Tonya Shannon, 40, a mother of four, was last seen in a red dress and gray fleece hooded jacket riding home from a holiday party on Sunday with her husband Dale Shannon, 41, behind the wheel, authorities said.
Ground operations began at 9 a.m. with air operations starting at noon. Shannon was last seen along with her husband Dale Shannon, 41, at a Christmas party Saturday night in Streator, about 17 miles west of Ransom, relatives told CNN affiliate WGN and the Chicago Tribune.
A photo of Tanya Shannon.
Police believe Mrs Shannon survived the crash because they found a set footprints leading from the car to the road.
They also found a shoe believed to be hers.
Authorities hope Shannon is alive, while also acknowledging the harsh winter elements. LaSalle County was blanketed with nearly 7 inches over the weekend, and temperatures dipped into the teens by Monday afternoon.