Boom or Bust? The 20 Largest Volcanoes in the U.S. (and the 5 Most Likely to Explode Next!)

If there’s one thing we love at Merlin’s Munchies Coffee Company, it’s bold flavors, cosmic mysteries, and anything that makes you question your entire existence over a cup of coffee. And few things on Earth capture the same level of awe, power, and 'holy crap, is that thing gonna explode!?' as volcanoes.

Think about it. These massive geological cauldrons sit quietly for centuries, biding their time like a villain in a multiversal saga, only to suddenly erupt in an explosion of fire and fury that reshapes the land itself. If that’s not metal, we don’t know what is.

And as coffee lovers, we have to ask: If a volcano erupted coffee instead of lava, would we be worried or just really, really excited?

Probably both.

So today, we’re diving deep into two lists that will blow your mind (hopefully not literally):

1. The 20 Largest Volcanoes in the United States – the sheer giants, the heavyweights, the behemoths of fire.
2. The 5 Most Likely to Erupt Next – because, let’s be real, the ground beneath us is just playing the world’s longest game of “not it.”

Grab your coffee, fasten your seatbelts, and let’s get into it.

The 20 Largest Volcanoes in the United States

Size matters—at least when it comes to volcanoes. Here are the biggest volcanic mountains in the U.S., ranked by sheer size and elevation:

1. Mauna Loa (Hawaii) – 13,681 ft
2. Mount Saint Elias (Alaska) – 18,008 ft
3. Mount Fairweather (Alaska) – 15,325 ft
4. Mount Bona (Alaska) – 16,550 ft
5. Mount Blackburn (Alaska) – 16,390 ft
6. Mount Sanford (Alaska) – 16,237 ft
7. Mount Rainier (Washington) – 14,411 ft
8. Mount Shasta (California) – 14,179 ft
9. Mount Wrangell (Alaska) – 14,163 ft
10. Mount Adams (Washington) – 12,281 ft
11. Mount Hood (Oregon) – 11,239 ft
12. Mount Baker (Washington) – 10,778 ft
13. Three Sisters (Oregon) – 10,358 ft
14. Glacier Peak (Washington) – 10,541 ft
15. Lassen Peak (California) – 10,457 ft
16. Mount Jefferson (Oregon) – 10,497 ft
17. Newberry Volcano (Oregon) – 7,989 ft
18. Crater Lake (Mount Mazama) (Oregon) – 8,159 ft
19. Makushin Volcano (Alaska) – 6,680 ft
20. Aniakchak Crater (Alaska) – 4,400 ft

These giants aren’t just sitting pretty—they’re part of a fiery history of eruptions, earthquakes, and geological chaos that helped shape the landscapes we see today. But let’s be honest, some of these are just flexing at this point. The real question is which of these is ready to wake up and cause some mayhem.

And that brings us to the list you’re really here for…

The 5 Volcanoes Most Likely to Erupt Next (And Why You Should Probably Keep an Eye on Them)

If volcanoes had personalities, these five would be the ones constantly whispering, "I might do something crazy… or maybe not… but you’ll never know until I do."

1. Kīlauea (Hawaii) – The Overachiever That Never Takes a Day Off

• Last Eruption: December 2023
• Expected Next Eruption: Honestly? Could be any second now.
• Fun Fact: This volcano has been erupting so often, it probably doesn’t even remember a time when it wasn’t.

Why is Kīlauea at the top of this list? Because this overachieving lava machine never quits. While other volcanoes sit around pondering their next move for centuries, Kīlauea just keeps the fireworks going. It erupted almost nonstop from 1983 to 2018, taking only a brief coffee break before getting back to business in 2020, 2021, 2023, and—let’s be real—probably again soon.

This volcano doesn’t just casually ooze lava—it has literally reshaped the island of Hawaii multiple times, covering entire neighborhoods, swallowing roads, and even adding hundreds of acres of new land to the island. Imagine waking up, stepping outside with your morning coffee, and realizing your backyard is now an active lava field. That’s just life on the Big Island.

In 2018, Kīlauea went all out, unleashing one of the most destructive eruptions in modern Hawaiian history. It wiped out over 700 homes, buried roads under molten rock, and permanently changed the landscape. Oh, and it also completely erased an entire lake. Yep. Just boiled it into oblivion. If that’s not overachieving, we don’t know what is.

And here’s the kicker—Kīlauea is dangerously close to major communities. Unlike some other volcanoes that like to keep their distance, this one lives way too close for comfort near Hilo and the surrounding towns. Scientists monitor it 24/7 because, let’s face it, this volcano is basically that one friend who can’t stop themselves from texting “you up?” at 2 AM.

So why is it #1 on this list? Because if any volcano in the U.S. is going to randomly decide to start spewing lava while we’re mid-coffee sip, it’s this one. And given its track record, we wouldn’t bet against it.

2. Mount St. Helens (Washington) – The Showstopper That Literally Blew Its Top

• Last Eruption: 2008 (but nothing major since 1980’s big one)
• Expected Next Eruption: Scientists say within the next few decades
• Fun Fact: Its 1980 eruption was the most powerful in U.S. history, blasting 1,300 feet off the top of the mountain and causing the largest landslide ever recorded.

If you weren’t around in May 1980, imagine this: one morning, Mount St. Helens decided it had had enough. After weeks of earthquakes and ominous steam plumes, the entire north side of the volcano collapsed in an instant—sending a wave of rock, ash, and pure destruction racing downhill at speeds of up to 670 mph.

The explosion was so intense that it flattened 230 square miles of forest (yes, miles) and sent ash as far as Oklahoma. Imagine waking up, pouring your morning coffee, and suddenly realizing the sky is literally falling.

But here’s the crazy part—it could happen again.

Since the eruption, Mount St. Helens has been slowly rebuilding itself, growing a new lava dome at its peak like it’s getting ready for round two. Scientists are keeping a very close eye on it because while it might not go full 1980 mode again, it’s far from finished.

Moral of the story? If you’re visiting the Pacific Northwest, maybe don’t challenge this volcano to a duel. It’s already proven it doesn’t mess around.

3. Mount Rainier (Washington) – The Sleeping Giant We Didn't See Coming

• Last Eruption: 1894​
• Expected Next Eruption: Scientists say it’s overdue​
• Fun Fact: If it erupts, the biggest concern isn’t lava—it’s lahars (giant mudflows) that could bury entire towns in minutes.​

So there we were, in Seattle for Emerald City Comic Con (ECCC), sipping our morning brews and admiring the skyline, when we noticed this massive, snow-capped peak dominating the horizon. Naturally, we turned to each other and asked, "Wait, is that a volcano?" A quick search later, we were both shocked and intrigued to learn that Mount Rainier, standing at a towering 14,410 feet, is not just any mountain but an active stratovolcano located about 59 miles south-southeast of Seattle.

Mount Rainier isn't just a backdrop for stunning photos; it's a geological force with a history of activity. The last recorded eruption was in 1894, and while it's been relatively quiet since, scientists consider it overdue for another eruption.

The real kicker? It's not the fiery lava flows that pose the greatest threat but the potential for lahars—massive volcanic mudflows. With 26 major glaciers, Mount Rainier holds more glacial ice than any other peak in the contiguous United States. In the event of an eruption, this ice could rapidly melt, combining with volcanic debris to create fast-moving lahars capable of burying entire towns in their path.

Given its proximity to Seattle and surrounding communities, Mount Rainier is under constant surveillance. Emergency management teams conduct regular drills to prepare for potential eruptions, ensuring that evacuation plans are up-to-date and that residents are informed about the risks. These proactive measures are crucial, as the impact of an eruption could be devastating, affecting not just the immediate vicinity but also the broader region.

So, next time you're in Seattle, sipping on your favorite brew and gazing at the majestic peak in the distance, remember: Mount Rainier is a sleeping giant, and it's always good to be prepared for when—not if—it decides to wake up.

4. Yellowstone Caldera (Wyoming) – The Supervolcano That Could End Us All (And Also Inspired a Parallel Universe for Merlin’s Munchies Coffee Company)

• Last Eruption: 640,000 years ago
• Expected Next Eruption: Scientists think it won’t happen for another 100,000+ years (but let’s hope they’re right).
• Fun Fact: If it erupts at full power, it could blanket the U.S. in ash and trigger a mini ice age.

Yes, Yellowstone is #4 on this list. And while it’s not expected to erupt anytime soon, we had to include it because if it does, it could quite literally change life on Earth as we know it.

An eruption from Yellowstone would obliterate everything within 50 miles, send ash across the country, block out sunlight, and cause a global temperature drop. It could trigger crop failures, food shortages, mass extinctions, and force human civilization to rethink its entire way of life.

You know, just light stuff.

And here’s something fun—this volcano is actually the reason we created Red Velvetstone National Park!

Four years ago, at about 2 AM, I was wide awake, flipping through channels when I stumbled upon a documentary on Yellowstone’s supervolcano. As I watched, half-horrified, half-fascinated, an idea hit me:

What if, in a parallel universe, Yellowstone was already erupting?

And so, in the multiversal version of our world, there exists Red Velvetstone National Park…. DUH

But there’s a kicker! Instead of a supervolcano catastrophe, the Red Velvet Cauldron in the parallel universe doesn’t destroy life—it fuels it.

Every time it erupts, it showers the land in rich, velvety, red lava that magically cools into delicious Red Velvetstone Roast coffee. Instead of panicking, locals grab their mugs, throw a block party, and welcome the freshest coffee blast in the multiverse.

Park rangers? They don’t wear heat-resistant suits—they wear barista aprons and giant foam coffee cup hats. Their biggest concern isn’t evacuations; it’s running out of whipped cream. Instead of bison blocking the roads, tourists get stuck behind roving herds of marshmallows migrating toward the nearest latte lake.

Moral of the story? In our universe, a Yellowstone eruption would be apocalyptic. But in the multiverse? It’s just another day in Red Velvetstone National Park—where the lava flows rich, the coffee flows richer, and the only real danger is drinking so much caffeine you start seeing through dimensions.

5. Mount Shasta (California) – The Wild Card That Might Be More Than Just a Volcano

• Last Eruption: 1786
• Expected Next Eruption: It’s been quiet for centuries, but geologists say it’s “active,” which is scientist-speak for “it could surprise us one day.”
• Fun Fact: It’s not just a volcano—it’s a hotspot for UFO sightings, hidden civilizations, and mystical energy fields.

Mount Shasta isn’t just a volcano—it’s an entire legend wrapped in lava rock and conspiracy theories. While some volcanoes make headlines for erupting in spectacular fashion, Shasta’s claim to fame is being one of the weirdest and most mysterious places in the U.S.

First off, it’s huge. Standing at 14,179 feet, it towers over Northern California, looking like it was ripped straight out of a fantasy novel. If you saw this thing in person and someone told you a dragon lived at the top, you’d probably believe them.

So why is it on this list?

Because it’s still an active volcano, and while it hasn’t erupted in over 200 years, it’s not extinct. Scientists keep a close eye on it because, historically, Shasta doesn’t mess around when it erupts.

This mountain has produced some of the most explosive eruptions in California's history, and if it wakes up again, it could send pyroclastic flows, lava, and ash raining down on nearby communities. And since tens of thousands of people live in the surrounding areas, including the city of Mount Shasta itself, an eruption would be a serious event.

But let’s talk about the real weirdness…

Shasta isn’t just a volcano—it’s a magnet for the bizarre.

• UFO sightings? Check.
• Underground civilizations of ancient beings? Double check.
• Portals to other dimensions? According to some locals, absolutely.

There’s an entire legend that a lost civilization of highly advanced beings called the Lemurians lives inside the mountain. Some believe they escaped a cataclysmic event in ancient times and built an underground city, where they now live in peace, occasionally surfacing to visit the local health food store.

And then there’s the Shasta energy vortex theory. Many believe the mountain is a spiritual epicenter, radiating powerful energies that attract meditators, mystics, and seekers of cosmic wisdom. Basically, if you ever want to combine volcano exploration with a deep dive into the multiverse, this is the place to do it.

So should we be worried?

Mount Shasta is a true wild card. It could remain peacefully dormant for another 500 years… or it could decide to shake things up tomorrow. The only thing we know for sure? If it does erupt, expect lava, ash, and probably some guy claiming he saw a Lemurian riding a UFO out of the crater.

Moral of the story? Whether you're into science, legends, or just want to see one of the most epic mountains in America, Mount Shasta is one to watch. Because when a place is known for both fiery eruptions and interdimensional portals, you know it’s got to be something special.

Thanks for reading!☕