Crater Lake: The Deepest Lake in North America

Among North America's major lakes, Crater Lake in Oregon holds the depth record at 592 m (1,943 ft)—making it the deepest in the U.S., second in North America only to Great Slave Lake (Canada, 614 m), and ninth globally.

Origin

Formed ~7,700 years ago when Mount Mazama, a Cascade volcano, collapsed after a cataclysmic eruption (42× Mt. St. Helens). The caldera filled with rain and snowmelt—no rivers flow in or out.

Unique Features

• Water clarity: Secchi depth up to 43 m (141 ft)—among clearest on Earth.
• Color: Intense blue from pure water absorbing longer wavelengths.
• Wizard Island: Cinder cone rising 230 m above lake surface.
• Phantom Ship: Rock formation resembling a ghost vessel.
• No fish native: Stocked with trout and salmon 1888–1941; now self-sustaining.

Comparison with Other Deep Lakes

• Great Slave Lake (NWT, Canada): 614 m
• Crater Lake (OR, USA): 592 m
• Lake Tahoe (CA/NV): 501 m
• Lake Chelan (WA): 453 m
• Lake Superior: 406 m (but largest by surface area)

Protection

Crater Lake National Park established 1902. No motorized boats; rim drive open seasonally. A pristine natural laboratory for limnology and climate research.

Crater Lake's depth, clarity, and volcanic origin make it a geological jewel of the continent.