Excelsior Geyser Crater

Excelsior Geyser Crater, located in the Midway Geyser Basin of Yellowstone National Park, is one of the most awe-inspiring and mysterious hydrothermal features in the park. Once one of the most powerful geysers on Earth, it now rests as a massive steaming crater filled with turquoise-blue water, quietly hinting at its violent past. 

The crater spans about 276 feet (84 meters) across, making it one of the largest active hot spring vents in Yellowstone. The sheer scale of Excelsior, combined with its vivid colors and continuous plumes of rising steam, makes it a captivating sight for anyone exploring the basin near the famous Grand Prismatic Spring.

Excelsior Geyser Crater

Excelsior Geyser Crater

Quick Reference: Excelsior Geyser Crater

Feature	Details
Location	Midway Geyser Basin, Yellowstone National Park, Wyoming, USA
Type	Geyser Crater / Hot Spring
Current Status	Dormant geyser, now an active hot spring
Dimensions	Approximately 276 feet (84 meters) across
Water Temperature	Around 199°F (93°C)
Eruption History	Last major eruptions in the late 1800s; minor activity noted in 1985
Historic Eruption Height	Up to 300 feet (91 meters) during the 19th century
Water Discharge Rate	Over 4,000 gallons (15,000 liters) per minute into Firehole River
Color	Deep turquoise-blue center with orange, brown, and green runoff channels
Surrounding Features	Grand Prismatic Spring, Turquoise Pool, Opal Pool, Firehole River
Accessibility	Easily accessible via boardwalk in Midway Geyser Basin
Best Viewing Time	Early morning or late afternoon (for light and steam effects)
Safety Note	Stay on boardwalks—boiling water and thin crust make off-trail access dangerous
Fun Fact	Once called the “Sleeping Giant,” Excelsior’s eruptions were so powerful they destroyed its vent, ending its geyser phase.

In the late 19th century, Excelsior was far from the tranquil pool visitors see today. It was a mighty geyser that erupted with explosive force, reaching heights of up to 300 feet (91 meters). Historical records show that its eruptions were unpredictable but spectacular, sending boiling water and steam skyward in immense volumes. However, the geyser’s power came at a cost—it blasted so violently that it destroyed much of its own vent. After its final known eruption in the 1890s, Excelsior fell silent for almost a century, transforming into a massive hot spring instead. The crater’s floor collapsed inward, creating the wide, deep pool that exists today.

Though dormant as a geyser, Excelsior remains an incredibly active hot spring. Its deep blue waters are heated by magma chambers beneath the surface, maintaining temperatures around 199°F (93°C). The water continuously overflows into the nearby Firehole River, discharging over 4,000 gallons (15,000 liters) of boiling water every minute—one of the highest outputs of any thermal feature in Yellowstone. The runoff creates streaks of orange, brown, and green thermophilic mats that flow down the crater’s slope, giving the surrounding landscape an otherworldly palette of colors. These vibrant microbial communities thrive in the extreme heat, turning Excelsior into a living laboratory for studying heat-tolerant organisms.

The environment around Excelsior Geyser Crater is shaped by both its heat and history. The steam rising from the surface carries a distinct sulfur scent and blankets the area with warmth, especially on cool mornings. The combination of scalding water, acidic minerals, and colorful thermophiles creates a dynamic and ever-changing ecosystem. The crater’s immense depth—believed to reach over 50 feet (15 meters)—gives the water a mesmerizing gradient of blues that shift depending on light and temperature.

Visitors today can view Excelsior Geyser Crater from the Midway Geyser Basin boardwalk, which offers close but safe access to its rim. While it no longer erupts, there have been small bursts of activity in the 1980s that suggested it still holds potential for future geyser behavior. Scientists continue to monitor the crater for thermal changes, as Yellowstone’s geothermal features are constantly evolving. Its proximity to Grand Prismatic Spring makes Excelsior a must-see stop, where the contrast between its serene blue water and the chaotic heat of the surrounding basin tells a story of transformation and raw geological power.

Excelsior Geyser Crater is more than just a remnant of the past—it is a symbol of Yellowstone’s living geology. Though silent, it hums with energy beneath the surface, reminding visitors that Yellowstone’s volcanic heart never truly sleeps. For those who stand before it, watching steam roll across the Firehole River and feeling the earth’s heat radiate through the boardwalk, Excelsior Geyser Crater offers a rare glimpse into the untamed forces that shape our planet.