Mount Allison University students and community members gathered to remember Chris Metallic on what would have been his graduation weekend.
Metallic was 20 when he went missing from the campus in 2012. He has not been found.
On Sunday, about 200 family, friends and members of his Listuguj First Nation in Quebec gathered at the Sackville, N.B., university to plant an oak tree in front of the Bigelow residence where he lived.
"I would much rather see my son graduate but I can't," his mother Mandy Metallic said.
Metallic was last seen leaving a house party. His shoes were found in a wooded area nearby, but extensive searching turned up no further trace of the young man.
His family has continued to look for him.
"I want to thank the grad students for making this happen. This means so much to all of us and I know Chris would be so honoured," his mother said.