The US 12 Heritage Trail Garage Sale is on. Friday August 11th to Sunday August 13th 2017! If you love shopping and searching for hidden treasures, this journey is for you! The US 12 Heritage Trail Garage Sale is aptly called, Michigans Longest Garage Sale!. Every year individuals clean out their attics and stake out their front yards along the US-12 corridor stretching over 180 miles from New Buffalo to Detroit.