What was the deadliest and most economically destructive volcanic eruption in the history of the United States?

The May 18th, 1980, volcanic eruption of Mount St Helens, Washington State (USA), was the deadliest, most economically destructive in U.S. History. This disaster killed 57 people and innumerable wildlife. It destroyed 250 homes, 47 bridges, 185 miles of highway and 15 miles of railway. It also grounded air traffic across the northwest United States, and disrupted surface transportation.the financial toll was $2.74 billion

The blast was heard hundreds of miles away and sent volcanic ash across a dozen states as Far East as Minnesota. Shockwaves and pyroclastic flows from the eruption flattened forests, melted glaciers and generated massive mud and debris flows.

A 5.2 earthquake at the base of the north face of St Helens triggered the largest landslide in recorded history and resulted in this deadly and destructive eruption. It reduced the the mountain's summit by 1300 feet.

Yellowstone Caldera (Montana), was a much greater eruption, but last erupted about 630,000 years ago. Long before the U.S. Existed.

Mount Lassen (Lassen Peak), California, had a series of 200-400 phreatic eruptions (steam explosions) from 1914 to 1921, which caused great devastation to the area, but nothing to the extent of St Helens.

Kilauea, in Hawaii, is one of the most active volcanoes in the world, but hasn't caused devastation comparable to St Helens.

These volcanoes are all part of our beautiful national parks, and also hold the potential to cause catastophic devastation!