ST. GEORGE, Utah  Some disapproving classmates called members of the new club “Satanists.” Another asked one of the girls involved, “Do you have a disease?”

But at three local high schools here this fall, dozens of gay students and their supporters finally convened the first Gay-Straight Alliances in the history of this conservative, largely Mormon city. It was a turning point here and for the state, where administrators, teachers and even the Legislature have tried for years to block support groups for gay youths, calling them everything from inappropriate to immoral.

The new alliances in St. George were part of a drastic rise this fall in the number of clubs statewide, reflecting new activism by gay and lesbian students, an organizing drive by a gay rights group and the intervention of the American Civil Liberties Union, which has threatened to sue districts that put up arbitrary hurdles. Last January, only 9 high schools in Utah had active Gay-Straight Alliances; by last month, the number had reached 32.

The alliances must still work around a 2007 state law that was expressly intended to stifle them by requiring parental permission to join and barring any discussions of sexuality or contraception, even to prevent diseases.