Grandpere is right. I think Xanterra runs the concession at Yellowstone. I was at Glacier last summer and was housed next to people who drove the Red Bus service for Xanterra at Glacier. They loved it! Lots of hours and you have to deal with the corporate structure, but overall it was a plus for them. They all said they would return. Imagine getting paid to drive people around and tell stories: and get paid! It doesn't get any better.