During its twentieth (and last) season "Gunsmoke" pulled out the stops and had some of the show's best episodes, showcasing most of the cast members. "Island in the Desert, Parts I and II" is centered around Festus, played by Ken Curtis, as the deputy is in pursuit of a murderous felon, superbly played by perennial villain William C. Watson. Festus's quest takes him into the desert where he meets a deranged prospector Ben Snow, played by the always dependable Strother Martin. Snow has been in the desert for more than a decade, searching for and acquiring a stash of gold, an accomplishment that he wants to return to his old stomping ground, a town called Ten Strikes. Snow wants to show his wealth to a former rival named Sam Bristol.
After being wounded by a bullet from the escaping criminal, Festus is cared for by Snow who later forces the deputy to serve as his "pack mule" to haul the gold through the desert toward Ten Strikes.
The pair must contend with the savage heat, Snow's frequent bits of paranoia, and the fact that Watson's character is still on the loose.
All of these are answered in the second installment that is just as riveting as the first.
Martin, Watson, and Curtis are good in their parts, with the former having a slight edge over the other two. Martin had a long career in Hollywood, with a long string of memorable roles, especially as the warden in Paul Newman's "Cool Hand Luke." "Ben Snow" became just another feather in a cap filled with performances to die for.
Another plus for the show is the impressive use of location, Glen Canyon National Recreation Area (Arizona/Utah). Sprawling vistas and panoramic landscapes add to the fact that the characters are far from civilization and at the mercy of the environment.