This is one of the great sites to see around the Las Vegas area. It's about a 40-45 minute drive to the dam from Vegas but it's worth it. You will be amazed on the size of this dam. Just to think this dam was man made is amazing.
I highly recommend taking the tour because you will get to see the inside walls of the dam and they will bring you down to the bottom of the dam to see the generators that generate electricity.