"Blood Meridian" by Cormac McCarthy (1985)
"The first of the herd began to swing past them in a pall of yellow dust, rangy slatribbed cattle with horns that grew agoggle and no two alike and small thin mules coalblack that shouldered one another and reared their malletshaped head above the backs of the others and then more cattle and finally the first of the herders riding up the outer side and keeping the stock between themselves and the mounted company."
Blood Meridian was published six years after Suttree, a book I've yet to read, and seven years before All the Pretty Horses, the first book of his Border Trilogy. I imagine that the long gap between Suttree and Blood Meridian indicates the vast amount of research the author had to do in order to write this book. Compared to McCarthy's earlier novels, it involves a higher order of detail altogether.
In the novel, a young man known only as The Kid leaves the East behind and joins a failed expedition to Mexico. This failed expedition leads to his incarceration in that country, after which point he joins up with a corporal Glanton and his associate The Judge. As they attempt to kill every last Indian they encounter, the party grows more and more bloodthirsty, and they spend much of their time as fugitives, fleeing authorities in both the U.S. and Mexico.
It's a really dense book. It is, perhaps, the densest thing that McCarthy has yet written. It's also breathtakingly violent, majestic, and saddening. And while the ending is somewhat ambiguous, it's still a satisfying read, and I would heartily recommend it.
Like all the greatest books, I think I'll be carrying parts of this one around with me for many years to come.