CASTLEROCK — WA
Data last updated: March 10, 2026
Area Codes
Top Carriers
| Carrier | OCN | NXX Count |
|---|---|---|
| TERRA NOVA TELECOM INC. | 145J | 1 |
| LEVEL 3 COMMUNICATIONS, LLC - WA | 6121 | 1 |
| QWEST CORPORATION | 9638 | 1 |
Data last updated: March 10, 2026
| Carrier | OCN | NXX Count |
|---|---|---|
| TERRA NOVA TELECOM INC. | 145J | 1 |
| LEVEL 3 COMMUNICATIONS, LLC - WA | 6121 | 1 |
| QWEST CORPORATION | 9638 | 1 |