When Kelli Peterson, an articulate, likable lesbian high school student in Salt Lake City, founded an extracurricular organization called the Gay-Straight Alliance three years ago, she had no inkling of the storm of hysterical outrage that would erupt in her conservative hometown.

The organization's opponents went so far as to as pressure the Utah State Legislature to pass a law banning all extracurricular high school clubs. (The ban was later overturned.) At the same time, Ms. Peterson's cause was taken up by thousands of sympathetic students who marched in the streets to demonstrate their support.

Her story, told largely in her own words, is the centerpiece of ''Out of the Past,'' a solemn, well-paced documentary written by Michelle Ferrari, directed by Jeff Dupre and narrated by Linda Hunt (in her best grand manner), which compares Ms. Peterson to several unsung heroes of the gay liberation movement....