Thousands of motorcyclists have descended on the nation's capital for the annual event known as Rolling Thunder. And while you may have seen packs of them leisurely cruising around town, they aren't here just to take in the sites - they're here with a message.
"It's an awesome experience, a very awesome experience," says Howard Goode, a Vietnam veteran.
Rolling Thunder is an emotional gathering for Vietnam veterans like Ricky Rasch.
"It gives me peace, peace of mind," says Rasch. "It's kind of hard. I came here to be with all the brothers that served in Vietnam for this great country of ours and to honor the dead.'
Artie Muller and a few friends created Rolling Thunder to draw attention to Vietnam veterans still missing in action.
"We wanted to do a march and we wanted to do a motorcycle run," Muller says. "And we started Rolling Thunder with both."
The event is 25 years old now, and what began as a rally of 2,500 in 1988 is now a massive undertaking involving 750,000 riders.
"We ride for those who can't [and] come down every year just to show our support for POW's and MIA's left behind," says Tim Exton.
They also ride for those who survived war but died later in life, like Bob McCallops from Cleveland, who passed away after a heart aneurism in 2008.
"His whole unit was in a fire fight," says Exton. "He was the sole survivor. Carried his commanding officer out of the bush."
On Sunday, Rolling Thunder participants rode across the Memorial Bridge to Arlington National Cemetery.
"When you come across that Memorial Bridge and you hear that crowd cheer, go down Constitution Avenue and they're eight to 10 deep you know Americans are out there and watching us and they care," says Scheffmeyer.
Biker and Vietnam veteran "New York Myke" has been here every year, riding cross country from California. His riding partner this year is Hollywood actor Robert Patrick.
"One thing that I've really been able to feel glad about is to really let these guys know how much they did for us," Patrick says.
As these veterans make their yearly ride, they also honor a new generation of veterans from Iraq and Afghanistan. They say they're paying the support forward, ensuring this Memorial Day tradition will live on for more than just the memories of those killed or missing in Vietnam.