USGS Mineral Resources Data System
Type: Historical mine record
Supports:
- mine identity
- development status
- commodities
- underground eligibility evidence
California · San Luis Obispo County
Sweetwater Chromite Mine
Unconfirmed Chromium Mixed Underground / Surface
Key facts
- State
- California
- County
- San Luis Obispo
- Development status
- Past Producer
- Mine type
- Mixed underground / surface
- Primary commodity
- Chromium
- Verification
- Unconfirmed
Also known as
- San Juan Mine, Sweetwater Chrome Mine, San Juan Chrome Mine, Pierce and Benadon Group
Mine Location
Approximate AreaDocumented underground workings
Source classification: Underground operation documented
Specific physical workings are not yet documented in discrete records.
Historical mapped workings
USGS historical topographic mapping. Features may no longer exist.
- 1 adit symbol
View individual source records (3)
Every underlying record used to build the summary above, for research/verification use.
- USGS MRDS working type: Underground
- MRDS work_type documents underground workings: Surface, Underground · work_type
- MRDS oper_type documents existing underground operation (dev_stat=Past Producer): Surface-Underground · oper_type
Verification
Unconfirmed
Source records support underground workings, but UndergroundMines has not yet independently verified this mine.
Why it's listed
Source records document both underground and surface mining.
History & operations
Historical record
- Development status: Past Producer
Operators / organizations
- John D. Hoffman-One Of Last Operators In 1957 · Historical operator · 1976
- Ruda And Negranti-Also Operated Minein 1955-1957 · Historical operator · 1976
- San Juan Chrome-Conflicting Owner-Ship Data · Source-reported owner · 1976
- U.S. Forest Service - Los Padres National Forest · Source-reported owner · 1976
Commodities & minerals
Reported minerals
- Chromite
- Magnetite
- Olivine
- Pyroxene
- Serpentine
Access & recent conditions
- Land
- unknown
Community reports
No community field reports yet.
I Visited This MineSources & evidence
USGS Historical Topographic Mine Features
Type: Historical mapped physical features
Dataset: DOI 10.5066/P9TAALR6
Supports:
- mapped adit symbols (1)
Historical mapped features may no longer exist.
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Historical mapped workings available