Kincheloe AFB, MI postmark dated October 15, 1963 The Kincheloe AFB, MI Post Office is a Contract Branch of the Sault Sainte Marie, MI Post Office and was established on October 17, 1959. When the base officially closed on October 1, 1977, the post office was named Kincheloe, and is in operation today using zip code 49788. / Contributed by Paul Petosky