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  Imperial Geyser
Feature Type: Geyser
Geyser/Spring Type: Fountain geyser

Lower Geyser Basin
Imperial Group

Imperial first erupted in 1927. There was a hot spring at this location prior to 1927 but the eruptions greatly enlarged the crater. These early eruptions were quite large, often approaching 75 feet in height and over 30 feet in width. It discharged a large amount of water during its two-hour duration. Unfortunately, this activity only lasted about two years and then Imperial went quiet. Since then, Imperial has had periods of activity and inactivity; some of these periods have lasted decades.

In 1997, a side vent of Imperial activated. This activity, shown in the accompanying image, was characterized by nearly constant bursting play, some reaching nearly 50 feet. More recently it has been the site of brief, intermittent play lasting some seconds at a time, punctuated by quiet periods lasting about as long as the bursts themselves or a bit longer, so that it is erupting half the time or slightly less. Heights are commonly listed as 20 to 60 feet; however, the author of this description has seen bursts that he estimated as approaching 70 feet, and one that might have reached 75. Rigorous measurements of eruption heights from "New Imperial," as this side vent is sometimes called, would be appreciated.

What to look for:
This is now basically a (near) backcountry geyser, reached by trail with a trailhead (the Fairy Falls trail) on the road at Midway Geyser Basin. If you make the trek past Fairy Falls to Imperial's beautiful, light-blue pool, you'll be rewarded with a New Imperial eruption soon enough without having to "look for" anything. (Make sure not to approach the pool too closely.) The round trip is around seven miles; other trail approaches are longer.

Update: Will Boekel reports that the Fairy Falls trailhead will again be closed for 2017. Access via a longer (9 miles round trip) trail from the end of Fountain Flats Drive is still possible, to the best of our knowledge.

Click for a larger image

This picture, taken by Steve Gryc, shows the 1997 activity from a side vent of Imperial.

Please note - this site is currently under constuction. Please visit for more information.  Last update 01-29-2017

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