“The Last Cowboy” follows South Dakota cattle rancher Vern Sager from 1980 to 2004---through frigid winters, dry summers and prices that are never high enough. Perhaps that's why Vern's six siblings are all in other lines of work. His son, Mark, doesn't stay on the ranch, either---he's a rodeo rider. And, in 2003, Vern's wife, Carol, also leaves the ranch. “Carol rode off into the sunset, but I haven't yet,” says Vern ruefully. “[She said] I cared more about my cows than I did her.”