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.
  • If you want to search an entire area code regardless of activity, leave both the next and past days fields set to zero.

Switch: SHLBMTMADS0

Remotes:

Switch Switch name Switch type
CTBNMTMARS1  CUT BANK  AXR 
EGPKMTMARS1  EAST GLACIER PARK  AXR 
STMYMTMARS1  SAINT MARY  AXR 
WGLCMTMARS1  WEST GLACIER  AXR 
NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
406-434 A Shelby MT 9636 QWEST CORPORATION 648      

Last updated: Tue, 13 Jan 2026 21:50:02 UTC

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