Last Thanksgiving Day, when 31.9 million people watched the New Orleans Saints play the Dallas Cowboys, 10.75 million of them were women. Overall, 44 percent of the National Football League’s fans are women.

If you follow the sport, this is no revelation. The football widow is an anachronism; girls and women populate stadiums and sports bars, and have for years. In a recent Washington Post survey of D.C. sports fans, 53 percent of this area’s women said they care about the NFL, and 25 percent said they care “a great deal.”

Yes, football is king, by far the most popular spectator sport in America, the true national pastime — for men and women both.

The more difficult thing for a young woman or girl to do in greater Washington is play the game.

There is no organized football league — tackle or flag — in the public schools of D.C., Maryland or Northern Virginia, according to the National Federation of State High School Associations, which lists 469 girls football programs in the United States, 290 of them tackle and 179 flag.

Some private outfits offer flag football leagues, though nothing as extensive as the ubiquitous Pop Warner tackle football programs for boys. Koa Sports in Montgomery County and i9 Sports in several areas of the region are two of them. But they still pale in comparison to the youth soccer system that has grown up since the passage of Title IX 40 years ago.

Look at Florida, where flag football for girls has become one of the fastest-growing varsity — that’s right, varsity — sports in the state’s high schools. According to a 2010 story in the New York Times, nearly 5,000 girls were playing statewide. Some schools field freshman and junior varsity teams, and some coaches grumble that girls football steals the best athletes from other spring sports. Flag football also is growing in places such as Texas, North Carolina and Alaska.

In fact, 25,000 girls have played high school flag football in the United States, according to Sam Rapoport, senior manager for a three-year-old program run by USA Football, an arm of the NFL, that develops the sport. USA Football donates all needed equipment to any school that wants to start a program.

Rules differ, but the basic girls game is seven-on-seven, with a quarterback on offense and one pass-rusher on defense. Everyone else goes out on pass patterns, which can be sophisticated at higher levels, Rapoport told me.

Instead of tackling, defenders must snatch a strip of cloth, or “flag,” that offensive players wear on a belt. There is no blocking, but the kind of screening you’d see on a basketball court is allowed.

It’s great exercise, and “girls are attracted to football for the exact same reasons as boys are,” Rapoport said. “It’s team oriented [and] it’s individually oriented.” More importantly, “it’s fun,” she said. Girls tell organizers they join because “this is more fun than any other sport.”

So what are the barriers to girls’ football opportunities? There is no consensus, but I think we can dispense with “it’s too rough a sport” without much debate. Flag football is not a contact sport. Girls probably collide more often in field hockey, lacrosse, soccer and perhaps basketball. I have a daughter who played club rugby in college and a niece who pancaked a few boys playing on the offensive line of a seventh-grade tackle team in upstate New York. Both those games were a lot more violent than flag football.

No, I think we have to look more deeply at ourselves and our sports system. “It’s this predominantly male, macho culture that doesn’t want to open this door,” says Donna Lopiano, a longtime activist for gender equity in sports, former All-American athlete and current president of Sports Management Resources, a consulting firm. “It’s sacred ground for guys.

“There is no physical reason why women shouldn’t be participating,” she added.

As a more practical matter, Rapoport says, coaches and athletic directors worry about having to share their facilities, which already may be overtaxed.

Rich Daniel, general manager of the D.C. Divas, the local women’s pro football team, says that until colleges begin to offer scholarships to girls who want to play football, parents will steer their athletes toward sports that hold that reward.

As “an active young female, you and your parents are focused on where you’re going next,” he said. “If you want your education to be paid for, you have to focus on a sport that has a scholarship associated with it.”

Until things change, girls’ options in this area are limited to private organizations. Koa Sports, a Montgomery County nonprofit, for example, has 70 girls from kindergarten through 10th grade playing flag football in the second year of its league. And Candace Love, a former D.C. Diva, has started a traveling team based at the SEED charter school in the District, Daniel said. There is word that District schools will offer flag football as a varsity sport in the spring, but I couldn’t reach anyone to confirm that.

“We sort of thought there would be a market to have girls play. The first year, we were laughed at,” said Wayne Cohen, one of Koa’s founders. “People said, ‘Girls aren’t going to come out and play. It’s never going to happen.’

“We were shocked at what [we] actually saw,” he added. “They were very competitive, and they really wanted to do it.”

Jeannine Shavitz of Bethesda signed up her tiny 8-year-old, Maddie. Her 6-year-old, Alexandra, joined after seeing how much fun her sister was having. “We live in a neighborhood with mostly boys her age, and they come home from school and start throwing the football around,” Shavitz said of Maddie’s interest.

“For whatever reason, she got herself focused on football, and she couldn’t wait for the season to get started.”