Y is for Yellowstone

Tim Iverson
Naturalist

(1/2020) Yellowstone is more than geology. Many visitors are attracted to the park to see the array of wildlife. The park is home to the largest concentration of mammals in the mainland United States. The iconic American Bison is the largest animal in North America, weighing in at over 2,000 lbs. In Yellowstone they freely roam in herds well into the thousands throughout the many valleys in the park.

The wildlife star everyone wants to see is the Gray Wolf. They are very elusive, but absolutely an integral and crucial key to the overall health and integrity of the Greater Yellowstone Ecosystem.

In the late 1800’s, during the period of westward expansion, people were moving from the east enmasse towards the rockies and Pacific coast. As settlers began putting down roots they feared for their personal and economic safety. To ensure their lives and the lives of their livestock people both outside, and shockingly, inside the park began killing all the wolves. By the early 20th century there were no wolves left in the region. Having been extirpated, or locally extinct, the loss of this apex predator created ripple effects throughout the entire Yellowstone ecosystem.

As the dominoes fell for one species they began falling for others. Elk, one of the largest mammals in the park, began multiplying unchecked in the park. Population numbers soon exceeded 20,000. The park is undeniably large, but it’s not big enough to sustain an elk population that of that size. Soon grasses and the forest understory were over browsed, causing plant and forest communities to get smaller because they were unable to regrow efficiently or in some at all. Elk can frequently be seen grazing near ponds and rivers. For all animals, what goes in must come out. As they graze near water sources their excrement is released into the water creating unhealthy nitrogen deposition killing aquatic plant and animal communities. Finally, there just wasn’t enough food to go around, giving way to disease and starvation among the large elk populations.

After decades of study, debate, and planning wolves had finally been approved for reintroduction into Yellowstone National Park. 31 Gray Wolves were released back into the park in January 1995. In the 25 years since reintroduction the park has seen the ecological balance restored. Today there is an average of 15,000 elk within the park. Though there are fewer elk the population is much healthier, showing fewer instances of disease and starvation. The aquatic habitat is cleaner and the forest and grasslands have begun to regenerate properly. By restoring the wolf population, environmental checks and balances have helped bring balance back to the natural processes within the park and broader ecosystem.

All national parks are unique with their own stories to tell. As the first Yellowstone National Park set the standard for the next 418 parks that followed suit. Otherworldly landscapes and features, dynamic and active geology, a land full of wildlife, and an archaeological and cultural history that date back thousands of years are all waiting to be explored in Yellowstone National Park.