I love this novel, having stumbled across it in a used bookstore some 20 years ago, having read it expecting not much more than stilted prose and shootouts, and having returned to it again and again since that first reading.
It's written in the first person, kind of like a memoir, by an old woman describing a youthful adventure. And what an adventure! Shootouts are the least of it.
Mattie Ross, the adolescent girl, is stingy, opinionated, unsentimental, and as tough as John Wayne, if not as big and strong. She conforms to Northrop Frye's concept of the "ironic" hero -- too naive to understand the things she's dealing with, like Voltaire's "Candide." When her ability to keep up during the pursuit of some outlaws is questioned, she answers defiantly, "Pappa took me on a coon hunt once." Camping overnight with the two lawmen, she registers a succinct complaint, "One of the officers made a wet snoring sound. It was disgusting."
But the prose is delirious throughout, like the events they describe. There's a laugh on almost every page, far too many to give examples. I should mention too that the prose is historically and regionally accurate. About a bucket of milk, Matty says, "It looks like bluejohn to me." I looked up "bluejohn" in the Dictionary of American Regional English, and there it was, an old term used in and around Arkansas for skim milk. Likewise, kerosene becomes coal oil. Tall scrubby weeds are a "brake." And all of these regionalisms are woven into a prose style that is memorably idiosyncratic and unintentionally funny as all get out! Rooster Cogburn intends to shoot an unsuspecting man in the back because, "It will give them to know our intentions is serious." Now that's a sentence to savor. First of all, there is the absurdity of the plan. Cogburn, instead of calling out and telling him that he's serious, is going to kill him just to be sure he and his friends know it. Second, there is the absence of contractions, as if the narrator is determined not to lapse into a casual style. And there is the attempt at elegance of expression -- "give them to know," and "our intentions [not just "we"]" are not to be taken lightly. And then there is the telling mixture of a plural noun ("intentions") with a single verb ("is"). The effect is disjointed. It's like hearing a rapper throw in an allusion to Thomas Aquinas.
I haven't read any other works by Charles Portis. I haven't gone out of my way to avoid them but I haven't sought them out either because I can't believe they could possibly match the humor, irony, character, and suspense of True Grit.