CATHEDRAL CITY, CA (AP) — Crews worked to dig roads, buildings and rescue residents from the mud across a wide swath of Southwestern U.S. desert Monday, as the first tropical storm to hit Southern California in 84 years headed north, prompting flood watches and warnings in half a dozen states.

The National Hurricane Center in Miami said Tropical Storm Hilary had lost much of its force as it headed to the Rocky Mountains but warned that “continued life-threatening and locally catastrophic flooding” was expected in parts of the region. Forecasters said the threat for flooding in states farther north on Monday was highest across much of southeastern Oregon into the west-central mountains of Idaho, with potential thunderstorms and localized torrential rains on Tuesday.

As Hilary moved east into the neighboring state of Nevada, flooding was reported, power was out and a boil-water order was issued for about 400 households in the Mount Charleston area, where the only road in and out was washed out. The area is about 40 miles west of Las Vegas.

Hilary first slammed into Mexico’s arid Baja California Peninsula as a hurricane, causing one death and widespread flooding before becoming a tropical storm. So far, no deaths, serious injuries or extreme damages have been reported in California, though officials warned that risks remain, especially in the mountainous regions where the wet hillsides could unleash mudslides.

In one dramatic scene, rescue officials in the desert community of Cathedral City, near Palm Springs, drove a bulldozer through mud to a swamped care home and rescued 14 residents by scooping them up and carrying them to safety, Fire Chief Michael Contreras said. “We were able to put the patients into the scoop. It’s not something that I’ve ever done in my 34 years as a firefighter, but disasters like this really cause us to have to look at those means of rescue that aren’t in the book and that we don’t do every day,” he said at a news conference.

It was one of 46 rescues the city performed between late Sunday night and the next afternoon from mud and water standing up to 5 feet. Flooding and mudslides were reported across Southern California’s inland desert and mountain areas.

In the San Bernardino Mountains, crews worked to clear mud that blocked the homes of about 800 residents, Cal Fire Battalion Chief Alison Hesterly said.

In the Coachella Valley city of Desert Hot Springs, Steven Michael Chacon said the roads in the housing development where he and his husband live were impassable due to flooding and he was concerned emergency crews might not be able to reach people. “Basically everybody’s got to stay put, there’s no way in or out,” he said Monday morning. Authorities also say a woman was unaccounted for after witnesses saw her trailer swept away in a flash flood.

Hilary shattered daily rain records in San Diego and likely dumped the equivalent of a full year’s worth on Death Valley National Park, forcing the park to be closed indefinitely and leaving about 400 people sheltering at Furnace Creek, Stovepipe Wells and Panamint Springs until roads could be made passable, park officials said. “We basically blew all of our previous rainfall records out of the water,” National Weather Service meteorologist Elizabeth Adams in San Diego told The Associated Press.

A tropical storm last roared into California in September 1939, ripping apart train tracks, tearing houses from their foundations and capsizing many boats. Nearly 100 people were killed on land and at sea.