100 Facts to Know About Washington State

The eruption of Mount St. Helens in 1980 was one of the most significant volcanic events in U.S. history.

Episode Summary

The eruption of Mount St. Helens in 1980 was one of the most significant volcanic events in U.S. history.

Episode Notes

The eruption of Mount St. Helens in 1980 was one of the most significant volcanic events in U.S. history.