The Custer Project consists of 1,380 BLM lode claims over an area of approximately 28,318 acres of prospective LCT-pegmatites occurring in a North-South corridor and containing many historic lithium mines.
Historic lithium bearing mines in Custer Project area include:
• Custer Mountain (spodumene, amblygonite, lepidolite)
• Earl Lode (spodumene, amblygonite)
• L5 No.3 (spodumene)
• Climax (amblygonite, lithiophilite-triphylite)
• Elkhorn (lithiophilite)
The Custer Mountain Mine has been mined for feldspar and beryl sporadically since 1942. Mapping of the mine in 1945 by the United States Geological Survey (“USGS”) described pegmatite zones rich in spodumene, amblygonite and lepidolite. Spodumene crystals were documented up to 1.5m long and 0.5m thick. The Climax Mine was one of the largest producers of mica in the Black Hills and has been intermittently operated since 1880. The pegmatite contains zones rich in lithium bearing minerals amblygonite and lithiophilite-triphylite.