One of the largest Southern Pacific Rattlesnakes I've seen at Upper Las Virgenes Canyon Open Space Preserve -- formerly Ahmanson Ranch. This one was on the East Las Virgenes Canyon Trail (aka Main Drag).

I counted 12 rattle segments, and as this HD video snapshot shows, the snake was nearly as long as the dirt road was wide.

From a run on Wednesday from the Victory trailhead to Las Virgenes Creek.