area codes 503 and 971 are area codes for oregon. area code 503 was one of earliest area codes ever created. it was made in 1947. it originally covered the entire state, but after it was split by 541 in 1995, 503 now covers only the northwest portion of the state. it covers towns such as its state capital salem, portland, and astoria. it was overlaid by 971 in 2000.