U.S. Route 23 (US 23) is a part of the U.S. Highway System that travels from Jacksonville, Florida to Mackinaw City, Michigan. In the U.S. state of Tennessee, the highway travels 57.5 miles (92.5 km) in the northeastern part of the state from the North Carolina state line at Sam's Gap in the Bald Mountains, north to the Virginia state line in Kingsport. With a predominant concurrency with Interstate 26 (I-26), US 23 is a divided four-lane freeway that follows Corridor B of the Appalachian Development Highway System (ADHS) and serves as a major thoroughfare in the Tri-Cities. Although I-26 is technically an east-west route, the highway predominantly travels in a north-south alignment in Tennessee. The route reaches a maximum elevation of 3,760 feet (1,150 m) at the North Carolina state line