A runner high-fives an inflatable llama along the race route. The llama was part of a booth for Bank of America, the marathon’s sponsor.
Ariyan Mansoore smiles through the first mile of the 2017 Chicago Marathon. Mansoore raced in the third of three heats, starting nearly an hour after the fastest runners.
Two girls cheer as their father runs by. More than a million spectators came to support the runners, carrying creative signs and cowbells.
Runners share the course with a wheelchair division athlete. 
Runners round the corner in the last 800 meters of the race.
Runners recover at the 27th Mile Post-Race Party in Grant Park. Athletes received emergency blankets, ice packs and medals after completing the race.
Volunteers help to clean water cups from the race route. Members of local running teams and community organizations gathered as early as 4 a.m. to set up stations, distribute water and clean up.
Photos by Claire Bugos / North by Northwestern
More than 40,000 athletes from all 50 states and more than 100 countries battled their way through Chicago Oct. 8 for the 2017 Bank of America Chicago Marathon. The course began and ended in Grant Park and wound through 29 Chicago neighborhoods. Galen Rupp, the first American in 15 years to win the marathon, finished with a time of 2:09:20. Tirunesh Dibaba of Ethiopia won the women’s race in 2:18:31. In its 40th year, the marathon drew over 1 million spectators.