From my reading and working in editing movies: The point of the book is not at all the visual, most of it is very subtle. One commentary that I heard that was

From my reading and working in editing movies: The point of the book is not at all the visual, most of it is very subtle. One commentary that I heard that was very astute pointed out that many parts of the book are specifically not detailed, one big example being that we rarely if ever witness the Kid killing or partaking in the murder/general viciousness of the gang. This means that a large part of the book is emulated in your brain while reading - did you infer that the kid is doing all this, and is just as bad as them? Is he an observer, like you, and doesn't leave because he doesn't know better? Does he actively try to avoid unnecessary violence? Your reading of these things will affect your reading of further parts - like the accusations of Holden, saying that the Kid was always a traitor to the spirit of the gang, which are not specific enough to be factual, but you absolutely know what he means while reading (depending on how you characterised the Kid). All this means that any one expression of the story would betray the oeuvre (in my mind), which aims to get you in the boots of these horrible men and understand that they are part of you (between other things). The stark writing and purposeful lack of factual descriptions of some key points make Blood Meridian a very evocative work, rather than descriptive. Half of it is and remains in your mind, and that's simply not what movies do. All this to say - you can do a movie showing what happens in the book, and it would be good! But it would contain very little of why the book is so beloved and respected.