In 1994, there were no Yellowstone National Park wolves to speak of. This absence had a lot to do with decisions that were made by the U.S. government way back in 1914. It was during this year that the government allocated funds for the purpose of destroying wolves and other animals that were believed to have a negative impact on "agriculture and animal husbandry." By 1926, wolves were all but completely eliminated in Yellowstone, and the widespread extermination process didn’t end until 1935.
It wasn’t until the mid-1990s that the Federal government got around to changing its views on wolves. Among other things, the reversal of opinion resulted in the reintroduction of wolves into Yellowstone National Park. While the park’s wolf population declined considerably between the years of 2007 and 2009 due to a decrease in the elk population, the reintroduction process in general was a success. Today, more than 300 descendants of the wolves that were originally reintroduced can be found in the general region. The more exact number as it relates to the wolves that actually live within the Yellowstone National Park boundaries is approximately 100.
The wolf species that was reintroduced into Yellowstone National Park is commonly known as the Mackenzie Valley Wolf species. Another name for the species is the Canadian Timber Wolf. No other subspecies of Gray Wolf in North America is larger, and it is interesting to note that the population has spread into a number of U.S. states since being reintroduced in Yellowstone National Park and central Idaho. These other states include Utah, Nevada, California, Oregon, Washington and Colorado. The preferred prey of the Yellowstone wolves includes a variety of animals, including elk, moose and bison. The wolves hunt in packs when trying to take down larger animals, and the fact that they can kill bison shows that they have had little trouble adapting to their relatively new environment.