sentences:  The source of the Swannanoa River, which joins the French Broad River in Asheville, is in northeast Buncombe County near Mount Mitchell which is a part of the range known as the Black Mountains.Mt.Mitchell is the highest point in the eastern United States at 6,684 ft.
  
  A milestone was achieved in 2003 when Interstate 26 was extended from Mars Hill (north of Asheville) to Johnson City, Tennessee, completing a 20-year, half-billion dollar construction project through the Blue Ridge Mountains.