Grand Prismatic Spring

#4 in Best Things To Do in Yellowstone
Grand Prismatic Spring picture1 of 3
Grand Prismatic Spring2 of 3
lorcel/Getty Images

Key Info

Grand Loop Road

Price & Hours

Free
24/7 daily

Details

Natural Wonders, Sightseeing, Free Type
1 to 2 hours Time to Spend
4.6scorecard
  • 5.0Value
  • 0.0Food Scene
  • 4.5Atmosphere

The Midway Geyser Basin's Grand Prismatic Spring is the largest hot spring in the United States, approximately 370 feet in size and around 121 feet deep. But its rainbow waters are what really make it fascinating: While the center of the pool's cerulean hue is pretty characteristic, the deep reds, bright yellows and fiery oranges encircling the edges are not. These colors are caused by pigmented thermophilic bacteria that thrive on the rich minerals produced by the geothermic activity. The color of the bacteria is determined by the temperature of the water – the center is too hot to support life – which is then reflected when light hits the organisms.

This natural wonder is one of the park's most photographed sights, so expect crowds when you visit. You may find fewer visitors if you arrive early, but fog is common until late in the morning on cooler days, so travelers recommend arriving around 10 a.m. No matter when you go, visitors say the attraction's Fairy Falls overlook will provide you with the best views.

Grand Prismatic Spring sits 2 miles southwest of the Lower Geyser Basin and 7 miles north of Old Faithful. Other nearby attractions include the Excelsior Geyser and the Turquoise Pool. Restrooms, a gift shop and multiple parking lots can be found at this attraction, but food and beverage concessions are not available.

The spring is free to visit 24 hours a day between April 20 and Nov. 6 (when roads to the attraction are open). But to access the park, you must buy a seven-day park pass. Additional details can be found on the National Park Service's Old Faithful Area page.

See all Hotels in Yellowstone »

More Best Things To Do in Yellowstone

Old Faithful1 of 8
Grand Canyon of the Yellowstone2 of 8
Type
Time to Spend
#1 Old Faithful

The world's most renowned geyser is a must-see for every Yellowstone visitor. Although it isn't the largest geyser in the world, Old Faithful's eruptions are definitely awe-inspiring, averaging around 130 feet high. Like its name suggests, you can count on Old Faithful erupting approximately every hour and a half (the nearby visitors center can provide you with a more accurate schedule). There are several ways to see Old Faithful's power: You can join the hordes of tourists who gather around the perimeter or find a less hectic spot in the nearby Old Faithful Inn's dining room. More adventurous travelers can enjoy the mile-long hike out to Observation Point for a bird's-eye view of the Upper Geyser Basin.

Recent visitors enjoyed seeing Old Faithful, although some felt it wasn't as impressive as other Yellowstone geysers. Many, however, said this geyser is worth checking out. Despite it's fairly predictable schedule, Old Faithful's eruptions occasionally occur sooner than expected, so consider arriving early.

Read more
pawel.gaul/Getty Images
See full list of Best Things To Do in Yellowstone »

Explore More of Yellowstone

When purchasing from our site, we may earn commissions. This does not affect the quality or independence of our editorial content.

Recommended

America's 15 Coolest Ghost Towns to Visit

From Kentucky to California, the U.S. is filled with eerie abandoned cities.

Lyn MettlerAugust 22, 2019

The 7 Best New Orleans Plantation Tours

Learn about the Big Easy's history through one of these daytrips.

Holly JohnsonAugust 21, 2019

22 Top Sonoma Wineries to Visit

Sip world-class wines while enjoying vineyard and mountain views.

Gwen PratesiAugust 19, 2019

30 Amazing Caribbean Islands to Visit

It's time to plan your next tropical getaway.

Holly JohnsonAugust 8, 2019

The Best Travel Rewards Programs for 2019-20

See which airline and hotel loyalty programs come out on top.

Erin ShieldsAugust 6, 2019

20 Surprising Ways to Earn Loyalty Program Points or Miles

Branch out beyond hotel stays and flights to maximize your earnings.

Christine SmithAugust 6, 2019

The 12 Best Cancun Tours

These excursions will show you what lies beyond the city's bright beaches.

Lyn MettlerJuly 26, 2019

Traveling With Toddlers: 16 Tips to Make Your Vacation Go Smoothly

These expert travel hacks guarantee a happy trip for the whole family.

Kyle McCarthyJuly 25, 2019

The 11 Best New Orleans Ghost Tours

Hear chilling tales of the city's paranormal activity on one of these guided tours.

Kim Foley MacKinnonJuly 25, 2019

The 10 Best Seattle Boat Tours

Take in the Emerald City's top sights from the water.

Kim Foley MacKinnonJuly 24, 2019