This was an odd, odd issue. I'm not sure what the point of this really was. I don't believe it picked up on any old West themes, other than that's which zombies happened to show up. This could just as easily have been a Ray special, he was as important to the story as any Western characters.
The main story involved Simon Stagg and a group of researchers led by Joshua Turnbull. Turnbull is the descendant of another DC Western character, but I don't know who. In fact, since I'm pretty clueless on most of these characters, the only ones I recognized were Jonah Hex and the Black Bison, except the Bison called himself Super-Chief. Weird. Most of the zombies were vaporized by the Ray (so the Ray and his Dad should probably not be hiding underground, but rather taking the fight to the zombies, right?) I'll take any Ray appearance I can get, but he seemed awfully mercenary in this issue. I'm reasonably confident he survived his confrontation too, although we don't see him make it out.
Dan DiDio does a nice job giving the whole issue a horror-movie feel. Turnbull is a jerk and sacrifices everyone to try and save himself, with predictable results. I guess he's never seen an episode of Tales from the Crypt!
Renato Arlem's photo-static looking art works sometimes and other times it is just odd. The big break-in page of the zombies blasting into the compound had absolutely no sense of motion, it looked like a collage. His character designs looked great; Simon Stagg, Ray, Black Bison, they all looked great.