Dead Man's Walk by Larry McMurtry

Set in the mid-19th century, the story follows young Texas Rangers Augustus "Gus" McCrae and Woodrow F. Call as they embark on a perilous expedition across the harsh and unforgiving landscapes of the American Southwest. Facing numerous challenges, including hostile Native American tribes, treacherous terrain, and the Mexican army, the two friends must rely on their wits and camaraderie to survive. As they confront the brutal realities of frontier life, they are tested both physically and morally, laying the groundwork for their legendary partnership and the adventures that lie ahead.