Crater Lake
Credit: Wikipedia photo by Arcataroger, CC BY 3.0.

Beautiful Crater Lake is about six miles (10 kn) across.[1] The intense deep blue color, while beautiful in photos, cannot entirely be captured by a camera and needs to be seen in person.

Crater Lake is also called Mount Mazama

Of all the national parks I’ve been to, and I’ve been to many of those in the western half of the United States, nothing in my opinion was as awesome to behold as Crater Lake. The size of it, and the incredible deep blue color, was just breathtaking. The fact that I love volcanoes helped too!

The mountain is still called Mount Mazama, although after huge eruptions, most of it collapsed forming a caldera that has filled with water.[2] A more accurate name would actually be Caldera Lake. For anyone unclear about the difference between a volcanic crater and a caldera, see my InfoBarrel article defining basic volcanology terms.

Mount Mazama used to be about 12,000 feet (3,650 meters) at the summit, and now has a maximum elevation of 8,159 feet (2,487 meters).[2] Imagine the force of an explosion that could knock off the top 4,000 feet (1,200 meters) of a mountain!

The current tallest peak in Oregon, another active stratovolcano, is Mount Hood near the city of Portland. Mount Hood has a peak elevation of 11,249 feet (3,429 meters),[3] which means that before Mount Mazama's massive eruption, it was the tallest peak in the area that is now the state of Oregon.

Mount Pinatubo 1991 Eruption
Credit: USGS public domain photo.

This is a photo of the eruption of Mount Pinatubo in the Philippines in 1991. This was the second-largest eruption in the world during the 20th Century.[4] The eruption of Mount Mazama that formed Crater Lake ejected an estimated 3.5 to 5 times as much material as Pinatubo's 1991 eruption.

The massive eruption of about 7,700 years ago

The gigantic eruption that destroyed the mountain occurred between 7,500 to 7,800 years ago, with many sources stating 7,700 years. It was likely witnessed by the Kalamath Tribe of Native Americans, who have always considered the lake sacred.  Other smaller eruptions from within the caldera have occurred since, with the most recent estimated at about 4,000 to 4,600 years ago.[2]

The giant eruption that created the large caldera was in fact once of the largest to occur in the past 10,000 years, with only seven occurring worldwide that were definitely larger. No eruptions so large have taken place anywhere on Earth since Mount Tambora in Indonesia erupted in 1815.[5]

Mount St. Helens to the north, in the state of Washington, is famous for an eruption that occurred in 1980, which had a force equivalent to ten modern nuclear bombs.  The eruption of that volcano ejected about one cubic kilometer (0.24 cubic miles) of material.[6] By comparison, Mount Mazama ejected at least 35 cubic km (8.4 cubic miles) of material. Some estimates state that it was 50 cubic km (12 cubic miles).[2]

Crater Lake in Fog
Credit: NPS public domain photo.

Crater Lake sometimes fills with fog. The cinder cone Wizard Island sticks up above the fog in the center of this photo.

The resulting caldera and Crater Lake

Crater Lake itself is nearly circular, and about 5 miles by 6 miles (8 km by 10 km) in size, with the walls standing all around about 2,100 feet (640 meters) above the water. The lake is about 1,100 feet (335 meters) deep on average, with the deepest point being about 1,943 feet (592 meters) deep.[1]

Crater Lake is actually the deepest lake in the USA, and only Great Slave Lake in Canada is deeper in all of North America. In the entire world, only eight lakes are known to be deeper.[1]

Crater Lake has no streams flowing into or out of it, and water enters from rain and snow. The surface of the water is at an elevation of 6,178 feet (1,883 meters)[1] and never gets much higher due to the way excess water goes through the porous walls of the caldera, keeping the lake level nearly the exact same at all times.[7]

The blue color of the water, as you look down at the lake, is otherworldly. I’ve never seen anything like it. It’s an intense deep blue that can’t really be described in words, and has to be seen in person to be understood. In the lake there is an island, called Wizard Island, which is a cinder cone which last erupted about 6,000 years ago.[1]

Other small eruptions within the caldera have taken place below the surface of the water as recently as 4,000 years ago.[1] In geological terms, this is a short amount of time, and the volcano is still considered to be active and is expected to erupt again someday.[8]

Crater Lake in Winter
Credit: Wikipedia photo by WolfmanSF, CC BY-SA 3.0.

Crater Lake during the winter months has an alternative but equally beautiful appearance. The mountain gets enough snow that it has often not entirely melted until a few weeks into summer, in about mid-July.[1]

Crater Lake National Park

The national park is not far from the city of Medford, in the southern part of the state. The park was established in 1902, making it the fifth-oldest national park in the United States. It is the only national park in the state of Oregon.[9]

Crater Lake National Park has a must-drive road that goes all the way around the rim of the crater, called Rim Drive. Boats operate on the lake in the summertime, and the best view of the crater and lake is from Mount Scott, which requires a fairly steep hike of 2.5 miles (4 km), starting at a trailhead that is located on Rim Drive.[9]

Video showing Crater Lake National Park's awesomeness

Beware: Video will make you want to go there