Rainbow Bridge Photo & Story

By Tim Lindenbaum

   Hidden at the end of a seldom-traveled dirt road near the old McLean County ghost town of Pleasant Hill, lies a relic of a bygone era on the Mackinaw River.  Named for its gracefully arched iron beams, Rainbow Bridge is one of the few remaining iron bridges that still span the main channel of the river.  Constructed in 1868 under the supervision of road commissioner Moses Cochran, it was the first iron bridge built in Lexington Township and just the second iron bridge in McLean County.  Situated on an unnamed ford, Rainbow Bridge was actually the second bridge erected on this site as the original one, called the Adams Bridge, succumbed to high waters in 1858. 

   The earliest bridges over the Mackinaw River (often fabricated with mud sills and wooden frames) frequently washed out with the first floods of spring.  Only three bridges existed in McLean County in the area between the present-day town of Colfax and Coon’s Ford to the west before the construction of Rainbow Bridge.  The building of the “new” bridge was a direct result of an incident in which a man and his team of mules drowned while attempting to ford the Mackinaw River near this location.  Rainbow Bridge became a great service to the citizens of Pleasant Hill and Lexington – particularly for those living south of the river, as most of the stores, schools and churches were located on the north side. 

   In the years before the railroad was built through Lexington, Pleasant Hill had one of the largest populations of any settlement in the county.  East of Rainbow Bridge was Isaac Smalley’s brickyard and Foster’s sawmill – powered by eight horses.  John Patton (who was the first white settler in Lexington Township) and his son dug a mill race across a horseshoe bend west of the bridge and set up a water powered saw and grist mill.  These mills (used only one season) washed out when the Mackinaw left its channel and overtook the mill race.

    The narrow iron bridges that were once common along the Mackinaw River valley have disappeared rapidly over the past fifty years as the needs of our society have changed.  Rainbow Bridge was condemned to motor traffic in the 1960’s and its wooden deck planks have deteriorated and been carried away by the countless floods.  In the 1980’s, a group of concerned citizens investigated the possibility of restoring Rainbow Bridge to its former glory and establish a public walking path across the river.  The plan was later dropped for lack of funding and community interest.  As it stands today, Rainbow Bridge is still in remarkably good condition for a structure that is over 134 years old.  

 References cited: 

“Stories of the Past & Poetry” by Morris W. (Casey) Jones

“Early Fords & Bridges on the Mackinaw” by A.V. Pierson - 1908