Saw this at a yard sale years ago. I figured I'd see what all the fuss was about. It finally worked its way to the top of its TBR stack. Yay!
It's long: my edition's last page is number 945. Took me a long damn time to get through. It's not your usual Western, either. I believe nobody gets shot until page 480 or so. And there's only one death before that, an unfortunate gruesome encounter between a cowboy and a nest of water moccasins (page 301).
But after that, people start dropping like flies.
Anyway: the novel centers around two ex-Texas Rangers, Call and Gus, making a living in Lonesome Dove, Texas, just a tad north of the Rio Grande. Their business model seems, roughly: when someone in the area is in the market for cattle or horses, they go down to Mexico and steal some, which they proceed to sell.
But it seems there's some restlessness: when their old buddy Jake shows up telling a tale of unspoiled land (and possible riches) up north in Montana, they organize a cattle drive and undertake a perilous trek.
A lot of colorful characters. The women are mostly prostitutes, none with hearts of gold (but not otherwise unsympathetic). Plenty of action in the last half of the book. Tragedy and humor throughout. (Humor mainly in the dialogue between Gus and Call, even in the bleakest of situations.)