Knob Hill Mine

The Knob Hill Mine is a silver and gold mine located in Ferry county, Washington at an elevation of 3,120 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: Knob Hill Mine
Secondary: Veins: Knob Hill
Secondary: Stewart
Secondary: Golden Promise
Secondary: South Cross
Secondary: Alpine
Secondary: Bailey

Commodity

Primary: Silver
Primary: Gold
Tertiary: Selenium
Tertiary: Tellurium
Tertiary: Arsenic
Tertiary: Copper
Tertiary: Antimony

Location

State: Washington
County: Ferry
District: Republic District

Land Status

Not available

Holdings

Not available

Workings

Not available

Ownership

Owner Name: Hecla Mining Co.

Production

Year: 1989
Material type: ORE - AU,AG
Description: Ap_Grade: ^3.60 Opt Ag Recovered Grade
Year: 1988
Material type: AG
Description: Ap_Grade: ^0.90 Opt Au Recovered Grade
Year: 1987
Material type: AU
Description: Ap_Grade: ^4.70 Opt Au Recovered Grade
Year: 1987
Material type: ORE - AU,AG
Description: Ap_Grade: ^0.97 Opt Au Recovered Grade

Deposit

Record Type: Site
Operation Category: Producer
Operation Type: Unknown
Year First Production: 1904
Discovery Year: 1904
Years of Production:
Organization:
Significant: N
Deposit Size: M

Physiography

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

Mineral Deposit Model

Model Name: Epithermal vein, Comstock

Orebody

Not available

Structure

Type: R
Description: The Republic Graben Trends Northeasterly And Is Bounded On The West By The Bacon Creek Fault And On The East By The Sherman Creek Fault.

Type: L
Description: Eureka Fault System.

Alterations

Alteration Type: L
Alteration Text: Propylitization And Silicification. See Geology Comments.

Rocks

Not available

Analytical Data

Not available

Materials

Ore: Electrum
Ore: Naumannite
Ore: Tetrahedrite
Gangue: Chalcedony
Gangue: Opal
Gangue: Marcasite
Gangue: Pyrite
Gangue: Calcite
Gangue: Quartz
Gangue: Realgar
Gangue: Stibnite
Gangue: Chalcopyrite
Gangue: Gypsum
Gangue: Barite
Gangue: Sericite
Gangue: Fluorite

Comments

Comment (Deposit): THIS RECORD HAS BEEN MERGED WITH SP00082, WHICH HAS BEEN DELETED.

Comment (Deposit): TWO VEIN TYPES ARE RECOGNIZED: 1) SHEAR VEINS - LONG DIMENSION IS ALONG STRIKE, SHORT DIMENSION IS DOWN DIP, NARROWER THAN DILATIONAL VEINS, GENERALLY HOST LOWER GRADE ORE, STRIKE NW, EXAMPLE IS BAILEY VEIN. 2) DILATIONAL VEINS - LONG DIMENSION IS DOWN DIP, SHORT DIMENSION IS ALONG STRIKE, WIDER THAN SHEAR VEINS, GENERALLY HOST HIGHER GRADE ORE.

Comment (Geology): ALTERATION COMMENTS: PROPYLITIZATION AND SILICIFICATION. AMPHIBOLES ALTERED TO CHLORITE-CARBONATE, FELDSPARS ALTERED TO SERICITE AND CARBONATE. SILICIFICATION IS PREDOMINANT PROXIMAL TO UPPER LEVEL VEINS. GEOLOGY COMMENTS: GOLDEN PROMISE VEINS OCCUR BETWEEN TWO RIGHT LATERAL STRIKE SLIP FAULTS, THE HERMES SHEAR AND THE CROSBY SHEAR, KNOWN IN MINE USAGE AS THE "SHEAR COUPLET". BLACK CHALCEDONY ASSOCIATED WITH THE THE GOLDEN PROMISE NO. 1 VEIN IS UNIQUE IN THE DISTRICT. IN THE GOLDEN PROMISE VEINS, VEIN TEXTURES RANGE FROM BANDED TO COLLIFORM TO BOTRYOIDAL TO "BAROQUE" (MINE TERM FOR A FLOWERY, ORNATE TEXTURE ASSOCIATED WITH THE HIGHEST GRADES). THE NEARBY STEWART, MOUNTAIN LION, AND MUD LAKE PITS ARE HOSTED IN PART BY VOLCANICLASIC SEDIMENTS (LOWERMOST KLONDIKE MOUNTAIN FORMATION?) AND ARE ASSOCIATED WITH ARGILLIZATION AND HYDROTHERMAL BRECCIATION.

Comment (Development): MILL.CAP: 270 TPD ; ECON.COM: IN 1990, CASH COST OF PRODUCTION WAS $130 PER OZ. OF AU AND FULL COST OF PRODUCTION WAS $150 PER OZ OF AU. STUDIES WERE SCHEDULED FOR 1991 ON WHETHER INCREASED RESERVES WOULD JUSTIFY AN INCREASE IN THE MILL'S 270 TPD CAPACITY.

Comment (Workings): THE MILL, CONSTRUCTED IN 1937, WAS OPERATING IN 1990 AT A RATE OF 270 TPD WHICH IS THE DAILY HOISTING CAPACITY OF THE NO. 2 SHAFT. THE NO. 2 SHAFT REACHES AN INCLINED DEPTH OF 2000 FT. DOWN THE DIP OF THE VEIN. OVERHAND CUT AND FILL IS THE MINING TECHNIQUE. BY THE END OF 1990, THE DECLINE RAMP BEING DRIVEN TO ACCESS THE GOLDEN PROMISE VEIN HAD REACHED A LENGTH OF 13,000 FT. THE DECLINE RAMP IS 13 FT. HIGH, 15 FT. WIDE, AND EXTENDS DOWNWARD AT A 14% GRADE. MOST OF THE WASTE ROCK FROM CUTTING THE DECLINE HAS BEEN USED BY FERRY COUNTY FOR ROAD FILL. THE NEW DECLINE ALLOWS RUBBER-TIRED TRUCKS TO DRIVE DIRECTLY TO AND FROM THE UNDERGROUND WORKINGS, PROVIDING AN INCREASE IN MINING AND DEVELOPMENT ACTIVITIES.

Comment (Commodity): APROX. 40% OF AU OCCURS AS FREE GRAINS OF ELECTRUM, THE REMAINDER PROBABLY AS SELENIDES AND TELLURIDES. THE PRINCIPAL ORE MINERAL OF AG IS NAUMANNITE. THE AU:AG RATIO RANGES 1:1.5 TO 1:9, AVERAGES 1:5, AND USUALLY DECREASES WITH DEPTH BY INCREASE IN AG GRADE.

Comment (Production): PRODUCTION FROM THE KNOB HILL NO. 2 SHAFT REACHED 2 MILLION OUNCES AU ON MAY 24, 1989.

Comment (Reserve-Resource): 1990 FIGURES REPRESENT PROVEN AND PROBABLE RESERVES AS OF 12/31/90.

References

Reference (Deposit): USGS BULL 1216, PG 114

Reference (Deposit): HECLA MINING CO., 1991, ANNUAL REPORT FOR 1990.

Reference (Deposit): UMPLEBY, J., 1910, GEOLOGY AND ORE DEPOSITS OF REPUBLIC MINING DISTRICT, WASHINGTON GEOLOGICAL SURVEY BULLETIN NO. 1.

Reference (Deposit): SALZER, T.A., 1990, EPITHERMAL GOLD-SILVER DEPOSITS, REPUBLIC DISTRICT, FERRY COUNTY, WASHINGTON, ORAL PRESENTATION AT 96TH ANNUAL NORTHWEST MINING ASSOCIATION CONVENTION, SPOKANE, WA, DECEMBER 7.

Reference (Deposit): MARTIN, W., 1988, THE GEOCHEMISTRY AND PETROGRAPHY OF SOME VEINS AND WALLROCKS HOSTING GOLD AND SILVER IN THE REPUBLIC DISTRICT, NORTHEASTERN WASHINGTON, UNPUBLISHED M.S. THESIS, EASTERN WASHINGTON UNIVERSITY.

Reference (Deposit): FULL, R. P. AND GRANTHAM, R. M., 1968, ORE DEPOSITS OF THE REPUBLIC MINING DISTRICT, FERRY COUNTY, WASHINGTON, IN RIDGE, J. D., ED., ORE DEPOSITS OF THE UNITED STATES 1933-1967 - THE GRATON SALES VOLUME, THE AMERICAN INSTITUTE OF MINING, METALLURGICAL, AND PETROLEUM ENGINEERS, INC., NEW YORK, P. 1481-1494.

Reference (Production): 1986-1990 ANNUAL PRODUCTION: HECLA MINING CO., 1991, ANNUAL REPORT FOR 1990. DAYTON, S.H., 1988, HECLA'S REPUBLIC UNIT: SMALL MINE PACKS A BIG EARNINGS PUNCH, ENGINEERING AND MINING JOURNAL, DECEMBER, P. 34-39. LASMANIS, R., WASHINGTON GEOLOGIC NEWSLETTER, VOL. 17, NO. 3, P. 9-11.

Reference (Deposit): DAYTON, S.H., 1988, HECLA'S REPUBLIC UNIT: SMALL MINE PACKS A BIG EARNINGS PUNCH, ENGINEERING AND MINING JOURNAL, DECEMBER, P. 34-39.

Reference (Deposit): LASMANIS, R., WASHINGTON GEOLOGIC NEWSLETTER, VOL. 17, NO. 3, P. 9-11.

Reference (Deposit): LINDGREN, W. AND BANCROFT, H., 1914, THE ORE DEPOSITS OF NORTHEASTERN WASHINGTON, USGS BULLETIN 550, P. 133-166.

Washington Gold

"Where to Find Gold in Washington" 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 Arizona. Read more: Where to Find Gold in Washington.