BANGOR, Maine — Whenever they're called, whatever the hour, they respond. They head to the military's easternmost U.S. way station and deliver aid to troops headed to and from war zones.

Cheers. Claps. Waves. A handshake. A "thank you."

The Maine Troop Greeters have done it for more than 1,800 flights since 2003 at Bangor International Airport, frequently the last U.S. stop for overseas-bound troops and their first taste of America on the return trip.

The volunteer group is reaching a milestone: Sometime next month it expects to greet its 500,000th service member since the Iraq war began.

"It's a good feeling because the guys really appreciate having someone here," said Joan Gaudet, who lives about 10 miles away in Bradley. "It's addicting. You hate to miss the flights."

Just off a 6,000-mile flight that began in Kuwait, members of the Red Bull Division of the Minnesota National Guard filed past one group of cheering Mainers recently and smiled back, many nodding appreciatively. They had just finished a 16-month deployment, serving longer in combat than any other U.S. military unit of the Iraq war, Lt. Col. Kevin Olson said.

"I'm just flabbergasted by these people here — it's great," said Sgt. Kent Westberg, a growth of beard attesting to his travel time. "It's so fantastic to see the smiles on their faces and they don't mind that you've been on a plane for 36 hours."

After handshakes and hugs, the soldiers grabbed donated cell phones from a cardboard box and scattered to make free calls to loved ones. The troop greeters also offer snacks and drinks.

There are troop-greeting activities in other states, but Bangor's may be the best-organized and longest-running, airport spokeswoman Risteen Masters said. The group's 130 official greeters get plenty of practice: Planes carrying troops often stop in Bangor to meet customs obligations, refuel and change crews for continuing flights.

Typically, dozens of greeters are waiting, but there may be only a handful of greeters for overnight flights.

"That's what separates the men from the boys," said Bill Knight, an 85-year-old World War II veteran who helped found the group during the Gulf War and kept it going when the fighting resumed in Iraq in 2003.

Knight said he was motivated by the memory of shabby treatment soldiers received when they returned home from Vietnam. Many of them were jeered at and some were spat upon.

"We made up our mind that that would never happen again if we could help it," Knight said.

Gaudet, who has two grandchildren in the Army Guard, has lost count of the number of times she's greeted troops since she started coming to the airport in 2003. At times, Bangor's had eight or nine flights a day, she said.

"We'd come down and stay for as many as we could and go home and sleep a couple hours and come back for the next ones," Gaudet said.