Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 406 [Rate centres in NPA 406] [Dial plan for NPA 406]

NXX: 972

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-972 A West Camp Crook MT BISNSDXADS0  1689 WEST RIVER COOPERATIVE TELEPHONE COMPANY 640      

Last updated: Sat, 02 May 2026 12:20:53 UTC

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