Crater Lake Facts

Crater Lake is a national park in Oregon, United States. It was created by the collapse of the Mount Mazama volcano in a cataclysmic eruption around 7,700 years ago. Over time, it filled with rain and snowmelt to become the deepest lake in the United States with a depth of 1,943 feet (592 m) and one of the clearest lakes in North America.

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Crater Lake Facts For Kids

  • It was formed after Mount Mazama collapsed.
  • The lake is 1,943 feet (592 m) deep
  • It’s famous for its clear water
  • It’s filled with rainwater and melted snow.
  • The lake is an endorheic basin meaning it has no natural outlet as it is sealed by the surrounding rock.

Everything You Need To Know About Crater Lake

It Has An Interesting Origin

Crater Lake is located in Crater Lake National Park, Oregon, United States. But did you know that the reason it came into existence over 7700 years ago was because of the collapse of the volcano Mount Mazama?

That makes it a volcanic crater lake. As it was created because of the collapse of a volcano, it’s also huge, in almost every way imaginable!

It Is VERY Deep

On average, it is around 1,148 feet deep. That means that divers and scientists have collected the depth of multiple spots in the lake and worked out the average.

There’s still some hydrothermal activity on the lake floor. In terms of average depth, this is the third deepest lake in the world and the deepest in the whole of the United States.

But they have found the deepest point to be 1,943 feet deep, making it the ninth deepest in the entire world based on the deepest point alone! So whichever way you look at it, it’s incredibly deep!


The lake itself is six miles long and five miles wide, but if you wanted to walk around the full shoreline, you would have to walk a whopping 21.8 miles.

The average walking speed of a human is approximately 3.5 miles per hour, so it would take you over 6 hours to walk around the full lake! Because it is so wide and so deep, it also has around 4.49 cubic miles of water in it too!

Water Lasts A Long Time There

The lake is only actually a lake because of rain falling down and filling the massive hole that Mount Mazama left behind all those years ago. But water doesn’t just fall and disappear again quickly as it does in a puddle on the street.

Scientists believe that this body of water will stay here for around 150 to 200 years before it evaporates. That means even after a fresh downpour of rain, you could still find drops of water in the lake that had fallen 200 years ago!

There Are Two Islands In The Lake

Yes, it really is big enough to have not one but two islands in it too. One is called Wizard Island, and the other is called Phantom Ship Island. Phantom Ship Island is really just a rock formation in the middle of the lake, but people have said for years that it looks like a phantom (or ghost) ship.

Apparently, during low light or foggy nights, it looks especially creepy. Wizard Island got its name in 1885 after a poet, William Gladstone Steel, said it looked like a Witch’s Cauldron and so christened it Wizard Island.

There Are Fish In The Lake

Given that it doesn’t have any rivers flowing to it, fish didn’t end up here naturally. Instead, they were introduced steadily from 1888 to 1941. Not all the species of fish that were introduced have survived, however, as it wasn’t an ideal environment for them.

Nowadays, you can find rainbow trout and kokanee salmon, and that’s pretty much it!

It Has Been Significant Throughout History

Of course, when it first formed 7700 years ago, that was pretty significant, but it’s been recognized multiple times since then as an important site. In fact, the Klamath tribe of Native Americans has long since thought of Crater Lake as a place of historic significance in their own stories and beliefs.

They believe that Mount Mazama didn’t simply erupt and collapse, but it was the site of an enormous battle between the Sky God, Skell, and the God of the Underworld, Llao. During this battle, the volcano was destroyed, and they left the lake in its place! That’s just one example of how important it is throughout history and different cultures.

It Is Also Known As A Caldera Lake

Caldera is simply a structure that has been formed in a massive volcanic eruption. These volcanic eruptions took place over many years, creating landslides and sending lava out across the landscape. Once the lava cooled, a new ‘ground’ was created – solid rock.

Even after Mount Mazama collapsed into the ground, there was still volcanic activity. Eventually, the caldera cooled, allowing water to stay there once the rain had fallen. Scientists can detect small amounts of hypothermal activity in the bottom of the caldera lake to this day – that means that, in theory, one day, the lake might erupt again!

The Water Is Very Pure

Anybody who sees it describes it as clear and very blue, and actually, at one point in history, it was called the ‘Deep Blue Lake.’ Scientists have conducted experiments on water quality, and it’s some of the purest in all of America. They believe this is because there are no rivers flowing into it, so the water can’t become polluted by other sources. Instead, the water is formed from rain and snow.

There Is Always Plenty Of Snow

Given that it only gets its water from rainfall and snow, it’s good to know that snow is around a lot in this particular area. In fact, snow covers the ground on Crater Lake National Park for an average of 8 months a year! When it melts, it also adds more water to the lake’s levels too, so nature works in unison to keep the waters high!

The Trees Surrounding It are Old Too

There are many stories of the trees around the lake, but did you know they are very old too? In fact, some trees that grow on Wizard Island are actually over 800 years old. It’s possible to take a boat across to Wizard Island during the summer months, so you can stand on a historical island surrounded by historical trees.

But did you also know that there is a tree floating in the lake that has been there for over 100 years? This tree is known as the Old Man of the Lake, and visitors love going to the water’s edge to spot it!

You Can See 100ft Below The Water’s Surface

That’s right! Remember how before we said the water was clear? Well, it’s so clear that you can see 100 ft down into the lake. Given that its deepest point is still 1943 ft deep, there’s still lots more exploring to be done, but seeing that far down is pretty amazing, anyway!

Frequently Asked Questions

Why is Crater Lake water so blue

The lake’s blue color comes from the snow or rain that falls on the surface and never mixes with other water. This implies that no mud or minerals deposit in the lake. The lake’s cleanliness is due to its high alkalinity and low acidity. It also has a natural water filter which helps it

How cold is the water at Crater Lake

Temperatures below 300 feet descend to 38°. In the summer, the surface is up to 55° or 60°.

How long did it take for Crater Lake to fill with water

It took about 250 years for Crater Lake to fill with water. Rain and snowfall are equal to the amount of water that evaporates or seeps into the ground.

Why is crater lake so dangerous

The main reason that Crater Lake is so dangerous is because of the depth of the lake. In the national park, rock and snow can often cause rockslides and avalanches. Also, thin layers of snow can form, especially around the rim, and collapse easily under a person’s weight.

Can you swim in little crater lake

Yes (at designated areas), but it is very cold.

What lives in crater lake?

Lake crater is home to many different types of fish. Some common examples are silver and rainbow trout, kokanee, and bass. You’ll also find different mammals like Deer, squirrels. Reptiles and amphibians like frogs and toads also live in the lake. In the surrounding forests, you’ll come across species like black bears, raccoons, and birds such as eagles.