MISSOULA, Mont. -

Coworkers, friends and family members are all searching tonight for a University of Montana student who's been missing since Tuesday

He was last seen in Banks, Idaho and was on his way back to Missoula for the start of the semester.

His friends tell us his plan was to stop in Stanley, Idaho to camp and possibly do some hiking.

His name's Lucius Robbi. He's 21 years old and has been working the summer in Idaho for a kayaking company.

We're told he was making the drive in his green Subaru Outback with two orange kayaks strapped to the top. The car is California license plates numbered 6CCP540.

He was expected in Missoula by Wednesday at the latest but he never made it.

A coworker we talked to this afternoon says Robbi was known for being responsible.

She says his friends and family are all worried.

"It's really unusual that we wouldn't have heard from him by now. I wouldn't have been surprised if he decided to hike or go back packing for a minute, but to be out of the loop and out of contact for this long is really surprising from him," said friend Jessica Stoll.

A missing person alert's been put out in Boise and Custer counties in Idaho and statewide in Montana.

Anyone with information's asked to call the Custer County Sherriff's Department at (208) 877-2232.