This Mystery Bridge article is in connection with a book project on the bridges along the Des Moines River. For more information about the book and how you can help, please click here for details.
The next mystery bridge features not only one, but SIX bridges, all within the vicinity of a lake. Saylorville Lake is the second of two man-made lakes along the Des Moines River in Iowa. The other is Red Rock Lake, located between Knoxville and Pella in Marion County (article on that can be found here). Yet Saylorville is the larger of the two, covering an area of 5,950 acres and 9 miles wide. The length of the lake is 17 miles long, starting at Woodward in Boone County and ending north of Des Moines. In the event of flooding, the lake is three times the length, extending as far north as Boone. The size of the lake is over 17,000 acres at flood stage, which was reached twice- in 1993 and 2008. The lake was authorized by the US Army Corps. of Engineers in 1958 as part of the project to control the flooding along the Des Moines River. It took 19 years until the lake was fully operational in September 1977. Yet like the Red Rock Lake project, the lake came at the cost of many homes and even bridges.
Before Saylorville, six bridges once existed over the Des Moines River within the 17 miles that was later inundated. Five of them consisted of multiple spans of steel truss bridges built between 1890 and 1910. The sixth one consisted of a steel and concrete beam bridge built in 1955 carrying a major highway. All of them were removed as part of the project between 1969 and 1975. Yet some information on the bridge’s type and dimensions were recorded prior to their removal for load tests were conducted to determine how much weight a bridge could tolerate under heavy loads before they collapse. Only a few pictures were taken prior to the project, yet information is sketchy, for the pictures did not describe the bridges well enough to determine their aesthetic appearance. Despite one of the bridges carrying a plaque, there was no information on the builder. All but two spans have a construction date which needs to be examined to determine their accuracies. In any case, the bridges have historic potential for each one has a history that is unique to the area it served before the lake was created.
While the bridges no longer exist as they are deep under water in a sea that is only 836 feet above sea level (that is the depth of Saylorville Lake when there is no flooding), it is important to know more about their histories so that they are remembered by the locals, historians, pontists and those interested in the history of the region now covered with beaches, marinas and houses. The bridges in question are the following:
Location: Des Moines River at Opal Lane in Boone County
Bridge type: Pennsylvania through truss with A-frame portal bracings and pinned connections (four spans)
Length: 660 feet (160 feet per span)
Location: Des Moines River at 145th Lane in Dallas County
Bridge type: Pratt through truss (3 spans total) with Howe Lattice portal bracings (2 spans) and A-frame portal bracing (1 span). Two of the three spans were pinned connected whereas the third span was riveted.
Built: ca. 1900; one of the spans was replaced later.
Length: 480 feet (180 feet per span)
Location: Des Moines River near Jester Park in Polk County
Bridge type: Pratt through truss (one span); two additional spans existed but type is difficult to recognize.
Built: ca. 1900; two newer spans replaced the original spans damaged in 1953
Length: 360 feet total (largest span: 150 feet)
Location: Des Moines River south of Polk City in Polk County
Bridge type: Pratt through truss with X-frame portal bracings and pinned connections (two spans)
Removed: 1975 but not before it collapsed under the weight of US Army tanks in 1972
Length: 312 feet total (156 feet per span)
Location: Des Moines River at 128th Street in Polk County
Bridge type: Pratt through truss with pinned connections. Portal bracing unknown (three spans total)
Removed: ca. 1975
Length: 444 feet total (148 feet per span)
Hwy. 98 Bridge:
Location: Des Moines River between Woodward and Madrid in Boone County
Bridge type: Steel plate girder
Replaced: 1973 with higher span
Length: 360 feet
The highway was later changed to Hwy. 210
What is needed from these bridges are the following:
1. More photos to better describe the structure
2. Information on the construction of the bridge, including the bridge builder and the year the bridge was built
3. Information and photos of the removal of the bridge
4. Stories and memories of the bridge during their existence prior to the creation of Saylorville Lake
If you have any useful information about these bridges, please contact Jason D. Smith at the Chronicles at firstname.lastname@example.org. The information will be useful for the book project but the Chronicles will keep you posted when information comes in on these bridges. The creation of the lakes along the Des Moines River came at the expense of bridges, villages and some livelihoods. Now it’s a question of piecing together the history of the areas affected to find out what the areas looked like, with the goal of the younger generation remembering them for years to come. This includes the bridges that were erased from the map and in some, memory. And while they are physically gone, history surely will not.
Thanks to Luke Harden for digging up some facts about the bridges as they were documented in a report published prior to the bridges’ removal. Please click on the names of the bridges as they serve as links to the bridges found on bridgehunter- also thanks to his contribution so far.