Yellowstone National Park forms the core of the Greater Yellowstone Ecosystem. At 28,000 square miles, it is one of the largest, nearly intact temperate-zone ecosystems on Earth.
Many environmental factors affect the health of this dynamic ecosystem. Ecological and geological processes continue to shape the environment as they have for millennia. Human-caused factors also have an influence. Air pollution, climate change, and the introduction of nonnative species have had an impact on natural resources worldwide. Yellowstone provides a place where scientists can study how these trends affect ecosystems, and foster an understanding of what changes we should expect in the future.
Did You Know?
Prior to the establishment of the National Park Service, the U.S. Army protected Yellowstone between 1886 and 1918. Fort Yellowstone was established at Mammoth Hot Springs for that purpose.