What are the motifs in The Crossing by Cormac McCarthy?

Coming of age is a recurring idea. Billy ages only a year over the course of the story but matures dramatically during that time. To fully understand this theme, it's important to understand Billy as he is at the beginning of the story. He is responsible, respectful of others and goes about his chores with no outward signs of rebellion. When Billy takes on the task of trying to catch the wolf, he goes about it seriously. He braves the elements without flinching and is thoughtful about the chore. In this way, Billy is already mature beyond his years. The coming of age occurs as Billy comes to realize that his life has taken specific turns and that there's nothing he can do to change it.