Centennial Phosphate Mine

The Centennial Phosphate Mine is a phosphorus-phosphates mine located in Clark county, Idaho at an elevation of 8,701 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: Centennial Phosphate Mine
Secondary: Ruby Mine
Secondary: Troublesome Ridge Phophate Deposit

Commodity

Primary: Phosphorus-Phosphates
Tertiary: Vanadium
Tertiary: Fluorine-Fluorite
Tertiary: Uranium

Location

State: Idaho
County: Clark

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: Targhee National Forest

Holdings

Type: Federal Lease

Workings

Not available

Ownership

Owner Name: J. R. Simplot Co., Fertilizer Division
Home Office: Idaho
Info Year: 1978

Owner Name: USA Federal Phosphate Lease
Percent: 100.0
Info Year: 1978

Production

Year: 1956
Description: Phosphate Rock 31% P2o5 76499 Mt Ore Per Year
Year: 1957
Description: Phosphate Rock 31% P2o5 135000 Mt Ore Per Year
Year: 1958
Description: Phosphate Rock 31% P2o5 31499 Mt Ore Pre Year

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Surface
Mining Method: Unknown
Year First Production: 1956
Years of Production:
Organization:
Significant: N

Physiography

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

Mineral Deposit Model

Not available

Orebody

Not available

Structure

Not available

Alterations

Not available

Rocks

Not available

Analytical Data

Not available

Materials

Unknown: Collophane
Unknown: Quartz

Comments

Comment (Deposit): SIMPLOT LEASED 5225 ACRES, 2330 IN MONTANA, 2895 IN IDAHO, THEY MAINTAIN THE LEASES AND MAY MINE THE DEPOSITS BY UNDERGROUND METHODS IN 1957 OPERATION WAS OPEN PIT, 7:1 SR, 1500 ST PER DAY IN SUMMER. EQUIPMENT:2 24 YD SCRAPERS, 2 D-9 CATS, 1 1YD SHOVEL, 18 25 ST TRUCKS. MINING METHOD:OVERBURDEN AND HENGING WALL REMOVED BY SCRAPERS AND BULLDOZERS. DOZERS BREAK ORE AND DOZE IT INTO PILES FROM WHICH SHOVEL LOADS INTO TRUCKS

Comment (Reserve-Resource): THIS TONNAGE FIGURE IS FROM JR SIMPLOT CO. TONNAGE IS FOR OPEN PIT OPERATION. A SIGNIFICANT TONNAGE OF ACID GRADE(>31% P2O5) IS THERE BUT COULD ONLY BE MINED BY UNDERGROUND METHODS. SIMPLOT FEELS THE TONNAGES GIVEN BY JEMMETT AND THE USBM FOR OPEN PIT MINING ARE MUCH TO HIGH. M1C5 OPEN PIT TONNAGE FROM JEMMETT (1955) MAX MINING DEPTH 38M. M2 UNDERGROUND TONNAGE FROM JEMMETT M3C5 UNDERGROUND TONNAGE FROM USBM MINERAL PROP. FILE M5C5 OPEN PIT TONNAGE FROM USBM MINERAL PROP FILE M4C5

References

Reference (Deposit): HONKALA,F.S.,1953,PRELIMINARY REPORT ON GEOLOGY OF

Reference (Deposit): CENTENNIAL RANGE, MONTANA-IDAHO,PHOPHATE DEPOSITS:U.S.

Reference (Deposit): GEOL.SURVEY OPEN FILE REPORT.

Reference (Deposit): JEMMETT,1955,MS THESIS, UNIV.OF IDAHO,MOSCOW,IDAHO 67P

Reference (Deposit): U.S. GEOLOGICAL SURVEY MISC. FIELD STUDIES MAP MF-1342-B, 1981.

Idaho Gold

"Where to Find Gold in Idaho" looks at the density of modern placer mining claims along with historical gold mining locations and mining district descriptions to determine areas of high gold discovery potential in Idaho. Read more: Where to Find Gold in Idaho.