The rockfall was discovered on Thursday when a park official came upon the boulders near the Dry Creek public parking area. No one was in the area at the time of the rockfall but a car that had been parked nearby was heavily damaged when it was struck by one of the mammoth rocks.
Park officials say boulders are strewn over the parking area and some made it down the road and into Tahoma Creek. The impact damaged the road, including leaving a crater 8 feet across and 3 feet deep.
The road will remain closed until scientists determine the likelihood of additional rockfalls and once deemed safe, the boulders are cleared.