Area code 918 is the telephonearea code serving the state of Oklahoma. It covers Tulsa, Bartlesville, McAlester, Muskogee, Henrietta and northeastern Oklahoma. The telephone or phone (Greek: tele = far away and phone = voice) is a telecommunications device which is used to transmit and receive sound (most commonly voice and speech) across distance. ... A telephone numbering plan is a system that allows subscribers to make and receive telephone calls across long distances. ... Official language(s) None Capital Oklahoma City Largest city Oklahoma City Area Ranked 20th - Total 69,960 sq mi (181,196 km²) - Width 230 miles (370 km) - Length 298 miles (480 km) - % water 1. ... Downtown Tulsa Tulsa is the second-largest city in Oklahoma. ... Bartlesville is a city located in Oklahoma. ... McAlester is a city located in Pittsburg County, Oklahoma. ... Muskogee is a city located in Muskogee County, Oklahoma. ... Henrietta is a feminine given name. ...