Morning Glory Pool

Overview

Morning Glory Pool sits at the far end of the Upper Geyser Basin boardwalk, a famously colorful hot spring named in 1883 for its flower-like shape. Even after decades of change, it’s still one of the basin’s most striking sights—an eye of deep blues ringed with yellows, oranges, and greens.

Why the Colors Look Like That

The palette comes from thermophiles—heat-loving microbes that thrive at different temperatures. Hottest zones favor colorless/yellow species; cooler edges host orange, brown, and green communities. Morning Glory averages around 159°F, with clear, hot water rising through open “plumbing” that keeps it a hot spring rather than a regular geyser.

A Cautionary History

Early visitors tossed coins, rocks, and trash into the pool, partially blocking its vent and reducing water flow. Cooler water let more microbes colonize the pool, shifting it from the legendary sapphire toward greens and golds. The old park road once ran right by here—easy access made littering worse—until it was rerouted in the 1970s. Cleanups helped, but the pool may never fully return to its early-blue look. Very rarely, it has behaved like a geyser after seismic activity, but don’t count on seeing that.

Getting There

Start at the Old Faithful/Upper Geyser Basin area and follow the paved path and boardwalk a little over a mile one way. Many visitors rent bikes at Old Faithful and ride the old road alignment out. There’s no roadside pullout at the pool itself. Alternatively, you can link in from Biscuit Basin via a connector trail from the north.

What You’ll See on the Way

The route is a greatest-hits stroll through the Upper Geyser Basin, with frequent pools and geysers and, not uncommonly, bison along or near the path. An observation platform lets you peer into Morning Glory’s deep, clear “throat.”

Best Times to Visit

• For fewer people: come early morning or late afternoon.
• For photography: midday sun often reduces steam and illuminates the colors well; calm conditions help clarity, while cold air can increase steam.

Photo Tips

• A circular polarizing filter can cut glare and intensify color.
• A little extra height (e.g., a selfie stick or holding your camera up) helps frame the full circle cleanly from the platform.

Facilities and Practicalities

A vault toilet is located near the pool. For flush restrooms, food, and water, use the Old Faithful developed area. Expect an out-and-back walk; bring water and sun protection.

Safety and Stewardship

Stay on boardwalks—thermal ground is thin and water can cause severe burns. Never throw coins or anything else into thermal features; debris can block vents and permanently alter these fragile systems.