A new viral video provides a fascinating look into the impact of ecosystems.

The video, released by SustainableMan, follows the 1995 reintroduction of wolves into Yellowstone National Park by the U.S. Fish and Wildlife Service—and the impact is incredible.

Wolves had been completely absent from Yellowstone for some 70 years before their reintroduction—the result of a century’s worth of of extermination by humans. But just two decades later, their return has affected not only wildlife on the surface of the park, but the waterways and geography underneath Yellowstone’s rivers and streams.

The video really is a beautiful look into the why restoring natural habitats is so important to wildlife conservation.

Gray wolves once roamed freely across the United States from the Atlantic to the Pacific, but their range is now limited to most of Canada and Alaska, as well as parts of just five other U.S. states. The National Park Service estimates that 400-450 gray wolves now reside in Yellowstone.

For more on the Yellowstone Wolf Recovery program, visit the National Park Service website.