Made from a variety of natural materials — including wood, tar, rawhide, and stone — Martin Puryear's distinctive sculptures combine modernist geometry with international craft traditions. Influenced by woodworking, basketry, and construction techniques, the pieces at times resemble familiar objects. By blending cultural references, however, Puryear avoids fixed associations of time and place. This major retrospective charts the artist's career from his first solo show in 1977 to the present. SFMOMA's presentation includes a special installation in the Haas Atrium including Ladder for Booker T Washington (1996), made from a 36-foot-long split sapling, and Ad Astra (2007), a 63-foot-tall work that rises to the museum's fifth-floor bridge.