All assignees
525 prefixes in 307 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 307-520 | MEDICINBOW | 013B | — | — |
| 307-522 | ROCK SPG | 581H | 2017-08-07 | Yes |
| 307-527 | CODY | 9636 | — | Yes |
| 307-529 | CHEYENNE | 450F | 2009-08-25 | Yes |
| 307-532 | TORRINGTON | 4531 | — | — |
| 307-533 | SHERIDAN | 6566 | 2006-12-05 | Yes |
| 307-534 | TORRINGTON | 4531 | — | Yes |
| 307-536 | — | — | ||
| 307-537 | PINEDALE | 2299 | — | — |
| 307-540 | JEFFREY CY | 013B | — | — |
| 307-541 | MORAN | 013B | — | — |
| 307-543 | MORAN | 9636 | — | Yes |
| 307-544 | JEFFREY CY | 3410 | — | — |
| 307-545 | OLDFATHFUL | 9636 | — | Yes |
| 307-547 | BURNS | 3410 | — | — |
| 307-548 | LOVELL | 2296 | — | — |
| 307-549 | OLDFATHFUL | 013B | — | — |
| 307-554 | GLENROCK | 450F | — | Yes |
| 307-555 | DIR ASST | MULT | — | — |
| 307-556 | RIVERTON | 450F | 2021-02-05 | Yes |
| 307-558 | — | — | ||
| 307-559 | — | — | ||
| 307-567 | GILLETTE | 013B | — | — |
| 307-568 | BASIN | 2296 | — | — |
| 307-575 | TORRINGTON | 6566 | 2002-06-28 | Yes |
| 307-576 | LEIGHCNYON | 2214 | — | — |
| 307-577 | CASPER | 9636 | — | — |
| 307-578 | CODY | 9636 | — | Yes |
| 307-586 | CODY | 7466 | 2005-04-01 | — |
| 307-587 | CODY | 9636 | — | — |
| 307-600 | COKEVILLE | 013B | — | — |
| 307-605 | — | — | ||
| 307-611 | XXXXXXXXXX | MULT | — | — |
| 307-620 | BUFFALO | 6566 | — | Yes |
| 307-621 | BUFFALO | 6566 | — | Yes |
| 307-622 | GILLETTE | 6010 | 2010-11-24 | Yes |
| 307-624 | DOUGLAS | 6010 | 2001-10-03 | Yes |
| 307-629 | NEWCASTLE | 6010 | 2004-12-21 | Yes |
| 307-630 | CHEYENNE | 6566 | — | — |
| 307-631 | CHEYENNE | 6566 | — | — |
| 307-632 | CHEYENNE | 9636 | — | — |
| 307-633 | CHEYENNE | 9636 | — | Yes |
| 307-634 | CHEYENNE | 9636 | — | — |
| 307-635 | CHEYENNE | 9636 | — | — |
| 307-637 | CHEYENNE | 9636 | — | — |
| 307-638 | CHEYENNE | 9636 | — | — |
| 307-639 | LANDER | 114J | 2026-03-31 | Yes |
| 307-640 | CHEYENNE | 6010 | — | Yes |
| 307-643 | WSPEARFISH | 9631 | — | — |
| 307-645 | CLARK | 2250 | — | — |
| 307-649 | CARPENTER | 3410 | — | — |
| 307-650 | CHEYENNE | 581H | — | Yes |
| 307-654 | ALPINE | 2295 | — | — |
| 307-655 | SHERIDAN | 9636 | — | Yes |
| 307-660 | GILLETTE | 6010 | — | — |
| 307-663 | W EDGEMONT | 1659 | — | — |
| 307-664 | FRANNIE | 2296 | — | — |
| 307-666 | CHEYENNE | 965H | 2019-05-23 | Yes |
| 307-667 | RAWLINS | 450F | 2021-02-28 | Yes |
| 307-670 | GILLETTE | 6566 | — | Yes |
| 307-672 | SHERIDAN | 9636 | — | — |
| 307-673 | SHERIDAN | 9636 | — | — |
| 307-674 | SHERIDAN | 9636 | — | — |
| 307-675 | SHERIDAN | 268A | 2003-01-30 | — |
| 307-677 | EVANSTON | 6566 | — | Yes |
| 307-679 | EVANSTON | 6566 | — | — |
| 307-680 | GILLETTE | 6010 | — | — |
| 307-681 | GILLETTE | 268A | 2010-04-16 | — |
| 307-682 | GILLETTE | 9636 | — | — |
| 307-683 | SHERIDAN | 9636 | — | Yes |
| 307-684 | BUFFALO | 9636 | — | — |
| 307-685 | GILLETTE | 9636 | — | — |
| 307-686 | GILLETTE | 9636 | — | — |
| 307-687 | GILLETTE | 9636 | — | — |
| 307-688 | GILLETTE | 9636 | 2004-05-24 | — |
| 307-689 | GILLETTE | 6566 | — | — |
| 307-690 | JACKSON | 6566 | — | — |
| 307-696 | GILLETTE | 6010 | 2008-09-22 | Yes |
| 307-699 | JACKSON | 6566 | — | Yes |
| 307-700 | — | — | ||
| 307-701 | CHEYENNE | 013B | 2002-12-27 | — |
| 307-702 | CASPER | 013B | 2002-12-27 | — |
| 307-703 | LARAMIE | 013B | 2002-12-27 | — |
| 307-704 | GILLETTE | 013B | 2002-12-27 | — |
| 307-705 | ROCK SPG | 013B | 2003-06-16 | — |
| 307-706 | SHERIDAN | 013B | 2002-12-27 | — |
| 307-707 | GREENRIVER | 013B | 2003-06-26 | — |
| 307-708 | EVANSTON | 013B | 2003-06-16 | — |
| 307-709 | RIVERTON | 013B | 2003-06-16 | — |
| 307-710 | RAWLINS | 013B | 2003-06-16 | — |
| 307-711 | XXXXXXXXXX | MULT | — | — |
| 307-712 | CODY | 013B | 2002-12-27 | — |
| 307-713 | JACKSON | 013B | 2003-06-16 | — |
| 307-714 | LANDER | 013B | 2003-06-16 | — |
| 307-715 | TORRINGTON | 013B | 2002-12-27 | — |
| 307-716 | POWELL | 013B | 2002-12-27 | — |
| 307-717 | DOUGLAS | 013B | 2002-12-27 | — |
| 307-718 | WORLAND | 013B | 2002-12-27 | — |
| 307-719 | BUFFALO | 013B | 2002-12-27 | — |
| 307-720 | WHEATLAND | 013B | 2002-12-27 | — |
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.