SACRAMENTO, Calif. (AP) - Sheriff's officials said Thursday they believe a woman who walked into a police station had been kidnapped as an 11-year-old in 1991 outside her South Lake Tahoe home. Two people were arrested on suspicion of kidnapping.

The woman came into a San Francisco Bay area police station and said she was Jaycee Lee Dugard, a blond, ponytailed girl when she was abducted as she headed to a school bus stop 18 years ago, said sheriff's Lt. Les Lovell of the El Dorado Sheriff's Department.

"We're 99 percent sure it's her," Lovell said. He said DNA tests were being conducted. The woman was in good health. It was not immediately clear when she had surfaced at the station.

Lovell said Concord police did an investigation after the woman surfaced, and he received a call Wednesday from investigators who had tentatively identified her as Dugard.

Her family has been contacted and they are in the process of arranging a meeting, said Lovell, who was a detective assigned to help investigate the kidnapping in 1991. "We are very confident at this point in time that it is her."

Jimmie Lee, a spokesman for the Contra Costa County Sheriff's Department, said FBI and El Dorado sheriff's deputies arrested two suspects Wednesday night. They were being held in the Contra Costa County Jail in Martinez.

Lee said the two were being held for investigation of several charges, including kidnapping, but he could not elaborate.

Law enforcement sources said authorities were also searching a home in Antioch.

Dugard's stepfather, Carl Probyn, said the news was like winning the lottery.

"To have this happen where we get her back alive, and where she remembers things from the past, and to have people in custody is a triple win," he told The Sacramento Bee.

Witnesses reported that a vehicle with two people drove up to Dugard and abducted her while her stepfather was watching on June 10, 1991, the Sheriff's Department said in a news release Thursday.

In media reports at the time, the girl's stepfather said he heard Jaycee scream then jumped on a bicycle and frantically pedaled after the car in a failed effort to follow it up a hill. He then turned around and screamed at neighbors to call 911.

The case attracted national attention and was featured on TV's "America's Most Wanted," which broadcast a composite drawing of a suspect seen in the car.

Probyn said his wife, Terry, had spoken with Dugard by phone on Wednesday. He said the mother and their 19-year-old daughter were flying from their Southern California home to meet with Dugard in Northern California.

Investigators first visited with his wife about three weeks ago, he said.

Probyn said he endured years of suspicion from FBI agents who believed he may have been involved in the abduction. He eventually lost hope that he would ever see his stepdaughter alive.

"Then you pray that you get her body back so there is an ending," Probyn said.

Lovell said investigators have been working the case consistently since she was abducted and new leads had surfaced over time.

"You bet it's a surprise. This is not the normal resolution to a kidnapping," he said.