Morning Glory Pool

Morning Glory Pool, located in the Upper Geyser Basin of Yellowstone National Park, stands as one of the most enchanting and recognizable thermal features in the world. Known for its mesmerizing color palette that shifts from deep blue to vibrant green, yellow, and orange, this hot spring has long been celebrated as the “jewel of Yellowstone.” Its beauty, however, tells a deeper story — one of geological wonder, biological balance, and the ongoing relationship between nature and humanity.

Morning Glory Pool

Morning Glory Pool

Quick Reference: Morning Glory Pool

Attribute	Details
Name	Morning Glory Pool
Location	Upper Geyser Basin, near Old Faithful, Yellowstone National Park, Wyoming, USA
Type	Hot Spring
Average Temperature	157°F–164°F (69°C–73°C)
Depth	Approximately 23 feet (7 meters)
Water Color	Blue center with green, yellow, and orange outer rings
Color Cause	Light scattering and thermophilic bacteria responding to temperature gradients
pH Level	Slightly acidic to neutral (around 6.5–7.0)
Elevation	About 7,300 feet (2,225 meters)
Formation Process	Superheated groundwater rises through cracks, depositing silica and minerals
Human Impact	Color altered due to debris and vandalism affecting circulation
Accessibility	1.5-mile paved trail from Old Faithful; accessible via boardwalk
Best Viewing Time	Morning or late afternoon for vibrant color and steam visibility
Nearby Attractions	Old Faithful, Castle Geyser, and Grotto Geyser
Fun Fact	Named in the 1880s for its resemblance to the morning glory flower

Named in the late 1800s for its resemblance to the morning glory flower, this nearly circular hot spring is both a natural masterpiece and a living laboratory of geothermal activity. The pool is about 23 feet deep (7 meters) and typically maintains temperatures ranging between 157°F (69°C) and 164°F (73°C). Its vibrant coloration results from the interaction of extreme heat, dissolved minerals, and thermophilic (heat-loving) bacteria that thrive within its depths. The clear, deep blue at the center of the pool indicates scalding water where few organisms can survive, while the outer rings of yellow, green, and orange mark cooler zones colonized by microbial mats — living organisms that form in response to temperature and chemical gradients.

Morning Glory Pool is situated just north of Old Faithful, making it one of the most visited features in the Upper Geyser Basin. Visitors can reach it by walking a pleasant 1.5-mile (2.4 km) paved trail from the Old Faithful area, following the Firehole River and passing several active geysers along the way. The pool rests quietly amid a landscape of steaming vents, spouting geysers, and colorful runoff channels. The moment it comes into view, Morning Glory captivates visitors with its almost surreal appearance — a window into the vibrant, dynamic world beneath Yellowstone’s surface.

However, the story of Morning Glory Pool is not solely one of beauty; it is also one of human impact and ecological change. Over the decades, careless visitors have thrown coins, trash, and even stones into the pool, clogging its delicate vent system. This interference reduced the circulation of hot water from below, allowing the temperature in parts of the pool to drop. The cooling water encouraged the growth of additional thermophilic bacteria, which in turn altered the pool’s color. Where the water was once a brilliant deep blue throughout, shades of yellow, green, and orange now dominate the outer edges. Though stunning, these new hues are a visible reminder of how fragile geothermal ecosystems can be — even a few degrees of change can shift the balance of life within.

In the 1950s and 60s, park rangers and scientists began cleaning out the debris to help restore the pool’s original temperature and circulation. Despite these efforts, some of the damage proved irreversible. Over time, parts of the pool’s plumbing system had been permanently altered. Yet, nature’s resilience continues to shine through; the pool remains active and beautiful, still a living geothermal spring that responds subtly to the changes beneath Yellowstone’s vast volcanic system.

Interestingly, Morning Glory Pool occasionally erupts like a geyser, although such events are rare. These eruptions typically occur when pressure builds up beneath the pool due to blockages or fluctuations in the underground plumbing system. When the pressure finally releases, a surge of boiling water and steam bursts upward, clearing some debris and restoring partial circulation. Historical records note a few such eruptions in the 1970s and 1980s, much to the surprise of onlookers who had assumed the pool was purely a passive feature.

The color variations seen in Morning Glory Pool are a fascinating display of geothermal biology. The blue in the center is caused by the scattering of sunlight in pure, clear, superheated water — much like the way sunlight creates the blue of the sky. As the water cools outward, it becomes habitable for thermophiles. These microscopic organisms form mats of different pigments depending on the temperature and mineral content. The result is a living gradient of color that transitions from blue to green to orange to brown — a stunning visual record of both life and heat beneath the surface.

For visitors, Morning Glory Pool is not just a stop on the trail but a symbol of Yellowstone itself — vibrant, delicate, and ever-changing. The boardwalks surrounding the Upper Geyser Basin allow for safe viewing, protecting both visitors and the fragile ground that overlays scalding, unstable terrain. Signs near the pool now educate the public about its history, encouraging respect for the delicate ecosystem that makes this feature possible.

In winter, when the snow blankets the surrounding landscape, steam rises from the pool in thick white plumes, making the vibrant colors stand out even more dramatically against the frosty air. In summer, the pool glows under the sunlight like a gemstone, drawing photographers and travelers from around the world. Regardless of the season, it offers a profound reminder of nature’s artistry and the importance of conservation.

Morning Glory Pool continues to inspire scientists and visitors alike. It embodies the intersection of geology, biology, and human stewardship — a place where life thrives in extremes, where color marks both beauty and change, and where the lessons of preservation are as deep as the pool itself. To stand before Morning Glory is to witness the ongoing story of Yellowstone: a story of heat, color, and the fragile balance of the natural world.