A FIRST NOVEL is almost by definition a sanctified mess. Or used to be, back in the days when unwashed novelists lived in garrets and starved as they committed their raw souls to foolscap. In that bygone, fairy tale era, the turbulence and excess of a first novel were indulged as the natural effervescence of youthful genius.

They don't make first novels like that anymore. Our unwashed novelist doesn't live in a garret--and garrets are no longer garrets; they're lofts, and they cost the earth-- but settles in for a stay at a comfy writer's colony like Yaddo. She--and I'm talking about Joanne Meschery, who generously acknowledges all the support she's had-- gets a grant from the National Endowment for the Arts. She learns her craft at writing workshops in Stanford and Iowa. Gone forever are the garret and the foolscap, but before we sink into a nostalgic reverie, and mutter that these new writers have it too soft and easy, I'd better warn you that In a High Place is far more accomplished than the first novel of yore.

Joanne Meschery writes with the assurance and aplomb of a novelist in mid-career. In a High Place is a large, ample, comic novel set in a town called Tullease on the eastern side of the Sierras. Meschery evokes wonderfully those high, wide-open, western spaces and the people who inhabit them. There is, first of all, Lily Baldwin, who has just left her husband on the Coast and come to town with her three children, "a speedy stalk of a woman with a stirred-up look in her eyes." That's how she looks to Warren Deegan, a 55-year-old giant in a wine-colored suit, with a fish hook for a tie clasp, who's been appraising women all his life. He's still a ladykiller (and one of his weapons is a bluejay feather--but I'm not going to explain) and he still has the "demanding flesh." A native of Tullease, he discourses on the demanding flesh and other subjects at the Tourist Club bar, where sooner or later everyone--the melancholy, misanthropic dentist, the slick dudes in new Levi's and Mickey Mouse watches, the tough honky-tonk queen with a voice like an angel's--shows up. It's a boozy, melodious crowd, and Meschery works it like a seasoned pro. By the time you finish this richly populated novel, you'll feel right at home in the Tourist Club.

Those Mickey Mouse watches belong to the Disney people, who have arrived in Tullease to buy up local real estate and to turn Mount Catherine into Mountain World. "Here on Mount Catherine's slopes," says the suave, impersonal voice on the loudspeaker, "we will create an alpine experience for thousands, inspired by the mountain itself. All who visit Disney's Mountain World will feel a renewed sense of wonder for nature and man's unique place in it. Mountain World is our testimony to wilderness." That's how the Disney people talk, even without loudspeakers. They are a different species from the natives of Tullease.

Lily Baldwin doesn't know quite where she fits in Tullease, and she has an affair with a Disney storm trooper, a vertebrate named Paul Valentine. He gives her his social disease, but he's not all bad; he also gives her the pills to cure it. Lily feels neither remorse nor self-recrimination after coupling with this stranger--like Deegan, she has the demanding flesh--and she enters into what amounts to a relationship: Valentine leaves his bottle of Cutty Sark at her house.

This affair makes clear how Lily differs from so many women in contemporary novels. She has no ideology, no particular ambition, no special talent. She does have children--the scenes with the children are splendid-- and she does have demanding flesh. She has spunk and fiber, and she takes life very much as it comes. While she may not be essentially sure who or what she is, she responds vibrantly to everything and everyone around her. Lily is not reflective but she acts--and this, in turn, makes clear how Meschery differs from so many contemporary novelists. In a High Place is a novel in which character is action.

Lily doesn't always forsee the consequences of her action. Early in the novel, she takes four children on a hike up the mountain, ignoring the natives' warnings about the weather. The winter closes down while they're on their hike. "There was no ignoring the cold now. Or the snow. It sifted across the slope, catching in seams of granite and in the dark moss that spread everywhere like a map." Only three of the children come back from that trip. The lost child does not reappear until the spring, when he is discovered, appropriately, by Deegan.

Deegan is everywhere in this novel, a courtly, western knight. One of his missions is to rescue children (he rescues Lily's children as they're being christened in a Baptist church in San Franisco). He comes to the aid of damsels in distress--meaning, of course, that he comes to Lily's aid. Their tentative, poignant, improbable romance grows over the course of the novel, until at last they find themselves, as the spring comes on, floating naked in the hot springs outside Tullease--and the town punk arrives and knocks Deegan's teeth out.

That's funny, I suppose. The chance event, the shocking event, is built into Meschery's scheme of things. It's another sign of her confidence as a novelist; she doesn't have to work in sterile, laboratory conditions but lets her plot imitate the random, untidy sequences of real life. And yet in this case, when Deegan and Lily finally kiss, when their long fumbling toward each other finally brings them flesh to flesh, I wanted this tirelessly inventive novel to stand still for one intimate moment--but in bursts the punk to slug Deegan.

That's one of several bewildering mistakes that pile up as Meschery brings her novel to its close. There's a parade, and a fire, and the spring thaw coming on, and the corpse of the lost child, and more Disney people, and Deegan roaring down the mountain on the train tracks --everything is happening at once, and everything is too much. In a High Place turns into an extravaganza.

The common flaw of the first novel? Yes, but Joanne Meschery is more than promising. She is more than a name to remember, more than a writer to watch. She's a writer to read, right now.