Twenty Grand Claim

The Twenty Grand Claim is a thorium and ree mine located in Custer county, Colorado at an elevation of 8,451 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

Name: Twenty Grand Claim  

State:  Colorado

County:  Custer

Elevation: 8,451 Feet (2,576 Meters)

Commodity: Thorium, REE

Lat, Long: 38.21083, -105.32861

Map: View on Google Maps

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.


Satelite image of the Twenty Grand Claim

Twenty Grand Claim MRDS details

Site Name

Primary: Twenty Grand Claim


Commodity

Primary: Thorium
Primary: REE


Location

State: Colorado
County: Custer
District: Wet Mountains Area; Mckinley Mountain Area


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

Not available


Production

Not available


Deposit

Record Type: Site
Operation Category: Prospect
Operation Type: Surface-Underground
Discovery Year: 1952
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: S


Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Southern Rocky Mountains


Mineral Deposit Model

Model Name: Thorium-rare-earth veins


Orebody

Not available


Structure

Type: R
Description: Wet Mountains

Type: L
Description: Nw-Trending Shear Zones


Alterations

Not available


Rocks

Name: Andesite
Role: Associated
Age Type: Associated Rock
Age Young: Cambrian


Analytical Data

Not available


Materials

Ore: Thorite
Gangue: Fluorite
Gangue: Quartz
Gangue: Galena
Gangue: Limonite
Gangue: Pyrite
Gangue: Barite


Comments

Comment (Location): NEAR RESERVOIR AT HEADWATERS OF RALPH GULCH ; INFO FROM LAND.ST :1976

Comment (Workings): SHAFT, PROSPECTS

Comment (Deposit): Discovery Year: EARLY 1950'S


References

Reference (Deposit): CHRISTMAN, R.A., BROCK, M.R., PEARSON, R.C. AND SINGEWALD, Q.D. 1959, GEOLOGY AND THORIUM DEPOSITS OF THE WET MOUNTAINS, COLORADO, A PROGRESS REPORT: USGS BULLETIN 1072-H, P.525-526


Colorado Mining Photos

Placer mines at Cripple Creek, Colorado ca. 1892

Check out this collection of Colorado's best historic mining photos: Incredible Photos of Colorado Mining Scenes.