- 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
09/20/21
This stone arch bridge carries the Union Pacific mainline across Clear Creek.
The structure is located between the Iowa State University communications building and 13th Street.
Built in 1882 and extended in 1900, the arch uses a standardized design. It was widened for the impending double tracking of the mainline, which would be completed in 1901.

Historic photo of the bridge. Credit to PhotoLibrarian on Flickr, used with Creative Commons permission.
The author has ranked this bridge as being locally significant, due to the common nature of the design throughout the area.
Fortunately, this bridge remains in good condition. The photo above is an overview.
The structure can be accessed Pammel Woods, and various local foot trails.