A 20-year-old San Diego woman was in critical condition Friday after falling and hitting her head on some rocks in Iao Valley, a Maui Fire Department spokesman said.

The woman was with friends and family when she fell about 3:30 p.m. and hit her head on rocks lining a river bank about a mile north of Iao Valley State Park in west Maui, an MFD spokesman said.

MFD workers treated her at the scene and a helicopter lifted her out of the valley about an hour later. She was taken to Maui Memorial Hospital with a critical head injury.