We saw Yellowstone through the eyes of our excellent guide Derek, who understood it's geology, history, animal life and beauty, with in depth knowledge of almost everything we were looking at. Derek was efficient, maximized our time but was able to pace the tour according to how our diverse little group was managing. (We had 2 children along, one on the spectrum) Needless to say, Derek was able to flex the schedule on a dime, with work arounds for bad weather, etc. I really felt like Derek was sincerely interested in helping our group have the most meaningful experience possible, with enthusiasm and good humor. We all enjoyed our tour and felt grateful for the wise use of our vacation time!