1973 : I-75 Completed in Michigan Calendar Add to Calendar Add to Timely Calendar Add to Google Add to Outlook Add to Apple Calendar Add to other calendar Export to XML When: November 1, 2021 all-day Repeats 2021-11-01T00:00:00-04:00 2021-11-02T00:00:00-04:00 Interstate 75 The state’s longest expressway, I-75 from the Ohio border near Toledo to Sault Ste. Marie (395 miles) was formally completed. Source: Interstate 75 in Michigan Wikipedia Entry.