It is classified as a dormant geyser, meaning it retains the capability to erupt but has remained quiet for decades.
The discharge from this crater flows directly into the Firehole River, significantly raising the river's water temperature.
Its intense deep-blue color is caused by the depth of the pool and the scattering of light in silica-rich water.
Major eruptions in 1985 propelled water up to 300 feet into the air.
The water within the crater contains high concentrations of dissolved minerals that accumulate along the edges.
Excelsior Geyser Crater is a massive, dormant geyser crater located in the Midway Geyser Basin of Yellowstone National Park. Measuring approximately 200 by 300 feet, it functions as a vibrant blue, steaming hot spring that discharges over 4,000 gallons of water per minute into the Firehole River. While it was once the world's largest geyser, its last recorded major eruptions occurred in the late 1980s. The pool maintains a constant temperature of roughly 199 degrees Fahrenheit. It is the primary contributor of mineral-rich water to the nearby Grand Prismatic Spring. The crater features steep, jagged walls composed of travertine deposits built up over centuries of geothermal activity.
From the elevated section of the boardwalk directly overlooking the crater's edge.
Stay strictly on the elevated boardwalk to avoid the dangerous, thin crust and scalding water.
Visit during cooler morning hours when the steam contrasts most visibly with the ambient air.
Use polarized sunglasses to better see through the steam and into the depths of the blue water.
Attempting to touch the water or throwing objects into the pool, which can damage the delicate geothermal plumbing.
Accessible only during the summer and shoulder seasons when park roads are open to general traffic.
Maintain strict adherence to boardwalk boundaries; thermal ground is fragile and dangerous.
