The Mills Tower Historic District encompasses the eastern portion of the Illinois Central railroad yard, on the eastern edge of Iowa Falls. The small district consists of six structures, only three of which are contributing and still standing, which date to the last two periods of Iowa railroad history. Most alterations to the district have been to Mills Tower, the oldest of the group.

Mills Tower is a good example of the second generation utilitarian support structures the Illinois Central built between the 1880s and 1930s to control traffic along their lines. Mills Tower is the only interlocking tower left in Iowa, out of nearly seventy in operation at various times and places.

Mills Tower probably replaced the original Iowa Falls junction in 1909, when the IC-RI built a new river crossing and the new line made the older junction obsolete. The actual date of construction is unknown. Unlike the first tower, which "was doubtless of the 'Armstrong' variety"(having manually operated levers) Mills Tower employed electrically-operated levers. Mills governed the switches in the IC yard west of the tower as well as the older Rock Island (BCRN) crossing with the IC. In 1985 The Chicago Central & Pacific Railroad (CCP) purchased the IC and its employees refer to the tower as a "relic" and a "fossil."

The first floor was once used for offices and the second floor is the control room, as its many windows attest. The key feature of the tower has always been the original electric control board sitting in the middle of the room. A large train order signal stands right next to the building, on the north side. Next to the tracks and just west of the crossing diamond is a smaller metal pole with two slender metal hoops. Train orders for the next segment of track were tied loosely to the hoops so the engineer could grasp the papers with his hand while the train slowed for the crossing.

The Mills Tower Historic District is located on East Rocksylvania, approximately 1/3 mile east of old freight house and Illinois Central Depot. The Mills Tower and two contributing buildings are undergoing a restoration; as is a caboose, restored to Illinois Central colors, now located on the property. For info or tour call Iowa Falls Historical Society (515) 648- 4603