An unusual view of a rich, violent period in the American West. Around 1875, the northern plains were beset by two wars: while settlers were wresting the land from the remaining Native Americans, scholars competed--often without scruple--to find dinosaur bones in Montana. Thad, a young American tracker, becomes the friend of Julian, son of an English paleontologist in another search group. Their intense and sometimes violent adventures, based on fact, include several historical figures: Thad helps Black Elk rescue children during the Powder River Massacre; he and Julian witness the Battle of the Little Big Horn. Despite daunting terrain and dangerous antagonists, they secretly unearth the first traceratops skull. An epilogue glimpses both Thad and Julian as aging, eminent paleontologists. There is plenty of action to hold attention here, though some (notably a beautifully written but melodramatic opening scene in which Thad's mother is murdered) is not intrinsic to the book's ultimate design. There are also vivid, believable portraits (Buffalo Bill, Custer, Crazy Horse); and Indian wars and dinosaurs are authentic (although uneducated Thad's sudden rise to responsibility and proficiency at 14 does stretch credibility). Vigorous, but of uneven quality; the subject should draw readers in spite of the length.