We made the drive from Vegas to Mammoth last year and it was a very interesting drive of about 5 1/2 hours. We drove North from Vegas on 95 and headed West on 266/198 over to Big Pine, CA. If you have time, check out the Ancient Bristlecone Pine forest. They are some of the oldest trees on the planet (some up to several thousand years old if you can believe it). If you drive this route, MAKE SURE YOU FILL UP WITH GAS in Beatty or you will be pretty dry by the time you reach Big Pine. There are no other gas stations between Beatty and Big Pine. I may be mistaken, but I don't think Scotty's Junction has a gas station.