Despite the best efforts of archaeologists, serendipity often plays a role in the most significant finds. In the case of the Mackinaw Cache, a group of boys hauling gravel on a farm near Mackinaw in 1916 uncovered about 40 spectacular “bifaces” on the slope of a hill just a quarter of a mile from the Mackinaw River. A biface is a stone implement that has been worked on both sides.