The race kicks off at 6:30 a.m. at the Lakefront Trail and East Monroe and ends in Grant Park. The course runs through the Loop, Magnificent Mile and along the lakefront, as well as the Near South Side and West Loop.
About 20,000 runners are registered from 50 states and 29 countries.
A 5K was held Saturday morning, and a health and fitness expo was held Friday and Saturday at McCormick Place.
Several streets will be closed Sunday for the half marathon.
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For more information, visit: http://www.runrocknroll.com/chicago/