Keller's Mill Bridge is Lancaster County's only covered bridge not painted red. It originally spanned Cocalico Creek at Rettew Mill Road, but increasing traffic led to its dismantling in 2006 and reassembly at Middle Creek Road in 2010, where an iron bridge was removed while a new concrete span was built at the original site. The bridge takes its name from the Keller family, who built a house and mill near the original location; the mill is gone, but the Keller house still stands on Rettew Mill Road. The first covered bridge there was built in 1873 and was destroyed by flood, and the existing bridge was constructed in 1891 by Elias McMellen, who had also built the earlier bridge. Other names connected with it include Rettew Mill, Guy Bard, Akron Roller, and Cocalico #5, reflecting the Rettew family's ownership of the Keller house and mill in the early 20th century and attorney Guy Bard's ownership of the properties in the 1940s and 1950s. The bridge is a Burr arch truss measuring 74 feet long with a 60-foot, 6-inch clear span and a total width of 17 feet, 4 inches, with a 13-foot deck, and it was added to the National Register of Historic Places on December 10, 1980.
