Area codes 503 and 971are telephonearea codesin theNorth American Numbering Plan(NANP) for the northwestern region of theU.S. stateofOregon.The numbering plan area (NPA) comprises the cities ofPortland,Salem,andAstoria.Area code 503 was one of theoriginal North American area codesof 1947, assigned to the entire state until 1995, when its extent was reduced to the northwestern corner. Area code 971 was assigned to the service area in stages, completed in 2008, to form anoverlayin the area withten-digit dialing.
History
editIn the initial configuration of the nationwidetelephone numbering plandesigned byAT&Tin 1947,[1]the state of Oregon was assigned a single area code, 503. Despite Oregon's growth in the second half of the twentieth century, particularly in theWillamette Valley(Portland andEugene), this remained so for 48 years, making Oregon one of the largest states by area with a single area code. 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. The rest of the state received the newarea code 541.[2]
Although this was intended as a long-term solution, the Portland area remained home to the great majority of Oregon's landlines, as well as most of its cell phones and pagers, the area continued to experience a shortage in telephone numbers. Within three years, further relief planning commenced. On July 1, 1999, area code 971 was created as a concentrated overlay for most of the numbering plan area, with the exceptions ofClatsopandTillamookcounties.[3]Initially,ten-digit dialingwas to become mandatory in that service area on January 30, 2000, but the date was extended until October 1, 2000.[4]
The previously exempted Clatsop and Tillamook counties were added to the overlay on April 27, 2008.[5]
Service area
editThe service area includes the following counties:
- Clackamas County
- Clatsop County
- Columbia County
- Linn County(far northern parts, includingScio,Lyons,andMill City)
- Marion County(except southernmost parts aroundJefferson)
- Multnomah County
- Polk County
- Tillamook County
- Washington County
- Yamhill County
References
edit- ^Mabbs, Ralph (Winter 1947–1948)."Nation-Wide Operator Toll Dialing—the Coming Way".Bell Telephone Magazine.26(4): 181.Retrieved2023-08-10.
- ^"Split of 503 (Oregon) Numbering Plan Area (NPA)"(PDF).North American Numbering Plan Administration.May 19, 1995.RetrievedMay 25,2012.
- ^"Concentrated Overlay of 503 Numbering Plan Area (NPA) with 971 NPA"(PDF).North American Numbering Plan Administration. July 21, 1999.RetrievedMay 25,2012.
- ^"Permissive Dialing Extended for the 503/971 Concentrated Overlay (Oregon)"(PDF).North American Numbering Plan Administration. December 10, 1999.RetrievedMay 25,2012.
- ^"Expansion of the Concentrated NPA 971 Overlay with NPA 503 (Oregon)"(PDF).North American Numbering Plan Administration. December 21, 2006. Archived fromthe original(PDF)on November 26, 2010.RetrievedMay 25,2012.
External links
edit| North:360/564 | ||
| West:Pacific Ocean | area codes 503/971 | East:458/541 |
| South:458/541 | ||
| Washingtonarea codes:206,253,360,425,509,564 | ||