One of the few pieces of documentation that I have been able to find on this bridge so far is from the General Laws of Minnesota for 1905. In Chapter 338, Section 13: "the sum of $1,800 to aid in building a bridge across the Minnesota river between the township of Ridgely in Nicollet county and the town of Home in Brown county, at or near what is known as Hinderman's Ferry. Said appropriation shall be expended under the direction of Captain Hinderman and William La Flamboy of Nicollet county and Hans Moe of the village of Sleepy Eye."
One interesting note is that this bridge does not appear on any historical maps from the era that I have located. It seems odd that a bridge would be established at this remote location when a bridge was already in place less than 5 miles upstream. So far, the only evidence that suggests that a bridge was at this location is a Minnesota state DNR canoe map that gives the location of the bridge remnants at river mile 170.9, and some wooden pilings on the edge of the river.
I attempted to check out the bridge site in the spring of 2008. The river was high, and was flowing across the approach road about a mile before the main river channel. Even in areas that were still above the river level, the road was muddy and had large sink holes. The north end of the bridge connects to a loop road that branches off of the Minnesota River Valley Scenic Parkway. That loop road was blocked off due to high water on each end.
I visited the bridge site a second time in July of 2008. The north approach road was open, but there was one spot that was impassable. This meant having to backtrack and reenter from the far end of the loop. I was not able to find the bridge landing on the north side of the river. I was able to travel the length of the approach road on the south side of the river. While it had some sink holes, it was generally passable. I was able to drive within a few feet of the edge of the river. From the south, you can tell where the road ended, and you can see a few wooden pilings one the far side of the river. This proves that there was something here at one time, perhaps a bridge.
Update—I was contacted in late summer 2009 by a gentleman from Hibbing who had relatives who lived in the area near Sleepy Eye and Fairfax. He recalled crossing the Hinderman Bridge as a child. One one memorable trip, his mother drove the family car over the bridge during the spring run-off. The water was so high that it was coming up from between the planks on the bridge deck. He didn't remember the specific date, but it probably was in 1943. He recalled that the bridge was washed out in the flood of 1951. There was a mid-river pier, and those pilings remained standing in the river channel until a flood in the early 2000s knocked them down. Finally, he recalled the bridge being a metal pony truss bridge that used rods and turnbuckles for internal support.
Update—I was contacted by the great-granddaughter of Captain Hinderman in January of 2012. She was able to fill in some of the gaps in this story, and also sent the newspaper photo that appears below. The bridge was open for 82 years. The structure had a 3 ton weight limit when it was finally declared to be more of a liability than an asset by the Brown County Highway Engineer. The county had just replaced the Beussmann Bridge downstream, and the MN-4 bridge was only 4 miles upstream. The low weight limit meant that it could no longer be used for farm traffic. As a result, the bridge was deemed to have little utility, and it was closed in the fall of 1987.
The photo above is looking north across the Minnesota River where the Hinderman Bridge once stood. The posts sticking up above the surface of the water at the edge of the river are piling from the bridge.