Heart Spring

Heart Spring is one of Yellowstone National Park’s hidden geothermal gems, quietly radiating beauty and tranquility within the vibrant Upper Geyser Basin. Though it may not have the fame of nearby features like Old Faithful or Morning Glory Pool, Heart Spring captivates those who take the time to pause and observe its striking colors and delicate formation. Its deep blue water, edged with white sinter and surrounded by radiant bands of orange and yellow thermophiles, creates a vivid contrast against the pale, mineral-rich landscape. 

Heart Spring

Quick Reference: Heart Spring

Feature	Details
Name	Heart Spring
Location	Upper Geyser Basin, Yellowstone National Park, Wyoming, USA
Type	Hot Spring
Discovered/Naming	Named by park geologist George Marler around 1959 for its heart-like shape
Dimensions	7.5 ft (2.3 m) by 10 ft (3 m) at the surface; about 15 ft (4.5 m) deep
Water Appearance	Deep, clear blue center with orange and yellow thermophilic outflow channels
Water Temperature	Approximately 184.8°F (84.9°C)
pH Level	Around 8.6 (alkaline)
Conductivity	Approximately 2021 µS/cm
Formation	Heated groundwater rises through volcanic fractures, depositing silica around the rim
Color Origin	Blue from light scattering in hot, clear water; orange and yellow from heat-loving microbes
Surrounding Features	Near Chromatic Pool, Beauty Pool, and Morning Glory Pool
Elevation	Around 7,300 feet (2,225 meters)
Accessibility	Easily reached via boardwalk trail in the Upper Geyser Basin
Best Viewing Time	Early morning or late afternoon for soft light and visible steam
Safety Note	Stay on designated boardwalks—ground near the spring is fragile and dangerously hot
Fun Fact	Its heart-shaped outline and vibrant colors make it one of Yellowstone’s most photogenic small springs

Heart Spring was named by park geologist George Marler around 1959, apparently because its shape resembles a human heart when viewed from above. This poetic naming reflects not only its physical appearance but also its quiet charm, often described by visitors as one of the most serene pools in the basin. 

The spring measures about 7.5 feet (2.3 meters) by 10 feet (3 meters) at the surface and is approximately 15 feet (4.5 meters) deep. Its waters are a brilliant, clear blue in the center—a color produced by light scattering in the superheated water that absorbs all wavelengths except blue. Surrounding the pool, vibrant orange and yellow microbial mats trace the outflow channels, showcasing thermophilic bacteria that thrive in high temperatures and mineral-rich conditions. Hard sinter—silica deposits formed from the cooling geothermal water—lines the edges of the pool, forming a delicate white rim that enhances the visual beauty of this natural feature.

Heart Spring maintains an average temperature of 184.8°F (84.9°C), an average pH of 8.6, and a conductivity of about 2021 µS/cm, indicating alkaline, mineral-laden water. The hot water rises from deep underground, where it is heated by the park’s immense volcanic system, before emerging at the surface through fractures in the Earth’s crust. As the water cools while flowing outward, it deposits silica and provides a habitat for different types of thermophilic microorganisms. This balance of heat, minerals, and life creates the unique colors and textures that make Heart Spring so captivating.

Standing before Heart Spring, one can easily understand why George Marler gave it such an evocative name. With its graceful form, vivid colors, and constant pulse of geothermal activity, it truly resembles the “heart” of the basin—a symbol of the life, heat, and motion that define Yellowstone itself.