I'm in Ohio, and I'm sure there are plenty of artifacts in MI.
Check out high,flat ground along waterways, areas around springs, almost any field you have permission to search is worth a walk through. Look for flint flakes. Good Luck.
unfortunately the law here in michigan requires you to turn in indian artifacts if found on any government land i think private land your ok but im not sure you'd also have to have the land owners permission and any site whether private or government land that is deemed indian burial grounds or a religious site is against the law