Like all the other 100,000 people along Greenville Avenue on Saturday, Janie Martinez was Irish – if only for a day.

Photos by MICHAEL AINSWORTH/DMN

Green derby hats, beads and other novelties were snatched up by spectators Saturday at Dallas' annual St. Patrick's Day parade. The luck of the Irish was with event planners: Saturday's weather was parade perfect, drawing tens of thousands of spectators to the 29-year-old event.

Janie, a freshman at the law magnet at Yvonne A. Ewell Townview Center, presided over a mobile quinceañera party of friends and family members who tossed beads and cardboard shamrocks from a homemade, green-as-guacamole float in Dallas' annual St. Patrick's Day parade.

Officials of the Greenville Avenue Area Business Association, which sponsors the event, estimated that participants numbering well over six figures partied with Janie in parade-perfect weather, the largest turnout ever for the 29-year-old event.

Police estimates were slightly smaller – 60,000 to 75,000 people for the parade and 10,000 to 15,000 more for a related gathering at the southern end of the route.

The quinceañera float was the idea of Janie's uncle, Hugo Acevedo, who offered it as a gift for Janie's 15th birthday, a milestone event for girls in most Hispanic cultures.

Janie's quinceañera party will be more formally celebrated March 29, but the float in Saturday's parade was intended as a warm-up to the main event, Mr. Acevedo said.

A conversation with Janie's mother, Rocio Acevedo, 34, made the melding of Hispanic and Celtic traditions seem almost inevitable.

"We love St. Patrick's Day, even if we're not Irish," said Ms. Acevedo, who lives in Uptown. "We go to these parades every year. We're really, really into it."

How into it?

"When Janie was born on March 17, I gave her the middle name Patricia," she said.

Participants in Saturday's parade represented a wide spectrum of ethnicities, cultures and apparently – when you include a group of cross-dressed in-line skaters – lifestyles.

A North Texas Irish Festival float was joined by marchers with bagpipes and kilts, Krishnas, Falun Dafa adherents, the Italian Car Club of the Southwest, the Weimaraner Rescue service and a self-styled "Hillbilly St. Paddy's Day" band.

But the Tex-Eire-Mex mix was particularly prominent.

The Lone Star flag and the strikingly similar banners of Mexico and Ireland snapped in the wind above crowds wearing sombreros, Stetsons and plastic leprechaun hats. Performers from the Million Dollar Saloon danced the Macarena across from the staging area.

So, Janie's float fit right in.

"It was going to be a surprise," Mr. Acevedo said. "And then I realized I wasn't going to be able to build it myself and have it ready in time."

He broke the news to Janie, who enlisted 30 friends, members of her quinceañera court and, she added, "lots and lots of cousins." Even then, the crew was up until 2 a.m. Saturday building and decorating the flatbed trailer and hand-writing "Janie's 15th" on the scores of cardboard shamrocks tossed to parade spectators.

The group then showed up not long after sunrise Saturday at the staging area in the Sam's Club parking lot on Park Lane. Ms. Acevedo brought supplies of pizza, doughnuts, orange juice, water and candy to fortify the partiers as they rode the converted flat-bed trailer down Greenville.

"I've always wanted to do this," Mr. Acevedo said. "I bought the trailer so we can do this every year. It's going to be a tradition."