But something strange happened on the way to the pantheon. In 1967, Bontecou was led off to rural western Pennsylvania by the temptations–or, depending on which gossip you listen to, the demands–of life with artist-husband Bill Self and their young daughter. In the 1970s, she became enmeshed in a long court battle with rifle-toting Ku Klux Klan supporters who didn’t appreciate arty types on their turf and tried to have her farm road closed. And just a few years ago, she had to fight off a nearly fatal bone disease.

Although Bontecou continued to work like hell in a spacious studio on their farm property, and made the commute to teach at Brooklyn College from 1971 until she retired in 1991, she essentially went missing from the art world. She kept her work largely to herself, and went 30 years without a solo show in New York. Why? Whatever the vicissitudes of her domestic situation, Bontecou is also a quietly intense person with an obsessive desire to be constantly in the studio. She’s never had much use for the downtown scene and its raucous, argumentative gallery openings, smoky bars and public posturing for attention.

But now Bontecou is back with a bang, and a retrospective as breathtaking as the climax of “The Natural,” where Roy Hobbs hits the dramatic home run that turns the whole stadium into a fireworks display. The first few galleries of the museum–to the work that earned Bontecou her initial fame–constitute a first-rate show all by themselves. After returning to New York in 1958 from a fellowship in Italy (where she produced sincere but formulaic sculpture of simplified animal forms), Bontecou developed a little dark box, with a five-inch hole in the front side, standing on four legs. She hung a subsequent box–a skin of dirty canvas pieces wired to a steel framework–on the wall, hole facing front, and put light-swallowing black velvet inside.

This may not seem like much to you, but for Bontecou the move was the equivalent of Picasso’s putting two eyes on the same side of a painted head. Not only did she manage to combine the heft of sculpture with allusions to abstract painting, but she gave herself a great platform–as they say in the car-design business–on which to build several years’ worth of increasingly intricate and powerful art.

By 1967 Bontecou had morphed and remorphed her premise into one large, complex, simultaneously lyrical and threatening relief sculpture after another. (Which is not to mention some of the most deftly beautiful pencil drawings ever to emerge from the otherwise pop-art-obsessed SoHo scene.) Bontecou’s art covered all the bases–genuine originality, impressive craft, a lovely touch and a muscular presence. Many of her wall sculptures made their way into such collections as the Museum of Modern Art’s, and the Centre Pompidou’s in Paris. And two of the biggest still grace one of the lobbies of Lincoln Center.

If you keep walking, however–past a comparatively flimsy retreat into translucent fish from the ’70s and some merely OK drawings from the ’80s–all the way to the newest work in the last chamber, you’ll get something as close to a religious vision as you’ll ever find in a show of contemporary art. Half a dozen large, lacy mobiles of dizzying delicacy, using ingenious combinations of materials (cloth, porcelain, wire) and gorgeously subtle muted colors, revolve slowly in the air, like angelic mother ships. On shelves and plinths sit small skeletal sculptures (some with actual animal bones in them) of equal grace. The room practically pulses with a kind of life force. So this is what she’s been up to!

It’s tempting to speculate about what Bontecou’s later work would have been like had she stuck it out in New York and suffered the slings and arrows of the outrageous art world. Deprived of immersion in nature (animal bones, pebbles, the forest), she might have gone ironic and conceptual. (Very doubtful.) Or her work might have remained tough, industrial-looking and sooty. (Plausible.) But it’s difficult if not impossible to believe that she could have improved on the oeuvre on view in L.A. (and, when the show travels, Chicago and New York). This wonderful exhibition is, after all, just about as good as it gets.