On the Fourth of July, hours before the first float rolled down Railroad Avenue, the San Geronimo Valley was awake and hungry. By 9 a.m., the line snaking through the Marin County Fire Department’s Woodacre campus was five firetrucks long. At the front, firefighters wielding spatulas flipped pancakes and scrambled eggs.

This breakfast is where the valley’s Independence Day celebration begins. It’s been happening since the ’80s, when then-Fire Chief Ken Massucco decided to reschedule it.

“Originally, we did it during fire prevention week in October,” said Mr. Massucco, who served the department for 37 years before hanging up his gear. “When I became the captain here, I decided it would be a nice community event to tie it into the Fourth of July parade and barbecue.”

Mr. Massucco flipped his first pancake as a volunteer firefighter in 1973. He still lives in Woodacre, just two blocks from the station. What he started as a modest fundraiser has grown into a community ritual, drawing valley natives and out-of-towners alike. On Saturday, they sat and ate at picnic benches in the apparatus bay. Firefighters who weren’t on griddle duty bussed plates, collected garbage, and refilled syrup dispensers. The most difficult job may have belonged to the poor soul in a Smokey Bear costume, who posed with children as the sun beat down on the asphalt.

Captain Jesse Rudnick, who joined the department in 2001, said firefighters expected to serve between 1,000 and 1,200 people this year. What makes the breakfast special, he said, is how little it has changed.

“That’s the cool thing about out here: This has been going on long before I started,” Mr. Rudnick said. “Fourth of July, we don’t really advertise it. We don’t need to. People just know we’re going to have an event. We love having the community here.”

The money raised by the pancake breakfast helps fund the San Geronimo Valley Emergency Readiness Group, or VERG, a nonprofit that coordinates evacuation drills, conducts emergency training, and helps neighbors find resources. 

The group’s president, Michael Glass, said they’ve been co-sponsoring the breakfast for decades. “We put up for the ingredients, we do all the P.R. We were here yesterday—we worked about four or five hours setting everything up, all the tables and chairs and grills, with the firefighters,” he said. 

The effort pays off. Mr. Glass and his volunteers use the morning to sign neighbors up for AlertMarin, the county’s emergency notification system. Every year, they register about 80 new residents. It helps, too, for people to see the trucks, the equipment, and the crews up close. “I think it’s good for everybody to be here on this campus and see what it does—see all these firefighters, see the equipment and resources, and see that these are human beings here to help them out.”

Toward noon, the crowd migrated to Railroad Avenue to watch the parade from folding chairs in the scarce shade. Teens on dirt bikes and go-carts opened the spectacle, popping wheelies and zig-zagging along the expanse of pavement. Next up were antique cars, stilt walkers in costumes, and a truck carrying teenaged climate activists, urging the crowd to “Vote Climate.” Most floats tossed candy, while others sprayed the crowd with water or cooled them down with leaf blowers. At the parade’s end, a lone motorcyclist carried a sign, inviting all spectators to follow him to Dickson Ranch. 

Without the ranch’s co-owner, Grace Tolson, the parade might have never happened. In 1976, she asked her husband, Chuck, to take her to a parade celebrating America’s 200th anniversary. He said he was too tired. Grace said, “Okay, if you won’t take me to a parade next year, I’ll make a parade.” And in 1977, she did.

That first year, the floats nearly outnumbered the spectators. 

“Everybody said, ‘But there was nobody watching it,’” she said. “And I said, ‘I didn’t guarantee an audience. I just guaranteed a parade.’”

The next year, the audience came. Half a century later, the parade fills the road, then flows toward Country Fun Day at the Dickson Ranch.

Here, past the old ranch house and spacious paddocks, barbecue smoke mixes with dust in the air. Walt Dickson, Grace’s brother, sits on a shady, creekside stage and sings in a growling voice as his Sky Blue Band chugs along behind him. Girls who rode their horses in the parade lounge in the shade, sporting denim and ribbons. Walls of hay bales topped with flowers divide the crowd from the sight and smell of porta-potties. 

The whole celebration—the pancake breakfast, the parade, and the fun that follows—is held together by valley volunteers. They spend hours mixing pancake batter, tinkering with old cars, and constructing hay-bale walls. Ms. Tolson bakes cookies and brownies, hunts down prizes for the children’s games, and hand-makes cards for parade attendees. There are no prizes for the floats, no ribbons, no reason to build a hand-sewn dragon or a castle of knights except that someone wanted to.

“There’s no reason to do it,” she said, “except the pleasure of doing it.”