Years constructed: 1875
Bridge type: Semi-Circular Stone Arch
National Register of Historic Places status: Listed
Length: Unknown
Width: Unknown
Spans: 1
Jurisdiction: City of Decorah
Location: Oneata Road under US 52 over Twin Springs Creek, West edge of Decorah, Section 20, T98N-R8W (Decorah Township)
Details
Spanning an unnamed stream in Twin Springs State Park, the Steyer Bridge, named after its builder Michael Steyer, is a short-span stone arch structure. Consisting of roughly-cut limestone voussoirs, the concrete-decked arch is supported by a stone and concrete substructure. The keystone of the arch is a block of dressed limestone, inscribed with "1875" and "Michael Steyer". Presumably, Winneshiek County contracted local stone mason Steyer in 1875 to erect this stone arch. Although stone arches are rare in Iowa, Winneshiek County is an area which was conducive for the construction of this particular bridge design. Stone suitable for the arch was readily available throughout the region. The central part of the county is floored primarily by Trenton limestone, which gradually changes to galena in the southwest corner. Several extensive quarry companies located in the county separated and cut the stone. Near Decorah, pure high-grade limestone of a light-grey color was quarried. Given the abundance of materials, the masonry arch seemed a logical and economical choice for small-scale crossings. Since its construction, the arch has carried moderate vehicular traffic in the park with no alterations of note. Because it is an example of vernacular engineering and is one of the few examples of stone arch design in Iowa, the Steyer bridge is therefore both a historically and structurally significant transportation-related resource [Crow-Dolby and Fraser 1992].