The Milwaukee Road, officially the Chicago, Milwaukee, St. Paul and Pacific Railroad (reporting mark MILW), was a Class I railroad that operated in the Midwest and Northwest of the United States from 1847 until 1980, when its Pacific Coast Extension was embargoed in the states of Montana, Idaho, and Washington. Its core Midwest system was merged into the Soo Line Railroad on January 1, 1986. The Pacific Coast Extension from the Midwest to the Pacific Northwest, planned between 1901 and 1906 and built between 1906 and 1909, was carried out under the auspices of the Chicago, Milwaukee and Puget Sound Railroad. This corporate entity was folded into its parent company in 1912.