Why waterfalls look different
A waterfall forms where a stream crosses from hard rock to softer rock, or drops over a step left by a glacier, a fault or a lava flow. The shape of that step decides how the water falls. A sheer cliff with an overhang gives a free-falling plunge. A steep but sloping face gives a horsetail or a cascade. Several steps in a row give a tiered fall.
The names below are the ones used by most waterfall guidebooks and by the World Waterfall Database. A single waterfall can fit more than one type: many tiered falls have a plunge in one tier and a horsetail in another.
The main types
| Type | What it looks like | How it forms |
|---|---|---|
| Plunge | Water drops free of the rock face for all or most of its height | An overhanging lip, usually hard caprock over softer rock that erodes back |
| Horsetail | Water stays in contact with the rock, fanning slightly as it falls | A steep face without an overhang |
| Cascade | Water tumbles down a series of small steps or a rough slope | Uneven, stepped bedrock |
| Tiered (multi-step) | Two or more distinct drops, each with its own pool | Several resistant rock layers separated by softer ones |
| Segmented | Water splits into separate streams across the lip | An uneven lip, or low flow over a broad ledge |
| Fan | Water spreads wider as it descends while touching the rock | A face that broadens downward |
| Punchbowl | Water shoots through a narrow gap into a wide, round pool | A constricted channel above a broad scoured basin |
| Block (curtain) | A wide sheet of water falls from a broad river | A large river crossing a wide ledge |
| Slide | Water glides smoothly down a sloping slab | A smooth, inclined rock face |
| Chute | A large volume forced through a narrow channel | A tight gap in resistant rock |
| Cataract | A large, powerful fall or series of rapids on a big river | High volume over a steep drop |
Plunge and horsetail: the two you will see most
Most waterfalls in trail guides are plunges, horsetails or a tiered mix of the two. The difference is whether you can see daylight between the water and the rock. At a plunge you can often walk behind the falling water, because the stream has eroded soft rock back under a harder ledge. At a horsetail the water hugs the face the whole way down.
Plunges tend to be the tallest single drops, and they are the ones whose heights are easiest to measure, because there is a clear top and bottom.
Why so many falls are tiered
Sedimentary rock comes in layers, and each hard layer makes its own ledge. Where a stream cuts down through several of them, it leaves a staircase of drops. The Appalachians, the Columbia River Gorge and the Finger Lakes gorges of New York all have many tiered falls for this reason. Glaciers made more by carving deep valleys and leaving side streams hanging high above the valley floor.
Tiered falls cause most of the disagreement about waterfall heights, because sources differ on whether to count the whole staircase or only the biggest drop. See how waterfall height is measured.
Using the types on a hike
The type tells you what to expect on arrival. Plunges throw the most spray, so expect wet rock and a cold breeze. Slides and cascades often have pools that are easier to reach, and more tempting to climb on, which is where people get hurt. Segmented and fan falls look their best in high water, and tiered falls sometimes reveal only one tier from the main viewpoint.
Find the ones near you with the waterfall map.