Twin 4-year-old girls climbed out of the wreckage of a deadly crash in Washington state and climbed up a 200-foot embankment to seek help, authorities said Saturday.

A motorist passed the pair on the winding road Friday and turned around and stopped to help, ultimately summoning authorities, said Trooper Heather Axtman of the Washington State Police. The woman's name was not released, but police are trying to reconnect with her, Axtman said.

The twins were hospitalized with minor injuries.

"The girls were extremely heroic and extremely brave," Axtman said.

The driver, pronounced dead at the scene of the Whidbey Island crash, about 80 minutes north of Seattle, was identified as Corey M. Simmons, 47, of nearby Langley, according to a state police report.

Seattle NBC News affiliate KING reported he is the father of the girls. They were later reunited with family members, Axtman said.

Authorities did not know why the vehicle veered off the road Friday night before colliding with trees, but weather was not believed to be a factor, Axtman said. There were no obvious signs of intoxication, but Simmons' blood would likely be tested for alcohol and narcotics, she said.

The girls appeared to have been legally strapped into booster seats, but the father was not using a seat belt, according to the report.

The after-dark crash happened on a stretch of highway that doesn't have roadway lighting, Axtman said.