With no new evidence or leads as to the location of a missing Menlo Park woman believed to have been hiking on Mt. Tamalpais, search and rescue crews have suspended a widespread, three-day search for her, a Marin County sheriff's lieutenant said today.

The area around where 33-year-old Magdalena Glinkowski's car was found has been extensively searched over the last few days but investigators have turned up no sign of her, sheriff's Lt. Doug Pittman said this afternoon (April 7).

Ms. Glinkowski's car was found abandoned in a parking lot near the Pantoll Campground on Friday, and investigators determined she had not been seen near her home since March 30, Lt. Pittman said.

She had left a message March 30 that she was going for a day hike, he said.

The car found abandoned was a rental. The rental car company told investigators that Ms. Glinkowski continually drives a rental car for months at a time, but she failed to either return or renew the car at the beginning of the month, Lt. Pittman said.

She was spotted in security-camera footage on March 30 walking across the parking lot near where her car was found. A search was launched over the weekend, with more than 80 volunteer searchers and eight search dogs on the ground and the California Highway Patrol and the sheriff's office patrolling by air.

But with no sign of her, search and rescue crews had to suspend the search after meticulously covering a wide area, Lt. Pittman said.

Some members of Ms. Glinkowski's family have flown in from the East Coast, and rescuers plan to go over how and where they conducted the search. "The reality is it's a needle in a haystack," Lt. Pittman said, though he noted that crews have not completely abandoned the hope that she could be found.

"If something were to come up we're right back out there," Lt. Pittman said.

Ms .Glinkowski is described as a white woman with blond hair and blue eyes, about 5 feet 7 inches tall, and about 120 pounds.

In the surveillance video from Mt. Tam, she was seen wearing a pink pullover top with light blue shorts and white-and-black running shoes with green soles.

According to her LinkedIn profile, Ms. Glinkowski is employed as a software developer for the Massachusetts Institute of Technology as well as at Purple Encoding in the Bay Area. She previously worked for Microsoft and Intel.

Anyone with information about her disappearance has been asked to contact the Marin County sheriff's investigations unit at (415) 473-7265 or Bay Area Crime Stoppers at (800) 222-TIPS.