Hunt goes on for hiker in Washington state
Mass. teacher sought in park
A search effort continued yesterday for an elementary school teacher and rowing coach from Arlington who vanished this week while hiking in Washington state.
Helicopters, dog teams, and ground crews combed the Sol Duc section of Olympic National Park, where officials believe that Mary O'Brien, 45, was hiking when she disappeared.
Officials believe that O'Brien set out on Monday. A friend in the Seattle area notified authorities Wednesday when O'Brien did not return.
"We're hoping and praying for her and waiting to hear good news that she'll come home safely," said Julie Buckley, a shift manager at Healthworks in Cambridge, where O'Brien has worked as a personal trainer.
O'Brien is also a part-time rowing instructor for Row As One in Newton and has conducted various clinics for the organization, according to an online biography.
She has coached rowing at Wellesley College and has coached crews of junior girls and masters women in Seattle, the biography says.
"Her favorite rowing moment was winning the lightweight pair with her sister at American Nationals," says the biography, posted on the Row As One website.
Her sister was due to arrive yesterday at the search site in Washington, park officials said.
A search dog picked up O'Brien's scent Thursday and followed it for about 2 miles, officials said.
O'Brien -- whom officials described as a strong, experienced hiker -- joined an online community of hikers at the University of Washington on June 11 and said she was looking for hiking partners to join her on a trek to summit Mount Rainier this week, according to the club's website.
O'Brien had tried to summit Mount Rainier before, including last July when someone in her party got sick and they had to turn back 500 feet from the peak.
Material from the Associated Press was used in this report. Donovan Slack can be reached at dslack@globe.com. 
