Orofino Group

The Orofino Group is a gold and silver mine located in Idaho county, Idaho at an elevation of 7,201 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

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Site Name

Primary: Orofino Group
Secondary: Mildred
Secondary: Estep
Secondary: Arrastre

Commodity

Primary: Gold
Primary: Silver
Tertiary: Copper
Tertiary: Bismuth
Tertiary: Tungsten

Location

State: Idaho
County: Idaho
District: Ramey Ridge 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: Payette National Forest

Holdings

Not available

Workings

Type: Surface/Underground

Ownership

Owner Name: Walter Estep, Ray Nissoula, Lew Morgan
Home Office: Idaho

Owner Name: Ray Nissoula, Lew Morgan
Home Office: Idaho

Production

Not available

Deposit

Record Type: Site
Operation Category: Past Producer
Deposit Type: Vein
Operation Type: Underground
Discovery Year: 1906
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: PINCH AND SWELL, LENTICULAR

Structure

Not available

Alterations

Alteration Type: L
Alteration Text: Fe Stains, Oxidation, Chloritization

Rocks

Name: Syenite
Role: Associated
Age Type: Host Rock
Age Young: Late Cretaceous

Name: Syenite
Role: Associated
Age Type: Associated Rock
Age Young: Late Cretaceous

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

Analytical Data

Analytical Data: ASSAYS HAD TRACE TO 0.52 OZ. AU/TON ON NW SIDE OF CREEK. ON SE SIDE, OVERALL GRADE IS 0.06 OZ AU, 0.11 OZ AG/TON, 0.15% CU. SOME SAMPLES HAD 0.05 - 0.14% BI, 0.02 - 0.11% WO3

Materials

Ore: Chalcopyrite
Ore: Bismuth
Gangue: Quartz
Gangue: Limonite
Gangue: Pyrite

Comments

Comment (Location): At Head Of E. Fk. Milligan Creek; Plotted At Corner Of 4 Sections Land Status Value Calculated 7-94 Using GIS Overlay Analysis With USFS Land Ownership Boundaries, 1:126,720 Scale.

Comment (Production): Value Item 8 $37 In Au; Value Item 9, $2718 In Au, Ag

Comment (Development): Mill, 5 Claims; Located In 1906 As The Mildred, Was Relocated As The Arrastre Group In The 1950'S And Was Later Changed To The Orofino Group

Comment (Deposit): 2 Or More Parallel Fracture - Filling Quartz Veins

Comment (Geology): Shenon And Ross (1936) Believe The Host Rocks Are Cret Gneissic Diorite Of Idaho Batholith; Lorain (1938) Believes It Is Quartz Magnetite Diorite Of The Batholith; Cater And Others (1973) Say It Is Syenite Of Ramey Ridge Complex

Comment (Commodity): Chip And Random Samples Produced Gold Values From Trace To 146 Grams, Silver Trace To 37.7 Grams Per Metric Ton, Copper From 0.01 To 6.4 Percent. Anomalous Amounts Of Bismuth, Tungsten Were Detected In A Few Samples Taken From Quartz Veins Exposed Near Three Adits.

References

Reference (Deposit): Lorain, S. H., 1938, Gold Mining And Milling In Idaho County, Idaho: USBM Inf. Circ. 7039, 90 P.

Reference (Deposit): Cater, F. W., And Others, 1973, Mineral Resources Of The Idaho Primitive Area And Vicinity, Idaho: USGS Bulletin 1304, 431 P.

Reference (Deposit): Shenon, P. J., And Ross, C. P., 1936, Geology And Ore Deposits Near Edwardsburg And Thunder Mountain, Idaho: Idaho Bureau Of Mines And Geology Pamphlet 44, 45 P.

Reference (Deposit): 1936 Geolmap Idaho Bureau Of Mines And Geology Pamphlet 44

Reference (Deposit): 1938 Recon USBM Inf. Circ. 7039

Reference (Deposit): 1973 Recon F. W. Cater And Others, Bulletin 1304

Reference (Production): Cater, F. W., And Others, 1973, USGS Bulletin 1304

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.