Meanwhile, neighboring caribou herds not subjected to moose control continued to decline.

During that time, though, they exist in huge numbers and can take up to 300 ml of blood per day from each animal in a caribou herd.

Wolves, grizzly, black bears and many members of three different caribou herds range over the refuge.

Several studies show that grizzly bears may follow the caribou herds year-round in order to maintain their food supply.

Caribou herds can be classified as a northern mountain woodland ecotype.

Mountain caribou make up a unique ecotype, which feed on the slow-growing lichen of centuries-old trees.

But their future, and the fate of other mountain caribou, remain precarious.

Many large mammals are present in the park, including grizzly and black bears, mule and whitetail deer, moose, mountain caribou, and mountain goats.

The ancient forests provide essential habitat for endangered wildlife such as the spotted owl, marbled murrelet and mountain caribou.