WASHINGTON (AFP) - A 16-year-old girl from the United States state of Washington was in hospital on Tuesday after surviving a small plane crash and spending days in the wilderness, a local newspaper reported.

Autumn Veatch was on the plane with her step-grandparents travelling to Montana on Saturday when it crashed in the state's northern stretch of the Cascade Mountain range, The Seattle Times reported.

Reported missing and feared dead, Autumn tried to pull her step-grandparents from the crashed plane and then followed a river to a road before making her way to a nearby store, the paper said.

After hiking through the rugged mountains, Autumn hadn't had anything to eat or drink for days, a first responder told the newspaper.

She was hospitalised on Monday in the Washington town of Brewster, where her father visited her later in the day, but had no serious injuries.

Crews are still searching for the plane, the paper reported, and the authorities have not confirmed the fate of the step-grandparents or said what may have caused the crash.