Yellowstone closes Biscuit Basin for the season after hydrothermal explosion

An area of Yellowstone National Park in Wyoming where a hydrothermal explosion launched steam and debris into the air Tuesday will be closed for the rest of the season because more blasts may occur, officials said.

No one was hurt in the blast at around 10 a.m. Tuesday in Biscuit Basin, 2 miles northwest of Old Faithful. Video showed some visitors running after the explosion.

The hydrothermal explosion was caused by “water suddenly transitioning to steam in the shallow hydrothermal system beneath Black Diamond Pool,” the U.S. Geological Survey said.

“Given the recent changes to the hydrothermal plumbing system, small explosions of boiling water from this area in Biscuit Basin continue to be possible over the coming days to months,” the USGS said in a statement.

Biscuit Basin will be closed for the rest of the 2024 season as a result, the park said. The Grand Loop Road remains open to vehicles and other thermal basins in the area are also open.

The geyser was hundreds of feet high, and rocks the size of grapefruit were found as far as hundreds of feet away, officials said. A boardwalk was also destroyed.

“Some blocks closest to the explosion site are about 3 feet (1 meter) wide and weigh hundreds of pounds,” the USGS statement said.

Hydrothermal explosions are relatively common on Yellowstone National Park, which is known for its hot springs and other thermal features, officials said.

Hydrothermal explosions happen in the park a few times a year, the USGS said, although often they happen in remote backcountry areas.