Casco Bay High School seniors pose for a photographs with Scott Shibles, the school's director of student life, before Friday's College March in downtown Portland.

Senior crew advisor Brooke Teller laughs with Ray Intwari as they wait for the bus to leave Casco Bay High School for downtown Portland.

With a smile on his face but no gloves on his hands, Casco Bay High School senior Ray Intwari steps off the school bus Friday on his way to the school's annual College March. Intwari, like most of his classmates, mailed thank-you letters to teachers who wrote his recommendation letters.

Even standing near the back for a group photo, Ray Intwari stands out with his bright smile and colorful L.L. Bean beanie.

Casco Bay High School senior Ray Intwari puts an arm around classmate Mazie Linsmith as the seniors prepare to march Friday. He has found a perfect fit in Casco Bay High. "We all encourage each other," he said.

Casco Bay High School seniors march down Congress Street toward the post office and Portland City Hall. They chanted periodically – “We are Casco Bay! We are Casco Bay!”

Ray Intwari marches with classmates Friday in Casco Bay High School's annual College March. Intwari, who came to the United States from Burundi in 2011, "is extremely gregarious, outgoing and hardworking," said Scott Shibles, the school's director of student life.

Senior crew advisor Brooke Teller holds a stack of letters that seniors from Casco Bay High School will mail as they complete their annual College March on Friday.

With most college applications already filed online, Casco Bay High School seniors drop thank-you letters, updated transcripts or test scores, waivers for application fees or notes for their families into a bin at the post office as they complete their College March on Friday.

Casco Bay High seniors are photographed on the steps of Portland City Hall after their annual College March on Friday. A girl in the front row led a chorus of “C-B-H-S! C-B-H-S!”