Mill Race Bridge is a historic structure located northwest of Eldorado, Iowa, United States. It spans the Turkey River for 120 feet (37 m). Its name is derived from its location near a riverside mill. Horace E. Horton, a civil engineer from Minneapolis, had designed wagon bridges for Fayette County in the 1880s. When he joined the Chicago Bridge & Iron Company late in the decade, he took the county with him as a client. Chicago Bridge & Iron was responsible for providing the county's bridges in the 1890s. This bridge was completed about 1892, but its concrete abutments are not original. While it remains in place, but it has been replaced by a newer span. The Mill Race Bridge was listed on the National Register of Historic Places in 1998.