^Westbound trailblazer at US Route 52 near Serena, June 2022.
Illinois Route 71 has two sections with two separate sets of characteristics. West of Ottawa, Illinois 71 runs east-west on the south side of the Illinois River, connecting to the Ottawa area, including Starved Rock State Park, and many other towns in Putnam and LaSalle Counties. East of Ottawa, Illinois Route 71 turns northeasterly and heads toward Oswego, connecting to outer western suburbs of Chicago.
Illinois 71's eastern end is at US Route 34 on the eastern side of Oswego, where the route begins running southwesterly: