Cross-Country Cartwheeling : WILD AMERICA AND OTHER STORIES <i> by Jayne Loader (Grove Press: $17.95; 256 pp.) </i>

When a writer finds her voice, it is an exhilarating experience for the reader. Jayne Loader is a woman of many voices--a sort of literary “Sybil”--as she proves in her collection “Wild America and Other Stories.” In 12 short stories, she displays a sure style, a controlled tone and a special affinity for the outer fringes of the American scene.

The experience is perhaps similar to the feeling one gets after seeing a good three-act play, the old-fashioned kind that worked like clockwork--where the first act contained the set-up, the second act laid out the story and the third ran as a series of payoffs. Not that these stories are predictable, but when Loader scores, which is more often than not, the reader has the feeling of being in the hands of a pro.

Loader has the nuances down. Whether the narrator is society scion Haskell du Pont or the desperate white trash Carrie Jo Starkweather, Loader can nail a character with one note. In a sort of fractured fairy tale with an unprintable name (something involving bestiality and a duck--you figure it out), a doctor decides: “Rissy Van Horn always had been stubborn, he thought. Too stubborn for her own damned good.” With these few words, an entire character can be deciphered: an influential, wealthy woman accustomed since childhood to getting what she wants, someone the town’s Establishment had long had to accommodate. In this story, Loader creates a believable character, sketches out the community’s social structure, throws in a surreal ending and somehow makes it all work in fewer than three pages.

In “Famous Last Words,” the story of the aforementioned Haskell du Pont and the endlessly desirable Daisy Duke, it is as if Louis Auchincloss were writing about New York’s downtown scene, with a splash of Dominick Dunne thrown in for bite. This has the hallmarks of a paradigm short story, an overbred, overschooled dilettante infatuated with a girl so dynamic that she succeeds at everything she tries (when she starts to write, her over-the-transom submissions are gobbled up by The New Yorker ), so much of a natural life force that she consumes the energy, the potency of all around her. Whether the couple are on Tony Fishers Island or the down-scale Horseshoe Bar, Loader has the atmosphere just right. She has the ending just right too.

The art world gets it in the teeth with “For Artists Only.” Jana Ann Mulcahey, who blamed Comme des Garcon clothes “for much of what was wrong with contemporary America,” wanted desperately to be an artist. With a slightly disinterested manner, she took a lot of risks, did a lot of unpleasant things--walked the streets, held up some stores, killed a man, spent time in an asylum--to inject some passion into her art. But, only after she commits suicide is her reputation made. Then, after a fast shuffle by an assistant curator with his eye on the prize, the art world sweeps her into its arms. But her biker-husband can’t be the only one to realize “The new paintings were just like the old ones.”

This husband, who is in jail at the story’s end, is the only one who really mourns Jana. He is keeping her memory alive, for he has taken a young, slim boy with hair the color of his dead wife’s.

Loader’s America is a study in the underside of society. People are desperate: creating an elaborate ruse to escape drug dealers they have double-crossed, trying to cope with a husband who appears to be literally turning into an animal, dreaming of a “cameraman slash husband” who has died, missing out on a passionate love by settling for someone who seems more reliable. A boy has no recourse against a popular teacher who was once a famous child star and now molests his young students. When a baby is crying in the ingenious title story, it could just as easily be killed as burped. Among Loader’s many voices, it is the Snopes-like that often prevails. In fact, her one sure miss, “Baldwin Country,” reads like Faulkner-manque.

Loader cartwheels across the country in “Wild America.” But she comes to rest in the collection’s final story, “Kismet.” Here, longtime best friends and former lovers, Brett and Jake--the allusion is what you think--deal with love and AIDS. Both find out what really matters in life. And, as she has before, Loader treats the subjects with the mastery of a pro.