Has anyone watched Longmire yet? I've seen a couple of episodes. It's ok so far, but, I think I see some similarities between it and the Hackberry Holland books. I haven't researched the tv series at all, to know whether or not it's based on an existing character, or if it's original on its own. But, in it we have an older, hardened sheriff of an otherwise desolate county...a county suddenly besieged by death on all sides. In the upcoming episode, Longmire laments the arrival of the drug cartel into his county (which is in Wyoming, I think), and how homicides had always been very few and far between, until recently. Longmire is also a widower, and has a spitfire female deputy working for him, and already there are overtones of her interest in him, starting to bubble just beneath her surface.
I don't think it's too much of a stretch to say someone must have enjoyed the Hack Holland books, and that has gone on to develop Longmire...maybe inspired by Hack?