Letterman Mine

The Letterman Mine is a gold mine located in Sanders county, Montana at an elevation of 2,799 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: Letterman Mine
Secondary: Montana Premier Mine

Commodity

Primary: Gold
Secondary: Lead
Secondary: Silver
Tertiary: Copper

Location

State: Montana
County: Sanders
District: Plains District

Land Status

Land ownership: Private
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.

Holdings

Not available

Workings

Not available

Ownership

Owner Name: Montana Premier Mining Co.

Production

Not available

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Year First Production: 1911
Year Last Production: 1940
Discovery Method: Unknown
Years of Production:
Organization:
Significant: N
Deposit Size: S

Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Northern Rocky Mountains
Physiographic Detail: Coeur D'Alene Mountains

Mineral Deposit Model

Not available

Orebody

Form: POD/LENS

Structure

Type: R
Description: Broad Folds In The Argillites Which Strike About N.

Type: L
Description: Fine Grained Dioritic Sill Is Exposed At The Adit Portal. Massive Fault, Six Ft Wide, Which Trends N 32 Deg W And Dips 72 Deg Sw.

Alterations

Not available

Rocks

Name: Diorite
Role: Associated
Age Type: Host Rock
Age Young: Neoproterozoic

Name: Diorite
Role: Associated
Age Type: Host Rock Unit
Age Young: Neoproterozoic

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

Name: Diorite
Role: Associated
Age Type: Associated Rock Unit
Age Young: Neoproterozoic

Analytical Data

Analytical Data: THREE CHANNEL SAMPLES HAD AN AVERAGE ASSAY OF 0.71 OZ/TON AU, 0.95 OZ/TON AG AND 4.6 % PB.

Materials

Ore: Gold
Ore: Galena
Gangue: Quartz
Gangue: Siderite

Comments

Comment (Location): ABUTS, IN PART, THE WEST SIDE OF COMBEST CREEK

Comment (Production): SMALL AMOUNT OF AU-AG-PB ORE WAS PRODUCED FROM 1911-1940.

Comment (Deposit): ORE SHOOT IS PARTIALLY CONTAINED WITHIN A MASSIVE FAULT AND IS KNOWN AS THE FISHER VEIN. ORE SHOOT DIPS LESS STEEPLY THAN THE FAULT AND STRIKES ABOUT N 15 DEG W. ORE SHOOT BECOMES RICHER IN SULFIDES AS ONE GOES NW. GALENA IS MEDIUM GRAINED AND OCCURS AS PODS UP TO 1 FT LONG AND AS SMALL VEINLETS ABOUT 1 IN WIDE. CERUSSITE CRYSTALS FILL VUGS.

Comment (Workings): PRINCIPAL DEVELOPMENT IS BY A 470 FT CROSSCUT ADIT WITH DRIFTS AT THE INTERSECTION OF THE FAULT ZONE. AS OF 1961 THE DRIFTS WERE ACCESSIBLE FOR A DISTANCE OF 280 FT. OTHER PROSPECT PITS AND SHALLOW WORKINGS WERE IN DISREPAIR IN 1961 .

Comment (Deposit): DEVELOPING (1962) ; INFO.SRC : 1 PUB LIT

Comment (Development): MINE LAST OPERATED IN 1940 . 180 PATENTED AND 70 UNPATENTED CLAIMS.

References

Reference (Deposit): GILBERT, F. C., 1935 , DIRECTORY OF MONTANA MINING PROPERTIES: MONTANA BUREAU OF MINES AND GEOLOGY MEM. 15 , P. 70 .

Reference (Production): CROWLEY, F. A., 1963 : MONTANA BUREAU OF MINES AND GEOLOGY BULL. 34 , PP. 25 - 26 .

Reference (Analytical Data): SRC.REF: CROWLEY, F. A., 1963 , MONTANA BUREAU OF MINES AND GEOLOGY BULL. 34 , P. 26

Reference (Deposit): MONT. BUREAU OF MINES & GEOL. BULL. 33, 1963, P. 30

Reference (Deposit): MONT. BUREAU OF MINES & GEOL. MEM. 31, 1950, P. 92

Reference (Deposit): CROWLEY, F. A., 1963 , MINES AND MINERAL DEPOSITS (EXCEPT FUELS) SANDERS COUNTY, MONTANA: MONTANA BUREAU OF MINES AND GEOLOGY, BULL. 34 , PP. 25 - 26 .

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.