A thorough, full-blown biography that celebrates Georgia O'Keeffe as a social and artistic pioneer who masters, not without cost, the struggle to put work at the center of her life. Novelist Robinson (Summer Light, 1988) begins her sweeping, sometimes flowery chronicle with O'Keeffe's ancestors settling the ""rounded swells of mahogany earth"" of Sun Prairie, Wisc., in the 1850's. It is from the Midwest and its tradition of self-reliant farm women (her mother included), Robinson argues, that O'Keeffe got her ""kind of nerve"" to break convention. Into the moving detail-packed account of O'Keeffe's life, Robinson weaves her art and her spirited voice: ""I've been working like mad all day--had a great time--Anita, it seems I never had such a good time--I was just trying to say what I wanted to say. . ."" But O'Keeffe must fight to sustain this ""nerve"" even in her legendary relationship with Alfred Stieglitz, where she played the often conflicting roles of wife, artist, and model. Already well-known when they met, Stieglitz championed O'Keeffe, exhibiting her work at his gallery, ""291,"" and drawing her into his circle of early modernists (Marsden Hartley, John Marin). He also brought her instant and problematic fame with his brilliant series of photographs that documented her every mood, her every inch. In part to escape his demanding presence, she began annual sojourns to the stark landscape of the Southwest in 1929. Revealing America's most celebrated woman painter as a complex and contradictory woman, Robinson holds her accountable for her far-from-flawless life. During her sad, last years in New Mexico, O'Keeffe was blind, cut off from friends and family, and increasingly dominated by her young companion, Juan Hamilton. In 1986, she died alone at 98. The almost-500-page, relentlessly balanced tale ends with the battle between Hamilton and her family over her $90-million estate. The most comprehensive O'Keeffe biography to date, this essentially feminist reading convincingly builds its case from a wealth of sources (some unavailable before her death) to explain less the woman-behind-the-myth than how and why the woman herself became myth-maker.