- 1903: 22 miles of double track completed from Lake Bluff, Illinois to Mayfair, Illinois by the Chicago Northern Railway
- 1903: Chicago Northern acquired by the Chicago & North Western Railway
- 1905: 17 miles of double track completed from Chicago Northern Junction to Wisconsin/Illinois State Line by the Chicago and State Line Railway
- 1905: C&SL acquired by the Milwaukee & State Line Railway
- 1906: 34 miles of double track completed from Wisconsin/Illinois State Line to St. Francis, Wisconsin by the Milwaukee and State Line Railway
- 1909: M&SL acquired by the Chicago & North Western Railway
- 1910: 11 miles of double track completed from Proviso to Deval, Illinois by the Des Plaines Valley Railway
- 1911: 10 miles of double track completed from Deval to Valley, Illinois by the Des Plaines Valley Railway
- 1913: Des Plaines Valley Railway acquired by the Chicago & North Western Railway
- 1954: Relocation due to O'Hare Airport
- 1960: Second track mostly removed between Gurnee and St. Francis
- 1995: Chicago & North Western purchased by Union Pacific Railroad
- 1995-Present: Union Pacific operates the Milwaukee Subdivision from Proviso to St. Francis Avenue, continuing north towards Butler
07/17/21
Located in Northbrook, this concrete arch bridge crosses Techny Road near Techny Prairie Park.
Built in 1911, this bridge features a single concrete arch span, set onto concrete substructures. In addition, another span bridge crosses a branch of the Chicago River nearby.
The concrete arch design is common for new constructions between 1910 and 1913 for the C&NW. During this time period, many structures were built with this same design for all new routes.
Overall, the bridge appears to be in poor condition, with some significant deterioration. primarily spalling.
The author has ranked the bridge as being locally significant, due to the common design.
The photo above is an overview.