BANGOR, Maine (CNN) -- Karen Walker has shaken half a million hands in the last few years -- at least that's her best guess.
Korean War veteran Don Guptill greets a returning soldier at Bangor International Airport in Maine.
She and the other 40 or so members of the Maine Troop Greeters have made it their mission to welcome every incoming and outbound flight of soldiers and Marines who use Bangor International Airport as a refueling stop.
No matter what time of day or night, there will always be applause, handshakes and hugs to make the troops feel appreciated.
The goal is clear: "Greet the troops, and thank them for what they do," says Korean War veteran Don Guptill. Watch the volunteers in action »
Guptill says he remembers coming home from that conflict and receiving no welcome at all.
Guptill and other veterans, including those who served in Vietnam and World War II, were determined not to let that happen again.
"It makes me feel good," said one soldier headed out on his first deployment. "I'm a little nervous," he continued, adding that the warm greeting helped ease his nerves.
Another soldier, firmly shaking the hands in line, said, "This is fantastic. These people are wonderful for coming down."
The group of volunteers first started during the Persian Gulf War in 1991 and continued following the invasion of Iraq in 2003. As of October, the group has seen off 3,598 flights, 727,292 troops and 135 military dogs, according to the greeters.
Besides the support of the receiving line, troops also are offered snacks and the use of a cell phone to call their loved ones, free of charge.
"All they do is put an ID card down and pick up a phone," says Bill Knight, who stands behind a counter giving out the phones. Cell phone carriers donate the minutes.
The airport donates the room where Knight works. Once a duty-free shop, it's now decorated with flags, unit patches, pins, photos and other items given to the Maine Troop Greeters as a show of appreciation from the many units that have passed through the airport.
While the firm grips of so many soldiers sometimes can make the greeters' hands a little sore, the volunteers get used to the strong handshakes.
"They used to [cause tenderness]," Walker says, "but not anymore."
When a handshake won't do, some military men and women will reach out and just hug the person who came by to welcome them home.
Meeting the troops also tugs at the emotions of the greeters. "It's a good feeling," Guptill says. "Some days it's a tear-jerker."
After about an hour and a half on the ground, it's time for an outbound flight to take off and head to a war zone.
The greeters line up again to wish the soldiers well as they head up the ramp to the plane, thanking them for their service.
Guptill says if the war ended tomorrow it would be fine with them, but adds, "We'll do this until this thing ends."