An entire roadside memorial for a teenager killed in a car crash near Cochrane has been stolen.

Brandon Thomas, 16, was killed in December when his Subaru was hit by a pickup truck on Highway 22 just south of the southern Alberta town. 

Mourners put up a large white cross with Brandon's name at the crash site. It was covered in trinkets, flowers and pieces of memorabilia and toys from his childhood.

Now it's missing. His mother Kim Thomas wants the items returned.

"This is stuff, but it’s still heartbreaking," she said. "We don't care who you are, we just want the stuff back. It’s important. It was given in love. Some of it was Brandon’s that I will never have again. Bring it out here. Leave it out here. We’ll pick it up."

RCMP are investigating, but aren't sure about motivation.

"The people who would have the right to take it down – being highway maintenance or any of those type people  – did not. As well as the property owners in the area did not," said Cpl. Greg Stannard.

Family and friends put a replacement memorial back on the crash site Monday.

The driver of the truck that hit the teen's Subaru faces numerous charges, including impaired driving causing death.