Black Pool

Overview

Black Pool is one of the marquee hot springs on the West Thumb Geyser Basin boardwalk, right on the shore of Yellowstone Lake. Despite the ominous name, it’s a stunner—clear, intensely blue water framed by pale sinter and colorful runoff.

Why the name

It was named for the dark green and brown thermophiles that used to thrive when the water was cooler. As temperatures rose, the microbial community shifted and the pool lost that dark cast, revealing the brilliant blue you see today.

What you’ll see

• A deep teal–blue spring with striking orange/yellow runoff patterns.
• Big-lake scenery: on calm days the pool mirrors the sky and nearby shoreline.
• Abyss Pool is just steps away, making this a quick, high‑reward boardwalk loop.

History and geology

In 1991, Black Pool heated up significantly. The hotter water killed the darker thermophiles and the pool even produced bursts of activity around that period. It remains very hot—look, don’t touch—and changes in color and behavior are reminders that Yellowstone’s hydrothermal system is alive and shifting beneath your feet.

Planning your visit

• Access is via the signed West Thumb Geyser Basin boardwalk; no separate pullout for Black Pool.
• West Thumb has restrooms and picnic tables, with broader services a few minutes away at Grant Village.
• Stay on the boardwalk—ground here is thin and water can cause severe burns.

Best time to visit

• Early or late in the day for easier parking and lighter crowds.
• For photography, aim for warm, calm conditions when steam is minimal and reflections pop. On cold mornings or windy days, steam can shroud the pool.

Is it worth it?

Yes. It’s a quick, low‑effort stop with big visual payoff, especially paired with Abyss Pool and the Yellowstone Lake views on the same loop.