| Name | C&NW Mill Creek Bridge (Moingona) Chicago & North Western Railway Bridge #640 |
| Built By | Chicago & North Western Railway |
| Currently Owned By | United States of America |
| Contractor | Unknown |
| Length | 12 Feet Total |
| Width | 1 Track (52 Feet) |
| Height Above Ground | 20 Feet (Estimated) |
| Superstructure Design | Stone Arch |
| Substructure Design | Stone Masonry |
| Date Built | 1881 |
| Traffic Count | 0 Trains/Day (Bridge is Abandoned) |
| Current Status | Abandoned |
| Chicago & North Western Railway Bridge Number | 640 |
| Significance | Local Significance |
| Documentation Date | 3/26/2013; 11/12/2017 |
In 1867, the Cedar Rapids & Missouri River Railroad (CR&MR) continued constructing a mainline westward from Boone, Iowa. In the late 1850s and early 1860s, the CR&MR had participated in constructing a line from Clinton, Iowa to Boone. The CR&MR was leased by the Chicago & North Western Railway (C&NW), which was seeking a route connecting Chicago to the Missouri River. In 1867, an impressive 150 miles were constructed between Boone, Iowa and Council Bluffs, Iowa, completing a connection between Chicago and the Missouri River. The line also allowed for a short spur from Missouri Valley, Iowa to the Missouri River opposite of Blair, Nebraska. This spur would eventually be extended across the Missouri River and into Nebraska. Between 1869 and 1872, Union Pacific Railroad (UP) constructed a bridge across the Missouri River between Council Bluffs and Omaha, Nebraska; and the C&NW obtained trackage rights over the bridge to reach Omaha. During the second half of the 19th Century, the C&NW had constructed and acquired a large amount of trackage throughout the Midwest. In 1884, the CR&MR was formally purchased by the C&NW; and this line quickly became a core asset of the C&NW system.
By the late 19th Century, traffic over this line had increased to the point significant upgrades were required. In 1893, a 5-mile section of railroad was relocated west of Jefferson, Iowa to improve grades and eliminate curves. One of the most significant barriers to efficient operation over this line was the Des Moines River Valley between Boone and Ogden, Iowa. The original route crossed the Des Moines River at Moingona, which was approached by winding and steep approaches on each bank. In 1899, C&NW subsidiary Boone County Railway (BCR) began construction on a more direct route between Boone and Ogden, Iowa; including a massive viaduct across the Des Moines River. The BCR was consolidated into the C&NW in 1900, and the new cutoff was completed in May 1901. The new alignment shortened the route by 3 miles, cut grades in half and only required two small curves. The original mainline through Moingona was maintained as an emergency backup and to serve industries in the area. Between 1901 and 1902, a second track was also constructed between Ogden and Council Bluffs, including a 5-mile realignment near Arcadia, Iowa. The double tracking of this line provided the C&NW with a well constructed double track mainline between Chicago and Council Bluffs.
By the 20th Century, the C&NW was operating an extensive railroad network, which radiated north and west from Chicago. The original mainline into Moingona was abandoned in 1930. This line served as the backbone of the C&NW, connecting transcontinental freight and passengers at Omaha to Chicago. Known as the Overland Route, this line became one of the most significant railroad routes in the United States. This route saw continuous upgrades during the 20th Century, including significant bridge, rail, tie and signal upgrades. In 1995, the C&NW was purchased by UP, which provided UP with a mainline into the railroad hub of Chicago. Into the 21st Century, the line has seen continuous upgrades, and remains one of the most significant railroad lines in the United States. Today, UP operates this line as the Boone Subdivision between Boone and Missouri Valley; and the Omaha Subdivision between Missouri Valley and Council Bluffs.
Located in Moingona, this stone arch carries an abandoned Chicago & North Western Railway mainline across Mill Creek. Originally, the C&NW mainline between Boone and Ogden turned southwest at Boone, following Honey Creek to its mouth at the Des Moines River opposite of Moingona, crossed the Des Moines River at Moingona and turned northwest to reach Ogden. This route required harsh grades, sharp curves and eight crossings of Honey Creek. The first bridge at this location consisted of a timber pile trestle bridge, constructed when the line was first built. As traffic over the line grew in the late 1870s and early 1880s, the C&NW made significant upgrades to the line, replacing timber bridges with stone and iron structures. In 1881, a new stone arch bridge was constructed at this location. Between 1899 and 1901, a new double track cutoff was constructed between Boone and Ogden, and the original line was downgraded to a branch line, before being abandoned in 1930 and removed in 1933. After the line was removed, several stone arches were left intact. Currently, the bridge consists of a 12-foot stone arch bridge, set onto stone substructures and constructed at a width of 52 feet. The structure follows a standard design, with a semicircular arch and stepped wing walls which extend at different angles from the bridge. In addition, the bridge is extremely tall for a 12-foot arch, giving it an unusual appearance. Stone for the bridge consists of a tan limestone, quarried at an unknown location, while an unknown contractor constructed the bridge. Since being abandoned, the bridge has remained intact, and is easily accessed by a short walking trail. Overall, the bridge appears to be in fair condition, with significant cracking and stone separation noted. The author has ranked this bridge as being locally significant, due to the common design.
Citations
| Build date | Chicago & North Western Railway Valuation Notes at the Chicago & North Western Historical Society Archives |
| Railroad History Citation | ICC Valuation Information, Compiled by Richard S. Steele |