I’ll echo what Don Nunn says. It’s about 10 hours from LA to Salt Lake City. From Salt Lake City West Yellowstone is about a 4-5 hour drive. Of course at West Yellowstone you’re not actually in the park yet.

From West Yellowstone it is about 30-45 minute’s drive to Old Faithful, under ideal conditions.

Yellowstone is well worth the drive. It’s a unique place that is everybody should take the opportunity to see if they have the chance to do it.

One thing that I would recommend is to go early in the season, like around Memorial Day. It’s a little bit on the cold side still, but the crowds are much smaller and the animals are down closer to the road. It’s a great experience.