During the 2006 incarnation of Rolling Thunder, some of the thousands of bikers ride across Arlington Memorial Bridge into Washington in for the annual “Rolling Thunder Ride for Freedom.” The tradition has stretched 29 years. (Melina Mara/The Washington Post)

One of the world’s largest motorcycle rallies — a monument-shaking ritual called Rolling Thunder that takes over the Mall each Memorial Day weekend — spends the rest of the year here, packed in the garage of a tidy colonial-style house in central New Jersey.

On Wednesday, jammed between a bag of Scotts grass seed and a toddler’s bicycle were stacks of POW banners, American flags, black T-shirts, biker patches and other accoutrements of the annual Harley howl of warrior brotherhood that will dominate Washington for the 29th year in a row.

These are the traffic cones, two-way radios and bales of Costco toilet paper that will guide, aid and comfort hundreds of thousands of bikers from across the country on their annual four-hour, four-abreast roll from the Pentagon, across Arlington Memorial Bridge, around the Capitol and back to the Vietnam Veterans Memorial.

“I haven’t been able to get my car in here since January,” said Elaine Muller, the grandmother (please don’t ask her age) who runs the office side of Rolling Thunder Inc.

But not for long. It was packing time, four days before Secretary of Defense Ashton B. Carter will blow the boat horn that unleashes a few million horsepower of leather­-vested POW-MIA advocacy onto the streets of D.C.

A 20-foot U-Haul truck was backing toward the garage, and most of the Rolling Thunder executive board was in the driveway waving directions at the side mirrors: the president, a high school building engineer and the treasurer, who recently retired after 31 years in the meat department of the local Acme supermarket.

“This is when the f-bombs usually start flying,” said Nancy Regg, the event’s national spokeswoman, who takes calls from reporters between stops on her job delivering dry cleaning.

“We’re not professional event planners, but we have been doing this so long we get it done somehow every year,” Muller said, standing before stacks of neatly labeled plastic crates: “Parking Staff Bandanas.” “Pentagon Table 8.” “Sunday Color Guard.”

Behind the wheel of the truck is her husband of 48 years, Artie Muller, the longtime guiding force behind Rolling Thunder. He climbed down from the cab with the bent stiffness of a 71-year-old who jumped out of too many helicopters as an infantry sergeant in Vietnam.

Artie Muller, a Vietnam veteran and founder of Rolling Thunder Inc., stands beside his 1992 Harley-Davidson FXRS Low Rider in Neshanic Station, N.J. Muller helps organize the annual Memorial Day weekend rally in Washington. (Ricky Carioti/The Washington Post)

A onetime mechanic at the nearby Exxon Mobil Corp. headquarters, he retired at 51 with severe peripheral neuropathy he attributes to Agent Orange exposure. His exquisitely maintained 1992 Harley-Davidson FXRS Low Rider (88,000 miles, original clutch) carries a handicap license plate. His patch-covered riding vest bristles with sharp metal studs to keep grateful vets from slapping his painful shoulder.

“It was agony before I figured out about the studs,” he said.

Artie Muller helped load the tents, cases of juice, stacks of chairs, boxes of Rolling Thunder CDs by country singer Rockie Lynne. But periodically, he limped down to his basement office, a vet cave of POW posters, Vietnam maps and stacked paperwork.

On the wall are copies of legislation Rolling Thunder has pushed in Congress, including a signed copy of S. 528, the National POW/MIA Recognition Act of 1997:“To require the display of the POW/MIA flag on various occasions and on in various locations.” There are photos of Muller with former president George W. Bush on the White House driveway, with Bush in the Oval Office, a letter of appreciation from Bush.

“President Bush was very good to us,” he said.

Other White Houses, Muller said, not so much. President Obama poked his head into a White House meeting but nothing more, Muller said. He used the b-word to dismiss one former and perhaps future occupant of 1600 Pennsylvania Ave.: Hillary Clinton. “Kiss the country goodbye if she gets into office,” he declared.

Muller doesn’t do email, or text, so all the last-minute fires he needed to put out were announced with another ring of the landline. The Pentagon wanted to bill him with an unexpected $11,000 surcharge for security related to Carter’s participation. There was a snag closing some of the highway ramps in Virginia.

And then there was Trump.

“Donald Trump’s a smart man, but he must have a couple of dumb guys working for him,” said Muller, running a hand through his brushed-back gray hair.

The presumptive Republican presidential nominee had agreed to come speak at the event’s Sunday rally. But he had just found out that Trump’s staff thought the appearance was Monday.

Trump would make it Sunday, they promised.

Muller supports Trump in spite of the New York billionaire’s disparaging remarks about POWs — “I like people that weren’t captured” Trump said as a dig at Sen. John McCain (R-Ariz.), a former POW in Vietnam.

“I’m not bothered by it,” Muller said. “Sometimes people say things. They don’t have time to think, and they say the wrong things.”

The phone rang again. It was his 8-year-old grandson, Gavin, who will ride in his first Rolling Thunder on Sunday on the back of Muller’s bike. Right next to the “Jane Fonda: American Traitor” patches is the huge Lionel train set Muller and Gavin are building together.

“Okay, I love you, Butchie,” Muller cooed into the phone. “I got your helmet in the truck.”

Bigger and bigger
Motorcyclists from around the country ride to the nation's capital for the annual Rolling Thunder “Ride for Freedom” aimed at honoring veterans. Here's what the 2015 ride looked like. (  / Reuters)

Elaine Muller remembers when their own sons rode in their first Rolling Thunder and packing for the event meant little more than loading the kids into her husband’s Ford Bronco on the morning of the ride.

“We never expected it to last this long,” she said.

It was in the mid-1980s that Artie Muller picked up a pamphlet at the Vietnam Veterans of America that accused the U.S. government of ignoring servicemen still living as captives in Southeast Asia.

“I couldn’t believe what I was reading, but I did my own research,” he said. “They were abandoned.”

He became an activist, giving out POW flags to town halls and police stations. In 1987, when he was thinking of organizing a march in Washington, he met Ray Manzo, a like-minded Vietnam War vet who thought a massing of motorcycles would have more impact.

“If we have 5,000 vans and pickups and cars come down to D.C., people are just going to say it’s a traffic jam,” Artie Muller said. “If we bring 5,000 motorcycles, they are there for a reason.”

In the fall of 1987, a letter from Manzo appeared in the back of Outlaw Biker magazine, calling for riders to descend on Washington the Sunday before Memorial Day. He talked the Defense Department into letting them stage at the Pentagon parking lot and persuaded D.C. police and the National Park Service to let them rumble over the Memorial Bridge and around the Mall. Manzo knew it would be an awesome sight. If anyone showed up.

“When the bikes started coming in, I couldn’t believe it,” said Manzo, 67, now retired in Jacksonville, Fla. “I couldn’t give a speech, I couldn’t talk to the press, I was crying my eyes out.”

Some 3,000 riders came for that first ride. By year five, it had ballooned into a massive rally of tens of thousands, with country-music star Billy Ray Cyrus playing at the end. In 1992, Manzo handed the reins to Muller.

“It was starting to take over my life,” Manzo said. “But I’m still more proud of it than anything I’ve ever done.”

The Memorial Day ride continued to grow, and so did the mission. The group helped get a POW/MIA postage stamp approved. They lobbied for the Missing Service Personnel Act of 1993, which prohibits the Pentagon from declaring a service member killed in action without substantial evidence.

“I think Rolling Thunder was really on the cutting edge of creating a better image for motorcycle riders,” said Ben Nighthorse Campbell, a Rolling Thunder regular and a former Republican U.S. senator from Colorado.

Rolling Thunder’s demands

Rolling Thunder’s national president Joe Bean, from left, national chairman Ted Zabohonski, national vice president Tom Dalessio and Artie Muller pack up merchandise and supplies for the rally, all stored in Muller's garage. (Ricky Carioti/The Washington Post)

Artie Muller’s year of prep begins 367 days in advance. On the Friday before Memorial Day, he hands in his permits to get dibs on the date for next year.

“There are always people who would love to take our spot,” he said.

Much of the planning has hardened into routine. A Rolling Thunder volunteer keeps the same set of rooms at the Hyatt Regency Crystal City booked three years in advance. Ordering 120 portable toilets takes little more than a fax to Don’s Johns.

“The folks who run this are extremely well-organized,” said Don’s Johns Chief Operating Officer Rob Weghorst. “Doing events on the Mall can be a little chaotic, but these guys know where they want their units.”

For Muller, the calendar is packed all year, a to-do a day: IRS filings for two nonprofits organizations; meet with Arlington police, D.C. police, Park Service police, Pentagon police; medical trailers and bike mechanics; signing up police motorcycle groups to provide security.

“There’s all kinds of terrorist stuff now that I’d rather not talk about,” he said.

In September, Muller sketched out his idea for the annual pin, Rolling Thunder XXIX, ready to send it to his manufacturer in Illinois. Last year’s featured dog tags dangling from a cross. This time, he returned to the iconic bowed head of a POW.

The pins, hats and shirts sell for $5 apiece, a price unchanged for three decades, and generate most of the roughly $120,000 it takes to produce the ride each year, Muller said. On Tuesday, there will be a raffle for a 2016 Harley-Davidson Electra Glide, and the proceeds from 15,000 tickets, expected to sell at $10 each, go to Rolling Thunder Charities, a 501(c)(3) nonprofit organization that provides about $200,000 in aid to veterans’ families a year, Muller said.

In his office, Muller flipped through a notebook with documentation of the 76 veteran families who have been given $72,000 so far this year. Mostly, the grants are a few hundred or few thousand dollars to make up missed rent payments or late electric bills. The charity pays directly to the landlords or utility companies, Elaine Muller said.

According to the philanthropy analyst Guidestar, the charity gave away more than 90 percent of its funds in 2014 and spent 3 percent on administrative costs.

The organization has one paid employee, the Mullers’ daughter-in-law, who makes $24,000 as an administrative assistant. All of their own labor is volunteer. Artie works in the basement, and Elaine goes each day to a three-room suite in an office park, where she maintains tidy files on 92 Rolling Thunder chapters.

“We want to have a nice setup so someone can take all this over,” Elaine Muller explained. Younger vets, including those who have served in Iraq and Afghanistan, have joined the chapters, she said, and make up many of the 1,000-or-so volunteers who help staff the ride each May. But an obvious successor to the Mullers’ full-time devotion to the organization hasn’t emerged.

“We’re all getting pretty old,” she said.

Time to ride

Artie Muller and other volunteers pray together Thursday in Flemington, N.J., before riding to Washington. (Ricky Carioti/The Washington Post)

Early Thursday morning, Artie Muller parked his bike in the handicap space in front of the Flemington Coffee Shop a few miles from his house. His son, Joe Muller, pulled up in the big U-Haul truck, and a half-dozen Harleys followed. It was time to ride.

The group downed eggs and coffee, then gathered in a circle in the parking lot. A white Toyota waited, not daring to honk at the group of aging, leather-clad bikers holding hands and staring down.

“Lord, please put your angels of protection around us going down to D.C. for another year,” prayed Rich Cox, chairman of Rolling Thunder’s Florida chapter.

“See you at Maryland House,” Muller said, firing his engine.

“Artie, your helmet,” someone called.

Muller donned the headgear, gave a curt nod and rolled out to take point. It was a small platoon, soon to swell in noise and number into an endless army.