Brazilian authorities said Wednesday that a 17-year-old Oregon girl missing since last weekend was seen hitchhiking to the capital of Brasilia from a small city about 80 miles away.

MyKensie Martin, a senior at Summit High School in Bend, Ore., on an exchange visit to Brazil, was spotted by a witness by the side of a highway leading to Brasilia about 6 p.m. Sunday, said Unai police Detective Celso Avila Pardo.

The witness talked with Martin as she was trying to hitchhike, and the girl said she was on her way to attend an event in Brasilia sponsored by the Mormon church and did not have enough money for a bus ticket, Pardo said. The girl is a Mormon. Unai is about 500 miles north of Sao Paulo.

Unai police visited local hotels in the city of 65,000 people, but found no one else who had seen Martin, Pardo said. Officials with the Mormon church in Brazil referred comment Wednesday to a media relations office in Sao Paulo, but no one answered the phone there.

While there was no immediate sign that anything suspicious had happened, Pardo said American Embassy officials and police in Brasilia had been notified. The witness told police the teen appeared nervous, but believed that was because she did not have enough money for a bus ticket, Pardo said.

The girl's parents were scheduled to fly Wednesday to Brazil. The FBI was also assisting in the case, said FBI spokeswoman Beth Anne Steele in Portland, Ore.

"We're preparing for the worst and hoping for the best," the teen's father, Steve Martin, told The Bulletin newspaper of Bend. "We just feel we need to get down there because we can't effectively communicate from here and we need to be there to find out anything we can."

Martin had last been in contact with her Bend family on Saturday, when they received an e-mail, said Ashley Martin, the missing teen's sister-in-law.

"She sounded like she was doing great, she sounded very upbeat," Ashley Martin said by telephone from Bend.

In the e-mail, she said she was getting ready to take guitar lessons and was a joining a gym, Ashley Martin said.

She called her sister-in-law "a very considerate, kind and loving person," a gifted student and singer, and said she is involved in student government and community services.

American officials in Brazil are in contact with the girl's family, said Maryann McKay, a spokeswoman for the American consulate in Rio de Janeiro, which handles cases involving Americans in the state of Minas Gerais, where Unai is located.

Martin reportedly left her host city of Carmo do Paranaiba in Minas Gerais state early Sunday to travel 38 miles by bus to the city of Patos de Minas, where she attends a Mormon church.

But instead of returning to Carmo de Paranaiba, she changed her bus ticket to travel 150 miles to Unai. The girl left Oregon in July for a yearlong stay in Brazil.

Martin's father told The Bulletin that his daughter last used her ATM card on Saturday, when she withdrew $12.

He said she understands Portuguese well enough to get around, but isn't fluent.