What is the author's style in Horseman, Pass By by Larry McMurtry?

Since this is a cowboy book, the characters talk like cowboys. Even the most refined, educated characters speak with a drawl and with poor grammar. This is only natural in an area like Texas, especially since the narrator himself is a cowboy. Most of the dialogue is spelled to indicate the country accents, with "of" often written as "a" and words like "running" spelled "runnin'." For those not familiar with farm terms, some of the words might be confusing, like "heifer" and "stock," but in general, the story makes sense even to those who do not understand exactly what the ranchers are doing in each scene.