| MMMartin Marietta Rigden Ready Mix | Fort Collins | — | ◇ UNVERIFIED |
| MCMathias Concrete - Alamosa Plant | Alamosa | — | ◇ UNVERIFIED |
| MCMathias Concrete INC | Monte Vista | — | ◇ UNVERIFIED |
| MCMathias Concrete - South Fork | South Fork | — | ◇ UNVERIFIED |
| MCMcatee Construction Co- Riverside | Sterling | — | ◇ UNVERIFIED |
| MSMeeker Sand & Gravel INC | Meeker | — | ◇ UNVERIFIED |
| MMMetro Mix LLC | Denver | — | ◇ UNVERIFIED |
| MWMillstone Weber - Concrete Plant #7001 | Denver | — | ◇ UNVERIFIED |
| MDMiyota Development Center of America | Longmont | — | ◇ UNVERIFIED |
| MMMonarch Marble INC | Denver | — | ◇ UNVERIFIED |
| MPMountain Park Concrete INC | Granby | — | ◇ UNVERIFIED |
| MRMountain Redi Mix | Cortez | — | ◇ UNVERIFIED |
| MRMountain Redi Mix | Cortez | — | ◇ UNVERIFIED |
| MSMountain Stone INC | Cortez | — | ◇ UNVERIFIED |
| OCOldcastle - Crested Butte Rmc Plant | Crested Butte Area | — | ◇ UNVERIFIED |
| OCOld Castle Dba United - Two Feathers Pit | Montrose | — | ◇ UNVERIFIED |
| OIOldcastle Infrastructure | Platteville | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group - 1771 Shields Dr | Steamboat Springs | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group, INC. Dba B&b Excavat | 0.5 Miles West of Edwardsq | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group, INC. Dba B&b Excavat | Eagle | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group INC. Dba Four Corners | Cortez | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group- Port Concrete Plant | Gunnison | — | ◇ UNVERIFIED |
| OSOldcastle Sw Grp - Gunnison Redi-mix Pit | Gunnison | — | ◇ UNVERIFIED |
| OPOmega Products International, INC. | Commerce City | — | ◇ UNVERIFIED |
| OBOwens Brothers Concrete CO | Arvada | — | ◇ UNVERIFIED |
| OIOwens Illinois Plant 28 | Greeley | — | ◇ UNVERIFIED |
| PCPavestone Company | Fountain | — | ◇ UNVERIFIED |
| PRPeak Ready Mix - Steamboat Springs Batch | Steamboat Springs | — | ◇ UNVERIFIED |
| PLPete Lien & Sons Dba Trans-colo.concrete | Colorado Springs | — | ◇ UNVERIFIED |
| PLPete Lien & Sons - Plant #2 Marksheffel | Colorado Springs | — | ◇ UNVERIFIED |
| PPPic Plastics | Denver | — | ◇ UNVERIFIED |
| PNPioneer Natural Res-concrete Batch Plant | Cokedale, 2.4 Mi Sw of | — | ◇ UNVERIFIED |
| PCPort-a-pour-portable Concrete Plant | Aurora | — | ◇ UNVERIFIED |
| PCPrecast Concepts, LLC | Henderson | — | ◇ UNVERIFIED |
| PPPrecision Pre-mix | Hayden | — | ◇ UNVERIFIED |
| PCPremier Countertops, INC. | Denver | — | ◇ UNVERIFIED |
| PEPueblo East Plant | Pueblo | — | ◇ UNVERIFIED |
| PFP.w. Feenstra - Port. Conc. Batch Plant | Maricopa | — | ◇ UNVERIFIED |
| QGQuikrete - Grand Junction, CO Plant | Grand Junction | — | ◇ UNVERIFIED |
| QMQuikrete- Monarch Mountain, Salida Plnt | Salida, 4.4 Mi Se of | — | ◇ UNVERIFIED |
| RRRapid Ready Mix Dba CO Materials Concret | Colorado Springs | — | ◇ UNVERIFIED |
| RMRaptor Materials - Plant 4 Erie | Erie | — | ◇ UNVERIFIED |
| RMReady Mixed Concrete CO - Del Camino | Firestone | — | ◇ UNVERIFIED |
| RMReady Mixed Concrete CO -franklin Plnt 2 | Denver Area | — | ◇ UNVERIFIED |
| RMReady Mixed Concrete CO Plant 6 | Castle Rock | — | ◇ UNVERIFIED |
| RMReady Mixed Concrete - Nix S&g Mine | Platteville | — | ◇ UNVERIFIED |
| RMRecrete Materials-port. Conc. Plnt | Aurora Area | — | ◇ UNVERIFIED |
| RMRecycled Materials CO. (nordberg Cr) | Arvada | — | ◇ UNVERIFIED |
| RMRinker Materials | Littleton | — | ◇ UNVERIFIED |
| RMRinker Materials Hydro Conduit | Denver | — | ◇ UNVERIFIED |
