All assignees
525 prefixes in 307 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 307-721 | LARAMIE | 9636 | — | — |
| 307-722 | THERMOPOLS | 013B | 2002-12-27 | — |
| 307-723 | KEMMERER | 013B | 2003-06-16 | — |
| 307-724 | CASPER | 013B | 2003-06-16 | — |
| 307-725 | — | — | ||
| 307-727 | KEMMERER | 013B | — | — |
| 307-728 | SHOSHONI | 013B | — | — |
| 307-730 | JACKSON | 013B | — | — |
| 307-731 | LOVELL | 013B | 2002-12-27 | — |
| 307-732 | JACKSON | 9636 | — | — |
| 307-733 | JACKSON | 9636 | — | — |
| 307-734 | JACKSON | 9636 | — | — |
| 307-735 | GLENDO | 9636 | — | Yes |
| 307-736 | ARVADA | 2251 | — | — |
| 307-737 | SOUTHESRDN | 2251 | — | — |
| 307-738 | KAYCEE | 3410 | — | — |
| 307-739 | JACKSON | 9636 | — | — |
| 307-740 | JACKSON | 013B | — | — |
| 307-741 | GLENROCK | 013B | 2002-12-27 | — |
| 307-742 | LARAMIE | 9636 | — | — |
| 307-744 | NEWCASTLE | 013B | 2002-12-27 | — |
| 307-745 | LARAMIE | 9636 | — | — |
| 307-746 | NEWCASTLE | 3410 | — | Yes |
| 307-747 | MT VIEW | 013B | 2003-06-16 | — |
| 307-749 | PINEDALE | 013B | 2003-10-20 | — |
| 307-750 | DECKER | 2251 | — | — |
| 307-751 | SHERIDAN | 6010 | — | Yes |
| 307-752 | SHERIDAN | 6566 | — | — |
| 307-754 | POWELL | 9636 | — | — |
| 307-755 | LARAMIE | 9636 | — | — |
| 307-756 | MOORCROFT | 3410 | — | Yes |
| 307-757 | CHEYENNE | 6566 | — | Yes |
| 307-758 | CLEARMONT | 2251 | — | — |
| 307-759 | LUSK | 013B | 2003-10-20 | — |
| 307-760 | LARAMIE | 6566 | — | — |
| 307-761 | LARAMIE | 6010 | — | Yes |
| 307-762 | BURLINGTON | 2296 | — | — |
| 307-763 | SHERIDAN | 6566 | — | Yes |
| 307-764 | POWELL | 7466 | 2005-04-01 | — |
| 307-765 | GREYBULL | 2296 | — | — |
| 307-766 | LARAMIE | 9636 | — | — |
| 307-770 | FARSON | 3880 | 2020-05-07 | Yes |
| 307-771 | CHEYENNE | 9636 | — | — |
| 307-772 | CHEYENNE | 9636 | — | Yes |
| 307-773 | CHEYENNE | 9636 | — | — |
| 307-774 | JACKSON | 6010 | 2005-06-22 | — |
| 307-775 | CHEYENNE | 9636 | — | — |
| 307-776 | CASPER | 197D | 2018-03-09 | Yes |
| 307-777 | CHEYENNE | 9636 | — | — |
| 307-778 | CHEYENNE | 9636 | — | — |
| 307-779 | WHEATLAND | 013B | 2003-10-20 | — |
| 307-780 | MT VIEW | 013B | — | — |
| 307-782 | MT VIEW | 2297 | — | — |
| 307-783 | EVANSTON | 9636 | — | — |
| 307-785 | WBLLFOURCH | 450F | 2017-04-19 | Yes |
| 307-786 | URIE | 2297 | — | — |
| 307-787 | LYMAN | 2297 | — | — |
| 307-788 | WEST LYMAN | 4531 | — | Yes |
| 307-789 | EVANSTON | 9636 | — | — |
| 307-790 | SUNDANCE | 013B | 2003-12-18 | — |
| 307-797 | CASPER | 6010 | 2001-10-03 | Yes |
| 307-798 | ROCK RIVER | 013B | 2007-11-06 | — |
| 307-799 | EVANSTON | 013B | — | — |
| 307-800 | KEMMERER | 450F | 2012-11-19 | Yes |
| 307-811 | XXXXXXXXXX | MULT | — | — |
| 307-823 | CHEYENNE | 879G | 2012-08-01 | Yes |
| 307-828 | KEMMERER | 9636 | — | Yes |
| 307-829 | CHEYENNE | 508J | 2014-11-21 | Yes |
| 307-834 | LA GRANGE | 4531 | — | Yes |
| 307-836 | GUERNSEY | 4531 | — | Yes |
| 307-837 | LINGLE | 4531 | — | Yes |
| 307-840 | RIVERTON | 6566 | — | Yes |
| 307-849 | BORDER | 9636 | — | — |
| 307-850 | RIVERTON | 013B | — | — |
| 307-851 | RIVERTON | 6566 | — | — |
| 307-854 | RIVERTON | 268A | 2007-12-10 | Yes |
| 307-855 | RIVERTON | 9636 | — | Yes |
| 307-856 | RIVERTON | 9636 | — | — |
| 307-857 | RIVERTON | 9636 | — | Yes |
| 307-858 | RIVERTON | 013B | — | — |
| 307-859 | DANIEL | 2299 | — | Yes |
| 307-864 | THERMOPOLS | 3410 | — | — |
| 307-867 | HAMITNDOME | 2296 | — | — |
| 307-868 | MEETEETSE | 2296 | — | — |
| 307-870 | GREENRIVER | 013B | — | — |
| 307-871 | GREENRIVER | 6566 | — | — |
| 307-872 | GREENRIVER | 9636 | — | — |
| 307-874 | MANILA | 2297 | — | — |
| 307-875 | GREENRIVER | 9636 | — | — |
| 307-876 | SHOSHONI | 3410 | — | — |
| 307-877 | KEMMERER | 9636 | — | Yes |
| 307-878 | SO ALZADA | 2251 | — | — |
| 307-880 | FREEDOM | 340D | 2005-06-22 | — |
| 307-881 | WHEATLAND | 268A | 2014-11-21 | Yes |
| 307-883 | FREEDOM | 2295 | — | — |
| 307-884 | AFTON | 013B | — | — |
| 307-885 | AFTON | 2295 | — | — |
| 307-886 | AFTON | 9636 | — | Yes |
| 307-887 | AFTON | 340D | 2005-06-22 | — |
| 307-888 | OLDFATHFUL | 073H | 2017-02-22 | Yes |
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.