Janfred, we took a Princess land/sea cruisetour in May 2008. We saw the most wildlife when we took the Tundra Wilderness tour at Denali Lodge. It was part of the cruisetour and did not cost extra.
We had been told that we probably wouldn't see bears thatearly in the season, but we saw a mother bear and two cubs. We also saw moose, caribou, and a large number of small animals and birds.
We saw a bear and also moose on the train ride to and from Denali. You have to really keep watching all the time because you just never know when an animal will appear. We even saw a bear along the shoreline at Glacier Bay.