Area codes 503 and 971
The numbering plan area (NPA) comprises the cities of Portland, Salem, and Astoria.In the initial configuration of the nationwide telephone numbering plan designed by AT&T in 1947,[1] the state of Oregon was assigned a single area code, 503.By the early 1990s, the proliferation of cell phones and pagers, particularly in the Portland area, put this status in jeopardy with the threat of exhaustion of the telephone numbering pool.On November 5, 1995, the numbering plan area was reduced to the more densely populated northwestern corner of the state, including Portland.[3] Initially, ten-digit dialing was to become mandatory in that service area on January 30, 2000, but the date was extended until October 1, 2000.
Area codes 503 and 971
Telephone numbers in El Salvadorarea codesNorth American Numbering PlanU.S. stateOregonPortlandAstoriaoriginal North American area codesoverlayten-digit dialingtelephone numbering planWillamette ValleyEugenearea code 541ClatsopTillamookClackamas CountyClatsop CountyColumbia CountyLinn CountyMill CityMarion CountyJeffersonMultnomah CountyPolk CountyTillamook CountyWashington CountyYamhill CountyNorth American Numbering Plan Administration541/458Pacific Ocean458/541Washington