America’s Most Beautiful Hot Spring Has Every Color of the Rainbow & Spans the Length of a Football Field

Yellowstone’s Grand Prismatic Spring

Grand Prismatic Spring in Yellowstone National Park is the largest hot spring in North America and the third-largest in the world, after Frying Pan Lake in New Zealand and Boiling Lake in Dominica. This natural wonder sits in the Midway Geyser Basin next to the Firehole River, stretching 370 feet across.

Its name comes from the rainbow-colored bands that circle its deep blue center. A powerful volcanic explosion thousands of years ago created the crater that’s now about 121 feet deep.

Here are some interesting facts about one of Earth’s most remarkable natural phenomena.

The Colors Change Through the Seasons

The orange and brown rings around the spring look different depending on the time of year. In summer, especially from June to September, the bands turn bright orange and red as the bacteria make more chlorophyll in the warm weather.

When winter comes, these same rings become dark green and brown as the bacteria change to handle the cold. The colors look brightest in the middle of sunny afternoons.

Water Flows Like a Small River Each Day

The spring pushes out 560 gallons of water every minute, which adds up to 800,000 gallons per day – as much as an Olympic swimming pool. This hot water starts deep underground before cooling a bit as it reaches the surface.

As the water flows out, it leaves behind minerals that form delicate, stair-like patterns in the rocky ground around the pool. This constant flow keeps minerals from building up too much in the spring.

The Blue Center Shows Pure Water’s True Color

The middle of the spring looks blue for a simple reason – it’s showing how light behaves in pure, deep water. Just like the sky, the deep water scatters blue light more than other colors, making the center look like a blue jewel.

The water in the middle stays so clear because it’s too hot for most tiny organisms to live there. This creates a perfect condition for the blue color to show through.

Steam Creates a Special Weather Zone

Hot steam rising from the 160°F water changes the weather around the spring. In winter, Yellowstone’s temperature can drop and this warm steam keeps snow from sticking near the spring.

Some unusual plants grow here because of this warm spot, including special algae and grasses that normally couldn’t survive in Yellowstone’s high altitude. On cold mornings, the meeting of hot steam and chilly air creates clouds that rise 200 feet high.

Ancient Hot Springs Left Their Mark

Scientists have found layers of old hot springs under today’s Grand Prismatic that existed 14,000 years ago. These layers tell the story of how the area’s hot springs have changed over time.

The spring continues to build new mineral layers today, growing about as thick as a credit card each year. These deposits create tiny ridges around the edge that scientists study to learn about Yellowstone’s past.

The Rainbow Rings Show Different Temperatures

Each colored ring around the spring marks where different types of bacteria live at specific temperatures. Brown and red bands on the outside usually stay below 113°F, where bacteria makes the pigments to protect themselves.

Moving toward the center, yellow/orange areas mean the water is about 149°F, and green zones show where it’s 155°F. The blue middle is the hottest at 160°F, where almost nothing can survive.

Satellites Can See the Spring from Space

At 370 feet across, the spring is so big that satellites can spot it from miles up in space. The spring’s round shape and bright colors show up clearly in satellite photos, making it a useful landmark for scientists.

Astronauts can even see the spring when they pass over Wyoming. This view from space helps researchers track changes in the spring’s size and heat patterns over many years.

The Bacteria Are Like Time Travelers

The bacteria that make the spring colorful are similar to Earth’s first life forms from millions of years ago. These tiny organisms can live without oxygen and get energy from sulfur and iron instead of sunlight.

Some of these bacteria species exist nowhere else on Earth – they’ve grown here in isolation for so long that they’ve become unique. Scientists study them to understand how life might have started on our planet.

The Spring’s Size Changes with Earth’s Movement

Yellowstone is one of the most seismically active areas in the United States. Approximately 700 to 3,000 earthquakes occur each year in the Yellowstone area; most are not felt.

The spring’s edge moves in and out as underground water levels and earthquake activity change. During times when many small earthquakes happen, the spring might grow larger or smaller.

The Water’s Journey Takes Five Centuries

The water bubbling up today first fell as rain or snow in the Gallatin Mountains 500 years ago. It slowly sinks through layers of volcanic rock, traveling down 10,000 feet where hot magma heats it up.

The water then rises back up through cracks in the rock, picking up dissolved minerals along the way. By the time it reaches the surface, this water has been underground since the 1500s.

Native American Tribes Consider the Spring Sacred

For over 11,000 years, tribes like the Blackfeet, Crow, and Shoshone have treated the spring as a spiritual place. According to their stories, the rising steam represents ancient spirits’ breath.

Archaeologists have found sacred objects from around 1400 CE near the spring, showing that people held ceremonies here. Different tribes saw special meaning in each of the spring’s rainbow colors.

The Spring Stays Hot in All Weather

The spring keeps its 160°F temperature even when Yellowstone’s winter brings -40°F weather. When hot water meets such cold air, it creates giant steam clouds that can rise 300 feet high.

Heat from Yellowstone’s underground magma chamber has kept the spring at the same temperature since scientists first measured it in the 1880s. This steady warmth creates a safe place for heat-loving bacteria all year long.