The church bells tolled in Abiquiu this month, and they were heard nationwide. Georgia O'Keeffe, who lived 98 years, had taken leave of the haunting New Mexico landscape that sustained her and her art for more than half a century. A pioneer of modernism, O'Keeffe left behind the sort of rich, powerful legacy that most artists only dream of: more than 900 works in all, many of them spare oversize abstractions of flowers, animal skulls and clouds that have floated into our permanent visual idiom. "Her art is a kind of national park that preserves for us a prehistoric purity and remoteness," art historian Robert Rosenblum commented. "She pared nature down to a bone-dry core."

It was 70 years ago that one of America's foremost photographers, Alfred Stieglitz, then also head of an avant-garde gallery, plucked a struggling young art teacher out of obscurity. "At last, a woman on paper!" he exclaimed when he first saw O'Keeffe's drawings. Championing her career, Stieglitz also captured his protégé and muse in more than 500 adoring, sensual photographs. He and O'Keeffe were married in 1924 and lived in Manhattan and Lake George, N.Y. until his death, in 1946.

O'Keeffe first visited New Mexico in 1929 and was dazzled by the blinding sunlight, the age-old reds and yellows of the mesas, the wide blue sky. But it wasn't until 1949 that she moved permanently to tiny Abiquiu, northwest of Santa Fe. A loner, she was as prickly as the cholla cacti that grew in the enveloping desert. But O'Keeffe was also a romantic: In her last decade her closest friend was a young potter, Juan Hamilton. Even in her 80s, still as agile as a girl, she climbed the hand hewed ladder to the roof of her adobe ranch house to gaze at the sky above, the earth below. "When I think of death," she once said, "I only regret that I will not be able to see this beautiful country anymore, unless the Indians are right and my spirit will walk here after I'm gone." It seems certain the Indians were right.