High water levels in the Gardner River erode Yellowstone National Park's North Entrance Road in Montana. Reuters

All entrances to Yellowstone were closed due to the deluge, caused by heavy rains and melting snowpack, while park officials ushered tourists out of the most affected areas.

READ MORE

Trump blasts US Capitol riot hearings as 'mockery of justice'

Court refuses to stop UK from deporting migrants to Rwanda

There were no immediate reports of injuries, though dozens of stranded campers had to be rescued by raft in south-central Montana. Authorities also said they would be assessing a potential "loss of homes and structures” in Montana’s Stillwater County.

Elsewhere, some of the worst damage happened in the northern part of the Yellowstone and the park's gateway communities in southern Montana. National Park Service photos of northern Yellowstone showed a landslide, a bridge washed out over a creek, and roads badly undercut by churning floodwaters of the Gardner and Lamar rivers.

This photo shows the washed out bridge from flooding at Rescue Creek in Yellowstone National Park. AP

The flooding cut off road access to Gardiner, Montana, a town of about 900 people near the confluence of the Yellowstone and Gardner rivers, just outside Yellowstone’s busy North Entrance.

At a cabin in Gardiner, visitor Parker Manning of Terra Haute, Indiana, got an up-close view of the water rising and the river bank sloughing off in the raging Yellowstone River floodwaters just outside his door.

"We started seeing entire trees floating down the river, debris,” Manning told The Associated Press. "Saw one crazy single kayaker coming down through, which was kind of insane.”

The Yellowstone River at Corwin Springs crested at 13.88 feet (4.2 metres) on Monday, higher than the previous record of 11.5 feet (3.5 meters) set in 1918, according the the National Weather Service.

Floodwaters inundated a street in Red Lodge, a Montana town of 2,100 that’s a popular jumping-off point for a scenic, winding route into the Yellowstone high country. Twenty-five miles (40 kilometers) to the northeast, in Joliet, Kristan Apodaca wiped away tears as she stood across the street from a washed-out bridge, The Billings Gazette reported.

The log cabin that belonged to her grandmother, who died in March, flooded, as did the park where Apodaca’s husband proposed.

"I am sixth-generation. This is our home,” she said. "That bridge I literally drove yesterday. My mom drove it at 3am before it was washed out.”

Yellowstone officials were evacuating the northern part of the park, where roads may remain impassable for a substantial length of time, park Superintendent Cam Sholly said in a statement.

But the flooding affected the rest of the park, too, with park officials warning of yet higher flooding and potential problems with water supplies and wastewater systems at developed areas.

"We will not know timing of the park’s reopening until flood waters subside and we’re able to assess the damage throughout the park,” Sholly said in the statement.

The park's gates will be closed at least through Wednesday, officials said. It was unclear how many visitors have been forced to leave the park.

The rains hit right as summer tourist season was ramping up. June, at the onset of an annual wave of over 3 million visitors that doesn’t abate until fall, is one of Yellowstone’s busiest months.

Associated Press