For a brief two-week spell in the Fall of 1976, a billowy white curtain snaked across the hills of Northern California before plunging into the Pacific Ocean. The shimmering mirage was the work of Christo and Jeanne-Claude , partners in art as in life, who had spent the preceding four years winning over local ranchers and navigating government bureaucracy all in the name of public art. Not that the couple complained. They saw the petitions and endless hearings as integral to the project as sketches and steel poles, elements that turned Running Fence into what they called the “ultimate art project.” Fifty years on, the Museum of Sonoma County is commemorating the seminal installation with an exhibition that brings together blueprints, original construction materials, and documentary photographs to tell the remarkable story of just how Christo and Jeanne-Claude made it happen. Christo and Jeanne-Claude, Running Fence , Sonoma and Marin Counties, California (1972–76). Photo: Wolfgang Volz.…