This route immediately became a part of the Chicago, Rock Island & Pacific. Connecting to St. Paul, Minnesota on the north and Kansas City to the south; the route was known as the Rock Island Spine Line.
Despite the great routing of the line, the Rock Island oftentimes faced financial issues, which led to deferred maintenance of this route.
By the time a judge ordered liquidation of the Rock Island assets, the route was in poor condition. The Chicago & North Western Railway and Soo Line Railroad entered a bidding war to win the Spine Line and its connections to Kansas City.
After the C&NW came out victorious, over a year was spent rebuilding the line to get it back into operating condition. The route opened in 1983, and provided the C&NW with a direct connection to Kansas City.
At Nevada, Iowa; a connection was built to the Clinton Subdivision to allow a connection between major routes. This connection opened up in 1983.
In 1995, the C&NW was purchased by Union Pacific. Today, Union Pacific continues to operate this line as the Mason City Subdivision.
06/26/21
This deck girder bridge crosses high above the Iowa River in Steamboat Rock.
Built in 1926, the bridge contains three deck girder spans crossing the Iowa River and a trail. The bridge was likely built to replace a truss.
The substructures are a combination of stone and concrete. In addition, the bridge is approached by trestle spans.
The author has ranked this bridge as being locally significant, due to the common design.
The photo above is an overview. The bridge can be accessed from the trail underneath.
| Upstream | Iowa Falls Rail Bridge (E) |
| Downstream | Iowa River Trail Bridge (Union) |