Yellowstone closed for first time in 34 years amid flooding, mudslides

Record flooding and rockslides unleashed by an unprecedented burst of heavy rains prompted the rare closure on Monday of all five entrances to Yellowstone National Park at the start of the summer tourist season, the park superintendent said.

The entire park, spanning parts of Wyoming, Montana and Idaho, will remain closed to visitors, including those with lodging and camping reservations, at least through Wednesday, as officials inspect the damage to roads, bridges and other facilities.

The closures come as Yellowstone was gearing up to celebrate its 150th anniversary year, and as local communities heavily dependent on tourism were counting on a rebound following COVID-19 travel restrictions over the past two summers.

All five park entrances were closed to inbound traffic for the first summer since a series of devastating wildfires in 1988. The National Park Service said it was working to evacuate visitors and staff remaining at various locations, especially in the hardest-hit northern flank of Yellowstone.

"It is likely that the northern loop will be closed for a substantial amount of time," the park superintendent, Cam Sholly, said in a statement.

The "gateway" community of Gardiner, Montana, just beyond the park's northern boundary and home to many of Yellowstone's workers, was cut off by a mudslide to the north and washed-out road surfaces to the south, according to the National Park Service.

Aerial footage released by the Park Service showed large swaths of the winding North Entrance Road between Gardiner and park headquarters in Mammoth Hot Springs, Wyoming, carved away by surging floodwaters along the Gardner River - washouts that will likely take months to fully repair.

Power outages were scattered throughout the park, and preliminary assessments showed numerous roadways across Yellowstone either washed away or covered in rocks and mud, with a number of bridges also damaged, the agency said.

Various roads in the park's southern region were on the verge of being flooded, with more rain in the forecast.

The flooding and slides were triggered by days of torrential showers in the park and steady rains across much of the wider Intermountain West following one of the region's wettest springs in many years. The park service characterised the rainfall and floods sweeping the park as unprecedented, with the Yellowstone River topping its banks beyond record levels.

A sudden spike in summer temperatures during the past three days also has hastened melting and runoff of snow accumulated in the park's higher elevations from late-winter storms.

The heavy rains and rapid runoff of snowmelt converged to create treacherous conditions in the park just two weeks after the traditional Memorial Day holiday weekend kickoff of the US summer tourist season, which accounts of the bulk of Yellowstone's annual 4 million visitors.

Yellowstone, established as the world's first national park in 1872 and treasured as one of America's top outdoor travel destinations, occupies some 2.2 million acres famed for its geysers, abundant wildlife and spectacular scenery.