← Area code 406
406-485 phone numbers
Numbers 406-485-0000 to 406-485-9999 are assigned to Mid-Rivers Tel. Coop., Inc. in Circle, MT. 2 of its ten thousand-number blocks are assigned to other carriers (number pooling).
Not assigned to any carrier: 406-485-0xxx, 406-485-4xxx, 406-485-6xxx — calls from these use spoofed caller IDs.
Source: North American Numbering Plan Administrator, Nov 3, 2026. Numbers can move between carriers.