The story starts off in the little town of Poker Flat. The mood of the setting is ominously quiet. The first paragraph contains two sentences intended to establish this mood:
. . . he [Oakhurst] was conscious of a change in its moral atmosphere since the preceding night. . . . There was a Sabbath lull in the air, which, in a settlement unused to Sabbath influences, looked ominous.
Oakhurst is an intelligent man with a great deal of worldly experience. He can sense that something out of the ordinary is brewing and that it could very likely involve him. The "moral atmosphere" of the preceding night was undoubtedly one of noise and rowdy behavior characteristic of mining camps during the California Gold Rush.The moral atmosphere of the morning is righteous and repentent.
Much of the story, though not all of it, is told from the point of view of John Oakhurst, mainly because he is more perceptive and more philosophical than the rest of the outcasts. He is a successful gambler because he is intelligent and philosophical. He accepts his fate with characteristic stoicism, which is unlike the reactions of his fellow outcasts. Evidently he has had similar experiences before, since people do not appreciate having a stranger coming in and winning their money. What Bret Harte is describing in the early part of the story is the kind of vigilante justice that was so common in the West.
It is interesting that the opening paragraphs of the story do not include any references to the other characters who become outcasts with Oakhurst. It is not until a body of armed men escort the group to the outskirts of the town that these others are identified. The ominous mood of the opening paragraphs does many things, including foreshadowing the disaster that will overtake the party when they stop overnight high in the Sierras.