| BBBig Bear Plant #35 | Big Bear Lake | 1–19 | ◐ LIKELY ACTIVE |
| CMCanam Minerals INC | Rancho Cucamonga | — | ◐ LIKELY ACTIVE |
| CUCox, USA | Ontario | 20–99 | ◐ LIKELY ACTIVE |
| EMEZ Mix Inc - Rialto | Bloomington | 20–99 | ◐ LIKELY ACTIVE |
| FPFontana Plant #4 | Fontana | 1–19 | ◐ LIKELY ACTIVE |
| HMHi-Grade Materials-Hesperia Transportation | Hesperia | 20–99 | ◐ LIKELY ACTIVE |
| HMHi-Grade Materials- Oro Grande | Oro Grande | 20–99 | ◐ LIKELY ACTIVE |
| HMHi-Grade Materials-Twentynine Palms Ready Mix | Twentynine Palms | 1–19 | ◐ LIKELY ACTIVE |
| IIIsolatek International- SBCA | San Bernardino | 1–19 | ◐ LIKELY ACTIVE |
| LILMI, Inc.-Ontario | Ontario | 100–499 | ◐ LIKELY ACTIVE |
| RCRialto, CA | Rialto | 1–19 | ◐ LIKELY ACTIVE |
| RPRialto Plant #24 | Rialto | 20–99 | ◐ LIKELY ACTIVE |
| RERobar Enterprises-Hesperia | Hesperia | 20–99 | ◐ LIKELY ACTIVE |
| TPThompson Pipe Group Precast Rialto | Rialto | 100–499 | ◐ LIKELY ACTIVE |
| TUToto USA Ontario | Ontario | 20–99 | ◐ LIKELY ACTIVE |
| VPVictorville Plant #42 | Victorville | 20–99 | ◐ LIKELY ACTIVE |
| WRWestlake Royal Roofing - Rialto | Rialto | 20–99 | ◐ LIKELY ACTIVE |
 Able Industrial Products INC | Ontario | — | ◇ UNVERIFIED |
| ACAcc Ca INC Dba Arcosa Crushed Concrete | Rialto | — | ◇ UNVERIFIED |
| AIAfg Industries INC | Victorville | — | ◇ UNVERIFIED |
| ACAlejandro Cedeno Dba Vac Marble & Granite | Rialto | — | ◇ UNVERIFIED |
| AGAl's Garden Art, INC. | Colton | — | ◇ UNVERIFIED |
| AEAmbient Enviromental | Highland | — | ◇ UNVERIFIED |
| ABAmerican Borate CO Dunn Plant | Ludlow | — | ◇ UNVERIFIED |
| AQAmerican Quartz Group, INC. | Barstow | — | ◇ UNVERIFIED |
| ACAmeron Concrete & Steel Pipe Sys, So Div | Etiwanda | — | ◇ UNVERIFIED |
| AIAmeron International | Etiwanda | — | ◇ UNVERIFIED |
| ABAngelus Block CO | Bloomington | — | ◇ UNVERIFIED |
| ABAngelus Block Co., INC. - Rialto Block Plant | Bloomington | — | ◇ UNVERIFIED |
| ACArrowhead Capital Investments, LLC | San Bernardino | — | ◇ UNVERIFIED |
| ALAtel, LLC | Chino Hills | — | ◇ UNVERIFIED |
| ATAuburn Tile | Ontario | — | ◇ UNVERIFIED |
| ACAz Countertops, INC | Ontario | — | ◇ UNVERIFIED |
| ACAz Countertops, INC. | Ontario | — | ◇ UNVERIFIED |
| BPBeta Properties | Montclair | — | ◇ UNVERIFIED |
| BRBoral Roofing, LLC | Rialto | — | ◇ UNVERIFIED |
| BPBrooks Products | Fontana | — | ◇ UNVERIFIED |
| BIBrubaker-mann INC | Barstow | — | ◇ UNVERIFIED |
| BIBurlingame Indust. INC Dba Eagle Roofing Products | Rialto | — | ◇ UNVERIFIED |
| BCBwm California LLC | Barstow | — | ◇ UNVERIFIED |
| CPCalifornia Portland Cement CO | Colton | — | ◇ UNVERIFIED |
| CCCalmat CO (owner) | Upland | — | ◇ UNVERIFIED |
| CBCemex - Black Mountain Quarry Plant | Apple Valley | — | ◇ UNVERIFIED |
| CCCemex California Cement LLC | Victorville | — | ◇ UNVERIFIED |
| CCCemex Construction Materials Pacific LLC | Apple Valley | — | ◇ UNVERIFIED |
| CSCentral School District | Rancho Cucamonga | — | ◇ UNVERIFIED |
| CLChina Lake Lime/westend | Trona | — | ◇ UNVERIFIED |
| CMChino Mhc Properties LLC | Chino | — | ◇ UNVERIFIED |
| COCity of Fontana | Fontana | — | ◇ UNVERIFIED |
| COCity of Ontario Fire Department | Ontario | — | ◇ UNVERIFIED |
