BLAIRSVILLE — Searchers expanded the hunt Friday for missing Buford hiker Meredith Emerson to a 401-square mile area in the North Georgia mountains.

Meanwhile, police are placing equal emphasis on finding Gary Michael Hilton, a 61-year-old man officials believe is the last person seen with Emerson before she disappeared from a hiking trail Tuesday afternoon.

"We are receiving information and we have talked to a lot of people," John Cagle, the GBI special agent in charge of the case, said at a news conference that ended shortly before noon Friday. "We have confirmed that [Hilton] was there."

Cagle said officials remain hopeful they can interview Hilton but declined to disclose any more details. No more press briefings have been scheduled for Friday.

"We're running leads and I'm not going to do anything to jeopardize that," Cagle said.

More than two dozen Gwinnett County Sheriff's Office deputies combed the icy ground of Blood Mountain through Thursday night with tracking dogs, but have yet to come up with her trail.

The investigation is still a search and rescue mission, said Kimberly Verdone, a spokeswoman for the Union County Sheriff's Office, although police have not discounted the possibility of foul play.

Police haven't released more information about Hilton beyond his description — a gray-haired white male about 5-foot-10 and 160 pounds, possibly driving a white minivan.

Police consider Hilton a "person of interest" and have not declared him a suspect in the disappearance.

Hilton last registered his van in 2007, Verdone said. But law enforcement found no sign of him at the DeKalb County address on the registration, she said.

It isn't clear if Hilton is hiding from police, Verdone said, adding, "If someone doesn't want to be found, they're going to be hard to find."

Peggy Bailey, a spokeswoman for the Emerson family, appealed Friday to Hilton to contact the police, hoping coverage of the missing 24-year-old had "softened his heart."

Addressing Hilton and people who might know Hilton, she said, "If you've been hesitant, don't be hesitant."

Emerson's family from Colorado remain in Georgia, and hasn't given up hope in finding their daughter.

However, "The third day is a hard day," Bailey said.

The case has drawn national attention since Emerson's car was found. Authorities said her water bottle and the leash for her black mixed-breed dog, Ella, were discovered a few hundred yards from her car. Hilton had his dog, Dandy, with him.

Emerson, a sales manager for a Winder packaging company and a 2005 University of Georgia graduate, is from Colorado. Her parents, Susan and Dave Emerson, flew in Wednesday from Longmont, Colo., to join the search.

Emerson's friends described her as fit and familiar with the outdoors. Martial arts practice and hiking a couple of times a week pounded her 5-foot-4, 120-pound frame into wiry shape.

She's athletic. Very athletic," said her roommate, Julia Karrenbauer, who on Friday announced she and other friends have launched a Web site — helpfindmeredith.com — to help with the search. "She runs all the time, walks all the time, hikes all the time. If faced with a situation, I'd be confident in her abilities."

But Emerson's athleticism led some of her friends to fear the worst — that if she were just lost or hurt, she would have made it off the mountain or been found by Thursday afternoon.

"Best-case scenario, she's not on that mountain," said Chris Hendley, her former boss from the Arena at Gwinnett Center. "Most of us are certain she's not lost."

Emerson went hiking about 11 a.m. Tuesday on the six-mile-long trail with her dog, police said. Before Hilton was connected to the case, several people told investigators they saw her with a gray- or silver-haired man, who wore a backpack and a yellow jacket with black elbow patches and stripes, Verdone said. Police say Hilton is about 5 foot 10 and 160 pounds.

In addition to Emerson's water bottle and the dog leash, searchers also found a police baton of some sort, but it hasn't been tied to Emerson's disappearance.

Meanwhile, miles away authorities investigating the presumed double murder of an elderly North Carolina couple are closely following the search for Emerson.

In that case, a surveillance video at a bank in Ducktown, Tenn. — about an hour away from where Emerson was last seen — captured someone wearing a yellow jacket using the couple's ATM card on Oct. 22. Nothing else is known about the suspect, Young said.

"Right now we don't see a correlation, but the yellow jacket certainly raised a flag," he said. "They call these things clues."

Anyone with information on Emerson's disappearance is asked to call the Union County Sheriff's Office at 706-439-6066.