Exploring the Hydrothermal Features in Yellowstone National Park

Yellowstone National Park became the first national park in 1872 and to me it will always be the most unique national park. When I think of national parks, I think of places to hike, visit waterfalls and see wildlife. Yellowstone has all of this but also has many hydrothermal features from it’s volcanic geology which makes it truly unique from other national parks in the US. I will be the first to admit, the hydrothermal features made me stop and think of how strange this planet really is. It makes you think of all the natural things going on under the ground that we just don’t think about. The hydrothermal features in Yellowstone are both strange and fascinating at the same time!

There are 5 different types of hydrothermal features located in Yellowstone National Park.

1. Hot Springs – The most common hydrothermal feature, these occur when rainwater and snowmelt seap into the ground and becomes hydrothermally heated and rise to the surface.
2. Geysers – These are hot springs where the water is prevented from circulating which in turn causes them to periodically erupt for the heat to escape.
3. Fumaroles – These steam vents occur when the water evaporates before coming to the surface.
4. Mudpots – Acidic hot springs that dissolve the surrounding rock.
5. Tavertine Terraces – Hot springs that rise thru limestone and create what looks like a cave turned inside out.

There are over 10,000 hydrothermal features located in Yellowstone National Park with over 500 active geysers, which make up half of the geysers in the entire world. This makes Yellowstone a great place to visit not just for Americans, but for citizens around the world.

There are multiple areas spread throughout the park that you can see the hydrothermal features. This post will discuss the top four areas you must visit Lower Geyser Basin, Midway Geyser Basin, Upper Geyser Basin and Mammoth Hot Springs.

Lower Geyser Basin: The Lower Geyser Basin is approximately 11 square miles, making it the largest geyser basin in Yellowstone. It includes multiple areas of thermal activity, the most popular of which is the Fountain Paint Pot Area.

This was the first spot that I stopped at in the park. I was amazed at the effect that the thermal activity and volcanic geology has on the area. It’s not just the hydrothermal features that are fascinating but also the effect on things like the trees and the surrounding ground. Looking around, I kind of felt like I was on another planet.

Fountain Paint Pots area included 4 of the 5 types of hydrothermal features, everything but the tavertine terraces. There was a trail that was approximately a half mile long. The trail was on a boardwalk. It’s important to stay on the boardwalk as the hot springs, geysers, mudpots and fumaroles are all extremely hot and would cause serious injury.

The most impressive thermal feature in this area to me was the Silex Spring. The color of it was beautiful, a good preview of the much more colorful hot springs that I would see later in the park. The Clepsydra Geyser was erupting and could be seen as i was driving up to the area. Even walking on the boardwalk, you ended up walking thru the steam from this geyser.

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Seeing the thermal features in action was a very interesting experience. It truly is amazing the things that occur on this planet! Check out this video of the Fountain Paint Pots:

Midway Geyser Basin: The Midway Geyser Basin has the least amount of thermal features, but also the most beautiful thing to see in the entire Yellowstone National Park in my opinion.

Excelsior Geyser was once the largest geyser in the world back in the 1880s. At present it is still a fairly large crater spouting lots of water and steam.

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There are two hot springs, Opal Pool and Turquoise Pool which are beautiful to see.

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When you compare these two pools to the star of the show in Midway Geyser Basin, Grand Prismatic, they sadly look unimpressive. Grand Prismatic is the largest hot spring in Yellowstone stretching 300 feet across, it is also the most colorful. The colors pop the most when the sun is straight overhead during the midday. Early in the morning there is usually too much steam obscuring the view. This is unfortunate as the parking lot at Midway Geyser Basin is pretty small and finding a spot mid day is quite difficult. I visited it around 6pm and even then had a hard time trying to get a parking spot. But Grand Prismatic was still very impressive to see even with the steam obscuring some of the color.

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If I had time I would have headed back to this area the following day and took the short hike to the overlook for a much better view. One mile down the road from Midway Geyser Basin is the Fairy Falls parking lot, which is a bit bigger than the parking lot at Midway Geyser Basin. From there you can take a .6 mile hike 105 feet up to the overlook and you can see Grand Prismatic in all it’s glory like the photo below, courtesy of wikipedia. I do regret not having time for this, just a reason to visit Yellowstone again sometime in the future I guess.

Upper Geyser Basin: The largest concentration of geysers in the world as well as some of the largest geysers in size in the world are located within one square mile at the Upper Geyser Basin.

Shortly before arriving at the main area where the famous Old Faithful Geyser is located is Biscuit Basin. This is a beautiful area to check out some of the hot springs with less of a crowd. There is a short half mile boardwalk trail to take here.

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The Old Faithful area is the busiest part of the park. Even people not into National Parks have dreams of seeing Old Faithful erupt in person. It’s a beautiful area but also a very touristy area. There is a visitor center, an inn and lodge, restaurants, gift shop, general store and gas station. But you just cannot come to Yellowstone and not see Old Faithful, even if it means standing in a huge crowd of people waiting for it to erupt.

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Old Faithful erupts more frequently than other large geysers in the park and it’s fairly easy to predict when it will erupt plus or minus 10 minutes, which is how it got it’s name. On average it erupts every 90 minutes but can be anywhere from 50 minutes to two hours in between eruptions. They are able to predict the timing of the eruption based on the last eruption and how long it lasted. The shorter duration of the eruption, the shorter amount of time in between that eruption and the next. The rangers post the predicted timing of the next eruption. I will say, I saw it erupt twice while I was there and it erupted within 5 minutes of their predicted time.

Check out the video below on the Old Faithful Geyser eruption:

Old Faithful is definitely not the only thing to see in Upper Geyser Basin. If you have the time take the Upper Geyser Basin Loop trail. This trail is mostly on boardwalk with some pavement and I clocked it at about 3 miles long. There are numerous hydrothermal features to see on the loop trail. It was interesting at 10:30am see some of the other geysers with predicted eruptions at 4 or 6pm and lots of empty seating in front of these geysers. You’d really have to be in the right place at the right time to see these erupt or sit for a while.

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There were many impressive hot springs and geysers along this trail but by far the most beautiful was Morning Glory Pool. The colors of this hot spring were so beautiful and it was such an impressive thing to see. Made up for not seeing Grand Prismatic without the steam. This alone makes taking the long trail worth it in my opinion.

Mammoth Hot Springs: The final major area of hydrothermal features is Mammoth Hot Springs located near the Northern Entrance to Yellowstone National Park. Like the Old Faithful area, this area can seem rather touristy, with visitors center, lodging, restaurants, gift shops and a gas station.

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But this is the area of the park that features the fifth type of hydrothermal features, tavertine terraces, so it’s definitely worth checking out. These terraces will make you feel like you are looking at something from another planet. There are a couple of ways to view the terraces, you can park by the lower terraces and walk the boardwalk all the way to the top. This is a great way to see all of the terraces. Or for the upper terraces, there is also a parking lot by them. I walked all the way from the lower to the upper terraces after being up since 4am and hiking for 6 miles, probably would have been better to park near each and save my already sore legs a bit.

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Seeing all these hydrothermal features at Yellowstone National Park was quite fascinating, kind of a surreal experience. Very different from the wildlife and nature also seen in the park. This alone makes Yellowstone a great destination for people all around the world to visit some day.

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