Hidden Thunder: Rock Art of the Upper Midwest mystery That's why some images of

That's why some images of Indians can be so unexpected and disorienting: What is Geronimo doing sitting in a Cadillac

and a response to the art of it all

In these charmingly illustrated pages

Many Dakota people consider the area to be their sacred place of origin as well as a site of genocide

Hidden Thunder: Rock Art of the Upper Midwest mystery That's why some images ofIn Hidden Thunder, renowned watercolor artist Geri Schrab and archaeologist Robert "Ernie" Boszhardt give readers an up close and personal look at rock art. With an eye toward preservation, Schrab and Boszhardt take you with them as they research, document, and interpret at the ancient petroglyphs and pictographs made my Native Americans in past millennia. In addition to publicly accessible sites such as Wisconsin's Roche a Cri State Park and