Flooding Closes Yellowstone, in a Sign of Crises to Come

Devastating rain and mudslides that tore out bridges, flooded homes and forced some 10,000 tourists to evacuate Yellowstone National Park this week will keep the northern reaches of the park, one of the nation’s most-visited natural wonders, cut off to visitors for the rest of the busy summer travel season. And officials warned that more rain and flooding could be on the way.

The entire park will remain closed for a week or so while the authorities deal with damaged roads and collapsed bridges, Cam Sholly, the park’s superintendent, said in a news conference late Tuesday, and the entrances on the northern half of the park will likely remain inaccessible until around Halloween.

Mr. Sholly described the floods and mudslides driven by four days of record rains and melting snow as a “thousand-year event, whatever that means these days. They seem to be happening more and more frequently.” He estimated that at least 10,000 people were visiting when the evacuations began.

Only a dozen campers remain in the park’s backcountry, he added. All are safe.

Despite some harrowing moments, the only injury reported from the storm was one person suffering a fatal cardiac arrest at a campground, officials said. On Tuesday, Gov. Greg Gianforte of Montana declared a statewide disaster.

Millions of tourists are drawn each year to the wilderness and active geysers in Yellowstone, the oldest national park in the United States, which sprawls across more than two million acres in the northwest corner of Wyoming and into Montana and Idaho. In 2021, more than 4.8 million people visited.

America’s national parks saw a surge in visitors during the coronavirus pandemic, but they face increasing strain as climate change and other factors generate more extreme weather, including droughts, wildfires and floods. Over the next few decades, Yellowstone is expected to see an increase in fires, dying forests, expanding grasslands, more invasive plants and shallower, warmer waterways.

The storm that caused the flooding and mudslides this week began with two to three inches of rain over the weekend. Combined with warming temperatures that melted 5.5 inches of snow, the rain created a major flood, Mr. Sholly said. Officials evacuated visitors from the battered north of the park on Monday, and floods were still raging late Tuesday.

Hundreds of homes were flooded in communities north of the park in Montana, including Gardiner and Cooke City, which were also cut off from supplies of food and clean water, officials said.

Ominously, some forecasts suggest more warmth and rain in four to five days, even as another foot of snow remains on Yellowstone’s mountains, raising the possibility of yet another series of floods, Mr. Sholly said.