development): Copied from deleted duplicate record 10167205 [copied as is, there are words missing, but can understand the gist]: APPROXIMATELY 100,000 TONS OF ORE CONTAINING ONE MILLION LB URANIUM CONCENTRATE WERE REMOVED FROM THE MINE BETWEEN 1959 SOME OF THE ORE WAS REPORTED TO BE 10-15 PERCENT U308 AND TH CUT-OFF GRADE FOR MINING WAS 0.25PERCENT U308. THE MOST RECENT ATTEMPTS TO RECOVER URANIUM BEGAN IN 1967 WI ATTEMPTS TO RECOVER URANIUM BY UNDERGROUND LEACHING METHODS. DATE,THIS METHOD HAS MET WITH ONLY LIMITED SUCCESS. FURTHER IS BEING DONE AS TO HOW TO RECOVER THE REMAINING URANIUM. INTENSIVE EXPLORATION IS ALSO BEING DONE IN THE MARSHAL PASS PRIMARILY BY HOMESTAKE MINING CO. MORE INFO. IN BACKUP FILE.

---

References

Reference (Deposit): MINING CONGRESS JOURNAL, NOV.1970, UNDERGROU LEACHING OF URANIUM AT THE PITCH MINE

Reference (Deposit): NASH, J.T., 1979, GEOLOGY, PETROLOGY, AND CHEMISTRY OF THE LEADVILLE DOLOMITE-HOST FOR URANIUM AT THE PITCH MINE, SAGUACHE COUNTY, COLORADO: USGS OPEN-FILE REPT. 79-1556, 51 P.

Reference (Production): COLO. DIV. MINES ANN OPERATOR REPTS.

Reference (Deposit): COLORADO DIV. MINES ANN. OPERATOR REPTS.

Reference (Deposit): WRIGHT, R.J., AND EVERHART, D.L., 1960, URANIUM-MARSHALL PASS DISTRICT, IN DEL RIO, S.M., MINERAL RESOURCES OF COLORADO-FIRST SEQUEL: COLORADO ST. MINERAL RESOURCES BD., P. 357-359

---

Colorado Mining Photos

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