For those who don't know, it is decently rare to see wildlife in Denali when compared to somewhere like Yosemite or Yellowstone. The winters are so cold, dark, and harsh, that 1 in 3 animals die every winter. Also, each animal needs a huge amount of space compared to other parks, because they have to eat crazy amounts of food to stock up fat for the winter.
Btw, it is a beautiful park in a beautiful state, and mount Denali is a stunning site if you are lucky enough to see it on a clear day. Everyone should visit Alaska at some point in their life.