The highway MN-210 Bridge between Carlton and Thomson is the last remaining Parker style through truss highway bridge on the Saint Louis River. These smaller truss bridges were once very common. High maintenance costs have resulted in newer style bridges such as prestressed concrete girder bridges being the current favorite bridge style in the state. The typical scenario that doomed so many of these truss bridges is that they were very old, and as a result, were not built to carry the weight of modern traffic, and they were not wide enough to comfortably carry two 12-foot traffic lanes. The MN-210 Bridge, however, was built relatively recently (for a truss bridge), and, as a result, it was built to handle current traffic loads and wide traffic lanes. This will hopefully allow this bridge to have a long life and serve as a relic of a past era when all bridges were visually interesting.

The MN-210 bridge sits in a very interesting spot on the Saint Louis River. It is located just below the Thomson Dam. From the outflow of the Thomson Dam down to Lake Superior is a drop of 449 feet. The first series of cascades on this fall are located at the MN-210 Bridge site. The river has a choke point where water exiting the dam has to collect and flow through a very narrow gap in the rocks. The MN-210 Bridge straddles this gap in the rocks. There are tremendous views of the river, the rapids, the dam, and the bridge starting at the parking lot of the UMD Outpost (located northeast of the bridge), and following trails along both sides of the river channel. One of the most interesting feature of the bridge is a catwalk that passes under the bridge, allowing visitors to cross under the highway to reach an observation deck at the southeast corner of the structure.

The MN-210 Bridge site is a great place to spend a few hours exploring. It makes a great destination for a day trip, or as an introduction to what you might see later on while exploring the Jay Cooke State Park or taking a trek on the Willard Munger State Trail. I found the walk along the rocks on the ridge between the MN-210 Bridge and the old railroad bridge on the Munger Trail to be well worth the effort. This was a challenging trail for me. And then I stopped to reflect on why this trail existed. In the era of the fur trappers, those adventurers had to climb that 577 foot cascade from Lake Superior to get into the clear water at Cloquet. Not only did they have to climb it, but they had to carry hundreds of pounds of supplies and their canoes. They did it with no GPS, cell phones, bug spray, or McDonalds. There were no easy days on the Grand Portage Trail.

Update—the MN-210 bridge will be closed starting June 6, 2012, through October of 2012. MN-DOT will be performing work on the bridge to replace gusset plates, replace some rivets, improve drainage, and paint the bridge charcoal (rather than its current silver).

The photo above is looking southeast towards the upstream north side of the highway MN-210 Bridge. The Thomson Dam is just off of the left side of the photo, while Jay Cooke State Park is to the right of the bridge. The vantage point is a ridge of rocks that runs parallel to and just north of the highway.

The photo above is a view of the highway MN-210 Bridge over the Saint Louis River between Carlton and Thomson, Minnesota. This view is looking north from a trail that runs along the rocks on the east side of the river. The Thomson Dam, part of the Thomson Energy Project, is located in the background. The photo below is a closer view of the bridge from the same vantage point.

The photo above is looking west through the truss structure down the length of the bridge deck. The photo below is a similar view looking east from near the southwest corner of the bridge. Note that the walkways are very narrow on each side of the traffic lanes, and the walkways are not protected from the traffic lanes. That is unfortunate for a bridge that sees so much pedestrian and bicycle traffic. As a result, the speed limit is set low on MN-210 between Carlton and Thomson.

The photo above is looking towards the northeast corner of the bridge. The vantage point is the lawn at the UMD Outpost. The railings protect a trail that leads to a pedestrian walkway under the bridge deck. The photo below is looking towards the southwest corner of the bridge. There is an observation area just to the right of the trees at the right edge of the photo.

The photo above is a view looking down the downriver south side of the highway MN-210 Bridge. The photo below is a similar view from a few feet further back, revealing the presence of an observation area on the south side of the river. This is accessible from a walkway that runs under the east end of the bridge.

The photo above is the walkway that passes under the east end of the MN-210 Bridge. This view is looking southwest from the north side of the bridge. The photo below is looking west across the Saint Louis River directly under the middle of the MN-210 Bridge. This walkway helps keep people from crossing busy highway MN-210, but it would be even more effective in this role if it was marked a little better.

The photo above is a view of the south face of the bridge as seen from the observation area south of the bridge on the west side of the Saint Louis River. This observation area is on a rock outcropping, allowing a view of the bridge from almost mid-span. Note that the walkway under the east end of the bridge is visible in the shadows on the far side of the river. The photo below is looking east form inside the truss structure. The vehicles parked on the far side of the crossing are parked at the UMD Outpost, the best place to park to explore this area.

These two photos are the bridge supports at each end of the truss structure. The photo above is the fixed support at the southwest corner of the bridge. This support is attached to the concrete abutment, but the pin connection allows for a bit of flex as the bridge expands and contracts during hot and cold cycles. The photo below is a movable support at the southeast end of the structure. The support is not attached to the abutment, rather, it has a rounded bottom, and it can rock back and forth. This allows the bridge to freely move lengthwise as the bridge expands longer or contracts shorter due to variances in temperature. Freely moving bridge bearings are essential to the health of the structure.

The photo above is looking downstream from the deck of the MN-210 Bridge. This photo is looking into the bright late summer sun. The photo below is the bridge plate.

These two photos show a highway water flow passing under the highway MN-210 Bridge. An early snowstorm dropped a foot of snow across northern Minnesota in October, 2010. The weather warmed up, causing the snow to melt very quickly, which resulted in the Saint Louis River rising several feet. The photo above is the outflow water from the Thomson Dam flowing towards the north side of the bridge. The photo below is a view from under the east end of the bridge.

The photo above is the Saint Louis River flowing south from the site of the highway MN-210 Bridge downstream towards the Jay Cooke State Park. Railings are visible at several locations along the east bank of the river. These observation decks offer a spectacular view of the river. The photo below is a drill rig that was parked at the northeast corner of the highway MN-210 Bridge in November, 2010. MN-DOT was doing drilling to prepare engineering specs for a future project to rehabilitate the bridge.