The Highway 243 Bridge crosses the Saint Croix River at Osceola, Wisconsin. It provides a highway river crossing between WI-35 on the east side of the river and MN-95 on the west side of the river, two highways that parallel the Saint Croix. The road on the west side of the river is designated MN-243, a highway that runs a grand total of 1-1/4 miles. The road on the east side of the river, WI-243, is the shortest state trunk highway in Wisconsin.

The Saint Croix River is much more calm here than upstream at the US-8 Bridge. The river flows through a wide valley rather than being confined between walls of rock found upstream in the Taylor's Falls area. The channel is wide and shallow with a calm current. The result is a longer bridge that is built much lower to the river.

The Highway 243 bridge gained a bit fame after the I-35W bridge collapse in 2007 due to the bridge being one of the few remaining deck truss bridges in Minnesota. A deck truss bridge has a metal lattice work of cross members, with the roadway being built on top of the truss. The deck truss is considered to be an obsolete style of bridge. The reasons include being fracture critical (i.e., non-redundant, which means that any one piece breaking can result in the entire bridge failing), they are very hard to inspect (the structure is under the road rather than above the road), they are easily damaged by road salt (which can leak though cracks in the deck and cause the steel to rust), and truss bridges are far more costly to maintain.

The Highway 243 bridge receives routine inspections every other year. An additional inspection was completed shortly after the I-35W disaster. The bridge is not considered to be deficient, so it is not being considered for replacement anytime soon. The bridge was closed, however, for a month in the Spring of 2010 for refurbishment. Highway 243 was repaved on both the Minnesota and Wisconsin side of the river as part of this project.

Bridge fan Jake Lennington alerted me to a book titled ‘Osceola A Village Chronicle Sesquicentennial 1844 1944’ that has a few photos of the old bridge that was replaced by the current deck truss bridge in 1953. The bridge consisted of a truss swing span on the Wisconsin side of the channel and a single through truss span on the Minnesota side of the river. It appears to have been a very light bridge, single lane, wood deck, and was braced mostly with cables and rods as opposed to beams. I do not know when the old bridge was built, but this construction style suggests that it was built as a wagon bridge prior to the establishment of the highway system in the 1920s. One of the photos in the book is dated 1910. A photo caption indicates that the through truss span failed and collapsed into the river in 1938, and was replaced with a new truss span. Even with this replacement span, the bridge still carried a 4 ton weight limit. The bridge abutment on the Wisconsin side of the river still exists, as does the road leading to the east side of the river. The roadway leading to the west end of the bridge is abandoned, but still visible on aerial photographs.

The photo above is looking west along the the downstream south face of the MN-243 Bridge. The vantage point is a riverfront trail on the Wisconsin side of the Saint Croix River. The photo below is looking southwest towards the upstream of the structure. Note that the water level is near the top of the bridge piers due to an unusual autumn flood in 2010.

The photo above is a profile view of the Highway 243 bridge as seen from a park located on the Minnesota side of the river just downstream from the river crossing. The photo below is another view of the structure from the same park on the Minnesota side of the river.

These two photos are views of the bridge deck looking east from the Minnesota side of the river across the Saint Croix River to the Wisconsin side of the river. The photo above was taken from the downstream south side of the highway, while the photo below was taken from the upstream north side of MN-243. Note that lack of sidewalks or bicycle paths, which is unfortunate given how scenic this area is and how many people visit the parks located on both sides of the river.

The photo above is looking east down the length of the bridge deck towards Wisconsin, with a vantage point located a little further west of the two photos above. The photo below is the Minnesota state line sign located on the west side of the river crossing.

These two photos are detail views of two trusses as they sit on top of a bridge pier. The photo above is looking north at the south side of the bridge, while the photo below is looking south at the upstream north side of the bridge. These repairs were made in 2010, in part due to the findings from the I-35W bridge disaster. Some of the rivets were drilled out and replaced with bolts. In addition, plate doublers (and additional steel plate) were installed over part of the gusset plates to strengthen the joints.

These are mid-span joints where steel truss members are joined with a gusset plate. Again, we see that some of the rivets have been drilled out and replaced with bolts.

These two photos are views of the east abutment of the old swing bridge that once crossed the Saint Croix River at this location. It is located at the west end of 2nd Ave in Osceola and is now on private property. The photo above is looking west down the hill leading to the old bridge. The photo below is a closer view of the abutment.

These two photos are additional views of the old swing bridge abutment on the Wisconsin side of the river.

The abutment of the old bridge no longer exists on the Minnesota side of the Saint Croix River, but the road leading to that location still exists in the forest just north of highway MN-243. The photo above is the end of that road where the abutment once stood. The photo below is the view looking east across the Saint Croix River along the path of the old bridge, with the east abutment located directly behind the small white shed that is between the two houses on the far side of the river.

The city of Osceola has built a path down to the Saint Croix River from Cascade Street, the main street that runs through town. The photo above shows the large stair structure that takes hikers down into Wilkie Glen, where Osceola Creek flows into the Saint Croix. Those who take this path are rewarded with a view of Cascade Falls. The photo below is the lower portion of the falls, but unfortunately, the view was looking directly into the midday sun. The city installed LED lighting for the falls in 2013 and they have developed additional trails that take hikers past the remains of early industry that used water power from this stream.

There is a view under the MN-243 Bridge from the trail that leads down into Wilkie Glen. The photo below is the eastern end of the structure, while the photo below is the Wisconsin state line sign posted just beyond the east end of the bridge.

These two photos are views of the downstream side of the MN-243 Bridge was seen from the riverbank on the Wisconsin side of the Saint Croix River. This location can be accessed from a trail that runs through Wilkie Glen from Cascade Street in Osceola. The photo above is looking almost due west, while the photo below is taken from a little further downstream.

These two photos are closer views of two different bridge piers as seen from the east side of the river. The photo above is the second pier (counting from the west), while the photo below is the third pier.

The photo above is the third pier (counting from the west end of the structure), which is on the Wisconsin side of the river. This view is from directly below the truss structure. The photo below is looking up at the bottom side of bridge deck.

These two photos are views of the MN-243 Bridge as seen from the boat ramp located on the Minnesota side of the river just downstream of the bridge. The photo above shows the first and second piers (counting from the west), while the photo below includes the second and third piers.

The photo above is the west bridge abutment. The photo below is the under side of the bridge deck at the west bridge abutment. These two photos were taken in November, 2011, just over a year after the bridge was repainted in 2010.