As part of a nature group, Ottorina "Trina" Bonaventura has hiked all over the world.

The 80-year-old Schererville woman and friends left for Yosemite National Park July 26, a trip that might have been old hat for her fit, independent mother, daughter Pam Crnkovich said.

But for almost a week, Bonaventura has been missing in the park, leaving Crnkovich feeling lost but hopeful.

"It's just so hard to go on like this," said Crnkovich, of Crown Point. "I just don't know what to think."

Authorities are "not ruling anything out" in their ongoing search for Bonaventura, which included dog teams, helicopters, and more than 100 people Saturday.

"As the days pass, the chance of survival diminishes," said Adrienne Freeman of the National Park Service's incident investigations unit. "But we're still optimistic."

Bonaventura was reported missing July 30, after she separated from her group on a day hike. She told friends she was returning to the Vogelsang High Sierra Camp.

"And then she was gone," Crnkovich said.

Tony Bonaventura traveled to Yosemite to help in his mother's investigation. From him, Crnkovich and others, investigators are learning traits about Bonaventura that could aid in finding her. Among them, Freeman said, is that "she's unlikely to ask for help."

She is an experienced hiker, but might not have a good sense of direction, Freeman added.

The retired computer programmer spends her mornings at the gym, Crnkovich said, and rides her bicycle around her neighborhood.

Freeman said workers have expanded their search area, but there's no sense of how long it might take to find Bonaventura.

"Every search is a little bit different," she said. "But we never stop searching."

For now, Crnkovich keeps in touch with investigators, and waits.

"I'm just at a loss," she said. "There's really not a lot for us to do."