Yep. Not into westerns at all but that one was able to get you hooked. There were quite a lot of differences between the show and the book.
From wiki:
Among the key differences between the books and the TV series are the character's age and backstory. In the books, it is established that Walt is a college graduate and
Vietnam War veteran, and has been the Absaroka County Sheriff since the early 1980s. However, on the TV show, no mention have been made or alluded to of a college or a military career (although those haven't been ruled out, either), and Walt's age has been established multiple times, via his having graduated from high school in 1981 and having been friends with Henry since they were 12 years old, 38 years earlier.
In a significant departure from the books, on the show, Walt's wife Martha did not die from cancer. Although she was diagnosed with the disease, in the TV series she was murdered, and the associated details are slowly revealed over several seasons, significantly affecting Walt's relationships with his deputy Branch and the Connally family.
While the TV series portrays Vic as being interested in Walt, her feelings aren't reciprocated like they are in the books. Instead, the TV series has Walt slowly recovering from losing his wife, unable or unwilling to maintain a relationship with a woman called Lizzie Ambrose, before finally showing enough interest in a member of the opposite sex to actively court Dr. Donna Sue Monaghan. Only as the show draws to a close does Walt start a relationship with Vic.
In the books, Absaroka County sees five murders in 24 years. The TV series sees 27 confirmed murders in the two first seasons alone.