I think you're a fan of the Bourne films, true? (Ferren fanatically loves them all!) So you've seen Joan Allen as the CIA agent who ends up sympathizing with Jason Bourne at the end of the Ultimatum. Her character is so unlike the steely one in Bourne, though I suppose you could, in Bonneville, call her a Steel Magnolia, Utah style. Here is an interview with Lange & Allen and others you could choose from once you're on the site. This one I watched was nearly 10 minutes and gives a good insight into their acting choices.
Coming back to edit this and mention something I whispered to Val during the movie--that the Kathy Bates character reminded me strongly of Serenity (wherever she may be) in her personality and mannerisms, having met Serenity a few times over the years.
You Tube Interview