Yogo Sapphire Mine

Producer in Judith Basin county in Montana, United States with commodity Gemstone
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. Host and associated rocks
  8. Nearby scientific data
  9. Geologic structures
  10. Ore body information
  11. Controls for ore emplacement
  12. Economic information about the deposit and operations
  13. Mining district
  14. Ownership information
  15. Workings at the site
  16. Links to other databases
  17. Bibliographic references
  18. General comments
  19. Reporter information

Geologic information

Identification information

Deposit ID 10070455
MRDS ID W013397
Record type Site
Current site name Yogo Sapphire Mine
Alternate or previous names American Mine
Related records 10148934

Geographic coordinates

Geographic coordinates: -110.34472, 46.8713 (WGS84)
Elevation 1630
Relative position 22 KM SOUTHWEST FROM UTICA

Site location context

Political divisions (FIPS codes)

Judith Basin(county)

Montana(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Indian Hill(quadrangle 1:24,000 scale)

White Sulphur Springs(quadrangle 1:100,000 scale)

White Sulphur Springs(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Judith(hydrologic unit)

Fort Peck Lake(hydrologic accounting unit)

Missouri-Musselshell(hydrologic subregion)

Missouri(hydrologic region)

Federal lands

Helena-Lewis and Clark 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 Montana Judith Basin

Public Land Survey System information

Meridian Township Range Section Fraction State
Montana Principal 013N 011E 21 Montana

Commodities

Commodity Importance
Gemstone Primary

Comments on the commodity information

  • MOST OF THE SAPPHIRES ARE PALE BLUE - CORNFLOWER BLUE - DESIRABLE COLOR FOR GEMSTONES

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Carbonate > Limestone
    Rock unit name Madison Limestone
    Rock description Madison Limestone
    Stratigraphic age (youngest) Mississippian
    Stratigraphic age (youngest) Mississippian

Nearby scientific data

(1) -110.34472, 46.8713

Economic information

Geologic structures

Type of structure Regional
Structure description East Flank Of Domal Uplift Little Belt Mts.

Ore body information

  • General form DIKE
    Strike N 75 E
    Dip 90
    Thickness 6M
    Length 5600M
    Depth to top 0M

Controls for ore emplacement

  • Monchiquite Dike

Economic information about the deposit and operations

Development status Producer
Commodity type Non-metallic
Deposit size Large
Significant No
Discovery year 1880
Discoverer J. Hoover
Year of first production 1895

Mining district

District name Yogo District

Ownership information

  • Type Operator
    Owner Sapphire International Corp.

Workings at the site

  • Type of workings Underground
    Overall depth 90M

Comments on the workings information

  • SAPPHIRES ARE ALSO RECOVERED FROM PLACER DEPOSITS

Comments on development

  • SAPPHIRES FIRST FOUND WHEN THE GRAVELS WERE WORKED FOR GOLD MINED FROM 1895 TO 1930 AND THEN FROM 1958 TO PRESENT

Reference information

Bibliographic references

General comments

Subject category Comment text
Deposit THE MONCHIQUITE DIKE INTRUDES MADISON LIMESTONE. THE SAPPHIRES IN THE PLACER DEPOSITS HAVE WEATHERED FROM THIS DIKE

Reporter information

Type Date Name Affiliation Comment
Reporter 01-FEB-1976 Berg, Richard B. (Krohn, D. H.) U.S. Geological Survey

Beyond USGS

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

Current status (per MSHA)

StatusAbandoned since 02/24/2026
MSHA mine ID2400775
Mine name (MSHA)YOGO SAPPHIRE MINE
Current operatorYogold U.S.A. Corporation
Current controller (parent)Jerod Edington
Mine typeUnderground (Metal / non-metal)

Inferred by coordinate + name similarity (1604 m, 1.00 match). Confirm against MSHA if precision matters — non-USGS-curated cross-references may occasionally point at a neighbouring mine.

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