| PPPro-cast Products INC | Highland | 100–499 | ● ACTIVE |
 A.w.i. Industries (u.s.a.) INC. | Chino | — | ● ACTIVE |
 Mindrum Precision INC. | Rancho Cucamonga | — | ● ACTIVE |
 Gw Partners International, INC. | Rancho Cucamonga | — | ● ACTIVE |
| APAdelanto Plant 19 | Adelanto | 20–99 | ◐ LIKELY ACTIVE |
| CPCal Portland Cement | Oro Grande | — | ◐ LIKELY ACTIVE |
| CCCemex Construction Materials Pacific Llc- Cemex Victorville -river Plant | Victorville | — | ◐ LIKELY ACTIVE |
| HPHesperia Plant 31 | Hesperia | 20–99 | ◐ LIKELY ACTIVE |
| JHJames Hardie Building Products | Fontana | 100–499 | ◐ LIKELY ACTIVE |
| RPRedlands Plant 3 | Redlands | 20–99 | ◐ LIKELY ACTIVE |
| CCCemex Construction Materials Al | Highland | — | ◇ UNVERIFIED |
| CFCemex Fontana Plant | Fontana | — | ◇ UNVERIFIED |
| HRHolliday Rock Ontario 28 | Ontario | — | ◇ UNVERIFIED |
 Mitsubishi Cement CO | Lucerne Valley | — | ◇ UNVERIFIED |
| OPOldcastle Pacific | Fontana | — | ◇ UNVERIFIED |
| 3O3m Oak Hills | Oak Hills | 20–99 | ◐ LIKELY ACTIVE |
| CCCemex California Cement LLC | Apple Valley | — | ◐ LIKELY ACTIVE |
| CPClark Pacific Adelanto | Adelanto | 100–499 | ◐ LIKELY ACTIVE |
| HMHi-grade Materials CO | Hesperia | — | ◐ LIKELY ACTIVE |
| OOntario | Ontario | 100–499 | ◐ LIKELY ACTIVE |
| PMProtech Minerals INC | Victorville | — | ◐ LIKELY ACTIVE |
| RRRancho Ready Mix Products, L.P Lake Elsinore | Colton | 1–19 | ◐ LIKELY ACTIVE |
| SBSan Bernardino Plant 12 | San Bernardino | 1–19 | ◐ LIKELY ACTIVE |
| AGAgc Glass-2008 | Victorville | — | ◇ UNVERIFIED |
| ASAmeron Steel Fabrication Division | Fontana | — | ◇ UNVERIFIED |
| ABAngelus Block CO INC | Fontana | — | ◇ UNVERIFIED |
| CCementpro | Ontario | — | ◇ UNVERIFIED |
| HBHiggins Brick CO | Chino Hills | — | ◇ UNVERIFIED |
| HRHolliday Rock - Adelanto | Adelanto | — | ◇ UNVERIFIED |
| HRHolliday Rock Chino 18 | Chino | — | ◇ UNVERIFIED |
| HRHolliday Rock Co., INC. | Rialto | — | ◇ UNVERIFIED |
| HRHolliday Rock Colton Plant 4 | Bloomington | — | ◇ UNVERIFIED |
| HRHolliday Rock Company - Mountain View | Upland | — | ◇ UNVERIFIED |
| HRHolliday Rock San Bernardino 29 | San Bernardino | — | ◇ UNVERIFIED |
| HRHolliday Rock - San Bernardino Facility | San Bernardino | — | ◇ UNVERIFIED |
| ICInland Concrete Products INC | Fontana | — | ◇ UNVERIFIED |
| IIIsolatek International INC | San Bernardino | — | ◇ UNVERIFIED |
 Jensen Enterprises INC Dba Jensen Precast | Ontario | — | ◇ UNVERIFIED |
| MAMagnum Abrasives INC | San Bernardino | — | ◇ UNVERIFIED |
| OPOlson Precast CO | Rialto | — | ◇ UNVERIFIED |
| RCRialto Concrete Products INC | Rialto | — | ◇ UNVERIFIED |
| RRRobertson's Ready Mix San Bernardino Plant 12 | San Bernardino | — | ◇ UNVERIFIED |
| RRRobertsons Rialto Batch and Rock Plant | Rialto | — | ◇ UNVERIFIED |
| SRService Rock Products | Barstow | — | ◇ UNVERIFIED |
| SGSunyeah Group Corporation | Ontario | — | ◇ UNVERIFIED |
| SRSuperior Ready Mix 29 Palms | Twentynine Palms | — | ◇ UNVERIFIED |
| TLTervita LLC | Rancho Cucamonga | — | ◇ UNVERIFIED |
| ABAngelus Block - Fontana | Fontana | 20–99 | ◐ LIKELY ACTIVE |
| ABAngelus Block - Rialto | Rialto | 20–99 | ◐ LIKELY ACTIVE |
| BPBarstow Plant #45 | Barstow | 1–19 | ◐ LIKELY ACTIVE |
