All assignees
525 prefixes in 307 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 307-300 | POWELL | 450F | 2019-10-10 | Yes |
| 307-301 | CASPER | 515J | 2023-10-09 | Yes |
| 307-302 | CODY | 081F | 2020-08-17 | Yes |
| 307-303 | GREENRIVER | 081F | 2020-11-09 | Yes |
| 307-304 | JEFFREY CY | 6010 | 2020-09-17 | Yes |
| 307-305 | MIDWEST | 6010 | 2021-03-05 | Yes |
| 307-306 | DOUGLAS | 495J | 2020-12-21 | Yes |
| 307-307 | — | — | ||
| 307-308 | — | — | ||
| 307-309 | GLENROCK | 6010 | 2006-09-08 | Yes |
| 307-310 | CHEYENNE | 624H | 2019-10-23 | Yes |
| 307-311 | XXXXXXXXXX | MULT | — | — |
| 307-312 | WSPEARFISH | 081F | 2012-06-19 | Yes |
| 307-313 | EVANSTON | 9416 | — | Yes |
| 307-314 | LARAMIE | 081F | — | Yes |
| 307-315 | CASPER | 792K | 2007-05-11 | Yes |
| 307-316 | CHEYENNE | 450F | 2006-03-20 | Yes |
| 307-317 | CHEYENNE | 450F | 2017-05-22 | Yes |
| 307-318 | WRIGHT | 081F | 2021-01-15 | Yes |
| 307-319 | SHOSHONI | 6010 | 2020-09-17 | Yes |
| 307-320 | RAWLINS | 013B | — | — |
| 307-321 | RAWLINS | 6566 | — | — |
| 307-322 | WHEATLAND | 9636 | — | — |
| 307-323 | PINEDALE | 9416 | 2019-07-22 | Yes |
| 307-324 | RAWLINS | 9636 | — | — |
| 307-325 | HANNA | 2297 | — | — |
| 307-326 | SARATOGA | 2297 | — | — |
| 307-327 | ENCAMPMENT | 2297 | — | — |
| 307-328 | RAWLINS | 9636 | — | Yes |
| 307-329 | SARATOGA | 013B | — | — |
| 307-330 | LANDER | 013B | — | — |
| 307-331 | WHEATLAND | 6566 | — | Yes |
| 307-332 | LANDER | 9636 | — | — |
| 307-333 | CASPER | 732J | — | Yes |
| 307-334 | LUSK | 9636 | — | Yes |
| 307-335 | LANDER | 9636 | — | Yes |
| 307-336 | DANIEL | 9416 | 2019-07-22 | Yes |
| 307-337 | CASPER | 792K | 2011-01-07 | Yes |
| 307-338 | TORRINGTON | 6566 | 2011-01-12 | Yes |
| 307-339 | HANNA | 013B | — | — |
| 307-340 | LUSK | 6566 | — | Yes |
| 307-341 | SOUTHWYOLA | 2250 | — | — |
| 307-342 | JACKSON | 450F | — | Yes |
| 307-343 | LARAMIE | 6566 | 2009-07-16 | Yes |
| 307-344 | MAMMOTH | 9636 | — | Yes |
| 307-345 | LANDER | 013B | — | — |
| 307-346 | CHEYENNE | 490J | 2021-07-14 | Yes |
| 307-347 | WORLAND | 3410 | — | — |
| 307-348 | HANNA | 2297 | — | — |
| 307-349 | LANDER | 6566 | — | — |
| 307-350 | ROCK SPG | 013B | — | — |
| 307-351 | DOUGLAS | 6010 | — | Yes |
| 307-352 | ROCK SPG | 9636 | — | Yes |
| 307-353 | ALTA | 2214 | — | — |
| 307-354 | ROCK SPG | 013B | 2001-03-27 | — |
| 307-355 | LA GRANGE | 6529 | 2020-07-29 | Yes |
| 307-356 | SHIRLEBSIN | 2297 | — | — |
| 307-357 | LARAMIE | 450F | 2023-10-01 | Yes |
| 307-358 | DOUGLAS | 9636 | — | — |
| 307-359 | DOUGLAS | 6566 | — | Yes |
| 307-360 | PINEDALE | 013B | — | — |
| 307-361 | BAGGS | 6010 | 2021-03-05 | Yes |
| 307-362 | ROCK SPG | 9636 | — | — |
| 307-363 | GILLETTE | 081F | 2010-08-30 | Yes |
| 307-364 | GREENRIVER | 081F | 2014-05-23 | Yes |
| 307-365 | CHEYENNE | 6010 | 2008-03-03 | Yes |
| 307-366 | TEN SLEEP | 2296 | — | — |
| 307-367 | PINEDALE | 2299 | — | Yes |
| 307-368 | AFTON | 6566 | 2021-02-10 | Yes |
| 307-369 | CHEYENNE | 792K | 2011-01-10 | Yes |
| 307-370 | RAWLINS | 6566 | — | Yes |
| 307-371 | ROCK SPG | 6566 | — | — |
| 307-372 | DOUGLAS | 450F | 2020-08-10 | Yes |
| 307-373 | GREYBULL | 009E | — | Yes |
| 307-374 | ROCK SPG | 197D | — | Yes |
| 307-375 | WORLAND | 3410 | — | — |
| 307-376 | ALPINE | 6010 | 2021-08-11 | — |
| 307-377 | CASPER | 013B | — | — |
| 307-378 | ROCK RIVER | 2297 | — | — |
| 307-379 | MEDICINBOW | 2299 | — | Yes |
| 307-380 | BAGGS | 013B | — | — |
| 307-381 | SHERIDAN | 081F | 2021-04-23 | Yes |
| 307-382 | ROCK SPG | 9636 | — | — |
| 307-383 | BAGGS | 2291 | — | — |
| 307-384 | AFTON | 939H | 2021-11-03 | Yes |
| 307-385 | JACKSON | 6529 | 2025-11-06 | Yes |
| 307-386 | LABARGE | 2297 | — | — |
| 307-387 | GILLETTE | 081F | 2021-10-01 | Yes |
| 307-388 | WORLAND | 6010 | — | Yes |
| 307-389 | ROCK SPG | 6566 | — | — |
| 307-390 | LABARGE | 013B | — | — |
| 307-391 | MOORCROFT | 6010 | 2005-03-14 | Yes |
| 307-392 | BORDER | 9416 | 2006-06-21 | Yes |
| 307-393 | EVANSTON | 581H | 2021-03-31 | Yes |
| 307-394 | CASPER | 6529 | 2021-05-21 | Yes |
| 307-395 | LARAMIE | 081F | 2021-08-11 | Yes |
| 307-396 | GREENRIVER | 081F | 2021-10-20 | Yes |
| 307-397 | HANNA | 6010 | 2021-11-05 | Yes |
| 307-398 | LABARGE | 6010 | 2021-11-05 | Yes |
| 307-399 | LARAMIE | 6566 | 2002-05-16 | — |
These are initial assignees from NANPA CO-code records — because of number portability, the current serving carrier of individual numbers may differ. Bulk export requires a membership.