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MSHA mine register by county

Mines in San Luis Obispo County, California

San Luis Obispo County, California has 40 mines on MSHA's register: 6 active, 4 intermittent, 30 abandoned. 218 accidents have been reported at these mines between 1983 and 2026. Inspectors have issued 943 citations.

Every mine MSHA has registered in San Luis Obispo County, working or not, with the accident, fatality and citation record each one carries on this site. Active mines are listed first, then the rest by the weight of their record.

Abandoned and historical mine features in San Luis Obispo County →

Mines on register
40
Active
6
Fatalities on record
0
Citations issued
943
0 underground · 38 surface · 2 facilities 0 coal · 40 metal and non-metal 4 intermittent 30 abandoned 218 reported accidents, 1983–2026
Local economic context
ⓘ County figures come from the US Census Bureau's American Community Survey, 5-year pooled estimates, so the 2023 vintage covers 2019 through 2023. The Census category is 'mining, quarrying, and oil and gas extraction', which is broader than MSHA jurisdiction and includes oil and gas workers no mine employs. These figures describe the surrounding county, not this mine, and are not a factor in any specific incident.
San Luis Obispo County, California · Population 281,486
0.2%
Mining share of county employment
$93,398
Median household income
Source: US Census Bureau, American Community Survey 2023 5-year estimates.
On the map 
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MSHA-registered mine, any status

Mines plot only where MSHA holds a surveyed coordinate for the site; mines the agency locates to a town, county or state centroid are in the counts and the list above but not drawn. Click a point for the mine's status and record.

Operators with the most mines herecurrent operator of record
Operator Mines Active Fatalities
Viborg Sand & Gravel, Inc. 4 0 0
David Crye General Engineering Contractor, Inc. 3 2 0
Calportland Construction 2 1 0
Pioneer Transit Mix Inc 2 0 0
Weyrick Sand & Gravel 2 0 0
Alamo Rock Company 1 0 0
Aman Brothers Inc 1 0 0
Bickford Concrete Inc 1 0 0
Blue Mountain Minerals PR LLC 1 1 0
California Community Services Gravel 1 0 0
Mines in San Luis Obispo County40 on register
  1. Blue Mountain Minerals PR LLC
    Surface metal/non-metal · Blue Mountain Minerals PR LLC · MSHA ID 0400099
    Active
  2. Santa Margarita Aggregates
    Surface metal/non-metal · Martin Marietta Northern California Aggregates,LLC · MSHA ID 0401616
    Active
  3. Rocky Canyon Plant
    Surface metal/non-metal · Calportland Construction · MSHA ID 0404634
    Active
  4. Navajo Rock & Block
    Surface metal/non-metal · David Crye General Engineering Contractor, Inc. · MSHA ID 0404240
    Active
  5. Bianchi Pit
    Surface metal/non-metal · David Crye General Engineering and Contractor, Inc · MSHA ID 0405561
    Active
  6. Whale Rock Quarry
    Surface metal/non-metal · Negranti & Sons · MSHA ID 0404635
    Active
  7. LOMPOC PLANT
    Facility metal/non-metal · Grefco Minerals Inc · MSHA ID 0402846
    Abandoned
  8. Schlegel North County Sand & Gravel, Inc
    Surface metal/non-metal · Schlegel North County Sand & Gravel, Inc. · MSHA ID 0405370
    Abandoned
  9. MTN SPRINGS RD. PIT
    Surface metal/non-metal · Viborg Sand & Gravel Inc · MSHA ID 0405040
    Intermittent
  10. PORTABLE PLANT D
    Surface metal/non-metal · Aman Brothers Inc · MSHA ID 0404845
    Abandoned
  11. Smith Sand Pit
    Surface metal/non-metal · Viborg Sand & Gravel, Inc. · MSHA ID 0405647
    Abandoned
  12. Paso Robles Plant
    Surface metal/non-metal · Calportland Construction · MSHA ID 0405492
    Intermittent
  13. Warrior 1800/Cone Crusher FT200
    Surface metal/non-metal · David Crye General Engineering Contractor · MSHA ID 0405895
    Intermittent
  14. Estrella Sand Pit
    Surface metal/non-metal · Viborg Sand & Gravel, Inc. · MSHA ID 0405891
    Intermittent
  15. Weyrick Plant
    Surface metal/non-metal · Weyrick Sand & Gravel · MSHA ID 0405859
    Abandoned
  16. Alamo Rock
    Surface metal/non-metal · Alamo Rock Company · MSHA ID 0404215
    Abandoned
  17. Bianchi Pit
    Surface metal/non-metal · Winsor Construction · MSHA ID 0404914
    Abandoned
  18. California Valley Community Services Gra
    Surface metal/non-metal · California Community Services Gravel · MSHA ID 0404398
    Abandoned
  19. California Valley Gyp Pit
    Surface metal/non-metal · W-R Gypsum · MSHA ID 0404359
    Abandoned
  20. Carrizo Plains Mine
    Surface metal/non-metal · Fannin-Superior Gypsum Company · MSHA ID 0404336
    Abandoned
  21. Cary Pit
    Surface metal/non-metal · Viborg Sand & Gravel Inc · MSHA ID 0405074
    Abandoned
  22. Dirtman Sand & Gravel #2
    Surface metal/non-metal · Dirtman Trucking · MSHA ID 0404851
    Abandoned
  23. Farming Camp Mine
    Surface metal/non-metal · Temblor Gypsum Company · MSHA ID 0404565
    Abandoned
  24. Gilbreath Gypsum Incorporated
    Surface metal/non-metal · Gilbreath Gypsum Inc · MSHA ID 0404190
    Abandoned
  25. Guerra Pit
    Surface metal/non-metal · Robert Guerra · MSHA ID 0400120
    Abandoned
  26. KRITZ/GOSS
    Surface metal/non-metal · Kritz Excavating & Trucking Inc · MSHA ID 0404994
    Abandoned
  27. Lone Oak Rock & Sand
    Surface metal/non-metal · Lone Oak Rock & Sand · MSHA ID 0405072
    Abandoned
  28. Morro Bay Plant
    Surface metal/non-metal · Pioneer Transit Mix Inc · MSHA ID 0403834
    Abandoned
  29. Morro Bay Plant
    Surface metal/non-metal · Pioneer Transit Mix Inc · MSHA ID 0404232
    Abandoned
  30. Morro Rock & Sand
    Surface metal/non-metal · Morro Rock & Sand Inc · MSHA ID 0401864
    Abandoned
  31. MUNARI PIT
    Surface metal/non-metal · Weyrick Companies · MSHA ID 0405093
    Abandoned
  32. Newhall Quarry
    Surface metal/non-metal · Granite Construction Company · MSHA ID 0404534
    Abandoned
  33. Paso Pit And Mill
    Surface metal/non-metal · Paso Constructors Inc · MSHA ID 0401905
    Abandoned
  34. River Sand & Gravel
    Surface metal/non-metal · River Sand & Gravel Inc · MSHA ID 0404924
    Abandoned
  35. Rodriques Pit
    Surface metal/non-metal · Bickford Concrete Inc · MSHA ID 0403480
    Abandoned
  36. Salinas Sand
    Surface metal/non-metal · Salinas Sand · MSHA ID 0405037
    Abandoned
  37. San Luis Brick Plant
    Surface metal/non-metal · San Luis Brick Inc · MSHA ID 0400603
    Abandoned
  38. San Simeon Mill
    Facility metal/non-metal · Lindseys San Simeon Gravel Company · MSHA ID 0403174
    Abandoned
  39. Santa Maria Pit And Mill
    Surface metal/non-metal · Santa Maria Sand Company · MSHA ID 0403814
    Abandoned
  40. Templeton Hot Plant
    Surface metal/non-metal · Madonna Construction Company · MSHA ID 0402690
    Abandoned

Status, type and operator are as reported to MSHA. Fatality and accident counts are MSHA's reportable accident records for the mine; citations are inspector-issued violations on record. Each mine's own page carries the full detail.

Other counties in CaliforniaAll counties →
How to read these numbers

The register is MSHA's Mine Data Retrieval System: every operation ever assigned a mine ID, including ones abandoned decades ago, so the count is a history of mining in the county, not a count of working mines. A mine's county is the one its operator reported to MSHA. Fatality and accident counts start with MSHA's reportable-accident records (1983 onward); citation counts are inspector-issued violations on record. We are an independent research tool, not MSHA.