Rather than repeat the much deserved accolades about how beautifully this book is crafted and written, I'll add that it seems to me that all the invoking of William Faulkner and Cormac McCarthy misses the heart of this story, which strikes me as deeply feminine and feminist.
It's a traditionally male story about a family of brothers in the American west, but with a twist: everything that goes right or wrong has ultimately to do with women, mostly with a woman not getting her due or being given a chance. From the start Machart seems to be aiming for the actual and metaphorical reconciliations of male and female necessary to the realization of humanity.
To start, Karel, the youngest son in the featured family, is blamed for the death of his mother, who dies giving him birth. Karel spends the rest of his life longing for all he missed as a result of not having a mother and trying to make it up to his father, who blames Karel for the loss of his wife. Without her, Karel's father proves incapable of compassion and civility.
Then there's the unattainable love of Karel's life. Her horsemanship and horse sense are second to none, but for all her brilliant qualities she's at the mercy of a mercenary father who marries her off to Karel's oldest brother in a business deal. Before the marriage she seduces a willing Karel, who is hoping she means to be his. It's not that simple or romantic, however; the machinations required for her own survival in a man's world resoundingly trump romance.
So much love is lost throughout, mostly on account of women being forced to play by men's rules. Karel's wife, Sophie, proves to be the exception. Over time she provides him with whatever continuity and redemption are to be had.
The book shifts back and forth in time, and it's not a spoiler to say that it ends with the recounting of Karel being nursed through his motherless infancy by a young woman who lost her infant son; it may be a man's world, but again and again in Machart's version, women are the source of wisdom, strength and hope.