All assignees
525 prefixes in 307 · initial assignments from the NANPA CO code file, 09/17/2026
| NPA-NXX | Rate center | OCN | Assigned | Pooled |
|---|---|---|---|---|
| 307-200 | JACKSON | 9416 | 2002-08-16 | Yes |
| 307-201 | JACKSON | 9416 | 2003-01-07 | Yes |
| 307-202 | POWELL | 6010 | 2003-01-21 | Yes |
| 307-203 | JACKSON | 6529 | 2001-03-14 | Yes |
| 307-204 | CODY | 581H | 2018-02-06 | Yes |
| 307-205 | LINGLE | 9416 | 2016-11-16 | Yes |
| 307-206 | LANDER | 7229 | 2013-12-05 | Yes |
| 307-207 | LAKE | 581H | 2018-12-06 | Yes |
| 307-208 | — | — | ||
| 307-209 | ROCK SPG | 6566 | 2014-12-19 | Yes |
| 307-210 | SOUTHESRDN | 6010 | 2020-04-03 | Yes |
| 307-211 | XXXXXXXXXX | MULT | — | — |
| 307-212 | ROCK SPG | 9416 | 2002-07-16 | Yes |
| 307-213 | CODY | 9416 | 2002-07-16 | Yes |
| 307-214 | CHEYENNE | 6566 | 2003-01-06 | — |
| 307-215 | CASPER | 081F | 2001-07-26 | Yes |
| 307-216 | LUSK | 6010 | 2002-10-09 | Yes |
| 307-217 | BUFFALO | 6010 | 2002-10-09 | Yes |
| 307-218 | SHERIDAN | 450F | 2019-08-13 | Yes |
| 307-219 | POWELL | 508J | 2015-03-26 | Yes |
| 307-220 | CHEYENNE | 6529 | — | Yes |
| 307-221 | CHEYENNE | 6529 | — | Yes |
| 307-222 | CHEYENNE | 9416 | — | Yes |
| 307-223 | LARAMIE | 9416 | — | Yes |
| 307-224 | CASPER | 9416 | — | Yes |
| 307-225 | LARAMIE | 792K | 2020-09-02 | Yes |
| 307-226 | AFTON | 7229 | 2015-12-28 | Yes |
| 307-227 | MAMMOTH | 450F | — | Yes |
| 307-228 | GILLETTE | 081F | 2014-05-23 | Yes |
| 307-229 | COKEVILLE | 6010 | 2015-02-17 | Yes |
| 307-230 | BORDER | 081F | 2022-07-19 | Yes |
| 307-231 | PINEDALE | 6566 | — | Yes |
| 307-232 | CASPER | 9636 | — | — |
| 307-233 | CASPER | 9636 | — | — |
| 307-234 | CASPER | 9636 | — | — |
| 307-235 | CASPER | 9636 | — | — |
| 307-236 | BURNS | 6010 | 2020-04-03 | Yes |
| 307-237 | CASPER | 9636 | — | — |
| 307-238 | HAMITNDOME | 6010 | 2017-08-22 | Yes |
| 307-239 | DUBOIS | 6010 | 2015-11-05 | Yes |
| 307-240 | RIVERTON | 6566 | — | Yes |
| 307-241 | WHEATLAND | 6010 | — | Yes |
| 307-242 | LAKE | 9636 | — | Yes |
| 307-243 | CASPER | 450F | — | Yes |
| 307-244 | FREEDOM | 2295 | 2019-05-15 | Yes |
| 307-245 | PINEBLUFFS | 3410 | — | — |
| 307-246 | ALBIN | 3410 | — | — |
| 307-247 | CASPER | 6010 | — | Yes |
| 307-248 | AFTON | 6566 | 2003-03-25 | Yes |
| 307-249 | JACKSON | 073H | 2017-03-24 | Yes |
| 307-250 | CODY | 6566 | — | Yes |
| 307-251 | CASPER | 6566 | 2006-04-13 | — |
| 307-252 | ROCK SPG | 1772 | — | — |
| 307-253 | CASPER | 9636 | 2008-03-10 | Yes |
| 307-254 | POWELL | 6566 | 2003-09-11 | Yes |
| 307-255 | EVANSTON | 1772 | 2002-07-15 | — |
| 307-256 | CHEYENNE | 5562 | 2004-01-05 | Yes |
| 307-257 | GILLETTE | 9416 | 2004-05-19 | Yes |
| 307-258 | CASPER | 6566 | — | — |
| 307-259 | CASPER | 6566 | — | — |
| 307-260 | BIG PINEY | 013B | — | — |
| 307-261 | CASPER | 9636 | — | — |
| 307-262 | CASPER | 6566 | — | — |
| 307-263 | CHEYENNE | 425J | 2019-10-16 | Yes |
| 307-264 | JACKSON | 792K | 2014-03-24 | Yes |
| 307-265 | CASPER | 9636 | — | — |
| 307-266 | CASPER | 9636 | — | — |
| 307-267 | CASPER | 6010 | — | Yes |
| 307-268 | CASPER | 9636 | — | — |
| 307-269 | WHEATLAND | 9416 | — | Yes |
| 307-270 | COKEVILLE | 013B | — | — |
| 307-271 | POWELL | 9416 | 2004-05-26 | Yes |
| 307-272 | CODY | 6566 | — | — |
| 307-273 | FARSON | 2299 | — | Yes |
| 307-274 | CHEYENNE | 7229 | 2004-07-14 | Yes |
| 307-275 | CHEYENNE | 6566 | 2005-01-12 | Yes |
| 307-276 | BIG PINEY | 2299 | — | Yes |
| 307-277 | CASPER | 6566 | 2003-08-21 | — |
| 307-278 | BUFFALO | 9416 | 2004-05-19 | Yes |
| 307-279 | COKEVILLE | 2290 | — | — |
| 307-280 | FARSON | 013B | — | — |
| 307-281 | SUNDANCE | 6566 | — | Yes |
| 307-282 | SUNDANCE | 6566 | — | Yes |
| 307-283 | SUNDANCE | 2251 | — | — |
| 307-284 | JACKSON | 110G | 2019-11-20 | Yes |
| 307-285 | BUFFALO | 581H | 2020-05-21 | Yes |
| 307-286 | CHEYENNE | 6566 | 2004-01-19 | — |
| 307-287 | CHEYENNE | 6566 | 2006-05-23 | — |
| 307-288 | EVANSTON | 9416 | 2004-05-19 | Yes |
| 307-289 | CHEYENNE | 318J | 2023-04-14 | Yes |
| 307-290 | SUNDANCE | 6010 | — | Yes |
| 307-291 | CODY | 939H | 2021-10-28 | Yes |
| 307-292 | CHEYENNE | 321J | 2020-06-17 | Yes |
| 307-293 | GUERNSEY | 450F | 2021-03-02 | Yes |
| 307-294 | BIG PINEY | 879G | 2023-08-01 | Yes |
| 307-295 | TORRINGTON | 450F | 2023-09-13 | Yes |
| 307-296 | CODY | 450F | — | Yes |
| 307-297 | GREENRIVER | 1772 | — | — |
| 307-298 | DOUGLAS | 9416 | 2004-05-19 | Yes |
| 307-299 | GILLETTE | 6010 | 2003-10-21 | — |
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.