Area code 308 is the telephone area code in the North American Numbering Plan for western Nebraska. It was created on July 1, 1954, by splitting the numbering plan area (NPA) 402 along a roughly S-shaped boundary line from the western half of the Nebraska–South Dakota border to the approximate center of the Nebraska–Kansas border. A roughly 50-mile segment of the line running northeast to southwest in the eastern third of the state follows the Platte River.