The Third River Bridge is built on a national forest access road. The road provides access to a campground in Winnie, MN, and connects to points north. It gets its name from the road, which eventually skirts around three sides of the Third River Flowage a few dozen miles north of the Mississippi River.

The bridge was built by the US Department of Agriculture, which is the agency that operates the National Forest Service. The bridge is relatively new, built in 1971, and features precast concrete girders. The railings, however, are of an obsolete style. The original bridge across the Mississippi River in this area was a half-mile downstream. It was a 1926 wooden trestle. When it needed to be replaced, the entire road was rebuilt along a new alignment to avoid a very swampy area. The old bridge remained in place, but caught fire and burned in 1975.

The photo above is a view looking north down the length of the bridge deck. The photo below is the bridge plate. The photo at the top of the page is a profile view from the southwest corner of the bridge. Note that the bridge is relatively high above the water compared with typical Mississippi River bridges located upriver from Brainerd.