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Carrier profile · USDOT 2496282 · MC1376430 · Data as of Oct 7, 2026

Cos LLC

DBA Castle Oilfield Services · Williston, ND · Interstate for-hire carrier · Since 2014
Authority active$1M BIPD on fileSatisfactory ratingNo hazmat
Cargo carriedLiquids/GasesOilfield Equipment
View on FMCSA SAFERCall (701) 572-1832
20
Power units
19
Drivers
8
Inspections · 24 mo
3
Crashes · 24 mo
251K
Annual miles
12 yr
Registered
80
/ 100
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Operating legally, with 2 flags to weigh

Authority and insurance are in order. Vehicle OOS well above average: 66.7% of vehicle inspections placed out of service vs 22.26% national. Driver OOS well above average: 50.0% of driver inspections placed out of service vs 6.67% national.

How we scored it · 5 factors
Operating authority20/20
Insurance20/20
Out-of-service rates0/20
Crashes & rating20/20
Continuity & identity20/20

Composite of public FMCSA authority, insurance, inspection and crash records weighted against the national fleet. Decision support, not an official FMCSA safety rating.

Safety

FMCSA inspections & crashes · 24 mo · AS OF OCT 7, 2026
Vehicle out-of-service
66.7%▲ above avg
National 22.26% · 4 of 6 inspections
Driver out-of-service
50.0%▲ above avg
National 6.67% · 4 of 8 inspections
Crashes
3
0 fatal2 injury3 tow-away
Crash rate 5.97 per 1M mi
Total inspections
8
Driver inspections
8
Vehicle inspections
6
People injured
2
Fatalities
0
FMCSA rating
Satisfactory (2026)

Enforcement

FMCSA closed cases

Closed enforcement cases — case numbers, violation codes and the amount settled — are available after you create a free account.

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Authority & insurance

FMCSA L&I · AS OF OCT 7, 2026
Carrier
Active
Broker
None
Docket
MC1376430
Revocation pending
No
Common Carrier (Property)

Coverage vs federal minimum

BIPD liability$1,000,000
$1M required minimum (49 CFR 387.9)
CargoNot required

Filings on record

  1. Mar 4, 2022Liability (BIPD) · Berkley Regional Insurance Company · $1,000,000

Equipment

SELF-REPORTED ON MCS-150
20
Power units
20
Trucks
3
Tractors owned
—
Trailers owned
19
Drivers
14
CDL drivers
Not registered for hazardous materials.

Operations & cargo

FMCSA CENSUS
InterstateAuthorized for Hire
Cargo carried
Liquids/GasesOilfield Equipment
Annual mileage
251,164 mi (2025)

Identity & federal record

FMCSA census · MCS-150
USDOT
2496282
MC / docket
MC-1376430
Legal name
Cos LLC
DBA
Castle Oilfield Services
Entity type
Carrier
Operation
Interstate
First registered
Apr 16, 2014
Last MCS-150
Jan 29, 2026
Safety rating
Satisfactory
Drivers (CDL)
19 (14)
Hazmat
No
Business type
—

Fraud & network signals

For review, not a verdict.

No prior revocation
FMCSA shows no link to a previously revoked authority.
Shared phone number
Same phone number as 1 other active USDOT.
Unique email address
Not shared with any other active USDOT.
Shared street address
Same street address as 1 other active USDOT.
Sharing this phone number · (701) 572-1832
Sharing this street address

Shared contact details can mean affiliated companies or a registration service, but they are also a common sign of chameleon carriers and identity theft. Confirm you're dealing with the company you expect.

Frequently asked

What is Cos LLC's USDOT number?

Cos LLC's USDOT number is 2496282 and its docket number is MC1376430.

Is Cos LLC authorized to operate?

Yes. FMCSA shows active carrier operating authority.

What is Cos LLC's safety record?

Over the last 24 months: 8 roadside inspections, a 66.7% vehicle and 50.0% driver out-of-service rate, and 3 reportable crashes (0 fatal). FMCSA safety rating: Satisfactory.

How big is Cos LLC's fleet?

20 power units and 19 drivers per its MCS-150 filed Jan 29, 2026.

What insurance does Cos LLC carry?

$1,000,000 in BIPD liability coverage is on file with Berkley Regional Insurance Company.

Where is Cos LLC located?

Cos LLC is located at 501 48TH Ave W, Williston, ND, 58801. Phone: (701) 572-1832.

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Source: FMCSA public records via the U.S. DOT Open Data Portal. Carrier Search presents the federal record and computed signals for decision support only. It is not an FMCSA safety rating and not a recommendation to use or avoid any carrier. Verify authority and insurance before tendering.