I've heard a lot of good things about Lonesome Dove, but haven't seen it. McMurtry won a Golden Globe for writing the screenplay to Brokeback Mountain, so I tend to be a little skeptical of him. I haven't read the book, but here was my take on the movie: Peter Bogdanovich was the director, and in an interview stated that the reason he filmed the movie in black and white was because the landscape in west Texas where he was filming was too beautiful and colorful. He wanted a depressing, lost look to the movie. Everyone in the movie was miserable, until one of the high school boys has an affair with the coaches wife. During the affair, they are blissfully happy. When he ends the affair, the joy leaves. The only grounded character in the movie, Ben Johnson as Sam, dies of a heart attack while the lead characters are out of town for a week and is buried before they get back. A retarded kid who spends his days sweeping the dirt street gets hit by a car and killed, and the only entertainment in the entire town, the picture show, shuts down. It seemed pretty nihilistic to me, and painted small town Texas as a place you wanted to escape from. Nobody went hunting, learned to run cattle, enjoyed playing on the high school sports team, or saw any kind of future for themselves. It, along with the movie Carnal Knowledge, was also one of the early movies to turn sexual morality on it's head. The girl who wouldn't have sex with one of the high school boys is portrayed negatively. The thirty-something wife who has an extramarital affair with one of her husband's students is portrayed positively. It was kind of the changeover from "nice girls don't" to "girls who don't are vindictive, angry b*ll busters."
Well as I said it was an exercise in delfating the old Hollywood myths (The myth of the West, of idyllic small town life). It was made in the first flush of freedom from the Production Code that had been in place from the mid 30s to the mid 60s. Filmmakers were reveling in their lack of restraints. It got old fast of course. The person metaphor for the loss of those old verities in the film was that downbeat old theater showing Red River (possibly the best Western ever made). Carnal Knowledge however is nihlistic. Or at least misanthropic. Then again the characters' actions and lifestyles don't lead to very satisfying lives in the end.