Okay, it's not exactly the span of the Mackinac Bridge, but it is a pretty scenic walk.  For the 11th year, the cities of Owosso and Corunna are partnering for the Labor Day Bridge Walk.  The walk crosses Heritage Bridge in Owosso and then takes participants down the James Miner Trail, a 3.5 mile walk that ends at Corunna's historic McCurdy Park.  The walk starts at 8am on Labor Day!  CorunnaNOW.com has more.