Dirty Eruption in Yellowstone Brings Wyoming a Muddy Morning Surprise

Mud flew, rocks bounced, and geologists cheered (quietly, from a safe distance) this past Saturday morning when Black Diamond Pool in Yellowstone’s Biscuit Basin let out a frosty, muddy “kablooey!”

The U.S. Geological Survey shared video of the eruption, which happened just before 9:23 a.m., showing mud shooting up into the crisp winter air. Biscuit Basin, nestled between park favorites Old Faithful and Grand Prismatic Spring, has been no stranger to explosive activity.

“This isn’t the first time Black Diamond Pool has made a dramatic entrance,” USGS scientists said. Last July, a hydrothermal explosion hurled rocks and mud hundreds of feet and damaged a boardwalk, leading to the area being closed to visitors due to safety concerns. Since then, “dirty eruptions” — geyser-like blasts of mud — have popped up sporadically, reaching up to 40 feet high.

Thanks to new cameras, seismic monitors, and temperature sensors installed this summer, scientists can now watch the pool’s antics more closely. While many eruptions over the past weeks were silent night-time events or hidden behind ice, Saturday’s blast was front and center, with snow-covered surroundings making the mud show even more dramatic.

So if you’re dreaming of a Yellowstone winter adventure, remember: some pools put on more than just a hot-spring steam show — they throw a muddy party, too.