What is the deepest lake in the United States?
Quick answer
Crater Lake in Oregon is the deepest lake in the United States, reaching about 1,949 feet (594 m). It formed about 7,700 years ago when a huge volcano, Mount Mazama, erupted and collapsed, leaving a basin that slowly filled with rain and snow.
Key facts
- Maximum depth
- ~1,949 ft (594 m)
- Location
- Crater Lake National Park, Oregon
- Formed
- About 7,700 years ago
- National park since
- 1902
The deepest US lakes
| Rank | Lake | State | Max depth |
|---|---|---|---|
| 1 | Crater Lake | Oregon | ~1,949 ft (594 m) |
| 2 | Lake Tahoe | California/Nevada | ~1,645 ft (501 m) |
| 3 | Lake Chelan | Washington | ~1,486 ft (453 m) |
| 4 | Lake Superior | Michigan/Minnesota/Wisconsin (and Canada) | ~1,333 ft (406 m) |
| 5 | Lake Pend Oreille | Idaho | ~1,150 ft (350 m) |
Crater Lake is also one of the deepest lakes in the world, often ranked around ninth or tenth.
How it formed
- Mount Mazama, a volcano about 12,000 feet tall, erupted violently around 7,700 years ago.
- The eruption emptied the magma chamber, and the top of the mountain collapsed, forming a caldera.
- Over centuries, rain and snowmelt filled it. No rivers flow in or out; evaporation and seepage balance the water.
Why it’s so blue
Because no rivers carry in sediment, Crater Lake’s water is extremely clear. Sunlight travels deep, and water absorbs the other colors, so mostly deep blue light scatters back to your eyes. It works much like why the sky is blue.
Visiting
- Rim Drive circles the lake with dozens of viewpoints.
- Wizard Island, a small volcanic cone, rises from the water.
- The park gets heavy snow, and parts are closed for much of the year.
For more US park records, see the largest national park in the US. Canada has the most lakes of any country: here’s why.
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