How Wide Is Crater Lake?

Written by Kathryn Dueck
Updated: August 23, 2023
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Crater Lake’s claim to fame is simple: it’s the deepest lake in the United States. Not only that, it’s the deepest volcanic lake in the world and one of the deepest lakes overall. The purity and sheer volume of its water are what give it that stunning blue hue. But how wide is Crater Lake? How does its width compare to its impressive depth? Read on to find out Crater Lake’s width, how long it takes to swim across, and more!

How Wide Is Crater Lake?

Crater Lake is approximately 5 miles (8 kilometers) wide. The lake is more or less circular with a single island near its western shore, Wizard Island. This island is a post-caldera cinder cone that formed as the lake was filling with water. It rises 763 feet above the surface of the lake. The small crater on its summit measures 300 feet across and 90 feet deep. Three similar volcanoes lie deep under the surface.

The table below lists several other measurements for Crater Lake:

Measurement TypeSize
Area13,180 acres (20.6 square miles)
Length6 miles
Maximum Depth1,943 feet
Average Depth1,148 feet
Volume4.6 trillion gallons
Height Above Sea Level6,178 feet
Summary table of various measurements for Crater Lake

Where Is Crater Lake?

Crater Lake lies in southern Oregon approximately 100 miles east of the Pacific Ocean. It sits on the crest of the Cascade Mountain range within a caldera (volcanic basin). It is the namesake and highlight of Crater Lake National Park, which encompasses 183,224 acres of protected mountains, woods, and the lake itself.

How Long Would It Take to Swim Across Crater Lake?

It takes approximately 2.5 hours to swim across Crater Lake at its widest point. This is based on the fact that the average person swims at a speed of two miles per hour. It also assumes that the swimmer will not slow down, take a break, or swim off-course.

A beautiful view of Crater Lake in Oregon.

Crater Lake is 5 miles wide, which would take the average person around 2.5 hours to swim.

© and videographer from Ukraine

Is Crater Lake Safe to Swim In?

Crater Lake is safe to swim in. Crater Lake National Park draws somewhere between 500,000 and 750,000 people per year, many of whom choose to swim in the crystal-clear waters. According to the National Park Service, the surface of the water warms up to 55°F to 60°F during the summer. The average temperature below 300 feet is significantly chillier at 38°F. The lake itself rarely freezes over due to its limited surface area compared to its massive volume. The last time it froze over was in 1949.

There is only one safe and authorized way to access the lakeshore: Cleetwood Cove Trail. This strenuous trail drops 700 feet in 1.1 miles via a series of steep switchbacks. The largely unshaded surface of the trail is comprised of crushed pumice, which shifts easily underfoot when dry. Cleetwood Cove Trail typically opens sometime in late June.

To preserve the lake’s pristine quality, the National Park Service does not permit swimmers to enter the lake wearing or carrying anything but bathing suits and basic clothing. Among other things, the prohibition applies to scuba and snorkeling gear, other swimming apparatus (including swim aids), waders, and motorized or unmotorized boats.

What Lives in Crater Lake?

Originally, Crater Lake did not contain any fish. From 1888 to 1942, authorities introduced five species to the lake. Today, it contains approximately 60,000 rainbow trout and kokanee salmon. This is in addition to over 165 species of phytoplankton and zooplankton. The lake is also home to various invertebrates, amphibians, and a type of native moss. Given that the fish species are non-native, the park permits fishing in Crater Lake without a license.

Is Crater Lake Polluted?

Winter Scene at Crater Lake Volcano

Crater Lake is one of the most pristine lakes in the world.

©Matthew Connolly/

Crater Lake is one of the most pristine lakes in the world with astonishingly low levels of pollution. This is largely because no rivers or streams feed the lake. The only moisture entering the lake comes from precipitation (i.e., rain and snow). Interestingly, Crater Lake receives twice the amount of precipitation that it evaporates, but the level of the lake changes very little. This is because water filters out through porous rocks on the northern shore, preventing the caldera from filling up. The lack of pollution keeps the lake clear, which helps preserve its gorgeous hue.

Visitors to the lake in June and July frequently notice unusual yellowish matter in the water. Though it often prompts concerns about pollution, this is just pine pollen, which is harmless. Like all sediment, it eventually sinks to the bottom of the lake.

Besides its pristine water, the area around Crater Lake is also known for its fantastic air quality. This helps ensure that pollutants do not get into the water. The major exception to this rule is wildfire season, which occurs in summer and fall. Smoke from nearby wildfires can significantly lower air quality.

How Does Crater Lake Compare to Other Well-Known American Lakes?

Below is a table comparing the width of Crater Lake to the widths of several other well-known or sizeable American lakes. All measurements are in miles and indicate the widths of the lakes at their widest points.

Crater Lake5 miles
Lake Huron183 miles
Lake Superior160 miles
Lake Michigan118 miles
Lake of the Woods59 miles
Lake Erie57 miles
Lake Ontario53 miles
Great Salt Lake28-35 miles *This lake’s size fluctuates considerably due to a number of factors.
Flathead Lake15.5 miles
Yellowstone Lake14 miles
Lake Tahoe12 miles
Lake Winnipesaukee9 miles
Summary table of well-known lakes and their widths compared to the width of Crater Lake

History of Crater Lake

Crater Lake National Park, National Park, Oregon - US State, USA, Wizard Island

Crater Lake was formed 7,700 years ago during the collapse of Mount Mazama.


Crater Lake was formed during the violent eruption and collapse of the 12,000-foot-high Mount Mazama approximately 7,700 years ago. Archeological evidence points to a Native American presence in the area before the eruption, though these tribes most likely did not form permanent settlements. Most tribes within Oregon and northern California considered the lake sacred, so sacred that the Makalaks/Klamath Indians believed anyone who gazed on it would die.

The first Europeans to find the lake arrived on June 12, 1853. They were part of a gold prospecting outfit headed by John Wesley Hillman. One of the prospectors, Skeeters, called it the “Deep Blue Lake.” However, because there was little to no gold in the area, the lake fell back into obscurity until another group of prospectors happened upon it in 1862. Subsequently, the first published reference to the lake appeared in the Jacksonville Oregon Sentinel.

Crater Lake finally gained public recognition through the efforts of Kansan William Gladstone Steel. In 1870, he found a reference to the lake in the newspaper he had used to pack his lunch. Intrigued by the description, he determined to see it for himself. He finally fulfilled this dream in 1885. After 17 years of continuous effort, he succeeded in establishing the region as a national park on May 22, 1902.

The photo featured at the top of this post is © Nature's Charm/

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About the Author

Kathryn Dueck is a writer at A-Z Animals where her primary focus is on wildlife, dogs, and geography. Kathryn holds a Bachelor’s Degree in Biblical and Theological Studies, which she earned in 2023. In addition to volunteering at an animal shelter, Kathryn has worked for several months as a trainee dog groomer. A resident of Manitoba, Canada, Kathryn loves playing with her dog, writing fiction, and hiking.

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