Being from MI, run the Dances with Dirt 50k in September. Very runnable with some mud, not too much in the way of hills. You have time to ramp things up and run it this year. It is run in conjunction with a team relay, so plenty of people around afterward with a fun atmosphere/music. Good competition up front and some interesting team costumes, including some scantily dressed ladies. You start earlier than the relay, so you will finish before most of the teams come through the start/finish area on their way the last 5 legs of their race. Bells Brewery sponsors the post race beer garden.