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: 838

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-838 A Cooke City MT CKCYMTMARS1  9636 QWEST CORPORATION 650      
406-838 0 Cooke City MT   9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650   2004-11-13   
406-838 1 Cooke City MT   624H ONVOY SPECTRUM, LLC 650   2025-01-16   
406-838 2 Cooke City MT   9636 QWEST CORPORATION 650      
406-838 3 Cooke City MT   994E BANDWIDTH.COM CLEC, LLC - MT 650   2015-05-31   
406-838 4 Cooke City MT   508J CENTURYLINK COMMUNICATIONS, LLC 650   2016-08-10   
406-838 5 Cooke City MT   453F ONVOY, LLC - MT 650   2011-10-20   
406-838 6 Cooke City MT   994E BANDWIDTH.COM CLEC, LLC - MT 650   2009-02-13   
406-838 7 Cooke City MT   453F ONVOY, LLC - MT 650   2007-04-14   
406-838 8 Cooke City MT   453F ONVOY, LLC - MT 650   2017-07-24   
406-838 9 Cooke City MT   453F ONVOY, LLC - MT 650   2017-07-24   

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

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