MILW I-90 Bridge

In 1872, the Southern Minnesota Railroad constructed 165 miles of new track in Southern Minnesota from La Crescent, Minnesota to Winnebago, Minnesota. The railroad was sold and reorganized in 1877 as the Southern Minnesota Railway. In 1878, the line would be extended an additional 138 miles to Flandreau, South Dakota by the The Southern Minnesota Railway Extension, which was controlled by the Southern Minnesota Railway beginning in 1880. In 1880, the Southern Minnesota Railway conveyed it's property to the Chicago, Milwaukee and St. Paul Railway. Known as the Milwaukee Road, the railroad was beginning to amass a large collection of railroads throughout Wisconsin, Minnesota and Iowa. The line would later be extended to Wessington Springs, South Dakota.

The Milwaukee Road operated this route as a secondary route, connecting cities and other lines in Southern Minnesota and South Dakota. The Milwaukee Road was often in financial trouble, especially after the costly Pacific Extension was completed in 1909. In 1925, the company declared bankruptcy, and reorganized as the Chicago, Milwaukee, St. Paul and Pacific Railroad in 1928. As the Milwaukee Road continued to face financial turmoil, branch lines began to see deteriorated conditions. By 1980, the Milwaukee Road was looking to reduce its trackage, and it abandoned this line between Ramsey and La Crescent, as well as Jackson and Flandreau. Portions of the line between Ramsey and La Crescent were purchased for trail use, and the portion of the line from Fountain to Houston was reused as the Root River State Trail. By 1985, a suitor for the Milwaukee Road was being sought, and the Soo Line Railroad, controlled by Canadian Pacific Railway (CP) purchased the Milwaukee Road in 1986. In 2023, CP merged with Kansas City Southern Railway to form CPKC, the current operator of the Ramsey to Jackson segment of this line.