Thirty years ago today — in fact, just about exactly, as I type this — Mount St. Helens erupted.

It was the worst volcanic eruption in the history of the United States, a five on the seven-point Volcanic Explosivity Index. As the summit and the volcanic bulge gave way, it created the worst recorded landslide in human history, traveling 70 to 150 miles and hour and covering 23 square miles, at an average depth of 150 square feet and a maximum depth of 600 square feet.  Ash fall covered 22,000 square miles, and totaled 1.4 billion cubic yards.  Pyroclastic flow, at a temperature of about 1,300 degrees, traveled as fast as 80 miles per hour and covered six square miles. It blew down enough trees to build 300,000 two-bedroom homes, killed 57 people, more than 7,000 animals.

(For perspective: The 1991 eruption of the Philippines Mt. Pinatubo was a 6 on the Volcanic Explosivity Index; it ejected ten times more material than Mount St. Helens. Iceland’s recent Eyjafjallajokull eruption merits a 4.  )

“Imponderables dust the air like volcanic ash,” intoned Dan Rather three days later,.  “It is an event that defies superlatives.” Quoting a geologist, he said,  “there is no record in geology in the last 4,000 years of anything like this happening before. The tremendous lateral blast is unprecedented.”

I was six years old when the volcano erupted, and although I was living in New York City, a continent away from Washington State, it was certainly one of my formative memories. I’d become a volcano buff thanks to the American Museum of Natural History, which had a planetarium show on Mt. Vesuvius and Pompeii that riveted me,  and the Metropolitan Museum of Art, which reconstructed a frescoed bedroom excavated near Pompeii — an essential stop on my frequent visits.

Looking back on it, I realize that my grasp on the difference between fact and fiction was tenuous.  I was a huge fan of Greek and Roman mythology and Mt. St. Helens sounded as mythical to me as Zeus or Athena. Also, I’m pretty sure I conflated a planetarium show I’d seen on The War of the Worlds with the one I saw on Pompeii — it wouldn’t have seemed any more remarkable to me if giant aliens had invaded as part of the volcano eruption.

Some of that is just the confusion of an imaginative kid, but also, lest we forget, this was the tail end of the Cold War: I vividly remember a blast map posted on the wall at the  health food store that my mother frequented, graphically depicting the  concentric rings of destruction that would result from a nuclear bomb drop on Manhattan, with flesh melting and all. It was a scenario no less fantastic than anything H.G. Wells could invent.

Anyway, although I’m fairly certain that I’m now able to sort out science fact from science fiction, volcanoes are still endlessly fascinating to me. But while I’ve visited two of the worlds’ most active volcanic spots, Iceland and Hawaii, I’ve yet to do more than fly over Mount St. Helens en route from Seattle to Portland. (Although my face was smooshed up as far as I could get it against the plane’s window!) I’m determined to get there this summer.

In the meantime, I could barely breathe as I read this terrific guide to visiting the volcano, written by my friend Andrew Collins. There’s plenty to see and do, but the highlight will definitely be the Johnston Ridge Visitor Center  — it’s the closest to the volcano and you can look into the crater and see the dome! I can’t wait.