Authorities said Thursday they were seeking a man believed to have been seen talking to a 24-year-old hiker missing since Tuesday in the vicinity of Blood Mountain.

Police said the man, described as 60 years old, weighing 160 pounds, was seen several times on New Year's Day with Meredith Emerson, 24, formerly of Longmont, Colo, and recently a resident of Buford, Ga., in suburban Atlanta.

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"This man was seen with her on multiple occasions during that day," Union County investigator Kimberly Verdone said on Thursday.

Verdone said witnesses said the man had a yellow jacket and a backpack with enough gear for at least a couple of days.

Late Thursday, officials said they believe the man was Gary Michael Hilton of DeKalb County, also in suburban Atlanta. They said it was possible Hilton was driving a 2000-2001 white Chevy Astro van.

"We want to find out who he was and kind of talk to him and see what happened and what their conversation was throughout the day," Verdone said.

Friends said Emerson went hiking with her black Labrador retriever on Tuesday. Her 1995 Chevrolet Cavalier was found abandoned Wednesday at the base of Blood Mountain.

Police confirmed that a water bottle and dog collar found near a hiking trail belonged to Emerson.

Other hikers who were on the trail Tuesday told authorities they saw Emerson talking to a white male, between 50- and 60-years old. The man had a red dog with him he called "Danny."

Witnesses told MyFoxAtlanta that Emerson and the man both chased their dogs into the woods. According to MyFoxAtlanta, a baton similar to that used by police and men's sunglasses were found with Emerson's belongings.

At the request of the Union County Sheriff's Department, the Georgia Bureau of Investigation sent four agents to join in the search Thursday morning, GBI spokesman John Bankhead said.

The Georgia State Patrol pitched in with a helicopter using an infrared device. The helicopter had been grounded by high winds on Wednesday.

"She's an experienced hiker and a blue belt in martial arts," said Julia Karrenbauer, Emerson's roommate. "She's athletic and has a good head on her shoulders. So we're just hoping for the best."

But despite a daylong search, rescue workers and a group of Emerson's friends found no trace of her or her dog in Wednesday's bitter cold.

Union County Fire Department spokesman Lt. Jeff Fortenberry said up to 30 emergency personnel and deputies planned to search a mountainous, six-mile stretch of trails south of Blairsville on Thursday. He said investigators have found no signs of foul play.