California underground mines
5,009 documented underground mines
California hosts one of the densest historic mining landscapes in the United States, from Mother Lode gold belts to desert tungsten, borate, and silver districts.
Open state mapUndergroundMines.com
Discover, document and explore the history beneath the surface.
A community-built database of documented underground mines, shafts, adits, tunnels and historic underground workings — focused on California, Nevada, and Arizona.
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Do not seek out dangerous unknown sites solely for verification.
Interactive underground mine map
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Explore by state
State indexes built from published underground mine records only.
Nevada underground mines
3,387 documented underground mines
Nevada's mining history spans Comstock silver, Carlin-style gold, and hundreds of mountain-range districts across the Basin and Range.
Open state mapArizona underground mines
3,507 documented underground mines
Arizona mining history includes major copper districts, historic gold camps, and extensive federal mineral-resource documentation across the Southwest.
Open state mapFeatured mine records
Selected underground catalog records with useful source depth, workings evidence, or historical documentation.
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Empire Mines Co.
California
Unconfirmed Gold
Historical mapped workings available
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Empire West
California
Unconfirmed Gold
Historical mapped workings available
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Kennedy
California
Unconfirmed Gold
Historical mapped workings available
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Ajo Peak Mine
Arizona
Unconfirmed Copper Mixed Underground/Surface
Documented shaft evidence
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Hazel-Goldfield
Nevada
Unconfirmed Gold
Historical mapped workings available
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Magma Chief Group
Arizona
Unconfirmed Lead
Historical mapped workings available
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Montana Tonopah
Nevada
Unconfirmed Silver
Historical mapped workings available
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Morenci Mine
Arizona
Unconfirmed Copper Mixed Underground/Surface
Historical mapped workings available
How UndergroundMines works
Discover
Search underground mines by name, county, commodity, and coordinates with radius tools.
Document
Every published record keeps source-backed underground evidence — USGS MRDS fields, workings notes, and citations.
Explore
Membership-aware maps separate public regional context from gated exact locations.
Preserve
Submit new underground mines with workings evidence for moderation — surface prospects alone are not published.
Share your explorations
Log the mines you've visited, group multiple mines into a trip, upload your photos, and share the story without sharing your stored mine locations.
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Explorer Pro is for exploring and documenting underground mines: exact coordinates where publication rules allow, personal visit tracking, and private notebooks. Checkout remains disabled until a Stripe price is configured for this site.
View membership detailsSafety & lawful access
A listing is not permission. Abandoned workings can contain unstable ground, vertical drops, water, and bad air. Public land does not mean underground entry is allowed. Read the safety notice and access disclaimer.