COS LLC

DOT #2496282 • MC #1376430 • DBA: CASTLE OILFIELD SERVICES
Active

COS LLC is a motor carrier based in WILLISTON, ND registered with the Federal Motor Carrier Safety Administration under USDOT number 2496282 and MC number 1376430. The company has been registered with the FMCSA since April 2014, a span of roughly 12 years. COS LLC reports a fleet of 20 power units and 19 drivers to the FMCSA. Cargo carried includes Liquids/Gases and Oilfield Equipment. Over the past 24 months, FMCSA records show 13 inspections with a driver out-of-service rate of 46.15% and 4 reported crashes. Recent inspections have been recorded in MT, ND, SD, TX, and WY. The FMCSA assigned a Satisfactory safety rating as of April 2026. Operating authority is active for: common carrier.

Company Information

Legal Name
COS LLC
DBA Name
CASTLE OILFIELD SERVICES
DOT Number
2496282
MC Number
1376430
Entity Type
Company Start Date
Apr 16, 2014

Location

Physical Address
501 48TH AVE W
WILLISTON, ND 58801
Mailing Address
PO BOX 1472
WILLISTON, ND 58802

Fleet & Operations

Power Units
20
Total Drivers
19
Truck Units
20
Operation Type
Interstate
Cargo Carried
Liquids/Gases Oilfield Equipment

Safety Summary (Past 24 Months)

FMCSA inspection and crash data recorded for COS LLC over the most recent 24 months. Out-of-service rates reflect the percentage of inspections that resulted in a driver or vehicle being placed out of service.

13
Total Inspections
13
Inspections with Violations
8
Out-of-Service Violations
46.15%
Driver OOS Rate
60%
Vehicle OOS Rate
4
Reportable Crashes
2
Crashes with Injuries

Source: Federal Motor Carrier Safety Administration. View the full inspection history for individual inspection records.

FMCSA Safety Rating

Rating
Satisfactory
Rating Date
Apr 3, 2026

Operating Authority

Authority granted by the FMCSA defines what type of freight a motor carrier or broker is legally permitted to haul or arrange. The records below reflect the most recent authority filings on record for COS LLC.

Docket Common Contract Broker Since
MC 1376430 Active None None 2022-03-16 00:00:00

Insurance Coverage

FMCSA-filed insurance policies on record. Carriers are required to maintain minimum liability coverage to legally operate in interstate commerce.

Type Coverage Insurer Effective
BI&PD 2022-03-04 00:00:00

Service Areas

States where COS LLC has had FMCSA inspections recorded recently. This is a useful indicator of where the carrier actively operates.

Premium Vetting Tools Available

Beyond the public FMCSA data shown above, SearchCarriers offers additional research and vetting tools for carriers like COS LLC. These tools require a paid plan and are not included in the public profile.

Risk Factor Analysis

Automated risk scoring and red-flag detection for COS LLC, including chameleon-carrier signals, recent authority changes, and insurance lapses. Available with a SearchCarriers vetting plan.

Associated Entities

Discover related DOT numbers, shared officers, and historically linked carriers tied to COS LLC. Useful for spotting reincarnated carriers. Available with a SearchCarriers vetting plan.

Crash & Inspection Details

Full per-inspection and per-crash records including violation codes, locations, vehicle and driver out-of-service details, and underlying inspection narratives. Available with a SearchCarriers data plan.

Shipper History

Historical shipper relationships and freight patterns associated with COS LLC, derived from inspection records and bill of lading data. Available with a SearchCarriers data plan.

Authority & Insurance History

Full historical timeline of operating authority changes, insurance filings, cancellations, and reinstatements. Available with a SearchCarriers data plan.

Vetting Report

A consolidated, exportable carrier vetting report for COS LLC covering safety, authority, insurance, and risk factors in a single document. Available with a SearchCarriers vetting plan.