Area codes 539 and 918
Area codes 918 and 539 are telephone area codes serving northeast Oklahoma. These area codes cover the following major cities: Bartlesville, Broken Arrow, Gore, Jenks, McAlester, Muskogee, Okmulgee, Sapulpa, Tahlequah, Tulsa, and northeastern Oklahoma.
Area code 918 was created in 1953 as a split from area code 405. Area code 539 was created as an overlay for 918. It became active on April 1, 2011 (although 539 numbers could have been assigned for activation before that date). Mandatory dialing of ten-digit area codes became active on March 5, 2011. It is the first overlay in Oklahoma.
The other two area codes for Oklahoma are 405, which covers the Oklahoma City Metropolitan Area and central Oklahoma, and 580, which covers western and southern Oklahoma.
Below is a full list of all towns and cities covered by the 539 and 918 area codes.
Coordinates: 35°30′N 95°30′W / 35.5°N 95.5°W
...
Wikipedia