If you are interested in the "mound" people, I strongly suggest books by Charles Whittlesey. He mapped many of the works for the Smithsonian in the 1840s. His

If you are interested in the "mound" people, I strongly suggest books by Charles Whittlesey. He mapped many of the works for the Smithsonian in the 1840s. His books "Descriptions of ancient works in Ohio" and "Ancient mining on the shores of lake superior" are available for free on google play books. He has others as well. There is some fascinating history that most dont know about. You can find mounds on google maps as well if you know what to look for and line up the maps etc.