Covered Timber Town Lattice Truss
National Register of Historic Places status:
Hogback Bridge Road over the North River, 4.2 miles northwest of Winterset, Section 14, T76N-R28W (Douglas Township)
During the 1870s Madison County contracted for a series of timber trusses covered with roofs and walls. In 1872, the board of supervisors acted to erect the county's first iron structures as a more durable alternative to all-wood construction. That summer the board contracted with the King Iron Bridge and Manufacturing Company of Cleveland to build a wrought iron span across the Middle River at Compton's Mill. The county soon after built iron spans at Bevington and Patterson. Erection of these three iron bridges marked the beginning of the end for wood truss construction in Madison County. The transition was to be a slow one, however, as the county continued to build covered bridges throughout the 1970s and into the 1880s. During this period the board of supervisors relied principally on two local contractors, Eli Cox and H.P. Jones, to build the timber bridges. Jones was responsible for the last all-timber truss built in the county. Known locally as the Hogback Bridge, it spanned the North River some four miles northwest of Winterset, the county seat. The Hogback Bridge extended almost 100 feet; like its immediate predecessors, the Cedar Bridges, it employed a Town lattice truss, overlaid by a queenpost frame. The truss was covered with plank siding and a bow roof, and it was supported by iron cylinder piers. Completed in 1884, the Hogback Bridge has continued to carry traffic to the present, with only maintenance-related repairs.
It is not known how many covered bridges were built in Iowa between 1850 and 1900, but a conservative estimate would be a hundred or so. Almost all have been destroyed by flooding, collisions, demolition or vandalism, leaving only a few remaining examples. All of these are located in Madison County, making this central Iowa county a mecca of sorts for covered bridge buffs. The Hogback is one of these outstanding early structures--a well-preserved example of one of the state's earliest bridge technologies. [adapted from Fraser 1992].