Company snapshot
- Legal name
- Cos LLC
- DBA
- Castle Oilfield Services
- USDOT number
- 2496282
- MC docket
- MC1376430
- Physical address
- 501 48th Ave W, Williston, ND, 58801
- Phone
- (701) 572-1832
- Power units
- 20
- Drivers
- 19
- Operation
- Interstate
- Operating radius
- Interstate <100 mi
- Cargo
- Liquids/Gases, Oil Field Equipment
- Last MCS-150 filing
- Jan 29, 2026
Operating authority
- Common authority
- Active
- Contract authority
- Not held
- Broker authority
- Not held
- Authority granted
- Apr 16, 2014
- MCSIP step
- 0
Insurance on file
- Insurer (writing paper)
- W. R. Berkley
- Filing form
- BMC-91X
- Coverage amount
- $1,000,000
- BI/PD on file
- $1,000,000
- Estimated renewal window
- Q1 2023
Safety record
- FMCSA safety rating
- Satisfactory
- Roadside inspections (24 mo)
- 10
- Out-of-service inspections
- 6
- Inspections with violations
- 10
- Crashes (24 mo)
- 3
- BASICs in alert
- 1
Source: FMCSA census, Licensing & Insurance (L&I) and SMS publications, mirrored and refreshed daily. Record last synced Jul 30, 2026. Native Base is not affiliated with FMCSA; always confirm against the live federal record before binding.
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