Grant and Hartford Mine

The Grant and Hartford Mine is a gold and silver mine located in Granite county, Montana at an elevation of 5,889 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: Grant and Hartford Mine

Commodity

Primary: Gold
Primary: Silver
Secondary: Copper
Secondary: Lead
Tertiary: Antimony
Tertiary: Barium-Barite

Location

State: Montana
County: Granite
District: Garnet (First Chance) District

Land Status

Not available

Holdings

Not available

Workings

Type: Underground

Ownership

Owner Name: Garnet Butte Gold Mining Co.

Owner Name: Garnet Butte Gold Mining Co.
Home Office: Butte, Mt

Production

Not available

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: S

Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Northern Rocky Mountains
Physiographic Detail: Garnet Range

Mineral Deposit Model

Not available

Orebody

Form: TABULAR VEIN WITH BANDED STRUCTURE THAT FOR THE MOST PART FOLLOWS THE BEDDING PLANE

Structure

Type: R
Description: Bearmouth Overthrust, Deep Creek Anticline, Mount Baldy Synclinorium

Type: L
Description: Deep Creek Anticline.

Alterations

Alteration Type: L
Alteration Text: Oxidation

Rocks

Name: Diorite
Role: Associated
Age Type: Associated Rock Unit
Age Young: Late Cretaceous

Name: Diorite
Role: Associated
Age Type: Associated Rock
Age Young: Pliocene

Name: Diorite
Role: Associated
Age Type: Host Rock
Age Young: Late Cambrian

Analytical Data

Analytical Data: OXIDIZED ORE 1.5-5 OZ/TON AU, 1.5-5 OZ/TON AG,

Materials

Ore: Gold
Ore: Tetrahedrite
Ore: Chalcopyrite
Gangue: Quartz
Gangue: Pyrite
Gangue: Barite
Gangue: Ankerite
Gangue: Calcite

Comments

Comment (Reserve-Resource): DOWNWARD PROJECTION OF STRUCTURE INDICATES VEIN WOULD INTERSECT GRANODIORITE ABOUT 1000 FT DOWNDIP FROM SURFACE, AND IT IS ESTIMATED THAT VEIN HAS BEEN MINED TO AT LEAST HALF THIS DEPTH. OXIDIZED ORE RAN ABOUT 3 TOZ/ST AU SO PRIMARY SULFIDE ORE MAY BE EXPECTED TO BE RELATIVELY RICH EVEN AT DEPTH.

Comment (Location): UTM LOCATION OF GRANT & HARTFORD ADIT

Comment (Production): ESTIMATES MADE USING DISTRICT PRODUCTION AND PRODUCTION VALUE . $30000 PRE 1910.

Comment (Deposit): THE VEIN OCCUPIES A BEDDING PLANE OF THE SHIST AND QUARTZITE EXCEPT WHERE IT CROSSES A SMALL GRANODIORITE DIKE. 200 FT FROM PORTAL THE VEIN IS LOST IN A NE FAULT ZONE, IT REAPPEARS E IN THE MAGONE AND ANDERSON ZONE.

Comment (Workings): VEIN DEVELOPED BY GRANT & HARTFORD ADIT ON EAST BANK OF FIRST CHANCE GULCH, TUNNEL NO. 5 DRIVEN SOUTH FROM GARNET STOCK, AND SEVERAL ADITS AT HIGHER LEVELS. HAD TRESSLE OVER ROAD TO CONNECT MAIN ADIT AND DUMP

Comment (Geology): VEIN LIES ON BEDDING PLANE ON N LIMB AND NEAR CREST OF DEEP CREEK ANTICLINE WHICH HERE TRENDS N 80 W AND PLUNGES AABOUT 30 W.

References

Reference (Production): USGS BULL. 660-F, MBMG MEM. 39

Reference (Deposit): USGS BULL 660, P. 188

Reference (Deposit): MBMG MEM NO 39, P. 28

Reference (Deposit): MBMG MEM NO 31, P. 30

Principal Gold Districts of Montana

In Montana, 54 mining districts have each have produced more than 10,000 ounces of gold. The largest producers are Butte, Helena, Marysville, and Virginia City, each having produced more than one million ounces. Twenty seven other districts are each credited with between 100,000 and one million ounces of gold production. Read more: Principal Gold Districts of Montana.