The mood of the novel shifts, sometimes ominous, sometimes melancholy, and—by the end—hopeful and at peace. Momaday uses descriptions of the land and environment to set the mood. For example, in Chapter 6, gathering thunderheads help build tension:
A low line of thunderheads lay on the high horizon in back of the northernmost peaks. They were deep in the distance and seemed always to have been there, dark and unchanging in the end of vision, in some sense polar and nocturnal. [Father Olguin] kept an eye on them and speeded up, half hoping to rush upon the scent of rain.
Even though the thunderheads are merely passing through, they overshadow the valley so completely that Father Olguin imagines that they have always been there. Father Olguin's speeding and other erratic behavior almost seems to be driven by the eerie drop in pressure that precedes a thunderstorm. It makes both him and the reader anxious. The thunderheads appear again and again throughout this chapter, each time layering on even more dread and seeming to drive characters to lose control. Just as the atmosphere threatens big and frightening things to come from the sky, it seems clear that there are big and frightening things to come for the characters. Momaday does not disappoint: by the end of the chapter, the rain comes down, and Abel stabs his sworn enemy in a dramatic payoff.
The atmosphere can create other feelings as well. The novel ends with Abel running toward the sunrise. It is not very pleasant running weather. It is both snowy and rainy. The rain is not clear, either; it stains the snow with soot. At one point, Abel falls and must haul himself out of a dirty, slushy snowbank. And yet, as he keeps running and looks off into the distance, he sees beauty in the way the sun's rays hit the raindrops and the snowy ground. His close-up experience of nature's ugliness and brutality makes for a last moment of pessimism in the novel before his far off view of the rising sun supplants that feeling with hope. The landscape thus helps Momaday convey the idea that a life that includes suffering can still be part of a long arc of beautiful survival. The sun keeps rising on the "house made of dawn," even on difficult days.