«Dead Man's Walk» by Larry McMurtry

In Streets of Laredo, McMurtry brought the story ahead, giving us Call in his old age. Now, in Dead Man's Walk, he takes us back to the days when Gus and Call were young Texas Rangers, first experiencing the wild frontier that will form their characters. We also meet Clara Forsythe, the unforgettable young woman whose effect on Gus McCrae is immediate and unshakable. Danger, sacrifice, comradeship, and love give them the strength and courage to survive against the almost insurmountable odds of the frontier.
In Dead Man's Walk, Gus and Call are not yet twenty, young men coming of age in the days when Texas was still an independent republic. Enlisting as Texas Rangers under a land pirate who wants to seize Santa Fe from the Mexicans, Gus and Call experience their first great adventure in the barren great plains landscape, in which arbitrary violence is the rule – whether from nature, or from the Indians whose territory they must cross in order to reach New Mexico.
From the Indians defending their land with unrelenting savagery, to the Texans attempting to seize and "civilize" it, and the Mexicans threatened by both, the reckless men of the untamed frontier make this at once a riveting adventure story and a powerful work of literature.