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Freight Carrier · Williston, ND

CASTLE OILFIELD SERVICES

501 48TH AVE W · Williston, ND 58801

Authorized: Property
(701) 572-1832 Tap to call
  • MC #1376430
  • USDOT #2496282 USDOT Active
  • 20
    Power Units
  • 19
    Drivers
  • Carrier
    Entity Type

About this carrier

CASTLE OILFIELD SERVICES is a Williston, ND freight carrier that is authorized for property in the state of North Dakota. This company has 20 truck(s) in their fleet and 19 truck drivers. Their motor carrier number is MC-1376430 and their USDOT number is 2496282.

Sourced from FMCSA SAFER · last filed 01/29/2026 · last updated Jun 10, 2026.

Carrier Details

  • Legal Name COS LLC
  • Operating Status AUTHORIZED FOR Property
  • MCS-150 Filed 01/29/2026
  • MCS-150 Mileage 251,164 (2025)

Authority & Operations

Operation Classification
  • Authorized for Hire
Carrier Operation
  • Interstate

Cargo Authorized

  • Liquids/Gases
  • Oilfield Equipment

Operating Territory

Map of states where this carrier has roadside inspections North Dakota — home base

Home base   Based in Williston, North Dakota. No roadside inspections on record in the past 24 months to map operating states.

Safety Record

1 Acute/Critical 11 Severe Violations Updated 6 days ago

Crashes (24 mo)

  • 0
    Fatal
  • 1
    Injury
  • 2
    Tow
  • 3
    Total

Behavior Categories (BASICs)

CategoryMeasureViolations Unsafe Driving 0.86 3 Crash Indicator Not Public — Hours of Service 1.23 3 Vehicle Maintenance 18.42 10 Drugs / Alcohol 0 0 Hazmat Not Public — Driver Fitness 2.23 7

Inspection Summary

  • 15
    Total
  • 2
    Clean
  • 13
    With violations

24-month window ending May 15, 2026

Violations Cited 57 unique codes

Critical 25

  • 393.75A3-TAOLTires - All others, leaking or inflation less than 50% of the maximum inflation pressure on tire not equipped with ATIS3× OOS×3 SW 8
  • 383.23(a)(2)Operating a CMV without a CDL1× OOS×1 SW 8
  • 383.23A2-LCDLNLicense (CDL) - Operate a CMV and does not possess a valid CDL1× OOS×1 SW 8
  • 391.11B5-LNCDLNVLLicense - Operate a CMV without a valid operators license, issued by one State or jurisdiction1× OOS×1 SW 8
  • 393.75C-TAOTD-LT2/32Tires - Less than 2/32 inch tread depth1× SW 8
  • 393.207F-SDASSuspension - Deflated air suspension1× OOS×1 SW 7
  • 393.207A-SUBLSuspension - U-bolt, u-bolt bottom plate, or other axle clamp bolt loose/cracked/broken/missing.1× OOS×1 SW 7
  • 393.209D-STGBLSteering - Gear box mounting bolt loose1× OOS×1 SW 6
  • 393.9A-LTSILighting - Turn signal - Any inoperative on the rearmost vehicle.1× OOS×1 SW 6
  • 393.9A-LSLIWRLighting - Stop lamps - Both inoperative when required to be on1× OOS×1 SW 6
  • 395.8A1-HOSPHOS (Property) - Failing to have a record of duty status using the method prescribed3× OOS×3 SW 5
  • 393.43D-BBrake - Missing or inoperable breakaway braking system on a trailer(s) or converter dolly2× OOS×2 SW 4
  • 393.43DBMABrake - Breakaway not attached to the towing vehicle1× OOS×1 SW 4
  • 393.45A-BLHFHydraulic Any Observed Leaking Hydraulic Fluid1× OOS×1 SW 4
  • 393.43(d)No or defective automatic trailer brake1× OOS×1 SW 4
  • 396.3A1-BALRAir Brake - Fails air loss rate test1× OOS×1 SW 4
  • 393.70D-CDTSDDCoupling - Trailer, safety devices wire/chain damaged.1× OOS×1 SW 3
  • 396.3A1-FFuel - Dripping leak.1× OOS×1 SW 3
  • 393.75G-TAOWTires - All others, weight carried exceeds tire load limit1× OOS×1 SW 3
  • 393.75G-TFWETLTires - Front, weight carried exceeds tire load limit1× OOS×1 SW 3
  • 393.23PTAll required lamps on towed vehicle inoperative due to no electrical connection1× OOS×1 SW 2
  • 396.3A1-HCMHubs - Bearing cap, plug or filler plug missing or broken1× OOS×1 SW 2
  • 391.11(b)(4)Medical (Certificate) - Operating a CDL (passenger or property carrying) vehicle that is non-excepted and the driver has self-certified as excepted interstate or excepted intrastate with the state driver's licensing agency.1× OOS×1 SW 2
  • 392.9A2-CCargo - Vehicle components or dunnage not secured1× OOS×1 SW 1
  • 396.3(a)1BOSBrake - Defective brake(s) are equal to or greater than 20% of the service brakes on the vehicle/combination3× OOS×3 SW 0

Vehicle Maintenance 28

  • 393.207F-SLASSuspension - Leaking 3 PSI in 5 minutes1× SW 7
  • 393.207A-SAPPCBLMSuspension - Axle positioning part cracked/broken/loose/missing.1× SW 7
  • 393.9A-HLLHLighting - Headlamp(s) fail to operate on low and high beam1× SW 6
  • 393.9A-LBLLighting - Backup lamp inoperative1× SW 6
  • 393.9A-LRLILighting - Tail lamp - Any inoperative1× SW 6
  • 393.9A-LHLILighting - Headlamp(s) - Any inoperative1× SW 6
  • 396.17C-PIOperating a CMV without documentation of a periodic inspection5× SW 4
  • 393.45D-BAir Brake - Audible air leak at a proper connection2× SW 4
  • 393.47(e)Brake Out of Adjustment - Roto, Clamp (Short & Long), DD-3, or Bolt2× SW 4
  • 393.48A-BIHEHydraulic/Electric Brake - Inoperative other than a steering axle.2× SW 4
  • 393.53B-BAir Brake - CMV manufactured on or after 10/20/1994 has an automatic airbrake adjustment system that fails to compensate for wear2× SW 4
  • 393.55(c)(2)CMV other than truck-tractor manufactured on or after March 1, 1998 not equipped with an antilock brake system.1× SW 4
  • 396.17(c)Operating a CMV without proof of a periodic inspection1× SW 4
  • 393.55D2-BAir Brake - ABS malfunction lamp defective on truck-tractor manufactured on or after March 1, 2001 for towed vehicle.1× SW 4
  • 393.45B2-BAir brake - Hose/tubing damaged or not secured1× SW 4
  • 393.48A-BIBDDrum Brake - Inoperative other than a steering axle1× SW 4
  • 393.51C-BNVLAWDAir Brake - No visual low air warning device manufactured on or after 1975.1× SW 4
  • 396.5B-LLubrication - Oil or grease leak1× SW 3
  • 393.95A1Emergency Equipment - Fire Extinguishers - no fire extinguisher present or not properly rated.3× SW 2
  • 393.95(f)Emergency Equipment - Stopped vehicle warning devices missing or improper2× SW 2
  • 393.9A-LILLighting - Identification lamp(s) inoperative1× SW 2
  • 393.93A-SBASeatbelts - Drivers seatbelt or passenger seatbelt (if equipped) - missing or defective1× SW 2
  • 393.205C-WRAWFLMIBWheel/Rim - Any wheel fasteners loose/missing/ineffective/broken.1× SW 2
  • 393.201A-FRCLSFrame - Cracked/loose/sagging/broken frame or chassis1× SW 2
  • 393.95A4-EENAEmergency Equipment - Fire Extinguishers - not readily accessible1× SW 2
  • 393.95(a)No/discharged/unsecured fire extinguisher1× SW 2
  • 393.78Wipers - Inoperative / missing / damaged wipers2× SW 1
  • 393.60(d)Windshield / Windows - Tinting permits less than 70% of light transmittance1× SW 1

Unsafe Driving 2

  • 392.2-SLLTCDState/Local Laws - Failed to obey a traffic control device - Permanent or Temporary - e.g., safety official, signal, sign, light, lane marking, other2× SW 5
  • 392.2-SLLMLState/Local Laws - Failure to maintain lane1× SW 5

Driver Fitness 2

  • 391.41A-MCPCMedical (Certificate) - Operating a commercial motor vehicle without showing proof of a valid medical certification upon request when medical certification is required.4× SW 1
  • 383.37(a)Knowingly allowing, requiring, permitting, or authorizing an employee to operate a CMV during any period in which the driver does not have a current CLP or CDL or does not have a CLP or CDL with the proper class or endorsements. An employer may not use a driver to operate a CMV who violates any restriction on the driver's CLP or CDL0× SW 0

Locations

Physical Address
CASTLE OILFIELD SERVICES
501 48TH AVE W
WILLISTON, ND 58801
Mailing Address
COS LLC
PO BOX 1472
WILLISTON, ND 58802

Location on Map

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Related Companies

Other entries in the FMCSA database that share data with this carrier — name, phone, or address overlap. Worth a closer look during vetting.

Same physical address 1

These carriers are registered at the same street + ZIP.

CompanyStatusPower UnitsDriversMC#USDOT#
STATELINE LLC
Legally STATELINE SERVICES INC
Williston, ND
USDOT Active Authorized: Property12107440282136935

Same phone number 1

These carriers list the same contact phone number.

CompanyStatusPower UnitsDriversMC#USDOT#
STATELINE LLC
Legally STATELINE SERVICES INC
Williston, ND
USDOT Active Authorized: Property12107440282136935

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