Animal bones were Georgia O'Keeffe’s first major subject series in New Mexico.
O'Keeffe first visited New Mexico in 1929 and was captivated by its desert light, mountains, adobe buildings, and broad horizons. Among the objects she collected and painted were bleached animal bones, especially cow skulls. These bones became central subjects in works such as Cow’s Skull: Red, White, and Blue and Cow’s Skull with Calico Roses.
Her bone paintings were not simply anatomical studies. O'Keeffe isolated the skulls against the sky or other sparse backgrounds, turning them into monumental forms. The combination of hard bone, vivid color, and open desert space became one of the most recognizable visual patterns in her New Mexico work.
Flowers were also essential to O'Keeffe’s career, especially during her New York years, and skyscrapers formed another important early series. However, the question asks about her first major New Mexico subject series, where animal bones are the specific answer. The bones did not replace flowers; both subjects remained important.