The field may be limited, but the enthusiasm is overwhelming. The 2021 running of the Mercy Health Glass City Marathon will take place on April 25. First held 50 years ago in 1971, the Toledo race has become an annual tradition and serves as a qualifier for the Boston Marathon. If you planned to participate, sorry: Both the main race and the Owens Corning Half Marathon are already at their capped capacity. As of press time there is still space for runners in the YARK-Subaru 5-Person Marathon Relay and the Savage 5k.