Mackinac Trail, or Mackinaw Trail is the name for two related, but separate, roadways in the US state of Michigan. In the Upper Peninsula: , previous designation of H-63, before the construction of the I-75 freeway , the entire road between St. Ignace and Sault Ste. Marie In the Lower Peninsula: , between Petoskey and I-75 south of Mackinaw City Old , between Reed City and Petoskey. County roads in Michigan Historic trails and roads in Michigan