Twilight Mine

The Twilight Mine is a gold mine located in Lemhi county, Idaho at an elevation of 3,999 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: Twilight Mine
Secondary: Sawlog Group

Commodity

Primary: Gold
Tertiary: Silver
Tertiary: Lead
Tertiary: REE
Tertiary: Thorium

Location

State: Idaho
County: Lemhi
District: North Fork - Shoup 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

Type: Underground

Ownership

Owner Name: Magnuson Bevan

Production

Not available

Deposit

Record Type: Site
Operation Category: Past Producer
Operation Type: Unknown
Years of Production:
Organization:
Significant: N
Deposit Size: S

Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Northern Rocky Mountains
Physiographic Detail: Salmon River Mountains

Mineral Deposit Model

Not available

Orebody

Not available

Structure

Type: L
Structure: Displacement

Type: L
Structure: Slickensides

Type: L
Structure: Faulting

Alterations

Alteration Type: L
Alteration: Leaching

Alteration Type: L
Alteration: Sericite

Rocks

Name: Gneiss
Role: Host
Description: Augen Gneiss
Age Type: Host Rock
Age Young: Pliocene

Name: Gneiss
Role: Host
Description: Augen Gneiss
Age Type: Host Rock Unit
Age Young: Neoproterozoic

Name: Pegmatite
Role: Associated
Description: Dike
Age Type: Associated Rock Unit
Age Young: Pliocene

Name: Pegmatite
Role: Associated
Description: Dike
Age Type: Associated Rock
Age Young: Pliocene

Analytical Data

Analytical Data: GEIGER COUNTER READINGS 1.5 TIMES BACKGROUND DUE TO THE THORIUM IN MINOR AMOUNTS OF MONAZITE

Materials

Ore: Galena
Ore: Monazite
Gangue: Pyrite
Gangue: Orthoclase
Gangue: Magnetite
Gangue: Quartz

Comments

Comment (Development): 5 - Ton Ball Mill; Total Of 7 Claims Worked By M. Bevan.

Comment (Location): Along Saw Log Gulch, .75 Of A Mi S Of Salmon R. & 10 Mi W Of North Fork, Idaho

Comment (Geology): Original Structures entry: Local - Faulting, Slickensides, Displacement

Comment (Geology): Original alteration entry: Local - Sericite; Leaching

References

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): Trites, A. F., And Tooker, E. W., 1953 , Uranium And Thorium Deposits In East - Central Idaho, Southwestern Montana: USGS Bulletin 988-H, P. 170

Reference (Production): Sturm, F. H., 1954, Univ. Of Idaho, M. S. Thesis.

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.