The Chicago, St. Paul, Minneapolis and Omaha Railway or Omaha Road (reporting mark CMO) was a railroad in the U.S. states of Nebraska, Iowa, Minnesota, Wisconsin, and South Dakota.

[5][6] Its main line from the junction with the Great Northern Railway at St. Paul to Elroy, along with branches from it, became known as the C. St. P. M.'s Eastern Division.

[7] The Land Grant Act of Congress approved March 3, 1857, when Minnesota was still a Territory and not a state, conferred on the then called Southern Minnesota Railroad Company "lands, interests, rights, powers and privileges" for the proposed line of railroad from St. Paul via Mankato, Minnesota, and other points named to the southern boundary of the state in the direction of the mouth of the Big Sioux river.

The name of the company changed on April 7, 1869, to the St. Paul and Sioux City Railroad.

[6] The route was a bow shape between Le Mars to the Twin Cities to Elroy, Wisconsin.

[13] In November 1883, control passed to the Chicago and North Western Railway Company.