US-41 / Sturgeon River
US-41 / Sturgeon River
About this Bridge:
Located on US-41, 1.4 miles south of Alberta, this long-span steel bridge crosses the Sturgeon River in L’Anse Township. Known locally as the Canyon Falls Bridge for its proximity to this natural feature, the structure is comprised of a two-hinged, girder-ribbed arch over the river’s channel. This is flanked on each side by a 52-foot, steel stringer approach span.
The main span extends 128 feet from pin to pin of the end hinges. It is comprised of five, riveted girder ribs that support a 45-foot-wide concrete deck. Each rib is made up of two back-to-back, built-up channels, riveted to batten plates and a continuous cover plate. These ribs bear into a massive concrete pedestal by means of cast-steel bearing shoes. The asphalt-surfaced, concrete roadway is borne by the ribs through a series of wide-flange columns, which are braced laterally by steel plate diaphragms. Mounted on top of each arch pedestal is a decorative concrete pylon with stepped vertical planes. Each pylon extends above, and is integrated with, the guardrail. The streamlined profile of the arch ribs, combined with the stepped bulkheads and pylons, give the bridge a distinctive Art Moderne character. Other than the recent installation of Armco beams inside the original guardrails, the Canyon Falls Bridge remains essentially unaltered and in excellent condition.
During the 1947-1948 biennium, the state highway department let contracts for eleven trunk line bridges on the Upper Peninsula. Five of these carried US-41, which the department was then reconstructing on a new alignment between L’Anse and Ishpeming. The largest and most striking of the M-41 structures was this span over the Sturgeon River. Completed in the summer of 1948, the Canyon Falls Bridge has since carried Vehicular traffic, in essentially unaltered condition.
The Canyon Falls Bridge is Technologically significant for its representation of steel arch design by the state highway department. The 128-foot arch on the Canyon Falls Bridge is a much more streamlined structure than a comparably scaled through truss. It represents MSHD’s emphasis on bridge aesthetics and efficiency. The Canyon Falls Bridge is a visually striking span – a well-preserved example of an uncommon structural type, built as part of a regionally important highway.