The Poplar Bridge is named after Fort Poplar, a historic army outpost in the 19th century. That fort was named after the Poplar River, which is a nearby tributary to the Missouri River. The Poplar River was given its name by a grove of Poplar trees that grew along its banks. The bridge itself is located nearest to the small town of Sprole. Sprole started as a trading post, and later as a stop on the Great Northern Railroad. The trading post was founded by Major Sprole, who was the commander at Fort Poplar at one time.

I know very little about the bridge, its history, or why it was even built in the first place. One end of the bridge connects to a gravel road that sees very little traffic. There are no towns or cities for dozens of miles on the south end, and very little farming. The bridge is typical of a 1960s steel girder bridge. It is somewhat narrow, lacks shoulders, and has the old style guard rails. That hardly seems to matter much since one would only cross this bridge if they really wanted to go out of their way to find it.