After a brief history of the Bonnie Doon Railroad and its main crossing over the Rock River in Lyon County, the next mystery bridge takes us down the Big Sioux River to its last original crossing, before the coming of the Interstate Highway era, until its confluence with the Missouri River. The Three Corner’s Bridge is located at the site of the Two Rivers Golf Course in Sioux River, spanning the river at the Iowa/ South Dakota border, approximately two miles west of the point where the two rivers merge, as well as the two states and Nebraska meet. The crossing used to be located north of the last physical crossing before its junction, the I-29 bridge, which has been serving traffic since the mid-1950s. It is most likely that the crossing is at the place where a pedestrian crossing, which provides access to the golf course, is located. Yet more information is needed to either support or counter these claims.
But before going into the debate on this structure’s actual location, let’s have a look at the bridge itself. The structure that used to exist appeared to have two different truss bridges built from two different time periods. What is clear is the truss span on the right appears to be much older- having been built in the 1880s and consisting of a pin-connected through truss bridge with V-laced end-posts and an X-frame portal bracings with curved heels. The diagonal beams appear to be much thinner than the vertical beams, this leading to the question of whether the former were built using thin iron beams or with steel wiring. In addition, the design of the bridge leads to the question of its stability, which leads to the question of whether the bridge collapsed under weight or by flooding and was replaced by the span on the left, a Parker through truss span, made of steel, with pinned connections, A-frame portal bracings and featuring beams that are thicker and sturdier. The span on the right, which appeared to be an all-iron structure, had at least two spans total- one of which spanned the main river channel and was replaced by the Parker span. The Parker span was one that is typical of many Parker spans along the Big Sioux River, having been built between 1900 and 1915 by the likes of Western Bridge Company of Lincoln, Nebraska, Clinton Bridge Company of Clinton, Iowa, and the bridge builders from the Minneapolis School of Bridge Builders- namely Commodore P. Jones, Alexander Bayne, as well as Seth and William S. Hewett. However, it does not mean that the Parker span replaced the lost iron span during that time. It is possible that it was put in place between the 1930s and 1950s, which was the time when bridges were relocated and reused as replacements because of the scarcity of steel on the count of the Great Depression, followed by the onset of World War II and later, the Korea War. With flooding that occurred during the 1940s, especially in 1945-6, it it possible that the Parker was relocated to the spot because of that. Records have already indicated multiple bridge replacements in that fashion, including those in Crawford, Harrison and Monona Counties in Iowa. It is unknown when the entire bridge was removed, but chances are because of the increase in urban development combined with the creation of the golf course, the bridge was removed between the 1960s and early 1980s.
To sum up, the bridge is very unique but has a lot of missing pieces in the puzzle, which if assembled thanks to help from people like you, can round off the story of the structure that contributed to the development of Sioux City’s infrastructure. What do you know about this bridge in terms of:
- The date of construction of both the iron Pratt and steel Parker structures
- The bridge builders for both structures
- When the iron bridge collapsed and how
- Whether the Parker span was original or if it was brought in from somehwere and
- If it was relocated, from where exactly and how was it transported
- The dimensions of the bridge and lastly,
- When was it taken down and why.
Use the question form below and see if you can help put the pieces together. You can also comment on the Chronicles’ facebook pages and encourage others to paricipate. Let’s see what we can put together regarding this bridge, shall we?
The bridge is pinpointed at a location where another truss bridge, a continuous Warren through truss, is located. This one is open to pedesrians accessing the golf course. If you know about this bridge, please feel free to add that to the comment section as well.
The I-29 Bridge was originally built in the early 1950s to accomodate traffic over the Big Sioux River enroute to Sioux City. The bridge collapsed in 1962 due to structural failure and flooding and was subsequentially replaced with a steel beam structure a year later. An additional span was added to accomodate southbound traffic.