"It was coming down good," said Maury Miller, a truck driver. "You could hear some thunder and it was dumping real hard, really hard."
The mud flow brought traffic to a standstill and stranded drivers in their cars. Motorists watched as Caltrans crews began digging out the roadway.
"I came up on a big old traffic jam," said Mary Hite of Jackson, Calif. "I'm trying to get over to the 5 [freeway] to go home and it looks like I have to go back through Tehachapi.
Earlier in the day, the National Weather Service issue a flash flood and thunderstorm warning for the area.
Pinon Hill resident Eric Newcomer says he found himself in the middle of the storm while trying to get home.
"I've seen it worse here I think, but it's never been this bad for traffic," he said.