Especially the latter.

Therefore he had survived to see the Apaches subdued, the range rights adjusted, his cattle increased to thousands, grazing the area of a principality.
Now, all the energy and fire of his frontiersman's nature he had turned to wiping out the third uncertainty of an uncertain business.

He found it a task of some magnitude.
For Senor Buck Johnson lived just north of that terra incognita filled with the mystery of a double chance of death from man or the flaming desert known as the Mexican border.

There, by natural gravitation, gathered all the desperate characters of three States and two republics.

He who rode into it took good care that no one should ride behind him, lived warily, slept light, and breathed deep when once he had again sighted the familiar peaks of Cochise's Stronghold.