When Vivian Vahlberg was a cub reporter, she covered the debate over the admission of women to the National Press Club from the restricted women's seats in the balcony. "There was one guy saying, 'We can't do this, we will have female chatter from morning to night.' And all I could think was how loud the debate was," recalls Vahlberg.

Last night, 11 years after that barrier-breaking decision to admit women was made, Vahlberg was sworn in as the first woman president of the club.

"After 74 years, it's about time," President Ronald Reagan told the crowd. In keeping with a tradition of official Washington's sanction of the event, the president and Mrs. Reagan attended the ceremony.

Reagan administered the oath of office to Vahlberg, doing a humorous takeoff on marriage vows, to which Vahlberg responded, "I do." Said the president, "I wish the answers at my press conferences were that simple. But then again, I guess these questions make more sense."

Also in keeping with the Washington tradition of not missing an opportunity, nearly 40 women marched outside the club protesting the Reagan administration's opposition to the Equal Rights Amendment, while saluting the new status of Vahlberg, an ERA supporter.

The president didn't miss his chance, either. "One of my favorite presidents, Cal Coolidge, dedicated this building," he said to a chuckling audience. Noting the historic occasion, Reagan said, "the club begins a new era, that's era, not ERA." While Nancy Reagan laughed, some in the audience hissed loudly.

"I feel a sense of humility, standing here at this moment in the same building where Silent Cal laid the cornerstone, Harry Truman played the piano and Richard Nixon ate a hamburger," Reagan told the crowd.

"What's left for me? The cornerstone is already in place, I can't play the piano and my food taster is home sick -- something he ate, no doubt. But like a second "Tip" O'Neill, I'll stoop to the occasion."

In administering the oath to Vahlberg, Reagan joked, "If anyone knows any reason why this ceremony should not take place, forget it! You've already voted, and it was unanimous."

The significance of Vahlberg's election has not been lost on her. She takes most of her lessons about pioneer jobs and feminism from her own family. "My maternal grandmother was divorced but put herself through law school and raised two very young children in the Depression," says Vahlberg. "And she practiced law and is still, at 91, a member of the Oklahoma bar." Vahlberg was born and raised in Oklahoma City. Her mother is a homemaker; her late father was an architect.

Vahlberg, 33, is the Washington correspondent for the Daily Oklahoman and Oklahoma City Times of Oklahoma and the Colorado (Colo.) Springs Sun. She has been active in the press club since 1972, and downplays the sexism she says she has experienced in her dealings there. "Not anything overt, but it gets into the category of underestimation," says Vahlberg, who was a club vice president last year and a member of the board of governors for five years. "In press club board meetings I would say something and it would be forgotten. Then a man would suggest it and it would be talked about for two weeks."

Yet when she speaks of the club's history and potential, and good newspaper assignments, like a trip to Norway to write about offshore oil rigs, Vahlberg has a pleasant manner, playful but emphatic. Vahlberg is reed-thin, with light blue eyes and practical short brown hair, and seems perfectly at ease in all her roles. Colleagues say they hope her personal vitality and progressive thinking, along with the $45-million renovation of the club, might quicken its current upswing from a dogeared image.

The club has also played another role in her life, one of romance. "One of the club's committees was trying to put together a manual for Washington journalists, the nitty-gritty details of where to get information. And at a meeting this man in the front row volunteered to do two chapters, not one but two. It was love at first sight -- no, not really," says Vahlberg, laughing. But after many committee meetings, earnest dinners and shared rides home to their Capitol Hill apartments, the volunteerism of Richard Gordon, the senior reporter for Advertising Age, turned to love and marriage.

This year Vahlberg, who joined the Daily Oklahoman staff after studying sociology at Rice University and the news business for six months at Northwestern University's Medill School of Journalism, is taking a leave of absence to work on the club projects and to care for her 18-month-old son, Brady Gordon. As president of the club, she is also president of the National Press Club Building Corp. "A leave was my compromise; I can't do the Wonder Woman routine," she says.

In a conversation in the club's lounge, Vahlberg enthusiastically debated the merits of the press club. "For a few years the club was considered unfashionable because, after the riots, downtown changed and people didn't want to come. Now there's a building boom. And people felt the club waited far too long to admit women," she said. The press and non-press, which includes former reporters, press secretaries and news sources, are evenly represented among the club's 5,000 members, Vahlberg explained. Only working journalists can vote or hold office at the club.

"It's one place where the president can come and say, 'I want to give an address,' and we can have it ready in 24 hours," says Vahlberg, emphasizing the large audience that can be reached with 240 National Public Radio stations and 900 cable outlets. New technology and luxury -- including a two-story cocktail lounge and a health club -- are planned for the next phase of the club's future.

As she prepared to welcome the Reagans to the club, Vahlberg's energy seemed to border on nervousness. And she admitted some apprehension about her presentations at public functions, where the club president traditionally introduces some of the world's most famous people. Last week it was Egyptian President Hosni Mubarak. "As a Daily Oklahoman correspondent, I can't say I cover the Mideast very much, so I didn't want to ask something profoundly ignorant. And I didn't," she says. Mubarak was one of the first to congratulate her as president, saying, "Now one of the last bastions of male chauvinism has fallen."