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.

Dodson, MT

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
406-383 A FTBNMTXCDS0  3310 TRIANGLE TEL. COOP. ASSN., INC. 648      

Last updated: Tue, 01 Sep 2026 00:40:05 UTC

Sponsored by: LES.NET

Like this site? We accept donations via PayPal.