Ends: 01/31/2021 2020 Detroit Marathon (October 18, 2020) Join Michigan's largest road race whether you are ready for the full 26.2, a 13.1 half, a 5K, a one mile Kids Run, or want to join a group and do a 26.2 relay. Share: Want to get involved? Create your own fundraiser. Already have an account? Sign in.