Michigan Compiled Laws, Chapter 259. Aviation § 259.80e

(a) Over any congested area of a city or village at an altitude below that which, if a power unit fails, will permit an emergency landing without undue hazard to persons or property on the surface, and in no case less than 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet from the aircraft.

(b) Over any other area at an altitude of less than 500 feet (153 meters) above the surface, except over open water or sparsely populated areas, in which case the aircraft shall not be operated less than 500 feet from any person, vessel, vehicle, or structure.