How big is Crater Lake?

Tucked within the caldera of a long-collapsed volcano in southern Oregon, Crater Lake is more than just a scenic landmark—it's a geological and hydrological marvel. Known for its stunning sapphire-blue water and striking volcanic scenery, Crater Lake is the deepest lake in the United States and one of the most pristine lakes on Earth. But just how big is it? Let’s take a closer look at the lake’s impressive dimensions and what makes it so special.

Surface Area and Shape

Crater Lake spans a surface area of approximately 20.6 square miles (53.2 square kilometers), making it moderately sized in terms of surface area. It lies entirely within the boundaries of Crater Lake National Park, a protected area established in 1902 to preserve this unique natural feature.

The lake occupies a vast, steep-sided volcanic caldera that measures about 5 to 6 miles (8 to 10 kilometers) in diameter. This caldera was formed nearly 7,700 years ago when Mount Mazama erupted and then collapsed, leaving behind a massive basin that slowly filled with rainwater and snowmelt over centuries.

Depth: The Deepest Lake in America

Where Crater Lake truly stands apart is in its depth:

Maximum Depth: About 1,943 feet (592 meters)

Average Depth: Around 1,148 feet (350 meters)

This makes Crater Lake not only the deepest lake in the United States, but also the ninth deepest in the world by maximum depth. In terms of average depth, it ranks among the top three globally. These depths give Crater Lake its dramatic underwater topography and are responsible for its high volume despite the relatively small surface area.

Volume of Water

Crater Lake holds an estimated 4.9 trillion gallons (19 trillion liters) of water. With no rivers flowing into or out of the lake, this enormous volume is maintained entirely through precipitation and snowmelt, balanced by evaporation and seepage. This hydrologic isolation is key to the lake’s clarity and stability.

Surface Elevation

Crater Lake sits at an impressive elevation of about 6,178 feet (1,883 meters) above sea level. Perched high in the Cascade Range, its elevation means the lake is snow-covered much of the year, with snowfall averages around 43 feet (13 meters) annually at the rim.

A Jewel of Clarity and Color

Crater Lake’s remote setting and lack of tributary inflows result in exceptional water clarity. Visibility often exceeds 100 feet (30 meters), and sunlight penetration runs deeper than in almost any other lake in the world. This, coupled with its great depth, creates the lake’s iconic deep blue hue—a signature feature that leaves a lasting impression on every visitor.

Iconic Features

Within the lake itself are several volcanic formations:

Wizard Island, a cinder cone rising 763 feet (233 meters) above the lake surface

Phantom Ship, a jagged rock island resembling a ghostly sailing vessel

These features add texture and intrigue to the lake’s already stunning scenery.

Final Thoughts

While Crater Lake isn’t the largest lake by area, its depth, clarity, and geological origin make it one of the most remarkable lakes in the world. Carved by volcanic fury and shaped by millennia of snow and rain, it stands today as a pristine and awe-inspiring natural wonder—a testament to the raw power and enduring beauty of the Earth.

If you’re planning a visit to Oregon or are simply fascinated by natural landmarks, Crater Lake is a must-see destination. Its immense depth and captivating color are more than measurements on a chart—they’re an experience of scale and serenity that words alone can hardly capture.