Three members of a San Francisco family missing for more than a week were found alive Monday along a snowy, treacherous roadway in southwestern Oregon, police said. A search continued for the father.

Investigators said a helicopter spotted 30-year-old Kati Kim waving an umbrella about 1:45 p.m. PST. Her daughters Penelope, 4, and Sabine, 7 months, were with her. They were airlifted to Three Rivers Community Hospital in Grants Pass.

"Mom arrived in an ambulance smiling and waving," Linda Rankin, vice president for patient care at the hospital, told The Associated Press. She said all three were in good condition, and would spend the night at the hospital.

Rescuers continued to look for Kati Kim's husband, 35-year-old James Kim. He left on foot two days ago to seek help, police said. Helicopters with thermal imaging technology were added to the search Monday night, and searchers were following the father's footprints over a ridge and down into a drainage.

Josephine County Undersheriff Brian Anderson said they family turned off a side road and got stuck in the snow. They had been traveling along rural roads that are often used as shortcuts to Gold Beach on the south Oregon coast. The roads are typically used by whitewater rafters in the summer, but often are treacherous and impassible during the winter.

Nursing supervisor Cynthia Russell said the mother nursed both the children while they were lost because there was no food or water in their car. The family stayed warm by running the car at night until they ran out of gas, and then they burned the tires, authorities said.

When the father struck out for help, he left wearing only tennis shoes, pants, a sweater and a jacket. His family said he had outdoor experience, and Oregon State Police Lt. Doug Ladd said there is "a very reasonable chance" that he is still alive. Russell said the family reported that he had eaten berries in the area, but they weren't sure if they were poisonous.

The family saw friends in Portland on Nov. 25 and then headed toward home after a Thanksgiving trip to the Pacific Northwest. They were last spotted at a restaurant that same day. They had reservations at a lodge, but never arrived.

During the past several days, authorities combed highways and byways using snow machines and helicopters. Troopers checked hotels and resorts along the south coast. They also tried to track the family by tracing their credit history and cell phone signals.

The area is in the same region where another family was found in their RV in March. The family, missing for more than two weeks, had also taken a shortcut and got stuck in the snow.