This is a venomous snake Crotalus cerastes cerastes. The Sidewinders are the easiest to recognize of all four species of venomous vipers living in Southern Nevada. Simply look for horn like formations above their eyes. There are no other rattlesnakes with "horns".
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.
Note, these snakes are common around Lake Mead. They often partially bury themselves in sand and are hard to spot.