South Ridges Combined

Past Producer in Lincoln county in Wyoming, United States with commodities Phosphorus-Phosphates, Uranium
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. Production statistics
  17. Reserves and resources
  18. Workings at the site
  19. Links to other databases
  20. Bibliographic references
  21. General comments
  22. Reporter information

Geologic information

Identification information

Deposit ID 10206113
MAS/MILS ID 560230101
Record type Deposit
Current site name South Ridges Combined

Comments on the site names

  • OTHER NAMES:TOP OF THE WORLD MINE, SOUTH MNT. MINE-COMMISARY RIDGE, ABSAKORA RIDGE.

Geographic coordinates

Point of reference Ore Body
Geographic coordinates: -110.6, 42.2167 (WGS84)
Elevation 2440
Location accuracy 10000(meters)

Site location context

Political divisions (FIPS codes)

Lincoln(county)

Wyoming(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Fontenelle Basin(quadrangle 1:24,000 scale)

Fontenelle Reservoir(quadrangle 1:100,000 scale)

Preston(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Upper Green(hydrologic unit)

Upper Green(hydrologic accounting unit)

Great Divide-Upper Green(hydrologic subregion)

Upper Colorado(hydrologic region)

Federal lands

Bridger-Teton National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State County
United States Wyoming Lincoln

Public Land Survey System information

Meridian Township Range Section Fraction State
6th Principal 026 N 116 W 27 Wyoming

Commodities

Commodity Importance
Phosphorus-Phosphates Primary
Uranium Tertiary

Materials information

Materials Type of material
Apatite Unknown
Calcite Unknown
Dolomite Unknown
Feldspar Unknown
Fluorite Unknown
Gypsum Unknown
Illite Unknown
Kaolinite Unknown
Limonite Unknown
Montmorillonite Unknown
Pyrite Unknown
Quartz Unknown
Sphene Unknown
Tourmaline Unknown
Zircon Unknown

Mineral occurrence model information

Model code 243
USGS model code 34c
Deposit model name Phosphate, upwelling type

Nearby scientific data

Ore Body (1) -110.6, 42.2167

Economic information

Ore body information

  • Thickness 60M
    Length 50000M
    Width 50M
    Depth to top 50M
    Field Value
    MAS Matrix # 1
    Type of Orebody #1 SEDIMENTARY
    Shape of Orebody #1 TABULAR
    Primary mode of Origin SEDIMENTATION
    Secondary mode of Origin RESIDUAL CONCENT
    Primary Ore Control LITHOLOGY
    Degree of Wallrock Alter. NONE
    Minimum Depth to Top 0
    Avg. Thick. Unconsol. Mat. 5
    Min. Thick. Unconsol. Mat. 0
    Date of Last Modification 801103
  • Thickness 60M
    Length 50000M
    Width 600M
    Depth to top 300M
    Field Value
    MAS Matrix # 3
    Type of Orebody #1 SEDIMENTARY
    Shape of Orebody #1 TABULAR
    Primary mode of Origin SEDIMENTATION
    Primary Ore Control LITHOLOGY
    Degree of Wallrock Alter. NONE
    Minimum Depth to Top 20
    Avg. Thick. Unconsol. Mat. 5
    Min. Thick. Unconsol. Mat. 0
    Date of Last Modification 801103
  • Thickness 60M
    Length 50000M
    Width 600M
    Depth to top 300M
    Field Value
    MAS Matrix # 4
    Type of Orebody #1 SEDIMENTARY
    Shape of Orebody #1 TABULAR
    Primary mode of Origin SEDIMENTATION
    Primary Ore Control LITHOLOGY
    Degree of Wallrock Alter. NONE
    Minimum Depth to Top 20
    Avg. Thick. Unconsol. Mat. 5
    Min. Thick. Unconsol. Mat. 0
    Date of Last Modification 801103
  • Thickness 60M
    Length 50000M
    Width 600M
    Depth to top 300M
    Field Value
    MAS Matrix # 5
    Type of Orebody #1 SEDIMENTARY
    Shape of Orebody #1 TABULAR
    Primary mode of Origin SEDIMENTATION
    Primary Ore Control LITHOLOGY
    Degree of Wallrock Alter. NONE
    Minimum Depth to Top 20
    Avg. Thick. Unconsol. Mat. 5
    Min. Thick. Unconsol. Mat. 0
    Date of Last Modification 801103
  • Thickness 60M
    Length 50000M
    Width 6000M
    Depth to top 1000M
    Field Value
    MAS Matrix # 6
    Type of Orebody #1 SEDIMENTARY
    Shape of Orebody #1 TABULAR
    Primary mode of Origin SEDIMENTATION
    Primary Ore Control LITHOLOGY
    Degree of Wallrock Alter. NONE
    Minimum Depth to Top 30
    Avg. Thick. Unconsol. Mat. 100
    Min. Thick. Unconsol. Mat. 0
    Date of Last Modification 801103
  • Thickness 60M
    Length 50000M
    Width 30000M
    Depth to top 2300M
    Field Value
    MAS Matrix # 7
    Type of Orebody #1 SEDIMENTARY
    Shape of Orebody #1 TABULAR
    Primary mode of Origin SEDIMENTATION
    Primary Ore Control LITHOLOGY
    Degree of Wallrock Alter. NONE
    Minimum Depth to Top 1524
    Avg. Thick. Unconsol. Mat. 300
    Min. Thick. Unconsol. Mat. 0
    Date of Last Modification 801103
  • Area 2000HA
    Field Value
    Total Surface Area (HA) 2000
    Date of Last Modification 910418

Comments on the geologic information

  • THE PHOSPHORIA FORMATION IS SUBDIVIDED INTO FIVE MEMBERS BY MCKELVEY (BIBLIOGRAPHY REF. L010), TWO OF WHICH (THE MEADE PEAK AND RETORT MEMBERS) CONTAIN SIGNIFICANT PHOSPHATE DEPOSITS. IN UTAH AND SOUTHWESTERN WYOMING, THE MEADE PEAK MEMBER, AND IN CENTRAL AND NORTHWESTERN WYOMING, THE RETORT MEMBER CONTAIN THE DEPOSITS OF POTENTIAL INTEREST. THE PARK CITY FORMATION OF UTAH AND CENTRAL WYOMING AND THE SHEDHORN SANDSTONE OF NORTHWESTERN WYOMING ARE STRATIGRAPHIC EQUIVALENTS OF AND INTERTONGUE WITH THE PHOSPHORIA FORMATION. THE PHOSPHORIA FORMATION AND EQUIVALENT FORMATIONS ARE UNDERLAIN BY EITHER THE TENSLEEP SANDSTONE, WEBER QUARTZITE, WELLS FORMATION, OR DIAMOND CREEK SANDSTONE AND ARE OVERLAIN BY EITHER THE WOODSIDE OR DINWOODY FORMATIONS.

Economic information about the deposit and operations

Operation type Surface-Underground
Development status Past Producer
Commodity type Non-metallic
Significant No
Discovery year 1904
Mining method Shrinkage Methods
Year of first production 1948
Year of last production 1949
Milling method Flotation

Mining district

District name Western Phosphate

Mineral rights holdings

Type of mineral rights Other

Land status

Ownership category Mixed

Ownership information

  • Type Owner
    Owner U.S. Government
    ID 4801290
    Interest 95
    Home office Dist Of Columbia
    Year 1980
  • Type Owner
    Owner State Of Wyoming
    ID 4801290
    Interest 5
    Home office Wyoming
    Year 1978

Comments on the ownership information

  • PHOSPHATE LANDS MAY BE LEASED FROM THE U.S. GOVERNMENT OR FROM THE STATE OF WYOMING. CURRENTLY, THERE ARE NO ACTIVE LEASES OR PROSPECTING PERMITS WITHIN THE AREA INCLUDED IN THIS DEPOSIT. THERE ARE NO PHOSPHATE MINERAL HOLDINGS IN THE DEPOSIT AREA.

Production statistics

  • Year 1949
    Period 1948-1949
    Description One Mine Produced In 1948-49 8000 Short Tons Ore

Comments on the production information

  • RECOVERIES IN THE YIELD DATA SET FOR TWO-PRODUCT MILLS ARE CALCULATED FROM THE TOTAL FEED TO THE MILL AND ARE NOT ACTUAL RECOVERIES WITHIN EACH ORE STREAM. WITHIN-ORE-STREAM RECOVERIES FOR TWO-PRODUCT MILLS PROPOSED IN THIS EVAL- UATION ARE 89.0 PERCENT FOR MILL K1, DEV SCH 1&2; 85% FOR MILL K3, DEV SCH 1; 72 PERCENT FOR MILL K3, DEV SCH 2; 83 PERCENT FOR MILL K5, DEV SCH 1; 62 PERCENT FOR MILL K5, DEV SCH 2. EXACT RECOVERIES USED IN CALCULATING PRODUCT OUTPUT TONNAGES FOR TWO PRODUCT MILLS PROPOSED IN THIS EVALUATION ARE 40.6743 PERCENT FOR PRODUCT A, DEV SCH 1&2; 48.3257% FOR PRODUCT F, DEV SCH 1&2; 59.7870 PERCENT FOR PRO- DUCT C, DEV SCH 1; 25.2130 PERCENT FOR PRODUCT H, DEV SCH 1; 50.6431 PERCENT FOR PRODUCT C, DEV SCH 2; 21.3569 PERCENT FOR PRODUCT H, DEV SCH 2; 40.2855 PERCENT FOR PRODUCT E, DEV SCH 1; 42.7145 PERCENT FOR PRODUCT J, DEV SCH 1; 30.0928 PERCENT FOR PRODUCT E, DEV SCH 2; 31.9072 PERCENT FOR PRODUCT J, DEV SCH 2.
  • THE SOUTH MOUNTAIN MINE, ALSO KNOWN AS THE TOP OF THE WORLD MINE, OPERATED IN 1948-49, AND WAS REPORTED IN A 1950 PUBLICATION TO HAVE PRODUCED 8000 SHORT TONS OF ORE. IT IS NOT KNOWN IF THIS FIGURE REPRESENTS THE TOTAL PRODUCTION FROM THIS MINE, AND THE GRADE OF THE ORE PROD- UCED IS UNKNOWN. THE MINE CONSISTED OF AN OPEN PIT AND AN ADIT LOCATED NEAR THE CREST OF COMMISSARY RIDGE. THE DATE OF DISCOVERY OF THE SOUTH RIDGES PHOSPHATE IS APPROXIMATE.
  • PRODUCTS A,B,C,D, AND E, WHERE PROPOSED IN THIS EVALUATION, ARE ACID GRADE PRODUCTS, AND PRODUCTS F,G,H,I, AND J, ARE FURNACE GRADE PRODUCTS. NOT ALL OF THESE PRODUCTS ARE USED IN THIS EVALUATION.

Reserves and resources

  • Type In-situ
    Estimate year 1963
    Inferred 1069799999mt ore
    Total resources 1069799999mt ore
    Commodity Subtype Grade units Group Importance Year
    Water, Free H2o 0 wt-pct Water, Free Trace 1963
    Phosphorus-Phosphates P2O5 18 wt-pct Phosphorus Major 1963
  • Type In-situ
    Estimate year 1963
    Inferred 159100000mt ore
    Total resources 159100000mt ore
    Commodity Subtype Grade units Group Importance Year
    Water, Free H2o 0 wt-pct Water, Free Trace 1963
    Phosphorus-Phosphates P2O5 24 wt-pct Phosphorus Major 1963

Comments on the reserve resource information

  • PROPERTY HAS BEEN SPLIT INTO 4 SEPARATE DEPOSITS FOR SUPPLY ANALYSIS WITH SEQUENCE NOS. 0560230182, 0560230183, 0560230184, AND 0560230185 RESPECTIVELY NAMED SOUTH RIDGES NO 1, SOUTH RIDGES NO 2, SOUTH RIDGES NO 3, AND SOUTH RIDGES NO 4. REFER TO THESE RESPECTIVE DEPOSITS FOR THEIR SPECIFIC RESERVES AND OPERATING DATA [ABWilson, 8-feb-2010, deleted these extra 4 records. They are duplicate records for this deposit. They did not contain any information not already in this master record.]

Workings at the site

  • Type of workings Surface
    Area 300HA
    Field Value
    MAS Development Schedule # 1
    Mining Record # 1
    Status of Mining Method PROPOSED
    Mining Method OPEN PIT
    Swell Factor .67
    Percent Waste Rock 95.9
    Avg. Overburden Thickness 5
    Primary Material Cover SAND, GRAVEL
    Percentage 100
    Hardness of Ore M-HARD ROCKS
    Avg. Bench Height (meters) 10
    Max. Pit Slope (degrees) 45
    Capacity 4000
    Capacity Units MT ORE/DAY
    Unit Production Cost 14.85
    Units of Production $/MT ORE
    Operating Days per Year 250
    Operating Shifts per Day 3
  • Type of workings Surface
    Area 300HA
    Field Value
    MAS Development Schedule # 2
    Mining Record # 1
    Status of Mining Method PROPOSED
    Mining Method OPEN PIT
    Swell Factor .67
    Percent Waste Rock 95.9
    Avg. Overburden Thickness 5
    Primary Material Cover SAND, GRAVEL
    Percentage 100
    Hardness of Ore M-HARD ROCKS
    Avg. Bench Height (meters) 10
    Max. Pit Slope (degrees) 45
    Capacity 4000
    Capacity Units MT ORE/DAY
    Unit Production Cost 20.29
    Units of Production $/MT ORE
    Operating Days per Year 250
    Operating Shifts per Day 3
  • Type of workings Underground
    Length 7300M
    Overall depth 100M
    Field Value
    MAS Development Schedule # 1
    Mining Record # 3
    Status of Mining Method PROPOSED
    Mining Method OVERHAND SHRINKAGE 10-67
    Swell Factor .67
    Percent Waste Rock 0
    Percent Recovery 90
    Hardness of Rock SOFT NONPLASTIC WITH LITTLE WATER
    Rock Characteristics ONE SYSTEM OF WEAKNESS PLANES
    Rock Support Chars. SUPPORTING
    Mine Support Chars. POST, HEADBOARD, CAPS, ROOF BOLTS
    Number of Shafts 1
    Length of Inclines (m) 0
    Avg. Length of Adits (m) 1000
    Number of Adits 1
    Capacity 1000
    Capacity Units MT ORE/DAY
    Unit Production Cost 18.01
    Units of Production $/MT ORE
    Operating Days per Year 250
    Operating Shifts per Day 2
  • Type of workings Underground
    Length 7300M
    Overall depth 100M
    Field Value
    MAS Development Schedule # 1
    Mining Record # 5
    Status of Mining Method PROPOSED
    Mining Method OVERHAND SHRINKAGE 10-67
    Swell Factor .67
    Percent Waste Rock 0
    Percent Recovery 90
    Hardness of Rock SOFT NONPLASTIC WITH LITTLE WATER
    Rock Characteristics ONE SYSTEM OF WEAKNESS PLANES
    Rock Support Chars. SUPPORTING
    Mine Support Chars. POST, HEADBOARD, CAPS, ROOF BOLTS
    Number of Shafts 1
    Length of Inclines (m) 0
    Avg. Length of Adits (m) 1000
    Number of Adits 1
    Capacity 1000
    Capacity Units MT ORE/DAY
    Unit Production Cost 18.01
    Units of Production $/MT ORE
    Operating Days per Year 250
    Operating Shifts per Day 2
  • Type of workings Underground
    Length 7300M
    Overall depth 100M
    Field Value
    MAS Development Schedule # 2
    Mining Record # 3
    Status of Mining Method PROPOSED
    Mining Method OVERHAND 10-38
    Swell Factor .67
    Percent Waste Rock 0
    Percent Recovery 90
    Hardness of Rock SOFT NONPLASTIC WITH LITTLE WATER
    Rock Characteristics ONE SYSTEM OF WEAKNESS PLANES
    Rock Support Chars. UNSUPPORTING NO FLOW
    Mine Support Chars. TIMBER
    Number of Shafts 1
    Length of Inclines (m) 0
    Avg. Length of Adits (m) 1000
    Number of Adits 1
    Capacity 1000
    Capacity Units MT ORE/DAY
    Unit Production Cost 41.58
    Units of Production $/MT ORE
    Operating Days per Year 250
    Operating Shifts per Day 2
  • Type of workings Underground
    Length 7300M
    Overall depth 100M
    Field Value
    MAS Development Schedule # 2
    Mining Record # 5
    Status of Mining Method PROPOSED
    Mining Method OVERHAND 10-38
    Swell Factor .67
    Percent Waste Rock 0
    Percent Recovery 90
    Hardness of Rock SOFT NONPLASTIC WITH LITTLE WATER
    Rock Characteristics ONE SYSTEM OF WEAKNESS PLANES
    Rock Support Chars. UNSUPPORTING NO FLOW
    Mine Support Chars. TIMBER
    Number of Shafts 1
    Length of Inclines (m) 0
    Avg. Length of Adits (m) 1000
    Number of Adits 1
    Capacity 1000
    Capacity Units MT ORE/DAY
    Unit Production Cost 42.44
    Units of Production $/MT ORE
    Operating Days per Year 250
    Operating Shifts per Day 2

Comments on the workings information

  • ABBREVIATION FOR MINING DISTRICT: WEST. PHOSPHATE = WESTERN PHOSPHATE FIELD.

Comments on other economic factors

  • Mining and beneficiation costs for each proposed operation were obtained by applying one of 34 basic mine models and 5 basic mill models developed for evaluating Utah and Wyoming phosphate deposits. Site-specific cost adjustments were made for land acquisition, infrastructure, unusual haulage distance to mill, the presence of multiple beds requiring mining of waste, and mill feed grade and recovery. All costs are in January 1980 dollars. The schedule of costs is based on the assumption that each proposed operation will be independently developed as soon as technically possible after the official January 1979 base date for the current phosphate study. Thus, land acquisition, exploration, and infrastructure capital costs are assumed to begin in 1979. Mine and mill capital costs include a contingency allowance of 15 percent of all other capital costs except working capital. Mine and mill working capital is estimated at 60 days of operating cost. A Bureau costing manual (bibliography data set ref. I030) was used to estimate surface and underground mine exploration, development, reclamation, plant, and equipment capital costs; underground mine operating costs; capital and operating costs for the calcining-hydration mill (if used) and for the flotation sections of other mills; costs of transporting products from proposed mills to existing final processing plants; and access road construction cost. Surface mine operating costs are size-scaled, using scaling factors from Bennett (bibliography data set ref. I001), and others (U.S. office of audit and investigation) for Idaho phosphate mines in 1976 and 1977. Infrastructure capital costs assigned to each proposed mine consist of only those railroad, transmission line, and access road costs which are needed for development of each mine. Railroad cost is estimated by the Richardson rapid construction cost estimating system (bibliography data set ref. I020). Transmission line cost is estimated from typical industry costs (A.W. Watts, 1980, Water and Power Resources Services, personal communication). Access road costs are estimated by using the capital and operating cost estimating handbook (bibliography data set ref. I030). Land acquisition costs are based on typical competitive bids for leases in southeastern Idaho, adjusted for specific deposit grade and thickness. Lease rentals and royalties are based on current rates for federal leases in the western phosphate field. Capital and operating costs for all mills, excepting the calcination-hydration mill (if used) and flotation sections of other mills, are size-scaled, using scaling factors from Bennett (bibliography data set ref. I001), from costs given for a sizing and calcining mill described by de Voto, et al. (bibliography data set ref. R030), vol. 2, appendix d. Site-specific cost adjustments for mill feed grade and recovery are made, using relative cost factors calculated from average cost and recovery curves for altered and unaltered ores (bibliography data set ref. I010).

Reference information

Bibliographic references

General comments

Subject category Comment text
Deposit THE NORTHEASTERN PORTION OF THE DEPOSIT EXTENDS INTO SUBLETTE COUNTY. DOMAIN - LAND CLASSIFICATION IS AS FOLLOWS WITH APPROXIMATE PERCENTAGES OF TOTAL OUTCROP AREA IN EACH CATEGORY SHOWN IN PARENTHESES: NATIONAL FOREST LAND (55), U.S. BUREAU OF LAND MANAGEMENT LAND (20), POTENTIALLY UNAVAILABLE ROADLESS AREA REVIEW AND EVALUATION (RARE II) LAND (20), AND STATE OF WYOMING LAND (5).
Deposit THIS MINERALS AVAILABILITY SYSTEM EVALUATION WAS DONE AS PART OF A 1980 STUDY OF UTAH AND WYOMING PHOSPHATE DEPOSITS BY THE INTERMOUNTAIN FIELD OPERATIONS CENTER, DENVER, COLORADO.

Reporter information

Type Date Name Affiliation Comment
Reporter 1997-07-30 B,D,D,S,Ww U.S. Bureau of Mines
Reporter 1995-04-24 Drescher, Theodore A. U.S. Bureau of Mines MAS records 0560230182-185 (newMRDS 10206042, 10143086, 101335539, 10206062)

Beyond USGS

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

Current status (per MSHA)

StatusTemporarily Idled since 08/11/2025
MSHA mine ID4801290
Mine name (MSHA)Oftedal Crusher #1
Current operatorOftedal Construction Inc
Current controller (parent)EH Oftedal & Sons Inc
Mine typeSurface (Metal / non-metal)

MSHA cross-reference per the original MRDS record. Mine status and operator reflect MSHA's last published Mines export (February 2025); MSHA's public bulk feed has been unavailable since, so this may be out of date. See the Mine Data Retrieval System for current status.

Open MSHA's Mine Data Retrieval System for inspections, accidents, and violations for this mine.