Mike,

Santa Cruz's are short and stocky. Big females are only about two feet and males are smaller. From what I've seen, wild California Red-sideds are much bigger inland than the types found on the coast (which are blue, like yours). Here's an inland California Red-sided Garter that I caught in April - they get bigger than this - sometimes in the four foot range.

Tim
Third Eye Herp
Third Eye Herp