The CSAH-31 highway bridge dates back to 1990, when a previous river bridge was replaced with this modern prestressed concrete girder bridge. The bridge features a reinforced concrete deck, modern style guardrails, and large T-shaped piers. Beyond the modern design, there are no decorative features on the bridge.
From Floodwood down to Scanlon, the release of water from glacial lakes cut a very distinct river channel about 40 miles long and 50 feet deep. Given the size of the glacial lakes, the water flow could have cut the majority of this river channel in just a few weeks as the lakes drained. At Brookston, the glacial river ran into a ledge of stone that would not yield to the water flow. Whereas the glacial river channel was far wider than the Saint Louis River that we see today, at Brookston, the glacial river cut a very wide channel down 15 to 20 feet, and then a very narrow channel that was up at the 40 feet deep. That deep channel eventually filled up with gravel and silt, resulting in the geography that we see in the modern era.
The photo above is looking east towards the upriver west side of the Brookston Bridge. This photo was taken at noon, so the bridge shadow is directly under the structure with neither side of the bridge being lit up. The photo below is a closer view of the river channel. It appears that some debris has built up along the upstream side of this bridge pier.
