Yes, there was too many moose that were eating too much of the food.
when there were no wolves in yellowstone park yellowstone park had to much elks so when the wolves arrived again the wolves killed all the elks
The wolves currently there are decendents of gray wolves brought to the park from Canada in 1995.
This might be a better starting point - cryingwolfmovie.com/
Wolves have affected nearly every organism in Yellowstone. Watch the video to see how.
Because the wolves where actually imported, and people living near Yellowstone often claim the wolves are pestering lifestock, pets, and kids.
1995....
One example is when over-hunting of the grey wolves in Yellowstone Park caused an increase in the herds of elks. The increase in the elk led to damage of the natural plant environment from overgrazing of the grasses and trees. The authorities have reintroduced the grey wolf to restore the natural balance.
Wolves ,bear.,and preadators
At the end of 2011, at least 98 wolves in 10 packs plus 2 loners occupied Yellowstone National Park. The population size (97 wolves) and number of breeding pairs (8) is the same as at the end of 2010. This is merely the wolf population that exists in the park. There are a number more which have already moved out of thepark to take up territory in the surrounding area
Grey wolves and coyotes, which are considered to be a species of wolf
of
humans hunted the wolves to almost extinction