The National Park Service announced a rain storm on Saturday that could affect the life of tens of thousands of visitors to the Grand Canyon.
The storm is expected to last until late Monday.
The National Weather Service said the rainfall will affect the canyon as well as areas in the San Gabriel Mountains and the Mojave Desert.
The rain could disrupt the flow of water from the Colorado River and cause landslides.
The NPS said the storm will likely hit in the morning or evening.
It will also affect tourists, but the agency said it is not currently warning people to avoid the canyon.
Some visitors may not be able to make it to the park in time.
The weather service said it expected heavy rain and heavy winds over parts of Southern California through Sunday night.
The agency urged anyone who may have been planning to visit the park to get in touch.
For more on the Grand Staircase-Escalante National Monument, visit azcentral.com/grand-staircase