COS LLC
USDOT 2496282 · Doing business as CASTLE OILFIELD SERVICES
Active, interstate carrier, mid-size fleet (20 power units) — safety rating: satisfactory.
Vetting summary
At a glance
- Out-of-service rate54.5% vs 19.1% national avg
- Crashes (24 months)4 reported — involvement does not imply fault
- Linked registrations1 share this carrier's phone or address
These signals summarize the records shown below — they are a starting point for your own checks, not a judgment of the carrier.
Registration
Carrier identity
| USDOT Number | 2496282 |
|---|---|
| MC Number | MC-1376430 |
| Legal Name | COS LLC |
| DBA Name | CASTLE OILFIELD SERVICES |
| Entity Type | — |
| Phone | 7015721832 |
| Address | 501 48TH AVE W, Williston, ND, 58801 |
Status
Authority & safety
| Operating Status | Active |
|---|---|
| Operation Type | Interstate |
| Safety Rating | S — Satisfactory (rated 20260403) |
| Hazmat Flag | false |
Safety ratings: S = Satisfactory, C = Conditional, U = Unsatisfactory. A carrier with no rating has not been through a full FMCSA compliance review — this is common and not itself a red flag.
Our scoring
Safety scores
| Unsafe Driving | 81 / 100 |
|---|---|
| Hours-of-Service Compliance | 92 / 100 |
| Driver Fitness | 96 / 100 |
| Controlled Substances & Alcohol | 0 / 100 |
| Vehicle Maintenance | 97 / 100 |
Scores are 0-100 rankings computed by us from public FMCSA inspection measures; higher = worse relative to peers. Not official CSA/BASIC percentiles. How these scores are computed.
Safety events
Inspections & crashes (last 24 months)
| Inspections | 11 |
|---|---|
| Out-of-Service Rate | 54.5% vs 19.1% national average |
| Crashes | 4 total (0 fatal, 2 with injuries, 4 towaway) |
- 2026-05-17 — ND — 1 injured, towaway
- 2026-04-15 — MT — towaway
- 2025-11-18 — ND — 1 injured, towaway
- 2024-07-29 — ND — towaway
Most frequent violation categories: 16 (13), 20 (9), 51 (9).
Crash involvement does not imply fault. FMCSA crash records list all reportable crashes involving a carrier, regardless of who caused them.
Signals
Linked registrations
1 other active carrier registration share this carrier's phone or address in FMCSA records.
Shared contact details can have many ordinary explanations, such as a shared dispatch service, registration agent, or office address.
Equipment
Fleet & operations
| Power Units (trucks) | 20 |
|---|---|
| Drivers | 19 |
| Recent Annual Mileage | 345,671 |
| Last MCS-150 Filing | 29-JAN-26 |
COS LLC operates 20 power units — a larger fleet than 97% of carriers registered in ND.
Nearby
Other carriers in Williston, ND
- BLACK HAWK ENERGY SERVICES LTD — USDOT 2465450, 170 power units
- GO WIRELINE LLC — USDOT 2150288, 143 power units
- OASIS WELL SERVICES LLC — USDOT 2209436, 111 power units
- NOBLE CASING INC — USDOT 2190704, 93 power units
- RED RIVER OILFIELD TRANSPORTATION INC — USDOT 2533139, 93 power units
Browse all carriers in Williston, ND or all ND carriers.