Searching for the Great Hopewell Road

I grew up in Adams County in southwestern Ohio, location of the famous Serpent Mound, and I've visited most of the moundbuilder sites mentioned in this documentary. I find it fascinating that ancient earthworks were built thousands of years ago in the same area I now call home. It's humbling to realize that today's civilization doesn't have a monopoly on public works built to precise specifications on an immense scale.