Tanya Shannon, of Ransom, Ill., was riding in a car that crashed early Sunday morning in LaSalle County. Her husband was killed in the accident in rural Brookfield Township. There were footprints in the snow near the car, but she has not been seen.
Aircraft and sonar imaging have been used in the effort to locate 40-year-old Shannon, but the search has not yielded any significant clues.
Now, more than two days after the crash, investigators say their hope of finding Shannon alive has begun to fade.
"Realistically, we have to be looking at it as a recovery effort if she's in fact out in the elements and outside," said Sheriff Tom Templeton, LaSalle County.
On Tuesday morning, police and firefighters scoured frozen farm fields for a third day hoping to find any trace of Shannon. She has been missing since early Sunday morning.
Shannon attended a holiday party in Streator with her husband Dale Saturday night. After the couple left, police say, they got into a single-car crash in a remote part of LaSalle County, which is surrounded by fields.
Dale Shannon, who was driving, was killed, but investigators believe Tanya Shannon survived and left the vehicle.
"What the extent of her injuries could've been, could she have some head injuries? Could she have been disoriented? Sure. The answer is clearly yes," said Templeton.
Footprints leading away from the crash scene were found by authorities, and investigators say they also found a woman's slipper-type shoe not far from the crash scene as well.
LaSalle County received more than six inches of snow over the weekend, and the wind chill dipped below zero Sunday morning.
Tanya Shannon is described as 5'2", 125 pounds, with shoulder length strawberry-blond hair, green eyes and glasses. She was last wearing a red party dress and a gray fleece hooded jacket.
It's unclear if Shannon has any additional winter weather gear with her. Police don't know if she sustained any injuries in the crash.
Police had about 50 personnel in the farm field continuing their search. They say they're hoping for any clue as to Shannon's whereabouts. But they had not received any contact from Shannon nor from anyone who believes they saw her. Though authorities say they are analyzing cell phone evidence, they won't say whether or not they think the phone is with her.
Sheriff Tom Templeton says the couple's four daughters are in the care of family.
At Turtle's Tap restaurant in Morris where Tanya is an assistant manager, co-workers say they're worried sick.
"We're as baffled as everybody else out there," said Candy Cox. "And it's cold, and it's snowy, and just the thought of her being out there alone and not knowing, it's awful."
"Just astonishment. It's like, oh my gosh, Dale's gone. Where's Tanya?" said Diane Eartly.
The Shannons live in Ransom, a town of just 500 about six miles from the crash scene.
Donations are being accepted at Jerry's Tap, a local watering hole, to help the couple's children.
"This is a really good community for rallying around any type of tragedies, any type of disasters, any type of problems," said Carl Watson, Jerry's Tap.
The Associated Press contributed to this report.