The Last Chance Prospect is a thorium and copper 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
Elevation: 4,501 Feet (1,372 Meters)
Commodity: Thorium, Copper
Lat, Long: 45.3961, -114.07330
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.
Last Chance Prospect MRDS details
Site Name
Primary: Last Chance Prospect
Commodity
Primary: Thorium
Primary: Copper
Secondary: REE
Tertiary: Titanium
Location
State: Idaho
County: Lemhi
District: Indian Creek 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
Owner Name: C. E. Brown, Ralph Malloy
Production
Not available
Deposit
Record Type: Site
Operation Category: Prospect
Operation Type: Surface
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
Form: THIN SEAMS, PODS, BUNCHLIKE CLUSTERS, STREAKS
Structure
Type: L
Description: Weak Foliation
Alterations
Alteration Type: L
Alteration Text: Gouge, Epidote, Clinozoisite, Chlorite, Sericite
Rocks
Name: Amphibolite
Role: Associated
Age Type: Associated Rock
Age Young: Neoproterozoic
Name: Amphibolite
Role: Associated
Age Type: Host Rock
Age Young: Neoproterozoic
Name: Amphibolite
Role: Associated
Age Type: Host Rock Unit
Age Young: Neoproterozoic
Analytical Data
Not available
Materials
Ore: Monazite
Ore: Rutile
Ore: Ilmenite
Ore: Xenotime
Ore: Chalcopyrite
Ore: Allanite
Gangue: Apatite
Gangue: Labradorite
Gangue: Zircon
Gangue: Albite
Gangue: Tourmaline
Gangue: Calcite
Gangue: Quartz
Gangue: Biotite
Gangue: Magnetite
Comments
Comment (Deposit): SW of deposit described above is small monazite occurrence which strikes N 20 Deg W, Dips 70 Deg SW, found in sandstone - like rock in schist
Comment (Deposit): Author Anderson states 2 contrasting, unrelated types of mineralization, shear zones and pegmatites in part in amphibolized gabbroic rock and in part in schistose and gneissic rocks.
Comment (Location): On upper canyon slope of Salmon River across from mouth of Dump Creek
Comment (Commodity): Spotty radioactivity over monazite; Allanite has high radioactivity
Comment (Development): 12 claims in group
References
Reference (Deposit): Anderson, A. L., 1958, Uranium, Thorium, Columbium, And Rare Earth Deposits In The Salmon Region, Lemhi County, Idaho: Idaho Bureau Of Mines And Geology Pamphlet 115, 81 P
Reference (Deposit): USBM WFOC Wilderness Studies
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.
