http://www.igougo.com/images/p220136...huttle_Bus.jpg
Here is a photo of the Wonder Lake Shuttle we did with ARAMARK in July 06.
I can't remember if the Tundra Wilderness bus was green or brown (I seem to recall brown however) . . . it was also a school bus type vehicle but had a set up for hot and cold drinking water out of the back of the bus. Someone recently posted somewhere that they now have viewing screens to see wildlife, but I don't know about that personally.
I think all of the tour vehicles operating in Denali NP are operated by ARAMARK, although some of the other tour companies do sell tickets for a marked up price. Princess Cruises was the biggest one back in 2006 with tickets marked up some 20% as I recall.
As for my Alaska/Denali travel journals, you will find them at the bottom of the list there.