grand prismatic spring midway geyser basin in yellowstone

Grand Prismatic Spring, Yellowstone National Park, Wyoming.

Grand Prismatic Spring is probably the most iconic geological attraction in Yellowstone National Park along with Old Faithful and Mammoth Hot Spring.
This hot spring is famous for its incredible colors of its acid waters and by the strangeness of the phenomenon. It embodies the mysteries of the planet Earth and this is what amazes visitors from all over the world.

That’s why we rushed to see this geological feature as soon as we arrived in Yellowstone National Park. We had it on our bucket list for so long. It is finally a dream comes true!

grand prismatic spring the site

Grand prismatic springs map

Grand Prismatic Spring

Jim Peaco, National Park Service, Public domain, via Wikimedia Commons

1. Where is Grand Prismatic Spring?

Consult the Yellowstone official map to locate Midway Geyser Basin.

Grand Prismatic is located in the Midway Geyser Basin geothermal area, halfway between Madison Junction and Old Faithful, along the Firehole River.
This geological depression is not the widest of the park but it shelters three striking attractions, Excelsior Geyser, Opal Pool and the famous Grand Prismatic Spring.

From the parking lot, boardwalks lead visitors around Midway Geyser Basin safely. In fact, this is one of the most dangerous area in the Yellowstone National Park.

Grand Prismatic area map

How to access Grand Prismatic Spring Yellowstone

2. What is Grand Prismatic Spring?

As we approach the source, we distinguish an horizontal cloud of turquoise blue vapor, which contrasts with the dark green background covered with firs. Because of its gigantic dimensions (370 feet diameter and 121-foot-deep waters) it is the third largest hot spring in the world, (after Frying Pan Lake in New Zealand and Boiling Lake in Dominica).

Can you imagine, it can swallow a 12-story building as big as a baseball field. This is for the size!

Grand Prismatic yellowstone

Red, orange and brown runoffs produced by Grand Prismatic Spring

What about the colors?
The boardwalks lead the visitors over red, orange and brown runoffs produced by the gigantic basin. These lively tints are due to the presence of millions of micro-organisms, thermophiles and bacteria that proliferate into waters at extreme temperatures.

We contemplate the yellow and green circles around the center of the spring whose deep blue waters rise to 160 ° F. The thin layer of liquid deposited on the warm ground enhances the liveliness of the colors.

Now, we understand why this giant source is called Grand Prismatic Spring!

It is best to visit Grand Prismatic Spring in the middle of the day, when the colors are the most vivid. It needs about half a day to visit the area.

Grand Prismatic yellowstone park

Grand Prismatic Spring

The view is so unreal that it leaves us stunned and speechless.

3. The view from Grand Prismatic Overlook

We are so dazzled by this incredible natural show ! We wish to observe Grand Prismatic Spring from above. There is a path that leads to a promontory overlooking the huge crater. But regretfully, a ranger informs us that it was closed this week because of renovations works.
If we had taken it, here is what we would have seen:

grand prismatic spring from above in midway geyser basin

Grand Prismatic Spring from above – Wikimedia Commons – Brocken Inaglory

4. A true story about Grand Prismatic

Over the years, some individuals have tried to dump stuff in the Yellowstone pools to see what would happen…or has wishing well. Of course, this behavior is both irresponsible and illegal. A few years ago,  a story has made the headlines :

In 2014 , a tourist flew a drone over Prismatic Spring eventhough the use of such remote-controlled device was banned. It crashed into the acidic waters, potentially damaging it the pool. The drone was never found by the park rangers.

Now, let us go to visit two more exceptionnal features in Midway Geyser Basin: Excelsior Geyser and Oval Pool.

5. Excelsior Geyser, it’s hot …

From the parking lot, the path crosses the Firehole River, into which Excelsior Geyser’s waters dump two large ocher runoffs.The path crosses the Firehole River, into which Excelsior Geyser’s waters dump two large ocher runoffs. We can’t see it yet but its presence is proved by the ultra-hot vapors rising up in the air. No doubt, we are getting close to it!

Run off Excelsior Geyser

Run off Excelsior Geyser in the Firehole River

A hundred feet further, we approach the huge crater filled with boiling turquoise liquid. Indeed, this water rising from the bowels of the Earth reaches 194 ° F. The steam is so dense that we cannot make out the other bank of the geyser. In addition, Excelsior Geyser’s rim is covered with a whitish substance, deposited by the overflowing waters.

Midway Geyser basin - Excelsior Geyser

Midway Geyser Basin – Excelsior Geyser

Although impressive, Excelsior Geyser’s activity is quite calm compared to what it was in the past. Indeed, extremely violent eruptions have created a crater from which water springs under pressure. The last eruption was recorded in 1985. Today, this giant pot still pours 17,000 liters of water per minute into the Firehole River. Fascinating!

6. Opal Pool

Then, from Excelsior Geyser, we head to Turquoise Pool and Opal Pool. These two sources are of great beauty. Opal Pool is a volcanic basin with blue waters, apparently quiet. It is rimmed with reddish deposits that reflect the presence of bacteria and other microorganisms present in its hot waters.

Midway Basin - Opal Spring

Midway Basin – Opal Spring

Is not our Planet magnificent!?

Lodging near Grand Prismatic Spring

Mammoth Lodge : book several months in advance.
Mammoth Campground: no reservations required but application of the principle: “First come, first served”. The campsite is open all year round.

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grand prismatic spring yellowstone

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