Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
  • Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information.
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Grass Range, MT

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
406-428 A RNDPMTXCDS0  2246 MID-RIVERS TEL. COOP., INC. 650      
406-428 2 RNDPMTXCDS0  2246 MID-RIVERS TEL. COOP., INC. 650      
406-428 8 BLNGMTWEIMD  6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 650   2018-12-17   
406-928 A BLNGMTWEIMD  6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 650      
406-928 0 BLNGMTWEIMD  6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 650      
406-928 8 BLNGMTWEIMD  6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 650      
406-928 9 BLNGMTWEIMD  6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 650      

Last updated: Sat, 21 Mar 2026 23:53:39 UTC

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