[1] This subdivision is formerly a Chicago and North Western Railway (C&NW) mainline,[2] on which the Twin Cities 400 operated in the mid 1900s.

[1] In 1935, the C&NW had the inaugural run of the Twin Cities 400, with this section of track on its route (see Passenger operations).

[6] The following day, all of Chicago and North Western's assets, including the Eau Claire and Stillwater Subdivisions, had officially become part of the Union Pacific.

They would serve bags, machines, metal, and copper to the Accu-Tech Tool & Design, Inc. in Hudson, and coal up to Spooner to operate plants.

From 2003 to 2015, the Norfolk Southern Railway ran their Triple Crown roadrailer trains (Symbol Z-EMCH, Twin Cities to Chicago) on the Altoona Subdivision using trackage rights.

Norfolk Southern ended 60 percent of their Triple Crown routes on December 11, 2015, including service to the Twin Cities and many others.

The Minnesota Commercial Railway, using trackage rights on the Altoona Subdivision, served Andersen Corporation with a weekly delivery of lumber and sand.

[10] As of 2015, the Altoona Subdivision is one of Union Pacific's less dense lines, usually seeing up to three to five trains per day on the Minnesota side.

In 2019, the 150th anniversary of the First transcontinental railroad, a Union Pacific excursion train ran on the Altoona Subdivision as part of the "Great Race Across the Midwest" celebratory tour.

The Big Boy traveled the entire Altoona Subdivision in one day, attracting many visitors in local communities.

The Twin Cities 400 experienced great success, resulting in the creation of an entire fleet of trains carrying the "400" name.