NumberingData
Verified Nov 1, 2026 · Source: NANPA CO Code Assignment Records

GLENDIVE prefixes in area code 406

NANPA records 6 assigned NXX blocks to rate center GLENDIVE in area code 406, 0.8% of the 754 blocks assigned in the code. A rate center is the billing geography a block is allocated to – NANPA truncates the name to ten characters, so read it as a NANPA label rather than a town. 4 holders hold those blocks, the largest being MID-RIVERS TELEPHONE COOPERATIVE, INC. (2), QWEST CORPORATION (2), LEVEL 3 COMMUNICATIONS, LLC - MT (1). The earliest assignment on record here is 2003-01-09 and the most recent 2003-01-09. 5 of them are in thousands-block pooling, so those prefixes are shared between carriers in 1,000-number lots.

6 assigned blocks – 0.8% of 406
4 holders of record
5 of them pooled in 1,000-number lots

Prefixes assigned here

PrefixHolder of recordAssignedPooledIn service
406-345 MID-RIVERS TELEPHONE COOPERATIVE, INC. – yes yes
406-359 Lumen QWEST CORPORATION – yes yes
406-365 Lumen QWEST CORPORATION – yes yes
406-377 MID-RIVERS TELEPHONE COOPERATIVE, INC. – no yes
406-948 Lumen LEVEL 3 COMMUNICATIONS, LLC - MT 2003-01-09 yes yes
406-987 Verizon CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT – yes yes

The holder is who received the block from the numbering administrator. It is not necessarily the carrier serving a given number: numbers move with their owners, and a pooled block is shared.

Who holds the blocks

HolderBrandBlocksShare here
MID-RIVERS TELEPHONE COOPERATIVE, INC. – 2 33.3%
QWEST CORPORATION Lumen 2 33.3%
LEVEL 3 COMMUNICATIONS, LLC - MT Lumen 1 16.7%
CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT Verizon 1 16.7%

Frequently asked

Which prefixes belong to GLENDIVE in area code 406?

6 blocks: 345, 359, 365, 377, 948, 987. The table above gives the holder of each.

Which carriers have numbers in GLENDIVE?

MID-RIVERS TELEPHONE COOPERATIVE, INC. (2 blocks), QWEST CORPORATION (2 blocks), LEVEL 3 COMMUNICATIONS, LLC - MT (1 block), CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT (1 block). These are the holders on record; the carrier actually serving a given number can differ, because numbers move with their owners.

Is GLENDIVE a city?

It is a rate center – the unit NANPA allocates number blocks to. Its name is abbreviated to ten characters and is not necessarily a settlement: we print it as recorded rather than guess at the full name.

Other rate centers in 406

All 754 prefixes in 406