Watch above: A 23-year-old UC Berkeley student is missing in Eldorado National Forest.

A massive search was underway Tuesday for a UC Berkeley student who disappeared Friday, when he planned to go on a hike alone near Placerville in the Eldorado National Forest.

About 80 personnel from the U.S. Forest Service as well as search and rescue teams from seven Northern California counties were looking for Vernon Cody Matthews, 23. He last spoke to his mother on the phone Friday before his hike, the El Dorado County Sheriff’s Department said in a statement.

Although authorities said there is nothing to indicate that Matthews fell victim to foul play, he has not used his cellphone since Friday.

Horse-mounted patrols, police dogs and swift-water rescue and off-road teams were searching for Matthews in the Ice House Road area, which is 5,500 feet in elevation.

Search and rescue teams began looking for Matthews on Saturday after his parents reported him missing because they had not heard from him and were concerned for his safety.

They dropped him off Wednesday at the family cabin in the Ice House Road area, where he had been staying alone. His personal belongings were still inside the cabin when investigators searched it Saturday.

Authorities described Matthews as an avid hiker and climber, who knew the area well.

Matthews is 6 feet 3 inches tall, weighs 160 and 220 pounds, with shoulder-length blond hair and a red beard. He described himself as a rapper, who went by MC Thor, according to his Facebook page.

Anyone with details about Matthews' whereabouts is asked to call the El Dorado County Sheriff’s dispatch center at (530) 621-6600.