Mount St. Helens National Volcanic Monument is a U.S. National Monument that includes the area around Mount St. Helens in Washington. It was established on August 27, 1982 by U.S. President Ronald Reagan following the 1980 eruption. The 110,000 acre (445 km²) National Volcanic Monument was set-aside for research, recreation, and education. Inside the Monument, the environment is left to respond naturally to the disturbance.