From the record
“Boeckman Bridge was a historic suspension bridge over Big Tavern Creek near St. Elizabeth, Miller County, Missouri, listed on the National Register of Historic Places.”
Wikipedia article Boeckman Bridge, CC BY-SA 4.0.
One of 9 National Register listings published here for Miller County · listed in 1979 · category: Structure.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service