Iowa's Rochester Cemetery is one of the most unusual and biodiverse prairies left in America, boasting more than 400 species of plants--337 of them native to the region--on its thirteen-and-a-half acres. Among them are fifteen massive white oaks that stood watch as the surrounding landscape was converted into farmland after Euro-American settlers arrived in the 1830s. The cemetery is the last resting place of these pioneers and their descendants,...