Mt. Emmons/Crested Butte

Past Producer in Gunnison county in Colorado, United States with commodities Copper, Gold, Lead, Molybdenum, Silver, Zinc
Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Public Land Survey System information
  6. Commodities
  7. Materials information
  8. Mineral occurrence model information
  9. Nearby scientific data
  10. Ore body information
  11. Economic information about the deposit and operations
  12. Mining district
  13. Mineral rights holdings
  14. Land status
  15. Ownership information
  16. Reserves and resources
  17. Workings at the site
  18. Links to other databases
  19. Bibliographic references
  20. General comments
  21. Reporter information

Geologic information

Identification information

Deposit ID 10215357
MAS/MILS ID 0080510492
Record type Site
Current site name Mt. Emmons/Crested Butte
Alternate or previous names Mt. Emmons, Crested Butte, Daisey Mine, Daisey, Chautauqua
Included sites Lucky Jack

Geographic coordinates

Point of reference Main Entrance
Geographic coordinates: -107.03923, 38.86889 (WGS84)
Elevation 2989
Location accuracy 10(meters)

Site location context

Political divisions (FIPS codes)

Gunnison(county)

Colorado(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Mount Axtell(quadrangle 1:24,000 scale)

Paonia(quadrangle 1:100,000 scale)

Montrose(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

East-Taylor(hydrologic unit)

Gunnison(hydrologic accounting unit)

Gunnison(hydrologic subregion)

Upper Colorado(hydrologic region)

Federal lands

Grand Mesa, Uncompahgre and Gunnison National Forests(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State County
United States Colorado Gunnison

Public Land Survey System information

Meridian Township Range Section Fraction State
6th Principal 014 S 086 W 06 NESENE Colorado

Commodities

Commodity Importance
Copper Tertiary
Gold Tertiary
Lead Tertiary
Molybdenum Primary
Silver Tertiary
Zinc Critical Tertiary

Materials information

Materials Type of material
Cassiterite Unknown
Galena Unknown
Huebnerite Unknown
Molybdenite Unknown
Sphalerite Unknown

Mineral occurrence model information

Model code 50
USGS model code 16
Deposit model name Climax Mo

Nearby scientific data

Main Entrance (1) -107.03923, 38.86889

Economic information

Ore body information

  • General form Arcuate
    Dome
    Thickness 91M
    Length 850M
    Width 762M
    Depth to top 366M
    Field Value
    MAS Matrix # 1
    MAS Column # 1
    Type of Orebody #1 FISSURE VEIN
    Shape of Orebody #1 OTHER
    Type of Orebody #2 STOCKWORK
    Shape of Orebody #2 DOMELIKE
    Primary mode of Origin HYDROTHERMAL
    Secondary mode of Origin METAMORPHISM
    Primary Ore Control FRACTURING
    Secondary Ore Control IGNEOUS
    Degree of Wallrock Alter. INTENSE
    Type of Wallrock Alter. #1 PROPYLITIC
    Type of Wallrock Alter. #2 POTASSIC
    Minimum Depth to Top 300
    Avg. Thick. Unconsol. Mat. 1
    Min. Thick. Unconsol. Mat. 1
    Date of Last Modification 800319
  • Area 1200HA
    Field Value
    Total Surface Area (HA) 1200
    Date of Last Modification 910418

Economic information about the deposit and operations

Operation type Underground
Development status Past Producer
Commodity type Metallic
Significant Yes
Discovery year 1976
Mining method Caving Methods - Block Caving
Milling method Flotation

Mining district

District name Elk Mountain District

Mineral rights holdings

Type of mineral rights Patented
Type of mineral rights Located Claim
Type of mineral rights Other

Land status

Ownership category Mixed

Ownership information

  • Type Owner
    Owner Cyprus-Amax Minerals Co.
    Interest 100
    Home office Colorado
    Year 1996
    First year 1987
  • Type Unknown
    Owner U.S. Energy And Crested Butte Corp. (6% Gross Royalty Int)
    Home office Colorado
    Year 1987
    First year 1987
  • Type Owner
    Owner U.S. Energy And Crested Butte Corp.
    Interest 100
    Home office Colorado
    Year 1987
    First year 1985
    Last year 1987
  • Type Owner
    Owner Cyprus-Amax Minerals Co.
    Interest 100
    Home office Colorado
    Year 1985
    Last year 1985
  • Type Lessee/Owner
    Owner Phelps Dodge Corp (Freeport-McMoran Copper
    Interest 100
    Year 1999
    First year 1999
    Last year 2006
  • Type Owner-Operator
    Owner US Energy Corp
    Interest 100
    Home office 877 North 8th West\nRiverton WY 82501 \n
    Year 2011
    First year 2006

Comments on the production information

  • MOS2 CONCENTRATE IS ASSUMED TO BE THE SAME GRADE AS HENDERSON ORE.
  • YIELDS DATA SET 90-PERCENT RECOVERY IS BASED ON THE HENDERSON MILL. ACTUAL RECOVERY MAY BE HIGHER.

Reserves and resources

  • Type In-situ
    Estimate year 1994
    Indicated 132448972mt ore
    Demonstrated 132448972mt ore
    Total resources 132448972mt ore
    Commodity Subtype Grade units Group Importance Year
    Molybdenum MoS2 0.43 wt-pct Molybdenum Major 1994
  • Type In-situ
    Estimate year 1998
    Total resources 151186000mt ore
    Remarks 0.12% Mo cutoff grade. \nSummarized in an April 10, 2007 Behre Dolbear & Company Inc. technical report filed on Sedar by Kobex Resources Ltd.
    Commodity Subtype Grade units Group Importance Year
    Molybdenum 0.228 wt-pct Molybdenum Primary 1998

Comments on the reserve resource information

  • Q1 COL1 P-50 LEVEL WAS INCREASED 15 PERCENT ABOVE THE P-75 LEVEL AND THE P-25 LEVEL WAS INCREASED 15 PERCENT ABOVE THE P-50 LEVEL. THE SAME IS TRUE FOR Q9 COL4.
  • AMAX, INC. RETURNED THE EMMONS PROPERTY TO U.S.ENERGY AND CRESTED BUTTE CONTROL IN 1985. IN 1987, AMAX INC. REGAINED 100% CONTROL OF THE PROPERTY FROM U.S. ENERGY AND CRESTED BUTTE AFTER A SERIES OF FINACIAL TRANSACTIONS BETWEEN THE THREE FIRMS.

Workings at the site

  • Type of workings Underground
    Field Value
    MAS Development Schedule # 1
    Mining Record # 1
    Status of Mining Method PROPOSED
    Mining Method BLOCK CAVING 10-79
    Swell Factor .6
    Percent Waste Rock 0
    Percent Recovery 92
    Hardness of Rock HARDROCK FISSURED WITH MODERATE WATER
    Rock Characteristics MULTIPLE SYSTEMS OF WEAKNESS PLANES
    Rock Support Chars. UNKNOWN
    Mine Support Chars. UNKNOWN
    Slope of Inclines 8
    Number of Inclines 2
    Number of Adits 4
    1st Condition of Workings OPEN
    Capacity 25400
    Capacity Units MT ORE/DAY
    Unit Production Cost 5.9
    Units of Production $/MT ORE
    Operating Days per Year 260
    Operating Shifts per Day 3
    Year of Information 1979

Comments on the workings information

  • THE MINING DISTRICT JOINS THE RUBY MINING DISTRICT IN THIS AREA. POSSIBLE OVERLAP.

Comments on other economic factors

  • THE FACILITY AT LANGELOTH, PENN. IS A CONVERSION PLANT THAT CONVERTS MOS2 CONCENTRATE INTO MOLYBDENUM TRIOXIDE. CONCENTRATE WILL BE TRUCKED FROM THE MILL TO A TRANSFER FACILITY AT MONTROSE, CO. WHERE IT IS LOADED ONTO TRAINS FOR TRANSPORT TO LANGLOTH, PENN.

Reference information

Bibliographic references

General comments

Subject category Comment text
Deposit THE MILS SET "POINT OF REFERENCE" REFERS TO THE PORTAL OF THE KEYSTONE MINE WHICH IS BEING USED FOR ACCESS TO THE OREBODY. THE MINE ENTRANCE IS LOCATED ON MT. AXTELL QUAD. AND THE OREBODY IS ON OH-BE-JOYFUL QUAD. THIS PROPERTY WAS REVIEWED BY RC SMITH, 4-87. AT THIS TIME, AMAX HAS RENEGOTIATED THE LEASE AGREEMENT AND CONTINUES TO CONTROL THE PROPERTY. THERE ARE NO PLANS IN THE NEAR FUTURE TO DO ANYTHING WITH THE PROPERTY. AMAX ONLY PLANS TO CONTROL THE PROPERTY.
General The property consisted of 2,209 ha of mineral claims, including 148 ha of patented claims granted in 2004. (Kobex PR 10/10/06)

Reporter information

Type Date Name Affiliation Comment
Reporter 02-OCT-1996 Smith, R.C. U.S. Bureau of Mines

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Operator history (post-MRDS)

MRDS records operators as of each record's last update (≤ 2019). Some of the operators listed here have since changed hands or dissolved:

Curated by qvyshift.com from publicly-reported M&A activity (SEC filings, press releases, USGS Mineral Yearbooks). Not authoritative — verify against primary sources before relying on it. The MSHA panel above is the current authoritative source for actively-permitted mines.

Authoritative Colorado resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.