Clepsydra Geyser

Overview

Clepsydra Geyser sits in the Fountain Paint Pot area of the Lower Geyser Basin. Its name—Greek for "water clock"—hints at its old habit of erupting on a regular rhythm. After the 1959 Hebgen Lake earthquake, that rhythm changed dramatically: today, Clepsydra erupts almost continuously and only occasionally pauses when nearby Fountain Geyser goes off. Typical bursts reach about 45 feet.

What You'll See

From the boardwalk, you’re up close to a reliably splashy show backed by drifting steam. The surrounding loop serves up the Lower Geyser Basin greatest hits—hot springs, geysers, mudpots, and fumaroles—so Clepsydra is rarely the only thing performing while you’re there.

Geology & Why It’s So Active

Yellowstone’s volcanic heat, groundwater, and a constricted underground "plumbing" system are the recipe for geysers. In features like Clepsydra, heat converts water to steam that forces water through narrow passages, creating eruptions. The Lower Geyser Basin sits on unstable glacial gravels over bedrock, making it especially sensitive to earthquakes and other shifts. The 1959 quake altered water supplies and plumbing paths here, turning Clepsydra from regular intervals to near-constant activity.

Visiting Tips

• Reach it via the easy Fountain Paint Pot boardwalk—no timing spreadsheets needed because it’s usually in action.
• Stay on boardwalks and supervise kids; the ground is thin and the water can severely burn. Avoid stepping on or disturbing the delicate hydrothermal mats.
• Watch wind direction; spray can be hot and rough on camera gear. Wildlife, including bison, sometimes use these corridors—give them ample space.

Best Time to Visit

Early morning or late afternoon gives better side light and dramatic steam in cool air, and generally lighter crowds than midday. Since Clepsydra runs almost nonstop, you don’t need to plan around an eruption window—just be aware it can briefly quiet during Fountain Geyser’s show.