Below is a list of Ontonagon County MI zip codes. For your research we have also included Ontonagon County Area Code, Time Zone, UTC and the local County FIPS Code. Each Ontonagon County Michigan zip code has a center Longitude / Latitude point (the Ontonagon County center is -89.263702392578 / 46.667499542236). For your convenience we have also indicated if that zip code in Ontonagon County observes Daylight Savings time.