Mount St. Helens was first called "Louwala-Clough", which means "smoking" or "fire mountain" in the language of the Native American Klickitat people. This volcano is well known for its explosions and flows of lava. Its most famous volcanic eruption was on May 18, 1980. In 1982, U.S. President Ronald Reagan and the United States Congress made the Mount St. Helens National Volcanic Monument, a 110,000 acre (445 km²) area around the volcano that is also a part of the Gifford Pinchot National Forest.