Abandoned mines in San Bernardino County, California

1. Mine openings

   shafts, adits, air shafts, portals and vertical openings: the ways into underground workings
   5,133 34.3%
2. Prospect pits and trenches

   shallow exploration diggings that never became a mine
   8,456 56.5%
3. Mines and surface workings

   labelled mines, open pits, strip mines, placer and hydraulic workings
   522 3.5%
4. Quarries, gravel and borrow pits

   construction-material and industrial-mineral extraction
   474 3.2%
5. Dumps, tailings, spoil and gob

   what mining left above ground
   391 2.6%

…and 139 more named features not listed here.

A name is the label printed beside the symbol on the map. "First mapped" is the earliest topographic edition that shows the symbol, which bounds the feature's age from above; it is not the date it was worked. Unnamed features (most prospect pits, adits and shafts carry no label) are in the counts above but not this list.

1. A R Rock Quarry

   Surface metal/non-metal · Fireman Rock & Nursery · MSHA ID 0405903
   Abandoned 2022-07-01
2. A-Block Co Inc/Needles Redi-Mix

   Surface metal/non-metal · Mohave Concrete Incorporated · MSHA ID 0404118
   Abandoned 2002-06-26
3. AIKEN CINDER MINE

   Surface metal/non-metal · Volco Research · MSHA ID 0401009
   Abandoned 1999-08-24
4. Alliance Ready Mix Inc

   Surface metal/non-metal · Alliance Ready Mix Inc · MSHA ID 0405530
   Abandoned 2010-12-04
5. Allstate Materials Portable #1

   Surface metal/non-metal · Allstate Materials Inc · MSHA ID 0405756
   Abandoned 2008-05-14
6. America Mine

   Surface metal/non-metal · America Mine Operator · MSHA ID 0404124
   Abandoned 1985-05-22
7. Angels No I-Ii-Iii-Iv

   Underground metal/non-metal · Vail Mining & Milling Company · MSHA ID 0404554
   Abandoned 1982-08-18
8. Atlas Mine

   Surface metal/non-metal · Victorville Industrial Minerals · MSHA ID 0403008
   Abandoned 2009-03-13
9. Atolia Mill

   Facility metal/non-metal · Mines Exploration Inc · MSHA ID 0403395
   Abandoned 1978-08-10
10. Atolia Moore (Placer) Property

    Surface metal/non-metal · World Minerals Development Inc · MSHA ID 0404548
    Abandoned 1984-08-29
11. Bagdad Chase Mine

    Surface metal/non-metal · Transcorp Technology Inc · MSHA ID 0404331
    Abandoned 1982-05-03
12. Bagdad-Chase Mine

    Surface metal/non-metal · Bentley Resources-U S Inc · MSHA ID 0404921
    Abandoned 1989-11-29
13. Balance Rock

    Underground metal/non-metal · Bccmd · MSHA ID 0404667
    Abandoned 1984-05-29
14. Barstow

    Surface metal/non-metal · Robertson's · MSHA ID 0401885
    Abandoned 2021-07-13
15. Barstow Plant

    Surface metal/non-metal · B & B Materials Inc · MSHA ID 0405656
    Abandoned 2006-08-30
16. Barstow Truck Parts

    Surface metal/non-metal · Barstow Truck Parts · MSHA ID 0405621
    Abandoned 2005-09-23
17. Bat Quarry #2

    Surface metal/non-metal · Breinholt Contracting Company Inc · MSHA ID 0404812
    Abandoned 1986-12-17
18. Ben Juan I-Ii-Iii

    Underground metal/non-metal · Vail Mining & Milling Company · MSHA ID 0404555
    Abandoned 1982-08-18
19. Benson Mine

    Underground metal/non-metal · Nova Extraction Technologies & Lewis D Hall Est · MSHA ID 0404689
    Abandoned 1992-07-10
20. BENSON MINE

    Surface metal/non-metal · HARRIS TRANSFER, INC. · MSHA ID 0405642
    Abandoned 2022-01-20
21. Best Rock Quarry

    Surface metal/non-metal · Best Rock Quarry, Inc. · MSHA ID 0405918
    Abandoned 2020-04-01
22. BEST ROCK QUARRY

    Surface metal/non-metal · M W Minerals Company Inc · MSHA ID 0405339
    Abandoned 1998-01-25
23. Big Horn Mine

    Underground metal/non-metal · Siskon Gold Corp · MSHA ID 0404482
    Abandoned 1992-03-17
24. Black Angel

    Surface metal/non-metal · Empire Rock Inc · MSHA ID 0405650
    Abandoned 2016-01-04
25. Blackhawk Mine

    Surface metal/non-metal · Sante Fe Gold Mines Inc · MSHA ID 0404972
    Abandoned 1990-04-26
26. Bonanza King Mine

    Underground metal/non-metal · Weaco Resources Ltd · MSHA ID 0404662
    Abandoned 1984-07-10
27. Bristol Dry Lake

    Surface metal/non-metal · National Chloride Company Of America · MSHA ID 0401052
    Abandoned 1982-05-21
28. Bryman Pit

    Surface metal/non-metal · Boral Resources Inc · MSHA ID 0404747
    Abandoned 1995-04-21
29. Cajon Mine

    Surface metal/non-metal · United States Tile Company · MSHA ID 0404837
    Abandoned 1987-08-07
30. Cajon Pass Sand & Gravel

    Surface metal/non-metal · Cajon Pass Sand & Gravel · MSHA ID 0404760
    Abandoned 1991-10-04
31. Cal Pacific Mill

    Facility metal/non-metal · Cal Pacific · MSHA ID 0404030
    Abandoned 1980-01-01
32. Calico Plant

    Surface metal/non-metal · Langley Pacific Resources LLC · MSHA ID 0405769
    Abandoned 2009-05-19
33. California Silica Products

    Surface metal/non-metal · Western States Wholesale · MSHA ID 0405847
    Abandoned 2023-01-06
34. Calspar Mine

    Surface metal/non-metal · Calspar Division-Steelhead Resources Inc · MSHA ID 0404114
    Abandoned 1988-11-07
35. Camp Rock Mine

    Surface metal/non-metal · National Resource Management Inc · MSHA ID 0404853
    Abandoned 1988-11-07
36. Cascade

    Facility metal/non-metal · Cascade Exploration · MSHA ID 0405080
    Abandoned 1990-12-03
37. CASTLE MOUNTAIN MINE

    Surface metal/non-metal · Mk Gold Company · MSHA ID 0405141
    Abandoned 2001-04-26
38. CASTLE MOUNTAIN MINE

    Underground metal/non-metal · Intermountain Mine Services Inc · MSHA ID 0405293
    Abandoned 1997-12-17
39. CEMEX Lytle Creek

    Surface metal/non-metal · Harris Transfer, Inc. · MSHA ID 0405723
    Abandoned 2021-03-27
40. CEMEX SITE

    Surface metal/non-metal · HARRIS TRANSFER, INC. · MSHA ID 0405913
    Abandoned 2020-04-29
41. Cima Cinder

    Surface metal/non-metal · Cima Cinder Products Inc · MSHA ID 0402667
    Abandoned 1984-10-23
42. CIMA CINDER QUARRY

    Surface metal/non-metal · Cima Cinder Quarry · MSHA ID 0405175
    Abandoned 2001-03-05
43. Cima Junction

    Surface metal/non-metal · Orex Inc · MSHA ID 0404915
    Abandoned 1988-05-17
44. Colosseum Gold Mine

    Surface metal/non-metal · Minproc · MSHA ID 0404884
    Abandoned 1988-01-04
45. Colosseum Mine

    Surface metal/non-metal · Industrial Constructors Corp · MSHA ID 0404917
    Abandoned 1993-02-09
46. Colton Aggregates

    Surface metal/non-metal · CalPortland · MSHA ID 0405677
    Abandoned 2019-09-30
47. Colton Plant

    Surface metal/non-metal · Owl Rock Products · MSHA ID 0402832
    Abandoned 1982-10-25
48. COLTON PLANT

    Surface metal/non-metal · Holliday Trucking Inc · MSHA ID 0403496
    Abandoned 2010-04-17
49. Colton Plant & Quarry

    Surface metal/non-metal · CalPortland · MSHA ID 0400037
    Abandoned 2011-12-30
50. Colton Quarry

    Surface metal/non-metal · California Portland Cement Company · MSHA ID 0404351
    Abandoned 1988-06-28
51. COLTON RIVER SAND

    Surface metal/non-metal · Dalton Trucking Inc · MSHA ID 0405321
    Abandoned 1999-04-21
52. CR-04

    Surface metal/non-metal · S L S & N Inc · MSHA ID 0405782
    Abandoned 2018-05-18
53. Cross-Wess Mine

    Underground metal/non-metal · Cross-Wess Claim · MSHA ID 0404177
    Abandoned 1979-04-09
54. Crystal Cave Mine

    Underground metal/non-metal · Exploration Inc Of Nevada · MSHA ID 0404800
    Abandoned 1988-03-29
55. Crystal Hills Sand & Gravel Company

    Surface metal/non-metal · Beazer West Of California Incorported · MSHA ID 0404846
    Abandoned 1993-04-26
56. Cushenbury Plant

    Surface metal/non-metal · Mitsubishi Cement Corp · MSHA ID 0404352
    Abandoned 1988-05-24
57. Daily Transit Mix, LLC

    Surface metal/non-metal · Daily Transit Mix, LLC · MSHA ID 0405860
    Abandoned 2024-02-06
58. Danby Mill

    Facility metal/non-metal · Vail Mining & Milling Company · MSHA ID 0404553
    Abandoned 1982-03-29
59. Day Creek Spreading Grounds

    Surface metal/non-metal · Jeff Carpenter Inc · MSHA ID 0405661
    Abandoned 2014-11-24
60. Dayton Trucking (Porter)

    Surface metal/non-metal · Dayton Trucking · MSHA ID 0405307
    Abandoned 2005-03-16
61. De Voe Mine

    Surface metal/non-metal · American Colloid Company Minerals Group · MSHA ID 0404709
    Abandoned 1985-05-08
62. Death Valley Iron & Gypsum

    Surface metal/non-metal · Death Valley Iron & Gypsum · MSHA ID 0404867
    Abandoned 1987-09-08
63. Demians Mine

    Surface metal/non-metal · Hesperia Ready-Mix · MSHA ID 0404654
    Abandoned 1985-07-08
64. Desert Air

    Surface metal/non-metal · Evans/Harris Mining · MSHA ID 0404829
    Abandoned 1988-05-17
65. Desert Rock Products

    Surface metal/non-metal · Desert Rock Products · MSHA ID 0405098
    Abandoned 1993-03-28
66. Dineen Trucking Inc

    Facility metal/non-metal · Dineen Trucking Inc · MSHA ID 0405522
    Abandoned 2002-09-10
67. Dunn Siding

    Facility metal/non-metal · Desert Mineral Products Corp · MSHA ID 0403132
    Abandoned 1982-06-01
68. E & F Milling

    Facility metal/non-metal · Ellsworth Metals Inc · MSHA ID 0404556
    Abandoned 1982-06-08
69. El Mirage Mill

    Facility metal/non-metal · Metaline Industries Inc · MSHA ID 0404248
    Abandoned 1979-08-01
70. Essex Pit

    Surface metal/non-metal · Desert Construction Company · MSHA ID 0404897
    Abandoned 1988-06-21
71. Excelsior Pit

    Surface metal/non-metal · Pfizer Inc · MSHA ID 0404505
    Abandoned 1985-05-21
72. Field'S Sand & Rock

    Surface metal/non-metal · Field'S Sand & Rock · MSHA ID 0403179
    Abandoned 1981-02-26
73. FNF Crushing 3

    Surface metal/non-metal · FNF Construction Inc · MSHA ID 0202774
    Abandoned 2023-03-29
74. Fontana Plant

    Surface metal/non-metal · Livingston Graham/Blue Diamond Materials · MSHA ID 0404150
    Abandoned 1996-10-02
75. FONTANA ROCK

    Surface metal/non-metal · Fontana Rock · MSHA ID 0405314
    Abandoned 1997-09-18
76. Fort Cady Quarry

    Surface metal/non-metal · CalMat Co · MSHA ID 0405626
    Abandoned 2015-01-01
77. Four Square

    Underground metal/non-metal · Four Square Mine & Mill Company · MSHA ID 0404582
    Abandoned 1982-08-27
78. Four Square Mill

    Facility metal/non-metal · Four Square Mine & Mill Company · MSHA ID 0404583
    Abandoned 1982-08-27
79. FOURTH STREET ROCK CRUSHER

    Surface metal/non-metal · Fourth Street Rock Crusher Inc · MSHA ID 0401773
    Abandoned 2002-05-06
80. FST CEMEX Redlands

    Surface metal/non-metal · FST Sand & Gravel Inc · MSHA ID 0405306
    Abandoned 2002-10-07
81. Garlock Pit

    Surface metal/non-metal · Boral Resources Inc · MSHA ID 0404913
    Abandoned 1995-12-08
82. Garnet

    Surface metal/non-metal · Granite Construction Company · MSHA ID 0402065
    Abandoned 2016-12-19
83. Gold Ace Mine

    Underground metal/non-metal · Gold Ace Mines · MSHA ID 0405201
    Abandoned 1993-08-03
84. Gold Mountain Mine

    Surface metal/non-metal · Gold Mountain Mine · MSHA ID 0405252
    Abandoned 2011-10-01
85. Golden Quail Mill

    Facility metal/non-metal · Golden Quail Resources · MSHA ID 0404282
    Abandoned 1989-04-14
86. Golden Quail Mine

    Surface metal/non-metal · Golden Quail Resources · MSHA ID 0404838
    Abandoned 1989-04-14
87. Gravel Gertie

    Surface metal/non-metal · Tri-State 95 South Sand Rock & Gravel Inc · MSHA ID 0404782
    Abandoned 1993-08-03
88. Great Northern

    Underground metal/non-metal · Vail Mining & Milling Company · MSHA ID 0404457
    Abandoned 1987-08-14
89. H E Burrier And W H Benson Claims

    Surface metal/non-metal · H E Burrier & W H Benson Partners · MSHA ID 0403064
    Abandoned 1980-09-18
90. Haney Rock Mine

    Surface metal/non-metal · HMRS L.L.C · MSHA ID 0405986
    Abandoned 2025-05-01
91. Hanmer Materials

    Surface metal/non-metal · Hanmer Materials · MSHA ID 0405122
    Abandoned 1992-08-04
92. Hector

    Surface metal/non-metal · Blackstone-Pacific, LLC · MSHA ID 0405747
    Abandoned 2009-09-16
93. Henagon Limited

    Surface metal/non-metal · Henagon Limited · MSHA ID 0404870
    Abandoned 2008-10-02
94. Heymenn #1

    Surface metal/non-metal · Heymenn Enterprises · MSHA ID 0404677
    Abandoned 1986-12-02
95. HGM Nebo

    Surface metal/non-metal · Hi-Grade Materials Co. · MSHA ID 0405931
    Abandoned 2023-06-08
96. Highland Plant

    Surface metal/non-metal · Ranch Rock · MSHA ID 0405793
    Abandoned 2012-01-01
97. Huntington Tile Mining

    Surface metal/non-metal · Huntington Tile Inc · MSHA ID 0401107
    Abandoned 1987-07-14
98. Illite

    Surface metal/non-metal · Pfizer Inc · MSHA ID 0404604
    Abandoned 1986-01-23
99. Industrial Rock Products

    Facility metal/non-metal · Custom Mining Company · MSHA ID 0402298
    Abandoned 1987-02-24
100. Infinityrmi

     Surface metal/non-metal · Infinity Recycling & Materials, Inc. · MSHA ID 0405892
     Abandoned 2024-03-10
101. Inland Rock Company Incorporated

     Surface metal/non-metal · Inland Rock Company Inc · MSHA ID 0405031
     Abandoned 1990-06-11
102. Inland Rock Plant

     Surface metal/non-metal · Hanson Aggregates Pacific Southwest Inc · MSHA ID 0405189
     Abandoned 2012-03-02
103. JaCore Aggregates LLC

     Surface metal/non-metal · JaCore Aggregates LLC · MSHA ID 0405598
     Abandoned 2007-08-24
104. K-1 PIT

     Surface metal/non-metal · Caltalc Inc · MSHA ID 0405183
     Abandoned 1999-02-24
105. Kingston Springs Mine

     Surface metal/non-metal · American Colloid Company Minerals Group · MSHA ID 0404721
     Abandoned 1987-09-08
106. Knight Investment Company

     Surface metal/non-metal · Knight Investment Company · MSHA ID 0404931
     Abandoned 1989-03-24
107. Kokoweef Mine

     Underground metal/non-metal · Exploration Inc Of Nevada · MSHA ID 0402965
     Abandoned 2003-08-29
108. LAKESIDE GRAVEL PIT

     Surface metal/non-metal · David Barton Enterprises · MSHA ID 0405264
     Abandoned 1997-01-13
109. Lavic Stone Quarry

     Surface metal/non-metal · Twin Mountain Rock Company · MSHA ID 0402664
     Abandoned 1988-06-21
110. Lenwood Materials

     Surface metal/non-metal · Lenwood Materials · MSHA ID 0404745
     Abandoned 1991-01-22
111. Lovelady-1

     Surface metal/non-metal · Lovelady Trucking & Material Inc · MSHA ID 0405513
     Abandoned 2011-02-28
112. Lucerne Valley

     Surface metal/non-metal · Robertson's · MSHA ID 0405693
     Abandoned 2018-05-01
113. Lytle Creek

     Surface metal/non-metal · Owl Rock Products · MSHA ID 0401886
     Abandoned 1993-06-16
114. Lytle Creek

     Surface metal/non-metal · Osborn Materials & Processing Company · MSHA ID 0405177
     Abandoned 1992-11-02
115. Lytle Creek/S-5 Extec

     Surface metal/non-metal · Barney Northcote Inc · MSHA ID 0405486
     Abandoned 2011-12-30
116. Marter-White Mine

     Facility metal/non-metal · Astro Minerals Inc · MSHA ID 0400187
     Abandoned 1988-03-17
117. Materials Solutions

     Surface metal/non-metal · Materials Solutions, LLC · MSHA ID 0405936
     Abandoned 2019-12-31
118. Mesquite Lake Gypsum Mine

     Surface metal/non-metal · Pacific Mining Group, LLC · MSHA ID 0405881
     Abandoned 2015-01-01
119. Morning Star Mine

     Underground metal/non-metal · Vanderbilt Gold Corp · MSHA ID 0404380
     Abandoned 1984-07-10
120. MORNING STAR MINE

     Surface metal/non-metal · Vanderbilt Gold Corp · MSHA ID 0404791
     Abandoned 2000-09-25
121. Mountain View Plant

     Surface metal/non-metal · Holliday Rock Company Inc · MSHA ID 0401693
     Abandoned 2014-01-01
122. Mud Hills Mine

     Surface metal/non-metal · Phelps Dodge Zeolites · MSHA ID 0404592
     Abandoned 2002-02-01
123. New Discovery

     Surface metal/non-metal · Ellsworth Metals Inc · MSHA ID 0404564
     Abandoned 1982-08-18
124. New Trail Mine

     Surface metal/non-metal · Valgold Mining & Milling Company · MSHA ID 0404999
     Abandoned 1990-09-04
125. Newberry Red

     Surface metal/non-metal · AR Rock Quarry · MSHA ID 0405934
     Abandoned 2023-09-05
126. Newberry Springs Plant

     Surface metal/non-metal · Hanson Aggregates LLC · MSHA ID 0404830
     Abandoned 2012-08-24
127. O K West #1

     Underground metal/non-metal · Vail Mining & Milling Company · MSHA ID 0404456
     Abandoned 1984-06-07
128. Omega Pit

     Surface metal/non-metal · Huntington Tile Inc · MSHA ID 0401106
     Abandoned 1985-05-21
129. Oro Grande Aggregates

     Surface metal/non-metal · CalPortland · MSHA ID 0405906
     Abandoned 2016-09-15
130. Oro Grande Plant

     Facility metal/non-metal · Riverside Cement Company · MSHA ID 0404348
     Abandoned 1988-10-20
131. ORO GRANDE ROCK PLANT

     Surface metal/non-metal · Calmat Company · MSHA ID 0404162
     Abandoned 2001-08-30
132. Owl'S Hole Mine

     Surface metal/non-metal · Jebco Mining Company Inc · MSHA ID 0404561
     Abandoned 1983-11-23
133. P-1 Open Pit Mine

     Surface metal/non-metal · Huntington Tile Inc · MSHA ID 0404738
     Abandoned 1985-05-21
134. PARTIN LIMESTONE PRODUCTS

     Surface metal/non-metal · Partin Limestone Products Inc · MSHA ID 0400217
     Abandoned 1998-03-17
135. PETERMAN HILL KINNE LIMESTONE

     Surface metal/non-metal · Kinne Limestone Products · MSHA ID 0405240
     Abandoned 1997-07-09
136. Pioneer Mine

     Surface metal/non-metal · Huntington Tile Inc · MSHA ID 0404364
     Abandoned 1984-07-10
137. Piute 1

     Surface metal/non-metal · S & H Custom Mining · MSHA ID 0404952
     Abandoned 1989-08-31
138. Placer Mines Ltd

     Facility metal/non-metal · Placer Mines Ltd · MSHA ID 0404487
     Abandoned 1985-08-26
139. Plant 1

     Surface metal/non-metal · Cutting Edge Aggregates Inc · MSHA ID 0405732
     Abandoned 2021-06-15
140. Plant 1

     Surface metal/non-metal · Aggrecon LLC · MSHA ID 0405853
     Abandoned 2018-03-05
141. Plant 2

     Surface metal/non-metal · Cutting Edge Aggregates Inc · MSHA ID 0405734
     Abandoned 2021-04-19
142. Plant 3

     Surface metal/non-metal · Cutting Edge Aggregates Inc · MSHA ID 0405750
     Abandoned 2019-12-31
143. Plant 4

     Surface metal/non-metal · Cutting Edge Aggregates Inc · MSHA ID 0405888
     Abandoned 2017-01-27
144. Plant 5

     Surface metal/non-metal · North American Recycling and Crushing, LLC · MSHA ID 0405521
     Abandoned 2018-06-18
145. Plant 5B

     Surface metal/non-metal · North American Recycling and Crushing, LLC · MSHA ID 0405520
     Abandoned 2019-09-03
146. PLANT B

     Facility metal/non-metal · Skanska · MSHA ID 0405406
     Abandoned 2007-07-15
147. Plant C

     Surface metal/non-metal · LB Crushing LLC · MSHA ID 0405770
     Abandoned 2009-07-01
148. PORTABLE

     Surface metal/non-metal · Skanska · MSHA ID 0405147
     Abandoned 2009-10-01
149. Portable #1

     Surface metal/non-metal · Pacific Aggregates Inc · MSHA ID 0405636
     Abandoned 2005-04-19
150. Portable Crusher (Rental)

     Surface metal/non-metal · Gail Materials · MSHA ID 0405554
     Abandoned 2020-06-08

…and 68 more mines not listed here.

Status and date are as reported to MSHA by the operator. Each mine's own page carries its accident, citation and inspection record.

• Inyo County 11,475
• Kern County 4,879
• Riverside County 3,227
• Mono County 2,946
• Siskiyou County 2,362
• Imperial County 1,232
• Mariposa County 1,079
• Tuolumne County 948
• San Diego County 901
• Calaveras County 840
• Shasta County 832
• Trinity County 685

1. USGS, Consolidated Prospect- and Mine-Related Features from 7.5- and 15-Minute Topographic Quadrangle Maps of the United States (USMIN)
   597,612 point and area features digitized from about 106,350 historical topographic maps published 1886–2006; public domain (CC0). A feature is a map symbol, not a field-verified site, and the map does not say whether it was still worked.
2. USGS Fact Sheet 2025–3003, The Abandoned Mine Inventory of the United States
   States that as of 2025 there is no comprehensive national inventory of abandoned mine features, and that the detailed national database now being built will not be published.
3. OSMRE, Abandoned Mine Land Inventory System (e-AMLIS), public Problems layer
   One row per abandoned mine land problem in a problem area, with its type, funding program and reclamation status; mostly coal mined before the 1977 Surface Mining Control and Reclamation Act. Coordinates are the problem area's.
4. MSHA, Mines dataset (Mine Data Retrieval System)
   Every mine registered with MSHA since the 1970s; a mine reads Abandoned or Abandoned and Sealed when its operator reported that status. Refreshed weekly.
5. US Census Bureau, 2023 cartographic county boundaries (1:500,000)
   Each feature's county is assigned by its coordinates against these boundaries, not copied from the source file.
6. GAO-20-238, Abandoned Hardrock Mines (March 2020)
   Federal agencies had identified at least 140,000 abandoned hardrock mine features on federal land and estimated more than 390,000 more not yet captured in their databases.
7. Abandoned Hardrock Mine Reclamation (AHMR) Program, US Department of the Interior
   The program the USGS inventory is compiled for. Its appropriations and the 674,000 field-confirmed feature count on this page were provided by the program manager, Office of Environmental Policy and Compliance, and are cited with permission (2026-09-08).
8. IMCC-NAAMLP Hardrock AML Report
   Page 48 carries the two figures this page leans on: USGS estimates 633,181 of the 725,690 mine features it recorded from historic topographic maps, 87 percent, are hardrock; and state and federal agencies have submitted more than 724,000 AML features to the national database being built, already more than the historic maps hold. Year-by-year AHMR funding is on page 35.