The City of Portland was a named passenger train operated by the Union Pacific Railroad between Chicago, Illinois, and Portland, Oregon. It started service in June 1935, using the streamlined M-10001 trainset. With only one set of equipment the train left each of its terminals five times a month (or six, for the first few months). The route used Chicago and Northwestern trackage between Chicago and Omaha, Nebraska until 1955, replaced by Milwaukee Road trackage.