For twenty years Dan O'Brien struggled to make ends meet on his cattle ranch in South Dakota. But when a neighbor invited him to lend a hand at the annual buffalo roundup, O'Brien was inspired to convert his own ranch, the Broken Heart, to buffalo. Starting with thirteen calves, "short-necked, golden balls of wool," O'Brien embarked on a journey that returned buffalo to his land for the first time in more than a century and a half. Buffalo for the...