(NewsNation) — Yellowstone National Park remained closed Tuesday because of Monday’s historic flooding, right as summer tourism in the area starts to ramp up.

A torrent of rain, combined with a rapidly melting snowpack, caused this torrent of flooding. Electricity was cut off, and there were numerous homes and other structures destroyed. No injuries were reported.

Yellowstone officials are now assessing damage from the storms that washed away bridges, caused mudslides and forced people in small towns to evacuate by boat and helicopter. Officials sealed off all five entrances into the park.

It is unknown exactly how many visitors are stranded and how many have been rescued or evacuated. In the 900-person town of Gardiner, Montana, flooding cut off road access, and evacuations were issued to Livingston residents. Flooding on the Stillwater River stranded 68 people at one campground.

Two helicopters were sent by the Montana National Guard to assist with evacuations.

The National Park Service has called the conditions at the 2 million-acre park “extremely hazardous.” Over the past few days, the Yellowstone River has broken its all-time record for flooding by nearly two feet.

It crested at 13.88 feet Monday, higher than the previous record of 11.5 feet set in 1918, according to the National Weather Service.

Yellowstone will not be reopened to tourists until floodwaters subside, and damage throughout the park can really be assessed, park superintendent Cam Sholly said.

This all comes during a high tourism season for Yellowstone: June is one of the park’s busiest months, with an annual wave of over 3 million visitors that doesn’t abate until fall.

Jennifer Ruth was on vacation with her family, intending to enter Yellowstone Monday morning. But as they pulled up, a sign was being put up on the road saying the park was closed.

“While we had noticed that water levels were pretty high, we had no idea that they were that bad,” she said on NewsNation’s “Morning in America.”

A man told them the park was being evacuated, so Ruth’s family went back to a visitor center, where they found others in their situation. Ruth and her family are now at a hotel in Jackson, Montana.

“We were all scrambling to try to find accommodation and alternative plans,” Ruth said. “We are quite disappointed. But very happy that we didn’t get stuck in a crisis situation.”

The flooding happened while other parts of the U.S. burned in hot and dry weather. More than 100 million Americans were being warned to stay indoors as a heat wave settles over states stretching through parts of the Gulf Coast to the Great Lakes and east to the Carolinas.