| OROceanside Rmc Plant | Oceanside | CA | — | ◇ UNVERIFIED |
| OCOconee Concrete Company, INC. | Opelika | AL | — | ◇ UNVERIFIED |
| OCOconee Concrete Company, INC. | Phenix City | AL | — | ◇ UNVERIFIED |
| OROconnor Ready Mix Plant 11 | San Antonio | TX | — | ◇ UNVERIFIED |
| OFOdessa Facility | Odessa | FL | — | ◇ UNVERIFIED |
| OIO&g Industries INC Beacon Falls | Beacon Falls | CT | — | ◇ UNVERIFIED |
| OOldcastle | Lockport | IL | — | ◇ UNVERIFIED |
| OOldcastle | Elgin | IL | — | ◇ UNVERIFIED |
| OOldcastle | Morgan Hill | CA | — | ◇ UNVERIFIED |
| OOldcastle | Kenosha | WI | — | ◇ UNVERIFIED |
| OAOldcastle Adams Products | Clarksville | TN | — | ◇ UNVERIFIED |
| OAOldcastle Apg Company, Great Lakes | Cincinnati | OH | — | ◇ UNVERIFIED |
| OAOldcastle Apg Mid-atlantic | Chesapeake | VA | — | ◇ UNVERIFIED |
| OAOldcastle Apg Mid-atlantic Crofton, Md | Odenton | MD | — | ◇ UNVERIFIED |
| OAOldcastle Apg Mid-atlantic Richmond, Va | Richmond | VA | — | ◇ UNVERIFIED |
| OAOldcastle Apg Natl I/emigsville | Emigsville | PA | — | ◇ UNVERIFIED |
| OAOldcastle Apg New England | Victor | NY | — | ◇ UNVERIFIED |
| OAOldcastle Apg New England | Cranston | RI | — | ◇ UNVERIFIED |
| OAOldcastle Apg Northeast, INC. | West Lebanon | NH | — | ◇ UNVERIFIED |
| OAOldcastle Architectural West INC | Rosenberg | TX | — | ◇ UNVERIFIED |
| OAOldcastle Architectural West INC | Austin | TX | — | ◇ UNVERIFIED |
| OAOldcastle Architectural West INC | Dallas | TX | — | ◇ UNVERIFIED |
| OCOldcastle - Crested Butte Rmc Plant | Crested Butte Area | CO | — | ◇ UNVERIFIED |
| OCOld Castle Dba United - Two Feathers Pit | Montrose | CO | — | ◇ UNVERIFIED |
| OIOldcastle Infrastructure | Platteville | CO | — | ◇ UNVERIFIED |
| OIOldcastle Infrastructure | Acworth | GA | — | ◇ UNVERIFIED |
 Oldcastle Infrastructure INC. - Courtland | Courtland | MN | — | ◇ UNVERIFIED |
| OMOldcastle Matt Stone Holdings Incorporated | Cowpens | SC | — | ◇ UNVERIFIED |
| OPOldcastle Precast | Lakeside | CA | — | ◇ UNVERIFIED |
| OPOldcastle Precast | Houston | TX | — | ◇ UNVERIFIED |
| OPOldcastle Precast | Mansfield | TX | — | ◇ UNVERIFIED |
| OPOldcastle Precast | Kalamazoo | MI | — | ◇ UNVERIFIED |
| OPOldcastle Precast | Easton | PA | — | ◇ UNVERIFIED |
| OPOldcastle Precast Brookshire Plant | Brookshire | TX | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC | Medley | FL | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC | Bartow | FL | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC | Chandler | AZ | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC | Manchester | NY | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC | Folsom | NJ | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC | Greensboro | NC | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC | Morrisville | PA | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC. | Edgewood | MD | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC. | Jacksonville | FL | — | ◇ UNVERIFIED |
| OPOldcastle Precast, INC. - Bellingham | Bellingham | WA | — | ◇ UNVERIFIED |
| OPOldcastle Precast, INC. - Jacksonvillesp | Jacksonville | FL | — | ◇ UNVERIFIED |
| OPOldcastle Precast, INC. - Tallahasseesp | Midway | FL | — | ◇ UNVERIFIED |
| OPOldcastle Precast San Antonio Plant | San Antonio | TX | — | ◇ 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 Group- Port Concrete Plant | Gunnison | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Grp - Gunnison Redi-mix Pit | Gunnison | CO | — | ◇ UNVERIFIED |
| OIOlipdp Ii LLC - Mggt-gl Production Facility | Vinton | LA | — | ◇ UNVERIFIED |
| OPOlympian Precast INC | Redmond | WA | — | ◇ UNVERIFIED |
| OPOmega Products International, INC. | Commerce City | CO | — | ◇ UNVERIFIED |
| OBOneonta Block CO | Oneonta | NY | — | ◇ UNVERIFIED |
| OPOneonta Plant | Oneonta | AL | — | ◇ UNVERIFIED |
| OPOrchard Park Plant | Orchard Park | NY | — | ◇ UNVERIFIED |
| ODOre Design North Salt Lake Assembly Facility | North Salt Lake | UT | — | ◇ UNVERIFIED |
| ODOre Designs INC | Woods Cross | UT | — | ◇ UNVERIFIED |
| OMOremus Material LLC | Chicago | IL | — | ◇ UNVERIFIED |
| OROrgain Ready Mix Concrete Co., INC. | Murfreesboro | TN | — | ◇ UNVERIFIED |
| OROrgain Ready Mix Concrete Co., INC. | Clarksville | 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 |
| 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 Concrete Products - Hampshire | Hampshire | IL | — | ◇ UNVERIFIED |
| OCOzinga Concrete Products Huntley | Huntley | IL | — | ◇ UNVERIFIED |
| OIOzinga Illinois Rmc INC | Monee | IL | — | ◇ UNVERIFIED |
| OIOzinga Illinois Rmc INC | Elgin | IL | — | ◇ UNVERIFIED |
| OMOzinga - Miami Plant | Miami | FL | — | ◇ UNVERIFIED |
| OROzinga Ready Mix | Roscoe | IL | — | ◇ UNVERIFIED |
| OROzinga Ready Mix | Naperville | IL | — | ◇ UNVERIFIED |
| OROzinga Ready Mix | Chicago Heights | IL | — | ◇ UNVERIFIED |
| OROzinga Ready Mix - 103rd St Plant | Chicago | IL | — | ◇ UNVERIFIED |
| OROzinga Ready-mix-belvidere | Belvidere | IL | — | ◇ UNVERIFIED |
| OROzinga Ready-mix-channahon | Channahon | IL | — | ◇ UNVERIFIED |
| OROzinga Ready-mix Concrete - Bremen | Bremen | IN | — | ◇ UNVERIFIED |
| OROzinga Ready-mix Concrete - Elkhart E | Elkhart | IN | — | ◇ UNVERIFIED |
| OROzinga Ready-mix Concrete - Gary | Gary | IN | — | ◇ UNVERIFIED |
