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The History of Wolves in Yellowstone

One of the best wildlife sightings in Yellowstone is the wolf, of course. But besides the grey wolf being one of the most majestic and illusive animals in the park, they are crucial to the ecosystem and survival of other species in Yellowstone. Let's begin...

It should be noted that wolves have historically roamed from Mexico, through the majority of the United States, and up into basically all of Canada.

The history of wolves in Yellowstone specifically, starts long ago, even before it was created as a National Park-- the wolf population was already declining due to ranchers, who hunted wolves that they thought were a threat to their livestock.

When the park was created in 1872, there were no regulations in place, so park administration, as well as tourists could hunt whatever they wanted, whenever they wanted.

In 1883, the Secretary of Interior created regulations on hunting wildlife inside Yellowstone National Park, but unfortunately, wolves, coyotes, bears and mountain lions were not on the list to be regulated.

Since the grey wolf was considered an undesirable predator, they were extirpated, which means they were made locally extinct, by 1926.

Without wolves in Yellowstone, the elk population began to rise because their main predator was missing. Naturally, when the elk population rose, deciduous trees, such as aspens and cottonwoods became overgrazed. The National Park Service saw this as a problem, and relocated elk, but when that proved to be ineffective, they began to kill them.

Additionally, without wolves in the park, the coyote population rose, which greatly affected the pronghorn population in Yellowstone.

In 1967, the grey wolf was placed on the Endangered Species list. However, it wasn't until 1973, that being on the list really meant anything. The passage of the Endangered Species Act of 1973 forced the Fish and Wildlife Service to create restoration plans for each of the species on the list.

Plans and revisions took place over the next 20 years, and finally in 1995, they began to reintroduce grey wolves into Yellowstone National Park.

Wildlife officials in the United States and Canada captured 14 wolves from multiple packs, east of Jasper National Park in Canada. The wolves were flown to Yellowstone and put in three large acclimation pens in Lamar Valley, where they stayed for approximately three months. In March of 1995, the pens were opened and the wolves were free to roam their new habitat. The following year, 17 more wolves were taken from Canada and released in the park.

Since the successful reintroduction of wolves in 1996, the population overall has increased. Any fluctuation in the population is due to conflict between members of the pack, outbreaks of canine distemper, or hunting when a wolf leaves the protection of the National Park. As of 2020, there are nine wolf packs in Yellowstone National Park, and possibly more in the Greater Yellowstone Ecosystem.

Now, for the exciting part...

As the population of wolves in Yellowstone has increased, the elk population has decreased-- on average, a single wolf will kill 22 elk each year. (Don't worry, there are still plenty of elk in the park; this predation is a good and natural thing.)

With a lower elk population, the overgrazed aspens and cottonwoods have began to thrive again.

Additionally, willow trees that live along river banks are not being overgrazed, which leads to a thriving beaver population. In 2001, there was one beaver colony in Yellowstone National Park. But since the willows' recovery, beavers have been able to survive winters, and there were nine beaver colonies recorded just ten years later in 2011! Beaver dams are essential for healthy watersheds because they even out seasonal flows, slow the water down and allow soil to stay in place. They also provide cool, shaded water for fish. Scientists can confidently say that it is directly because of the reintroduction of wolves that the beaver population and entire riparian ecosystem has recovered so immensely.

In 1969, Robert T. Paine introduced the concept of keystone species. He claimed that there are a variety of essential species, some apex predators (like the wolf), and some not (like the ochre starfish), that play a critical role in maintaining the structure of their ecosystem. Just like an arch would crumble without it's keystone, an ecosystem would be completely different or just not exist without it's keystone species.

Wolves are beautiful and thrilling to look at in Yellowstone, but they are so much more than that. You could say that wolves are the reason the Yellowstone ecosystem looks the way it does, and you wouldn't be wrong. The vitality of every ecosystem is dependent on the interactions of one organism to another-- from the wolf all the way down to the soil. It's pretty amazing when you look at life like that.


Nomadic By Nature offers guided backpacking and day hiking trips through Yellowstone. The best part about joining a guided tour is the amount of knowledge that the guide will share.

If you thought this post was interesting, just wait until you're out on tour

This guided backpacking trip through Lamar Valley, in the northeast corner of the park, covers some of the best scenery Yellowstone has to offer. You will hike through wide-open meadows scattered with bison, pronghorn, and other big mammals, all the while following the majestic Lamar River. Eventually, the trail takes you over the mighty Mist Pass and drops into Pelican Valley — a massive expanse of rolling grass, slow-moving creeks, and a true wildlife stronghold.

Of all the trips Nomadic By Nature offers, this trip offers the best chance to see wildlife in the backcountry.

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