| OAOldcastle Architectural West INC | Rosenberg | TX | — | ◇ UNVERIFIED |
| OAOldcastle Architectural West INC | Austin | TX | — | ◇ UNVERIFIED |
| OAOldcastle Architectural West INC | Dallas | TX | — | ◇ UNVERIFIED |
| OCOld Castle Dba United - Two Feathers Pit | Montrose | CO | — | ◇ UNVERIFIED |
| OIOldcastle Infrastructure | Platteville | CO | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC | Greensboro | NC | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC | Medley | FL | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group - 1771 Shields Dr | Steamboat Springs | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group, INC. Dba B&b Excavat | 0.5 Miles West of Edwardsq | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group, INC. Dba B&b Excavat | Eagle | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group INC. Dba Four Corners | Cortez | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Grp - Gunnison Redi-mix Pit | Gunnison | CO | — | ◇ UNVERIFIED |
| OIOlipdp Ii LLC - Mggt-gl Production Facility | Vinton | LA | — | ◇ UNVERIFIED |
| OPOneonta Plant | Oneonta | AL | — | ◇ UNVERIFIED |
| OMOpta Minerals | Baltimore | MD | — | ◇ UNVERIFIED |
| OMOpta Minerals Harseeville Plant | Hardeeville | SC | — | ◇ UNVERIFIED |
| OPOrchard Park Plant | Orchard Park | NY | — | ◇ UNVERIFIED |
| OMOremus Material LLC | Chicago | IL | — | ◇ UNVERIFIED |
| OROrgain Ready Mix Concrete Co., INC. | Clarksville | TN | — | ◇ UNVERIFIED |
| OROrgain Ready Mix Concrete Co., INC. | Murfreesboro | TN | — | ◇ UNVERIFIED |
| OCOsage County Industries Inc-linn | Linn | MO | — | ◇ UNVERIFIED |
| OCOsborne Co., LTD. | Valley View | OH | — | ◇ UNVERIFIED |
| OIOsborne INC. | Cleveland | OH | — | ◇ UNVERIFIED |
| OROscar Renda Contracting, Biloxi North Facility | Biloxi | MS | — | ◇ UNVERIFIED |
| OCOsceola Concrete LLC | Osceola | MO | — | ◇ UNVERIFIED |
| OPOswego Public Works Department | Oswego | NY | — | ◇ UNVERIFIED |
| OTO Tex Pumping Fenelton | Fenelton | PA | — | ◇ UNVERIFIED |
| OROverland Ready Mixed Super 8 | No City Name | NE | — | ◇ UNVERIFIED |
| OSOverton Sand & Gravel CO | Lexington | NE | — | ◇ UNVERIFIED |
| OSOverton Sand & Gravel Company | Overton | NE | — | ◇ UNVERIFIED |
| OBOwens Brothers Concrete CO | Arvada | CO | — | ◇ UNVERIFIED |
| OAOxford Auxiliary Division of B and B Concrete Company INC | Oxford | MS | — | ◇ UNVERIFIED |
| OBOzark Building Materials, LLC Plant 1 | Saint Louis | MO | — | ◇ UNVERIFIED |
| OROzark Ready Mix | Eldon | MO | — | ◇ UNVERIFIED |
| OROzark Ready Mix Company INC. | Linn Creek | MO | — | ◇ UNVERIFIED |
| OROzark Ready Mix Company, INC. | Lebanon | MO | — | ◇ UNVERIFIED |
| OROzark Ready Mix Kc - Kansas City, Kansas | Kansas City | KS | — | ◇ UNVERIFIED |
| OROzark Ready Mix Kc - Kansas City, Missouri | Kansas City | MO | — | ◇ UNVERIFIED |
| OROzark Ready Mix Kc - Olathe, Kansas | Olathe | KS | — | ◇ UNVERIFIED |
| OROzark Ready Mix - Osage Beach | Osage Beach | MO | — | ◇ UNVERIFIED |
| OROzark Ready Mix - Show Me Ready Mix | Lake Lotawana | MO | — | ◇ UNVERIFIED |
| OBOzinga Bros INC | Joliet | IL | — | ◇ UNVERIFIED |
| OBOzinga Bros Inc-mccook Plant | Mccook | IL | — | ◇ UNVERIFIED |
| OCOzinga Cement Incorporated Contractor of Cleveland-cliffs Bu | Burns Harbor | IN | — | ◇ UNVERIFIED |
| OCOzinga Concrete Products - Hampshire | Hampshire | IL | — | ◇ UNVERIFIED |
| OCOzinga Concrete Products Huntley | Huntley | IL | — | ◇ UNVERIFIED |
| OIOzinga Illinois Rmc INC | Elgin | IL | — | ◇ UNVERIFIED |
| OIOzinga Illinois Rmc INC | Monee | IL | — | ◇ UNVERIFIED |
| OMOzinga - Miami Plant | Miami | FL | — | ◇ UNVERIFIED |
| OROzinga Ready Mix | Roscoe | IL | — | ◇ UNVERIFIED |