what area code is 503

The 503 area code is located in northwestern Oregon and covers cities such as Portland, Salem, Gresham, Hillsboro, and Beaverton. It was one of the original North American area codes of 1947, assigned to the entire state until 1995, when its extent was reduced to the northwest corner. Area code 971 was assigned to the service area in stages, completed in 2008, to form an overlay in the area with ten-digit dialing. The 503 area code covers roughly 736,073 phone numbers, with Portland being the largest city within this area code with a population of about 635,659.