The Chicago, Milwaukee, St. Paul and Pacific Railroad (often referred to as the Milwaukee Road) , was a Class I railroad that operated in the Midwest and Northwest of the United States from 1847 until 1980, when its Pacific Extension (Montana, Idaho, and Washington) was abandoned following a bankruptcy. The eastern half of the system merged into the Soo Line Railroad on January 1, 1986. The company went through several official names and faced bankruptcy several times in that period. The railroad no longer exists as a separate entity, but much of its trackage continues to be used by its successor and other roads, and is commemorated in buildings like the historic Milwaukee Road Depot in Minneapolis, Minnesota and in railroad hardware still maintained by railfans, such as the Milwaukee Road 261 steam locomotive.