YOSEMITE NATIONAL PARK, Calif.—Park managers have closed off part of a main road through Yosemite National Park after a rockfall launched granite chunks onto the valley floor.

Rangers say they heard the sound of falling rocks starting Tuesday afternoon, and rocks continued falling overnight. No one was injured and no buildings were harmed.

The section of Northside Drive between Camp 4 and the Pohono Bridge is expected to remain closed through Christmas, or until visibility improves once the storm system clears.

Park spokeswoman Adrienne Freeman says rockfalls are common in the winter months, when precipitation and recurring freeze-and-thaw cycles cause soil to loosen.