GOLETA, CALIF. -- Last June, Phyllis Gibson, an administrative assistant at the University of California, Santa Barbara, was preparing for a week at camp with Boy Scout Troop 129, which has long absorbed her energies and those of her two sons, Ron, 18, and Chad, 15.

For five years, she had served as a temporary adult supervisor at Camp Rancho Alegre near Lake Cachuma across the Santa Ynez Mountains. Gibson liked the break from the telephone and television. Her sons, whom she had raised since her divorce in 1978, loved camping. It was an experience the three of them could share.

Several other scouts in the troop also came from single-parent homes, and the shortage of available camp supervisors this year was so great that Gibson had been forced to set up a rotation for the week. Three fathers and three mothers, including Gibson, each agreed to take one day and one night. Then Gibson saw the letter from the county Boy Scout Council:

"As you plan your camp leadership schedules, bear in mind the National BSA policy that adult troop leadership is a men-only situation . . . . Anyone who may be a temporary substitute for the scoutmaster in camp must also be male and over 21 years of age."

A January memo from the national organization's chief scout executive, Ben H. Love, to the council had noted the "important role" women had played in American scouting from its beginning in 1910 and said "virtually all volunteer positions in the scouting movement are open to adult females."

But the organization insisted that scoutmasters and den leaders in the Webelos (the last step before scouting), as well as scout and Cub Scout camp supervisors, be men under "the principle that developing boys {of that age} need a close association with adult males who can provide models of manhood." The Boy Scouts say that has been their policy since 1910.

Psychologists and "other child development professionals" backed the policy, Love said. David K. Park, the national Boy Scout legal counsel, said in a recent interview that the organization felt it had the right to offer such an opportunity to boys and parents who wanted it.

"If a woman wants to go camping with her kids, she can go camping with her kids" on her own or with some other program, Park said. "But we want to be able to offer something unique."

Distressed and enraged, with only two days before the week at camp began, Gibson called every family in the troop in a frantic search for three more men. She said a scout executive told her the female supervision at previous camps had been winked at, but now the scout national headquarters in Irving, Tex., was "cracking down." She joked about considering marriage if that would solve the problem. But in the end the troop's week at camp had to be canceled for lack of men. Gibson and her sons felt cheated -- and angry.

"It had never occurred to me I couldn't do something I wanted to do and was capable of doing," she said. She had been a cub pack and scout troop committee chairman. Ron was an Eagle scout, and Chad had almost reached that pinnacle. Gibson had helped at least four other boys organize the difficult final projects that earned them Eagle rank.

So Gibson called Gloria Allred, the state's leading feminist attorney, and filed suit Sept. 30 alleging that the scouts' men-only policy violates state civil rights law.

"In an era in which many boys are living in female single-parent households, it is unfair to deprive the boys of the Boy Scout experience simply because there are not enough fathers to assume leadership responsibilities," Allred said.

"Boy Scouts are encouraged to earn merit badges . . . and to judge others according to their merits. We ask that Ms. Gibson and other women be judged on their merit, rather than their sex, thereby fulfilling the equal-opportunity policy of our country while at the same time helping young boys to become not only model scouts, but also model citizens."

Asked recently about the men-only regulation, Dr. Irving Philips, president of the American Academy of Child and Adolescent Psychiatry, said he knew of no research on the question and could not express an informed opinion. "But it strikes me as a rather sexist rule. I don't think in this day and age it makes a hell of a lot of difference" whether a camp supervisor is male or female.

Dr. John Schowalter, due to be academy president in a year, said, "I don't see {that} it would be a great problem developmentally for a woman to lead one of those things."

The Boy Scouts have spent more than a decade fighting an effort by Catherine Pollard, a Connecticut scouting enthusiast, to be formally declared scoutmaster of a troop she successfully, but unofficially, led for several years. Her troop disbanded after her effort met official resistance. Gibson said the same fate may befall Troop 129.

Don Marsh, Troop 129's former scoutmaster, decided last summer that three years on the job was enough, and Gibson has been unable to find another man willing to take over. She said she could do it, if that option were not foreclosed. She could take her boys camping outside the scouting program, she said, but that would deprive them of the benefits of what she called the "wonderful" scouting experience.

This year, in ruling against Pollard, the Connecticut Supreme Court avoided the issue and said the case did not fit under state antidiscrimination laws because Pollard was an unpaid volunteer. California courts already have ruled that the Boy Scouts are covered under the state's civil rights law, Allred said, and that may give Gibson a better chance than Pollard had in court.