The flash flood swept large boulders, metal structures and other debris into the Colorado River, the National Park Service said.
60 people had to be evacuated from the tourist destination Phantom Ranch. Fifty hikers at Bright Angel Campground also had to leave the area by helicopter.
More than 20 people were missing or could not be located after the flood, but no injuries have been reported.
Tourist destinations Bright Angel Campground, Phantom Ranch and parts of the North Kaibab Trail were closed, and rafting on the Colorado River was halted.
Up to 25 millimetres of rain fell in just 30 minutes.
