No stranger to north Georgia's mountains, the 24-year-old University of Georgia graduate frequently drove an hour and a half from her home in Buford, Ga., to hike trails with her 1-year-old dog, Ella, or run up and down them with a partner, friends say.
So friends and family members became concerned Wednesday when Ms. Emerson, formerly of Longmont, Colo., did not return from a New Year's Day hike with Ella near Blood Mountain.
Their concern turned into a search investigation when friends found her 1995 Chevrolet Cavalier on Wednesday at the parking lot for Freeman Trail at the base of Blood Mountain. The trail is a popular day route that intersects with the Appalachian Trail, the through-hiking route that stretches from Georgia to Maine.
"She loved hiking," said friend and former co-worker Ronnie Tompson. "She loves to be outside and with the dog."
Clear weather on Friday allowed rescue workers, canine teams and search helicopters to continue looking for Ms. Emerson and for a man they described as a "person of interest" in her disappearance.
Union County investigator Kimberly Verdone said 15 professional search and rescue teams searched for Ms. Emerson throughout the day as volunteers traveled across north Georgia and parts of North Carolina to post fliers with pictures of her and Ella, her Labrador retriever that friends say was with her when she disappeared.
The searchers were combing a 401-square-mile area of rugged terrain that crosses part of the Appalachian Trail.
Officials said they are seeking Gary Michael Hilton, of DeKalb County in suburban Atlanta. They said Mr. Hilton, who is in his 60s, drives a 2000 or 2001 white Chevrolet Astro van and is believed to have missing or bad teeth. He was reportedly seen several times on New Year's Day with Ms. Emerson.
"It's not that, you know, he's a suspect. He is somebody that was last seen talking to her, last seen with her," Investigator Verdone said during a news conference.
She said investigators want to know when he last saw Ms. Emerson and what they talked about.
John Cagle, the special agent in charge with the GBI's Field Division, declined to specify how investigators learned Mr. Hilton's name and other details about him.
"We are making every attempt to locate him," Agent Cagle said.
Authorities say they have found a water bottle and a dog leash that belonged to Ms. Emerson.
One of Georgia's oldest and most popular state parks, Vogel State Park is located at the base of Blood Mountain in the Chattahoochee National Forest.
Searchers have had to work in rugged, hilly terrain that rises from 3,000 to 4,500 feet above sea level and still has remnants of snow that fell Tuesday evening.
Friends and co-workers said Ms. Emerson left a note with her roommate that she was going to go hiking with her dog Tuesday. They began searching for her the next day when she had not returned home and did not report for work at Process Container and Display in Winder, Ga.