Mike Steve Donovan, better known as Blueberry, is a rebellious cavalry lieutenant who travels across the American West in the years following the Civil War. A brilliant marksman, compulsive gambler, and frequent opponent of authority whenever he considers it unjust, he repeatedly becomes involved in conflicts between the army, settlers, Native American peoples, outlaws, and powerful economic interests. His missions take him from desert frontiers to rapidly growing towns, through political conspiracies, local wars, manhunts, and personal vendettas. Beneath his careless appearance, Blueberry fiercely defends his freedom and refuses to tolerate injustice, even when doing so means placing himself outside the law.