This is a bridge that I know very little about. It was built by the Chicago, Milwaukee, Saint Paul, and Omaha Railroad, which became the Chicago & North Western, which is now the Union Pacific Railway. The railroad bridge at this location dates back to 1872, but likely has been upgraded or replaced since then. The bridge is still in operation, and it frequently opens and closes in the summertime.

This bridge is located in an area of the Saint Croix where sandbars naturally occur. The bridge is located close to the Minnesota shore, and connects to a long causeway built across a relatively wide part of the Saint Croix river. On the Wisconsin side, the causeway branches off into two different wye-configurations. One branch of the second wye runs along the river shore, crossing a dam that holds back a tributary of the river forming Lake Mallalieu. The river crossing paths vary from 3,150 feet to as much as 4,550 feet. Only one path currently has rails, which supports the Union Pacific mainline. That path is approximately 3,922 feet. Each of the four paths coming out of the two wye junctions has a small bridge where it connects to the Wisconsin shore.

The photo above was taken from the old US-12 causeway that is part of the old highway toll bridge that once connected Minnesota and Wisconsin. The view is looking northwest towards the Minnesota shore on the west side of the river. The photo below is looking north towards the swing span as seen from a riverside park on the Minnesota side of the Saint Croix River.

These two photos are views looking southeast from the edge of the river bluffs just off of Minnesota highway MN-95. The photo above is the swing span, which is in the open position. The photo below are the two fixed bridges spans. The larger is a through truss, while the shorter span is a pony truss. The land directly behind the bridge is a natural sandbar. The causeway in the background is the roadway leading to the old US-12 toll bridge.

These two photos are more views from the river bluffs on the Minnesota side of the river. The photo above is an overview of the bridge spans. The photo below is a view of the railroad causeway leading leading to the bridge from the Wisconsin side of the river.

These two photos are views of C&NW Railroad bridge at Hudson as seen from the Walnut Street Causeway. The causeway leads to the site of the old Toll Bridge that once carried highway US-12 over the Saint Croix River. The photo above is a view looking north at the west end of the swing bridge, which crosses the river navigation channel. The photo below is looking northwest towards the swing span and the two smaller truss spans at the east end of the structure. The bridge is a little hard to see in this view given that the late fall background is nearly the same color as the bridge structure.

The photo above is the north side of the C&NW bridge as seen from the marina that is located about a mile north of the bridge. The photo below is a smaller side channel bridge on the Wisconsin side of the river crossing. It carries the railroad mainline into the north end of Hudson, where it will gradually climb out of the Saint Croix River valley and head towards Roberts, Hammond, Baldwin, and Menomonie.

These two photos are a road bridge on Saint Croix Street leading to an island in the river where the railroad once had Y-track. At one time, this was a railroad trestle, but is now used as a driveway leading to the railroad property on the island. The photo above is looking west down the length of the bridge, while the photo below is looking northwest towards the south face of the structure.

The photo above is a building located at the east end of the railroad trestle on Saint Croix Street. This building might have been an old railroad building, but I suspect that it is likely a well house for the city of Hudson. The photo below are the remains of a trestle located just south of the bridge on Saint Croix Street. This branch of the railroad crossing over the Saint Croix River once fed a route heading to River Falls, Wisconsin.

These two photos are an old railroad trestle on yet another branch of the Saint Croix River railroad crossing. This one leads north from the Y-track at the east end of the river crossing. This bridge crosses the mouth of Lake Mallalieu where it flows into the Saint Croix River. This line led to industries in North Hudson, and may possibly have headed north out of the city. The photo above is looking north along the east side of the bridge, while the photo below is looking north down the length of the bridge deck.

These two photos are additional views of the railroad bridge over the mouth of Lake Mallalieu. The photo above is looking north along the west side of the bridge. The photo below is looking northwest towards the east side of the bridge from across the lake.

The photo above is a dam that controls the water flow between Lake Mallalieu (to the right) and the Saint Croix River (to the left). Note the railroad trestle just to the right of the dam. The photo below is a bridge on Bridge Street leading to the dam. There is a small dam under the bridge, which is another outlet for Lake Mallalieu.