What is Mount Lassen?

What’s the Deal with Mount Lassen?

Okay, so you’ve heard of Mount Lassen, right? Or maybe Lassen Peak? Either way, we’re talking about the same impressive volcano, a real landmark in Northern California, about 50 miles east of Redding. It’s the star of Lassen Volcanic National Park, shooting up to a cool 10,457 feet (that’s 3,187 meters for you metric folks). But Lassen isn’t just any mountain; it’s a volcanic dome, a “plug dome” to be exact. Think of it like toothpaste squeezing out of a tube, but with molten rock. It marks the southern end of the Cascade Range, that famous string of volcanoes that stretches all the way up into British Columbia.

Digging into the Geology

Now, this is where it gets interesting. The Lassen Volcanic Center has been cooking for around 825,000 years! That’s a seriously long time. All this volcanic activity? Blame it on the Gorda Plate diving under the North American Plate. It’s a geological slow dance that creates some serious heat. Picture this: about 600,000 years ago, a massive volcano called Mount Tehama started building up in the southwest corner of what’s now the park. We’re talking stratovolcano big. But around 350,000 years ago, BOOM! Mount Tehama blew its top and collapsed, leaving behind a huge caldera, about 3 miles wide. Fast forward to roughly 27,000 years ago, and Lassen Peak makes its grand entrance, pushing up through the side of old Mount Tehama. And let’s not forget the glaciers! They really sculpted Lassen Peak into the shape we see today, between 25,000 and 18,000 years ago.

Lassen Peak is one of the biggest lava domes on the planet, holding a whopping 0.6 cubic miles of rock. To put that in perspective, that’s enough to bury a city. It’s the biggest of over 30 lava domes inside Lassen Volcanic National Park, all formed over the last 300,000 years. These domes are like the shy kids of the volcano world, too thick to really flow anywhere.

A History of Eruptions (and a Good Nap)

Here’s a fun fact: everyone thought Lassen Peak was done for, totally extinct, until it woke up on May 30, 1914, after a 27,000-year nap! That was the start of a volcanic party that lasted until 1917. The first eruption was just a little steam explosion, making a small crater at the top. But over the next year, things got more exciting, with over 180 steam explosions!

Then, on May 22, 1915, all hell broke loose. A huge eruption sent rocks and pumice flying, creating a massive crater. The ash cloud reached over 30,000 feet – you could see it all the way in Eureka, 150 miles away! A river of hot ash and gas, called a pyroclastic flow, wiped out 3 square miles of land. And a lahar, basically a volcanic mudslide, traveled 15 miles from the volcano. That May 22nd eruption was the big one, sending ash almost 300 miles east.

Even after 1915, steam explosions kept happening for years, a sign that things were still hot under the surface. One last big steam explosion in May 1917 made another crater on Lassen Peak’s summit. In total, there were around 400 eruptions between 1914 and 1921. And get this – those were the last eruptions in the Cascade Range until Mount St. Helens blew its top in 1980.

Lassen Volcanic National Park: More Than Just a Mountain

Because of all that crazy volcanic activity, Lassen Peak, Cinder Cone, and the surrounding area became a National Park on August 9, 1916. The park is pretty big, covering 166 square miles, and it’s surrounded by Lassen National Forest. What makes Lassen Volcanic National Park special is that you can see all four types of volcanoes there: shield, plug dome, cinder cone, and composite volcanoes. It’s like a volcano sampler platter!

And the park is still alive! You can find boiling mud pots, fumaroles (steam vents), and hot springs. Bumpass Hell is the biggest of these geothermal areas. Trust me, it smells as bad as it sounds, but it’s worth checking out.

Get Your Hike On!

Lassen Volcanic National Park has over 150 miles of hiking trails. Here are a few of the popular ones:

• Lassen Peak Trail: Five miles round trip, and you get to stand on top of a volcano!
• Bumpass Hell Trail: Three miles to the stinkiest (but coolest) part of the park.
• Cinder Cone Trail: A tough 4.6-mile hike to the top of a cinder cone volcano.
• Kings Creek Falls Trail: A pretty 2.8-mile hike to a waterfall.
• Manzanita Lake Loop: An easy 2-mile stroll with great views and wildlife.

A Little History

Before the tourists, Native American tribes like the Atsugewi, Yana, Yahi, and Maidu called this area home. They hunted and gathered here for centuries. European settlers showed up in the mid-1800s, and they used Lassen Peak as a guide. The peak is named after Peter Lassen, a Danish blacksmith who helped those settlers find their way. So, next time you’re in Northern California, take a trip to Lassen Volcanic National Park. It’s a place where you can see the power of nature up close and personal. And who knows, maybe you’ll even feel the earth rumble beneath your feet!