Officials are ratcheting down the scope of their search for a Schererville woman, a week after she went missing in Yosemite National Park.

Investigators are at a "pivotal point" in their hunt for 80-year-old Ottorina "Trina" Bonaventura, said Adrienne Freeman, of the National Park Service's incident investigations unit.

Workers are still aggressively looking, but are no longer issuing a large-scale call for rescue workers or resources. The downgrade means the size of rescue teams will drop, but Freeman said she did not know by how much.

"It doesn't change what we do," she said. "We've pretty much done what we can with what we have. We have to manage the search based on what we're finding."

What they're finding are some leads, but no answers as to why Bonaventura, an experienced hiker, vanished last week.

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 has not been seen since.

Freeman said the NPS never stops looking for hikers, but that the chance for survival dwindles with each day someone is missing.