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.