16 To 1 Mine
Nevada · Esmeralda County
Unconfirmed Silver Producer Underground
Documented adit evidence
Underground
Records whose USGS work type documents underground workings. · 3432 records
In mining terminology, underground workings are excavations accessed by shafts, adits, tunnels, or inclines beneath the surface.
Many USGS MRDS records state “Underground” without naming a specific shaft or adit. UndergroundMines preserves that distinction rather than inventing feature types.
4-M Lease
Nevada · Elko County
Unconfirmed Gold Past Producer Underground
Historical mapped workings available
A & B Reeves
California · Amador County
Unconfirmed Gold Past Producer Underground
Documented adit evidence
A. C. Smith
California · Mariposa County
Unconfirmed Copper Past Producer Underground
Documented adit evidence
Abbey Mine
California · Madera County
Unconfirmed Gold Past Producer Underground
Historical mapped workings available
Abbie L.
California · Tuolumne County
Unconfirmed Gold Past Producer Underground
Historical mapped workings available
Abbott
California · Lake County
Unconfirmed Mercury Past Producer Underground
Historical mapped workings available
Abe Lincoln Mine
Arizona · Yavapai County
Source Corroborated Copper Past Producer Underground
Documented adit evidence
Abe Reed Mine
Arizona · Graham County
Unconfirmed Lead Past Producer Underground
Documented shaft evidence
Accident Mine
Nevada · Clark County
Mindat Confirmed Lead Past Producer Underground
Historical mapped workings available
Ackers
California · Fresno County
Unconfirmed Copper Occurrence Underground
Acme Cons
California · Amador County
Unconfirmed Gold Prospect Underground
Historical mapped workings available
Acquisition Mine
Arizona · Yavapai County
Unconfirmed Gold Producer Underground
Historical mapped workings available
Adams
California · Placer County
Unconfirmed Gold Past Producer Underground
Adams Gulch
California · El Dorado County
Unconfirmed Gold Past Producer Underground
Adams Mine
Nevada · Esmeralda County
Unconfirmed Gold Past Producer Underground
Historical mapped workings available
Adams Mine Group
Arizona · Yuma County
Unconfirmed Lead Past Producer Underground
Historical mapped workings available
Adamson Mine
California · Inyo County
Unconfirmed Tungsten Plant Underground
Documented adit evidence
Addie
California · Calaveras County
Unconfirmed Gold Past Producer Underground
Documented adit evidence
Adelaide
California · Sierra County
Unconfirmed Gold Past Producer Underground
Historical mapped workings available
Adelaide
California · Siskiyou County
Unconfirmed Gold Past Producer Underground
Documented adit evidence
Adelaide
California · Calaveras County
Unconfirmed Gold Past Producer Underground
Historical mapped workings available
Adelaide Crown Mines
Nevada · Humboldt County
Unconfirmed Gold Past Producer Underground
Historical mapped workings available
Adelia
California · Calaveras County
Unconfirmed Gold Past Producer Underground