A Hurricane in the Desert? Hilary Floods Hiking Trails in Death Valley, Other National Parks

As the remnants of Hilary moved inland, floods trapped visitors and boosted flood risk across the southwestern US.

Photo: Death Valley National Park/NPS

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On Sunday, Tropical Storm Hilary inundated southern California, causing strong winds and flooding across the region. Now, with the storm over, national parks as far away as Utah are beginning to assess the damage—and warning visitors that more floods may be on the way

Death Valley National Park closed its gates to visitors in anticipation of the storm and is now beginning to quantify the damage. The park, which usually has an annual rainfall of 2.2 inches, received that amount in Furnace Creek on Sunday alone according to preliminary measurements, which would make it the park’s rainiest day on record. Pictures posted by the park on Sunday evening showed cracked and washed-out roads, with Death Valley officials writing that 400 visitors and workers were sheltering in place as crews attempted to clear the road out of the park and law enforcement searched for stranded motorists and hikers.

“At this point, Hilary has passed and now we are assessing roads,” Abby Wines, the management analyst of Death Valley National Park told Backpacker. Some of the difficulties that the park is facing include high waters and a lack of electricity. Wines also noted that park officials will be on the lookout for damage to the park’s power lines, water supply, and sewer systems as they continue to assess the hurricane damage. 

Like Death Valley, Joshua National Park is at a risk of flooding. While Joshua Tree is set to reopen to day use on Tuesday, August 22, all campgrounds and dirt roads remain closed.

In a message, the park reminded visitors not to attempt to drive through flood waters, should they encounter them. 

Flash floods are rivers of mud and rocks that can easily sweep cars off roads,” they wrote. “Emergency responders may not be able to reach people in need.”  

Hilary’s impacts haven’t been limited to California parks, either. Heavy rains boosted the risk of flash flooding to its highest level in Zion National Park on Saturday, with park personnel warning hikers to avoid slot canyons over the weekend. Bryce Canyon and Capitol Reef National Parks also saw higher-than-normal risks of flooding. 

While it might seem odd that a tropical storm could impact the Utah desert, Zion, like much of the southwest, is particularly prone to flash flooding because its soil is often sun-baked and less absorbent than other types of ground. This means that the region can experience flooding with even the relatively small amounts of rain that Hilary dropped as it petered out, creating a dangerous environment for outdoor recreationists. 

Those who choose to hike in this region in the near future should monitor flood conditions and contact rangers prior to their visit. In addition to flooding, Hilary’s aftereffects could also increase the risk of mudslides and rockfall. 

Hilary was the first tropical storm to hit California since 1939. Although meteorologists downgraded it from a class 4 hurricane to a tropical storm prior to landfall, the impacts of it are likely to last for weeks to come.

From 2023