Monolith Group Mine

The Monolith Group Mine is a gold mine located in Lemhi county, Idaho at an elevation of 4,501 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: Monolith Group Mine

Commodity

Primary: Gold
Tertiary: Silver
Tertiary: Lead
Tertiary: Zinc

Location

State: Idaho
County: Lemhi
District: Mineral Hill District

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: Salmon National Forest

Holdings

Not available

Workings

Not available

Ownership

Not available

Production

Year: 1913
Material type: ORE
Description: Ap_Grade: ^2. % Pb, 5. % Zn, 3 Oz/Ton Ag

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Underground
Discovery Year: 1882
Years of Production:
Organization:
Significant: N
Deposit Size: S

Physiography

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

Mineral Deposit Model

Not available

Orebody

Form: TABULAR

Structure

Type: L
Structure: Brecciation

Type: L
Structure: Gouge

Type: L
Structure: Faults

Alterations

Alteration Type: L
Alteration: Sericitization

Alteration Type: L
Alteration: Oxidation

Alteration Type: L
Alteration: Calcite

Rocks

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

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

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

Analytical Data

Not available

Materials

Ore: Sphalerite
Ore: Galena
Gangue: Muscovite
Gangue: Feldspar
Gangue: Biotite
Gangue: Pyrite
Gangue: Quartz

Comments

Comment (Development): Tramway, 20 - Stamp Mill; Claims Include The Johnson, Johnson No. 1, Douglas, Douglas No. 1, Massachusetts And Merry Widow

Comment (Location): E Side Of Boulder Creek

Comment (Production): $175,000 Production In 1913 ; $200,000 Produced In Ag ( Gray, 1929 )

Comment (Geology): Original Structures entry: Local - Minor Faults; Schistosity Dips 35 - 44 Deg N , Gouge, Breccia

Comment (Geology): Original alteration entry: Local - Oxidation, Sericitization, Calcite

References

Reference (Production): Umpleby, J. B., 1913, USGS Bulletin 528, P. 143.

Reference (Deposit): Gray, F. A., 1927, Ore Deposits Of The Mineral Hill District, Lemhi County, Idaho: Minneapolis, Minnesota, Univ. Of Minnesota, Phd Thesis.

Reference (Deposit): Sturm, F. H., 1954, General Geology Of Some Replacement Monazite Deposits In Lemhi County, Idaho: Moscow, Idaho, Univ. Of Idaho, M.S. Thesis, 64 P.

Reference (Deposit): Umpleby, J. B., 1913, Geology And Ore Deposits Of Lemhi County, Idaho: USGS Bulletin 528, P. 143.

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.