Crater Lake fills the collapsed caldera of Mount Mazama - the deepest lake in the USA. Toggle the depth marker to see how far the true floor lies below the surface, and the water-clarity marker to see how far down you can actually see.
Published figures: maximum depth about 594 m (1,949 ft) - the deepest lake in the USA; average depth about 350 m (1,148 ft); water clarity readings around 44 m (143 ft), among the clearest lake water on Earth; no rivers flow in or out.
Drag to orbit and scroll or pinch to zoom. Everything renders on your device with WebGL.
Crater Lake 3D Explorer
This browser explorer shows Crater Lake as a cross-section of a collapsed volcano: a nearly circular caldera rim, a steep inner wall plunging almost straight into the water, a small cinder-cone island breaking the surface, and two toggleable markers that compare how far you can actually SEE into the lake against how far the floor really lies.
Crater Lake formed about 7,700 years ago when the stratovolcano Mount Mazama erupted violently and its emptied summit collapsed into a caldera. Rain and melting snow are the only water source - no river flows in and none flows out - so almost no sediment ever reaches the lake. That is why Crater Lake is regularly measured among the clearest lake water on Earth, with visibility readings around 44 m (143 ft), even though the true floor lies about 594 m (1,949 ft) below the surface - the deepest of any lake in the USA.
- Toggle the max-depth marker to see the 594 m drop to the caldera floor
- Toggle the water-clarity marker to compare it against the roughly 44 m you can actually see through
- Read elevation, depth, clarity, and island figures in the panel
- Drag to orbit, scroll or pinch to zoom
- Runs fully in the browser with the vendored three.js engine - no account, no upload
| Figure | Published value |
|---|---|
| Maximum depth | about 594 m (1,949 ft) - the deepest lake in the USA |
| Average depth | about 350 m (1,148 ft) |
| Surface elevation | about 1,883 m (6,178 ft) above sea level |
| Caldera diameter | about 8 km (5 miles), roughly circular |
| Water clarity | secchi-disk readings around 44 m (143 ft) - among the clearest lake water on Earth |
| Water source | no inflowing or outflowing rivers - fed only by rain and snowmelt |
| Wizard Island | a cinder cone rising about 230 m (760 ft) above the lake surface |
| Formed | about 7,700 years ago by the collapse of the Mount Mazama volcano |
For the deepest lake in the world by comparison, open the Lake Baikal 3D Explorer, or see another volcanic system up close in the Old Faithful 3D Explorer.
The whole Crater Lake caldera - the rim, the steep inner wall, Wizard Island, and the two depth markers - is built and drawn on your own device with WebGL through the site-vendored three.js engine. Orbit the scene to look down into the caldera, and toggle the markers to compare the shallow depth you can see through against the true depth of the basin. Nothing about your visit is uploaded to a server, and the engine loads once (about 0.7 MB) and is then cached.
This is an educational approximation - the caldera profile, island shape, and vertical scale are schematic teaching cues, not survey data.
Frequently Asked Questions
Why is Crater Lake so deep?
It fills the caldera left when Mount Mazama's summit collapsed after a violent eruption about 7,700 years ago. The floor lies about 594 m (1,949 ft) below the surface - the deepest of any lake in the USA.
Why is the water so clear?
No river flows in or out, so almost no sediment ever reaches the lake - it fills only from rain and snowmelt. Visibility readings around 44 m (143 ft) put it among the clearest lake water on Earth.
What is Wizard Island?
A cinder cone that rises about 230 m (760 ft) above the lake surface near the west side of the caldera - a small volcano that grew inside the larger collapsed one.
How was Crater Lake formed?
The stratovolcano Mount Mazama erupted catastrophically about 7,700 years ago, emptying its magma chamber; the unsupported summit then collapsed inward, and the resulting caldera filled with rain and snowmelt over the following centuries.
Where is Crater Lake?
Inside Crater Lake National Park in southern Oregon, USA.
Is this a scientific terrain model?
No. It is an educational explorer using published figures - the caldera profile, island shape, and vertical scale are schematic teaching cues, not survey data.