1939+1990+2023 IL-17 over Illinois River at Lacon, IL

(Bridge Hunter; Historic Bridges; Satellite)

Art Kistler, IDOT, 1939 photo via Bridge Hunter

"This is one of those bridges that looks exactly like a cantilever truss, with a variable depth truss forming 'towers' over the piers, however it appears to lack hinges which means that it functions as a continuous truss, not a cantilever truss." [Historic Bridges]

 

IDOT
"The 1,573-foot long [480m], 29-foot [8.8m] wide structure is a steel continuous through-truss bridge." The bridge handles almost 7,000 vehicles/day.

Art Kistler, IDOT, 1937 photo via Sene Smania comment via Bridge Hunter
[This is one of four photos of the pontoon bridge that this truss bridge replaced.]

Street View

Lisa Ruble posted four photos with the comment:

Lacon Bridge not long after it opened in 1939. Near the bridge a ferry boat service can be seen. The third photo is a 2012 photo of the bridge taken by Steve Conro. The 1939 bridge replaced the Pontoon bridge in the second photo. The last photo is the Pontoon bridge looking east.

The Pontoon bridge (removed in July 1937) replaced the previous Pontoon bridge (built in 1881) that was washed away in 1907 and had partially burned in 1882. The second Pontoon bridge was the last highway bridge of its kind in the United States when it was removed in 1937. The bridge was sold then floated down river to the "narrows" north of Peoria. The bridge had operated as a toll bridge until the state took it over in 1935. Before the three bridges there had been a ferry that was established in 1832.

The Dedication of the new 1939 half a million-dollar Lacon Bridge took place on August 31st and September 1, 1939, during the 75th Annual Marshall County Old Settlers Reunion.

Illinois River

The Lacon Bridge connects the cities of Lacon and Sparland.

Marshall County

Robert Schini posted
Lacon 6-30-21

 

Harold Hopkins posted
"Welcome to Lacon. The Friendly Town on the Illinois."

The river was running a little high in May 2025. (It is just 15' and action is not until 22' at Henry, IL. [noaa])

Michael Magee posted

Travis Guthman posted
Lacon Bridge

Travis Guthman posted
Perfect timing with the water like glass!

Travis Guthman: Bridge at Lacon, IL

Street View

18-wheelers fill up most of a lane. This old bridge has a lot more traffic than we have seen on some 4-lane replacement bridges in other states.

Street View

Travis Guthman posted
Illinois river, Rt 17 bridge, Lacon IL

Frank Holocker: smoke does wonders.... [Chicagoland had a few days of "bad air" warnings because of Canadian wildfires. One of those days was supposed to be the worst air in the world.]

Betty Schlacter commented on Travis' post

2023 Rahabilitation

While researching the C&A Depot in Lacon, IL, I noticed that Google Maps indicated that this bridge was temporarily closed. So I investigated.

The plan is to be closed from Mar 18, 2023, until Nov 3, 2023. [LaconIllinois]

The almost 8-month outage caused by the $10.1m project is a hassel for the locals during the outage, but it is good to here that IDOT is will to save one of their truss bridges. IDOT is detouring the traffic to the North to use the IL-18 Bridge at Henry. [CentralIllinoisProud]

"The project includes steel repair, bearing rehabilitation, joint replacement, bridge deck overlay, roadway and navigational lighting updates, drainage improvements, painting, and other related work." [IDOT]