Police searching for missing Wisconsin college student

(CBS/AP) STEVENS POINT, Wis. - The search resumed Monday in Wisconsin for a college student who remains missing despite an extensive weekend search by police and dozens of volunteers.

University of Wisconsin-Stevens Point student Eric Duffey disappeared early Saturday after leaving a bar in downtown Stevens Point. Duffey's parents, from Fitchburg, say their son was celebrating his 21st birthday.

Police told reporters Sunday they did not suspect foul play, and that they believed alcohol was a factor in Duffey's disappearance, the Stevens Point Journal reports.

Volunteers helped police scour neighborhoods near downtown Sunday, searching through snowy backyards, checking outbuildings and looking under decks..They knocked on doors and passed out fliers with Duffey's photo.

The Stevens Point Journal reports that police began searching the Wisconsin River this morning. Police reportedly say found evidence late Sunday that led them to the river, although they would not say what it was.

Eric Duffey was wearing an orange flannel shirt, blue jeans, a brown jacket and possibly a gray and white stocking hat. He is about 6 feet tall, and 150 pounds, with red hair and green eyes.

Police tried to use cellphone pings to locate the student, but the pings only showed that his phone was in the Stevens Point area.