Grand Island Group
Keystone, South Dakota
43.9052°N 103.4297°W
Mine Overview
The Grand Island Group is near Keystone, South Dakota. Historically the site has been associated with the Keystone Mining District which is now part of the Black Hills National Forest. Mine operations consist of underground workings. There is one known shaft. Subsurface depth reaches a maximum of 30 meters (100 feet). The ore mined is composed of silver, gold and pyrrhotite with waste material consisting primarily of quartz. Associated rock in this area is diorite from the Neoproterozoic era 1.00 to 0.54 billion years ago. The Black Hills of the Interior Plains characterize the geomorphology of the surrounding area.
Site identification and general characteristics. Learn about USGS mines.
Commodities
Additional textual information about a site or mine.
- Commodity Type Importance
- Gold Metallic Primary
- Silver Metallic Primary
Location Info
- Pennington , South Dakota County / State
- Continent Country State County
- North America The United States South Dakota Pennington
Notes
ADJACENT TO AND SOUTH OF THE EGYPTIAN GROUP.
Development
ORE IS LOW GRADE
Workings
Workings at the site.
Underground Workings #1
- Type: Underground
- Sub Surface Depth: 30.48 Meters
Physiography
Physiographic area where the resource is found.
- Division Province? Section
- Interior Plains Great Plains Province Black Hills
Ore Control
Controls on emplacement of ore such as faults or other structural features.
- Text?
- Shear Zone
Nearby Deposits
Other deposits in the same region.
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Bismark-Ida Florence Group
- Gold commodity Site type Mine status
- Pennington, South Dakota
- 0.02 miles
-
Bismark Gold Mine
- Gold commodity Site type Mine status
- Pennington, South Dakota
- Surface And Underground
- 0.02 miles
-
Juniper Silver Mine
- Gold commodity Site type Mine status
- Pennington, South Dakota
- 0.11 miles
-
Egyptian Group
- Gold commodity Site type Prospect status
- Pennington, South Dakota
- Underground
- 0.15 miles
-
Nathaniel Pope Lode
- Gold commodity Site type Mine status
- Pennington, South Dakota
- Underground
- 0.28 miles
-
Grand Island Group
- Gold commodity Site type Prospect status
- Pennington, South Dakota
- Underground
- 0.41 miles
-
Egyptian Group
- Gold commodity Site type Mine status
- Pennington, South Dakota
- 0.43 miles
-
Gold Coin Mine
- Gold commodity Site type Mine status
- Pennington, South Dakota
- Underground
- 0.45 miles
-
Sitting Bull Lode
- Beryllium commodity Site type Mine status
- Pennington, South Dakota
- Surface
- 0.47 miles
-
Nathaniel Pope Silver Mine
- Gold commodity Site type Mine status
- Pennington, South Dakota
- 0.51 miles
Nearby Places
- Keystone (0.88 miles away)
- Rockerville (5.08 miles away)
- Hill City (7.48 miles away)
- Colonial Pine Hills (9.08 miles away)
- Johnson Siding (12.40 miles away)
- Hermosa (12.72 miles away)
- Custer (12.75 miles away)
- Silver City (14.06 miles away)
- Rapid City (15.62 miles away)
- Rapid Valley (17.79 miles away)
- Blackhawk (18.03 miles away)
- Green Valley (18.21 miles away)
- Fairburn (18.64 miles away)
- Summerset (20.13 miles away)
- Nemo (20.30 miles away)
- Pringle (22.07 miles away)
- Piedmont (22.64 miles away)
Nearby Mining Districts
- Keystone Mining District (0 miles away)
- Hill City Mining District (2.36 miles away)
- Spokane Mining District (3.52 miles away)
- Spring Creek Area (4.48 miles away)
- Custer Mining District (5.93 miles away)
Nearby Lands
- Black Hills National Forest (0 miles away)
- Mount Rushmore National Memorial (1.06 miles away)
- Black Elk Wilderness (2.32 miles away)
Footnotes
* Mine bounds on map indicate the general area that a mine occupies. For an detailed map, refer to the overseeing BLM field office.
** The mine central point is based on an average of the mine's bounding box(es) and does not necessarily fall on the claim itself.
1 World-class significance is determined by total endowment of the contained commodity. This includes all past production and remaining reserves. Each commodity is considered separately and commodities cannot be combined to arrive at a significant size. The tonnage thresholds are from the mine model grade-tonnage studies. As of June 2008, many entries were classified as significant under less strict rules.
Mining Claim News From The Diggings™
Learn more about the Bureau of Land Management, Public Land Survey System, and mining claims.
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Understanding Claim Ownership
We receive lots of emails from people who find their name or a relative’s name on our site and want to know if this means they have some right to the land listed under that name.
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Understanding BLM Administrative Areas
Whether it is filing a mine or researching one, the administering BLM office is going to be the definitive source.
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Understanding Location Data
Mine handled by the Bureau of Land Management are not mapped by latitude and longitude, instead, these mines harken back to the Public Land Survey System.
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Understanding Townships
A “township” can refer to two different things. Both are part of the PLSS measurement system but have different uses.
Deposit
SAME MINERALIZED SHEAR ZONE AS THE KEYSTONE & BULLION PROPERTIES.