Area codes 541 and 458

North American area code 541 covers the majority of Oregon in terms of surface area, except the northwest part of the state. Its service area includes the cities of Eugene, Springfield, Corvallis, Albany, Medford, Bend, Ashland, Klamath Falls, The Dalles, Burns, Lakeview, and Pendleton, as well as the coastal region from Lincoln County to the California border. It began its split from area code 503 on November 5, 1995, and finished June 30, 1996. It is overlaid with area code 458, effective February 10, 2010.

Area code 503 was used for the entire state of Oregon until November 5, 1995, when area code 541 began service. On that date, 503 was cut back to the heavily populated northwest corner of the state–including Portland and Salem–while the rest of the state moved to 541. This was intended as a long-term solution, as northwest Oregon has the great majority of Oregon's landlines and cell phones. However, by 2007, 541 was on the brink of exhaustion due to the proliferation of cell phones and pagers, particularly in Eugene, Corvallis and Medford. The supply of numbers was further limited because the 541 territory is split among four local access and transport areas. Most of the numbering plan area is part of the Portland LATA, while the southwest portion is the Eugene LATA. Malheur County is part of the Boise/southern Idaho LATA, while the northeast is part of the Spokane, Washington LATA.

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