Unknown Rattlesnake - Reptilandia Reptile Lagoon

It looks like a Crotalus sp. The possible species include; Western Chihuahuan Ridge-Nosed Rattlesnake, Rock Rattlesnake, Mexican West Coast Rattlesnake, Eastern Diamondback Rattlesnake, Western Diamondback Rattlesnake, Northern Black-Tailed Rattlesnake, and Timber Rattlesnake

Most of the species mentioned by @MOG2012 can easily be ruled out based on appearance.

However, Northern Black-Tailed Rattlesnake seems to be a pretty good match.

I agree with @ralph on Northern Black-tailed, based on the patterning and coloration.