On what date did the 1980 eruption of Mount St. Helens, in which "Crater Glacier" was formed, occur?
Crater Glacier: The Crater Glacier (also known as Tulutson Glacier) is a geologically young glacier that is located on Mount St. Helens, in the U.S. state of Washington. Crater Glacier:  The glacier formed after the 1980 Eruption and due to its location, the body of ice grew rapidly, unknown to the public for nearly 20 years. 1980 eruption of Mount St. Helens: On May 18, 1980, a major volcanic eruption occurred at Mount St. Helens, a volcano located in Skamania County, in the state of Washington, United States.
May 18, 1980