Surprise Blast of Rock, Water, and Steam in Yellowstone Sends Dozens Running for Safety

The park staff assess the damage to Biscuit Basin boardwalks after a hydrothermal explosion at Biscuit Basin in Yellowstone National Park, Wyo., on July 23, 2024. National Park Service via AP

CHEYENNE, Wyo.—A surprise eruption in Yellowstone National Park shot steam, water, and dark-colored rock and dirt high into the sky Tuesday and sent sightseers running for safety.

The hydrothermal explosion happened around 10 a.m. in Biscuit Basin, a collection of hot springs a couple of miles north of the famous Old Faithful Geyser.