Writing letters to Santa is a treasured holiday tradition, but have you ever wondered where all those letters end up or who responds to them?

This year is the 105th anniversary of the United States Postal Service’s Operation Santa program, which is responsible for providing a written response to many of those letters.

It started back in 1912 when Postmaster General Frank Hitchcock officially authorized employees and citizens to start responding to the increasing number of letters written to Santa each holiday season.Charities, community organizations and corporations were also invited to participate in the 1940s because of the influx of letters to Santa, according to the USPS.

Now, post offices across the country “adopt” letters to Santa and volunteers provide a written response signed by Father Christmas himself.

For safety reasons, in 2009 the USPS started redacting all references to the child’s address and assigning a number to each letter to Santa. Now those who choose to adopt letters to Santa have to fill out an official form and when they’re ready to mail their response, the post office simply matches the number on the letter to the child’s address.

Although Santa Claus, Indiana, isn’t officially part of the Operation Santa program, they too receive letters every year because of the town’s name.

Patricia Koch, the founder of the Santa Claus Museum and Village, said her father came home from World War I and realized the village’s postmaster was overwhelmed by the number of letters to Santa.

“So he decided to ask other people to help,” Koch explained. “At one point the villagers, the people who lived here, would just go to the post office, pick up letters and answer them. So it’s a community legacy to actually to do this.”

In the early 1940s, when Koch was just 11 or 12 years old, she started helping her father with all the letters.

“These children are writing from the heart.”

Patricia Koch

But it wasn’t until about 1976 that the operation, now known as Santa’s Elves Inc., became what it is today.

Now, Koch and the rest of Santa’s helpers gather around a big table in the back room of the town’s original post office building every year after Thanksgiving to begin responding to all those letters.

“We’re up to about 19,000 letters so far this year,” Koch said.

Koch added that she and the other elves will be working hard to get responses out by Dec. 21 so they arrive before Christmas.

Although children are more likely to print or type letters to Santa nowadays, rather than writing in cursive, Koch said the sentiment behind the wishlists and notes remain the same.

“These children are writing from the heart,” Koch said. “I mean they’re telling Santa everything”

For Koch, just knowing that she’s bringing a little bit of joy to children she responds to makes it all worthwhile.

Read more stories from Alix Hines on Circa.