Section R. 259.248 - Unimproved airstrip airportsRule 248.
(1) An unimproved airstrip public airport license shall be granted if all of the following minimum services and facilities are provided and maintained: (a) Have an airport manager licensed by the commission.(b) At least 1 runway equipped with a 1,200-foot landing length in each direction from a clear approach slope of 20:1 and a 50-foot usable width with an additional 25-foot minimum width on each side which is free of obstructions.(c) An approach slope at a ratio of 20:1 with a width of not less than 100 feet. The approach slope shall be based on a clearance of all objects within the approach area, including a roadway clearance of 15 feet or 17 feet over an interstate highway and a railway clearance of 23 feet. Runway lights shall not be considered obstructions in the runway width required to be free of obstructions.(d) A permanent monument established on the centerline at or beyond each end of the runway.(e) A runway that is well defined by mowing, use of markers, or low peripheral farming with clearly marked displaced thresholds.(2) A person using an unimproved airstrip shall do so at his or her own risk.(3) No commercial operations may be based at an unimproved airstrip airport.Mich. Admin. Code R. 259.248