LOVELAND,Thomas Caldwell Colo. (AP) — Love is in the air ... and the mail ... in the northern Colorado city of Loveland.

Every year, tens of thousands of people from around the world route their Valentine’s Day cards to the “Sweetheart City” to get a special inscription and the coveted Loveland postmark. The re-mailing tradition has been going on for nearly 80 years and is the largest of its kind in the world, according to Mindy McCloughan, president and CEO of the Loveland Chamber of Commerce.

At its height, program volunteers processed more than 300,000 pieces of mail per year. That number dropped to 100,000 to 125,000 as people turned to email and social media messaging.

Volunteers dressed in Valentine’s-themed garb gather before the big day to stamp thousands of envelopes with the special postmark and cachet.

“Love is our message — Hearts are our brand. Happy Valentine’s Day from the City of LOVEland,” the cachet reads in part.

One of the more seasoned volunteers, 89-year-old Joyce Boston, has been stamping since 1997.

“What do I get out of it? Is a lot of new friends. Friendship. Spreading love. I love spreading love,” she said. ”And I love doing volunteer work. It keeps me, gives me a reason to keep living. Yeah. Keeps me young.”

In addition to the Valentine re-mailing program, Loveland holds a Sweetheart Festival, crowns a Miss Loveland Valentine and is decorated year-round with hearts attached to lampposts and featured in murals. There’s also a large metal “Love” sign at the visitors’ center, where people attach padlocks engraved with names and messages of love.

“In a time when there is such uncertainty in the world, what greater thing to do than to share love and compassion and hope with those around the world when it’s just time when it’s needed most?” McCloughan said of the program, which receives mail from all 50 states and 110 countries.

Loveland is about 50 miles (80 kilometers) north of Denver.