The reintroduction of wolves to Yellowstone National Park had a positive impact on the beaver population. Wolves preyed on elk, who were known to graze on willow trees along riverbanks, which are important food sources for beavers. With the decrease in elk populations due to the presence of wolves, the willow trees were able to regenerate and provide more food and habitat for beavers. This led to an increase in the beaver population and overall ecosystem health in Yellowstone National Park.
