- 1857: 44 miles completed from Clinton to Wheatland, Iowa by the Chicago, Iowa and Nebraska Railroad
- 1858: 20 miles completed from Wheatland to Lisbon, Iowa by the Chicago, Iowa and Nebraska Railroad
- 1859: 17 miles completed from Lisbon to Cedar Rapids, Iowa by the Chicago, Iowa and Nebraska Railroad
- 1861: 41 miles completed from Cedar Rapids to Belle Plaine, Iowa by the Cedar Rapids and Missouri River Railroad
- 1861: 41 miles completed from Cedar Rapids to Chelsea, Iowa by the Cedar Rapids and Missouri River Railroad
- 1862: 29 miles completed from Chelsea to Marshalltown, Iowa by the Cedar Rapids and Missouri River Railroad
- 1864: 29 miles completed from Marshalltown to Nevada, Iowa by the Cedar Rapids and Missouri River Railroad
- 1865: 29 miles completed from Nevada to Boone, Iowa by the Cedar Rapids and Missouri River Railroad
- 1867: 150 miles completed from Boone to Council Bluffs, Iowa by the Cedar Rapids and Missouri River Railroad
- 1867: 6 miles completed from Missouri Valley to California Junction, Iowa by the Cedar Rapids and Missouri River Railroad
- 1884: CI&N and CR&MR officially acquired by Chicago & North Western Railway
- 1887: 6 miles completed from Beverly to Otis, Iowa bypassing Cedar Rapids by the Linn County Railway
- 1887: Linn County Railway acquired by Chicago & North Western Railway
- 1891-98: Second track constructed between Clinton and Cedar River
- 1898-1900: Second track constructed between Cedar River and Mashalltown
- 1898-1901: New alignment completed between Boone and Ogden, Iowa; including the Des Moines River Bridge
- 1900-02: Second track constructed between Marshalltown and Council Bluffs
- 1933: Old route via Moingona between Boone and Ogden abandoned
- 1995: Chicago & North Western purchased by Union Pacific Railroad
- 1995-Present: Union Pacific operates the Clinton Subdivision between Clinton and Boone
- 1995-Present: Union Pacific operates the Boone Subdivision between Boone and Missouri Valley
- 1995-Present: Union Pacific operates the Omaha Subdivision between Missouri Valley and Council Bluffs
06/26/21
This unique Double Intersection Warren Pony Truss crosses over the Union Pacific mainline between Boone and the Kate Shelley High Bridge.
The bridge was built in 1900 using a recycled pony truss span. It is unknown where this was originally located, although research is planned to answer the question.
In addition, the original build date of the bridge is unknown. It is likely that the only pieces of the original railroad bridge include the truss frame. These pieces likely date to the mid 1880s.
A number of bridges like this were constructed over double track mainlines for township and county roads.
The main truss span is a heavily modified Double Intersection Warren Pony Truss with riveted connections.
This bridge is approached by wooden trestle, and is set onto wooden piers. These wooden piers are set on concrete substructures.
Overall, the bridge remains in fair condition. Serving only a couple locations, it is likely that the bridge will eventually be closed and possibly replaced.
The author has ranked this bridge as being moderately significant, due to the unique history and design.
The photo above is an overview. It can be accessed from the road it carries.