This is a venomous rattlesnake Crotalus cerastes cerastes. The Sidewinders can be easily recognized by the "horns" above their eyes as there is no other rattlesnakes with horns like that. These snakes will not hurt you if you leave them alone.
This one was just about a foot long. We encountered him on the way back from
S Cove Wash in April 2008.
Lake Mead Area, Nevada.