King Road Bridge

Information and Findings From Michigan Historic Bridge Inventory

Narrative Description

Located in Limestone Township near the Marquette County line, this medium-scale concrete bridge spans the Whitefish River on King Road. King Road is actually an old 1 1/2 -mile-long segment of US-41; the current highway alignment extends roughly east-west about a half-mile south of this bridge. The Whitefish River Bridge is comprised of two concrete through girders, supported on a skew by concrete abutments and a center pier with bullnosed cutwaters. Built from a standard design by the Michigan State Highway Department, the bridge features straight girders, which form the guardrails on either side of the concrete slab deck. The small amount of architectural expression is limited to the rectangular recessed panels on the girders and the bronze "Trunk Line Bridge" plate mounted on the girders' inside walls. The Whitefish River Bridge has suffered a considerable amount of concrete spalling and chipping, especially on the center pier, but the structure is unaltered.

During the 1910s three trunk line roads were developed in Alger County: an east-west route that extended through the center of the county between Munising and Marquette, a north-south route that extended from Chatham south to Rapid River, and a short diagonal route that connected the other two between Trenary and Skandia. By 1916 this last road was graded from the county line almost to Diffin; by 1920 the diagonal route was complete. The last link on this road was the bridge over the Whitefish River, about halfway along its length. For this crossing MSHD engineers in 1919 designed Trunk Line Bridge No. 264, a concrete structure comprised of two skewed 35-foot through girders. MSHD awarded a contract to build the bridge to Samuel Mills of Escanaba. Mills completed the bridge that year for $1,688.25. The trunk line was later incorporated into US-41, and later still abandoned to the county following a re-alignment of the highway. Although no longer on the main line, the bridge continues to carry local traffic.

The concrete through girder that MSHD built here in 1919 used a standard design that the agency had developed in 1913-14 biennium. During the 1910s and 1920s, the highway department delineated straight girders in five-foot increments between 30 and 50 feet for use in a wide variety of application. "The reinforced concrete through girder is the design generally employed for spans from thirty to fifty feet in both the eighteen and twenty-foot clear roadway from curb to curb," MSHD stated in its Seventh Biennial Report. "This design lends itself in the majority of cases on account of its very shallow floor system, thereby giving the waterway a maximum clearance under elevation of roadway crossing the bridge." By 1930 the through girder had largely fallen out of favor with the state and county highway departments, but before it was discontinued, perhaps hundreds of these utilitarian structures were built throughout Michigan. The Whitefish River Bridge in Alger County is noteworthy among the remaining through girders in Michigan for its relatively early construction date and its two-span configuration. Built as an integral part of one of the Upper Peninsula's most important routes, it is a significant transportation-related resource.