The city of Boulder is gearing up for a series of running events that promise to test the limits of local athletes while impacting travel plans for area residents this weekend. The Boulderthon, which includes a full marathon, half marathon, 10K, and 5K races, is scheduled to take place Sunday, Sept. 29, drawing participants and spectators from across the region. According to Boulder County, the courses will be active from 8 a.m. to 3 p.m.