The San Berdoo parvs, which are the most common, have that classic checkerboad-like ventral patterning.....quite like a typical corn. Whenever I've been asked to identify what someone thinks to be a z or wants to know what ssp (formerly.....dangit....) I use the ventrals to rule out San Berdoo parv right off the bat if it looks to be either parv or pulchra. I have San Jac's that have clean red rings going through the ventrals, but every San Bernardino parv I've ever seen over the years has that including mine here at home.

Looks like a beautiful snake....can we get another shot of it?
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Jerry Kruse

And God said, "Let there be zonata subspecies for all to ponder..."