| The green area represents the Blast Zone, devastated by the hydrothermal blast through the side of Mount St. Helens in 1980. It is roughly 18 .5 miles (30 km) by 12.5 miles (20 km). |
| The green area represents the Blast Zone, devastated by the hydrothermal blast through the side of Mount St. Helens in 1980. It is roughly 18 .5 miles (30 km) by 12.5 miles (20 km). |