| OSOldcastle Sw Group Dba United Companies | Norwood | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group Dba United CO of Mesa | Rifle | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group Dba United CO of Mesa | Montrose | 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 Group- Tri County Pit | Hotchkiss | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group - Wattenberg West | Brighton, 2.0 Mi Nw of | 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 |
| OCOmans Contracting INC | Hesperia | MI | — | ◇ UNVERIFIED |
| OPOmega Products International | Sacramento | CA | — | ◇ UNVERIFIED |
| OPOmega Products International, INC. | Commerce City | CO | — | ◇ UNVERIFIED |
| OMOmg Midwest Dba Cessford Construction CO | Burlington | IA | — | ◇ UNVERIFIED |
| OMOmg Midwest INC | Johnston | IA | — | ◇ UNVERIFIED |
| OEOmni Engineering Plant 02 | Omaha | NE | — | ◇ UNVERIFIED |
| OEOmni Engineering Plant 02 | Omaha | NE | — | ◇ UNVERIFIED |
| OBOneonta Block CO | Oneonta | NY | — | ◇ UNVERIFIED |
| OPOneonta Plant | Oneonta | AL | — | ◇ UNVERIFIED |
| OROpen Road Asphalt CO LLC | Marshall | IL | — | ◇ UNVERIFIED |
| OROpen Road Asphalt CO. LLC - Fairmount | Fairmount | IL | — | ◇ UNVERIFIED |
| OROpen Road Asphalt Company LLC | Paxton | IL | — | ◇ UNVERIFIED |
| OCOrange Crush LLC | Wheeling | IL | — | ◇ UNVERIFIED |
| OCOrange Crush LLC | Des Plaines | IL | — | ◇ UNVERIFIED |
| OCOrange Crush LLC | Skokie | IL | — | ◇ UNVERIFIED |
| OCOrange Crush LLC | East Dundee | IL | — | ◇ 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 |
| OSOriental Sand & Gravel | Yabucoa | PR | — | ◇ UNVERIFIED |
| OOriskany | Oriskany | NY | — | ◇ UNVERIFIED |
| OPOrlando Paving Company | Oviedo | FL | — | ◇ UNVERIFIED |
| OPOrlando Paving Company | Orlando | FL | — | ◇ UNVERIFIED |
| OPOrlando Paving Company | Apopka | FL | — | ◇ UNVERIFIED |
| OPOrlando Paving Plant #11 | Orlando | FL | — | ◇ UNVERIFIED |
| OPOrlando Paving Plant #5 | Apopka | FL | — | ◇ UNVERIFIED |
| OROrosi Rock LLC | Orosi | CA | — | ◇ 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 |
| OMOverland Material and Manufacturing INC / Astec 2 | Durant | OK | — | ◇ UNVERIFIED |
| OMOverland Material and Manufacturing INC / Astec 4 | Ada | OK | — | ◇ UNVERIFIED |