Mill Bridge is an unincorporated community and populated place officially registered as Mill Bridge in 1874. It is located primarily in Atwell Township and Steele Township in Rowan County, North Carolina, United States. With part extending into Mount Ulla Township. The prominent features include the Kerr Mill, Thyatira Presbyterian Church, and Millbridge Sp…Mill Bridge is an unincorporated community and populated place officially registered as Mill Bridge in 1874. It is located primarily in Atwell Township and Steele Township in Rowan County, North Carolina, United States. With part extending into Mount Ulla Township. The prominent features include the Kerr Mill, Thyatira Presbyterian Church, and Millbridge Speedway.