Just two hundred years ago, Lobos Creek Valley was part of a vast natural area of rolling sand dunes that covered one third of San Francisco. Lobos Creek, fueled by rains and gathering water from the inner Richmond district, provided water and food for the Ohlone Indians for thousands of years. Lobos Creek also provided water for early inhabitants of urban San Francisco. It still runs year-round, and provides most of the water used by the Presidio residents, tenants, and employees. As San Francisco grew, Lobos Creek Valley, was changed to accommodate a variety of human uses including cattle grazing, vegetable plots, and an Army balloon hangar. Slowly the millenia-old native habitat was nearly eliminated. The Xerces butterfly fluttered its last flight in the valley in 1942, a casualty of the habitat loss. Lobos Creek was the first major natural restoration project undertaken after the Presidio became a national park site in 1994. The area was a derelict ball field in 1995 when the City of San Francisco determined that a sewer pipe in the Valley needed repair work. Due to the presence of a threatened wildflower species, San Francisco Lessingia, the city contributed to the cost of the habitat restoration project. This small member of the sunflower family had been reduced to less than 100 plants when the Park Service began managing the site. Today, there are hundreds of thousands of Lessingia plants smattered like gold dust across the valley.