| HAHanson Aggregates Pacific Southwest INC | San Diego | — | ◇ UNVERIFIED |
| HRHarbor Ready-mix | Redwood City | — | ◇ UNVERIFIED |
| HBHiggins Brick CO | Chino Hills | — | ◇ UNVERIFIED |
| HHHm Holloway INC - Gypsum Mines | Lost Hills | — | ◇ UNVERIFIED |
| HRHolliday Rock Canoga Park 31 | Canoga Park | — | ◇ UNVERIFIED |
| HRHolliday Rock Chino 18 | Chino | — | ◇ UNVERIFIED |
| HRHolliday Rock Colton Plant 4 | Bloomington | — | ◇ UNVERIFIED |
| HRHolliday Rock Company, INC | Littlerock | — | ◇ UNVERIFIED |
| HRHolliday Rock Company - Van Nuys | Van Nuys | — | ◇ UNVERIFIED |
| HRHolliday Rock San Bernardino 29 | San Bernardino | — | ◇ UNVERIFIED |
| HRHolliday Rock Westminster 20 | Westminster | — | ◇ UNVERIFIED |
| HCHoya Corporation USA | Fremont | — | ◇ UNVERIFIED |
| IMIndustrial Minerals CO | Sacramento | — | ◇ UNVERIFIED |
| ICInland Concrete Products INC | Fontana | — | ◇ UNVERIFIED |
| IIIsolatek International INC | San Bernardino | — | ◇ UNVERIFIED |
 Jensen Enterprises INC Dba Jensen Precast | Ontario | — | ◇ UNVERIFIED |
 Johns Manville CORP | Corona | — | ◇ UNVERIFIED |
| KSK Source INC. | Compton | — | ◇ UNVERIFIED |
| LGLibbey Glass INC | Industry | — | ◇ UNVERIFIED |
| LSLucas Site | La Puente | — | ◇ UNVERIFIED |
| LSLundberg Studios | Davenport | — | ◇ UNVERIFIED |
| MAMagnum Abrasives INC | San Bernardino | — | ◇ UNVERIFIED |
| MPMar-con Products INC | San Marcos | — | ◇ UNVERIFIED |
| MPModerno Porcelain San Diego LLC | Santee | — | ◇ UNVERIFIED |
| MGMountain Gate Quarry | Redding | — | ◇ UNVERIFIED |
| NINewport Industrial Glass INC | Stanton | — | ◇ UNVERIFIED |
| NUNewport-mesa Uni Sch Dist | Costa Mesa | — | ◇ UNVERIFIED |
| NRNor-cal Rock INC | Hayward | — | ◇ UNVERIFIED |
| NANorth American Recycling and Crushing LLC | Anaheim | — | ◇ UNVERIFIED |
| NSNorth Star Water Treatment Facility | Grass Valley | — | ◇ UNVERIFIED |
| OROceanside Rmc Plant | Oceanside | — | ◇ UNVERIFIED |
| OPOlson Precast CO | Rialto | — | ◇ UNVERIFIED |
| OPOmega Products International | Sacramento | — | ◇ UNVERIFIED |
| OBOrco Block & Hardscape | Riverside | — | ◇ UNVERIFIED |
| OFOrient & Flume Art Glass | Chico | 1–19 | ◇ UNVERIFIED |
| OROrosi Rock LLC | Orosi | — | ◇ UNVERIFIED |
| OMOutback Materials | Friant | — | ◇ UNVERIFIED |
| OGOwens-brockway Glass Container INC | Antioch | — | ◇ UNVERIFIED |
| PRParadise Ready Mix | Paradise | — | ◇ UNVERIFIED |
| PPParamount Precast Design INC | Sun Valley | — | ◇ UNVERIFIED |
| PCPhilips Components Discrete P | Los Angeles | — | ◇ UNVERIFIED |
| PNPilkington North America Incorporated | Lathrop | — | ◇ UNVERIFIED |
| PSPulp Studio INC | Gardena | — | ◇ UNVERIFIED |
| RPResco Products INC | Santa Fe Spgs | — | ◇ UNVERIFIED |
| RPRmc Pacific Materials (dba Cemex) | Davenport | — | ◇ UNVERIFIED |
| RPRmc Pacific Materials Incorporated | San Jose | — | ◇ UNVERIFIED |
| RRRobertson's Ready Mix | Corona | — | ◇ UNVERIFIED |
| RRRobertson's Ready Mix | French Camp | — | ◇ UNVERIFIED |
| RRRobertson's Ready Mix | Corona | — | ◇ UNVERIFIED |
| RRRobertson's Ready Mix San Bernardino Plant 12 | San Bernardino | — | ◇ UNVERIFIED |
