Mackinac TrailMackinac 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. MarieIn the Lower Peninsula:*, between Petoskey and I-75 south of Mackinaw City*Old, between Reed City and Petoskey.