WSOR River Street Bridge

In 1853, the Southern Wisconsin Rail Road completed an 8 mile spur from an existing railroad at Milton Junction, Wisconsin to Janesville, Wisconsin.  In 1856, the railroad would be acquired by the Milwaukee & Mississippi Rail Road (M&M), which owned the existing mainline at Milton Junction.  At the same time, the Mineral Point Railroad (MPR) constructed 17 miles of new railroad between Warren, Illinois and Darlington, Wisconsin.  In 1857, the M&M completed an additional 34 miles of railroad to Monroe, Wisconsin.  In addition, the MPR completed an additional 15 miles north to Mineral Point, Wisconsin.  The M&M was acquired by the Milwaukee and Prairie du Chien Railway (M&PdC) in 1861, which was sold to the Milwaukee & St. Paul Railway (M&StP) in 1867.  In 1874, the M&StP changed its name to the Chicago, Milwaukee & St. Paul Railway (Milwaukee Road).  In 1880, the MPR was acquired by the Milwaukee Road, and the following year an additional 22 miles would be constructed to connect Monroe to Gratoit.  

This line served as a secondary route for the Milwaukee Road, mainly providing access to valuable metal deposits in southwest Wisconsin.  The route also allowed for the construction of numerous branch lines, including branches to Shullsburg, Wisconsin and Platteville, Wisconsin.  By the 20th Century, the Milwaukee Road had become a prominent railroad in the United States, operating an expansive network of railroad lines, primarily in the Midwest.  The Milwaukee Road was often in financial trouble, especially after the costly Pacific Extension was completed in 1909. The branch between Gratoit and Warren was abandoned in 1923.  In 1925, the company declared bankruptcy, and reorganized as the Chicago, Milwaukee, St. Paul and Pacific Railroad in 1928. Throughout the 20th Century, conditions on the Milwaukee Road continued to deteriorate.  This line began to fall into disrepair, and was downgraded to a branch line.  

The railroad again entered bankruptcy in 1977, and was forced to liquidate unprofitable lines.  By the late 1970s, much of the railroad was extremely overgrown, and the tracks in very poor condition. In 1980, the entire branch was sold to the State of Wisconsin, which leased it to the Chicago, Madison and Northern Railway (CM&N) that year. The CM&N was short lived, and became part of the Central Wisconsin Railroad in 1982, which became part of the Wisconsin & Calumet Railroad (WICT) in 1985.  The same year, the entire branch west of Monroe was abandoned and turned into a trail.  In 1993, the WICT was acquired by the Wisconsin Southern Railroad, and was formally merged in 1997.  Since WSOR began operations of the line, significant upgrades have been made to the line, significantly improving service.  Today, WSOR continues to operate the Milton Junction to Janesville segment as part of the Madison Subdivision and the Janesville to Monroe segment as the Monroe Subdivision.  The Cheese Country Trail currently uses the right-of-way between Monroe and Mineral Point.