Prefix overview
Phone numbers in prefix 406-378
This page covers the 406-378 prefix in the United States. It shows where numbers come from, which carrier is linked to the range, and how this block is structured.
If you are looking for a specific number, you can continue to its dedicated phone page. Otherwise, this page helps you understand the broader number block behind it.
PREFIX
406-378
RATE CENTER
BIG SANDY
CARRIER
TRIANGLE TEL. COOP. ASSN., INC.
MT
Prefix range
The prefix 406-378 includes numbers from 4063780000 to 4063789999.
This range is associated with the BIG SANDY rate center and was originally assigned to TRIANGLE TEL. COOP. ASSN., INC..
Numbers in this prefix
20 numbers