all local supply, the company created a monopoly on San Francisco's water. It was not until 1908, when the city approved construction of O'Shaughnessy Dam creating the Hetch Hetchy Reservoir in the Sierra Nevada mountain range, that the city gained municipal control. Prior to the construction of the dam, Lake Merced was to serve as the city's main reservoir, with plans to expand the lake into land that is now the San Francisco State University campus. Around this time, Spring Valley sold off some of its land on Lake Merced, making way for the golf courses that exist today. In 1940, Metropolitan Life bought the last of Spring Valley's land to build the Parkmerced apartment complex. Ecology The lake is fed by an underground spring, and at one time it did have an outlet to the ocean as shown on an 1869 United States Coast and Geodetic Survey Map. The salt level was always fluctuating, and therefore some species of fish which inhabit the lake are salt and freshwater adapted. There is active recreational fishing at the lake. The lake's water level had been shrinking for decades, endangering the historic role of Lake Merced to support a healthy ecosystem. Due to better management of the aquifer and occasional additions of water, lake level has been rising since 1990. The only natural freshwater lakes in San Francisco are Pine Lake, Lake Merced, and Mountain Lake. Famous duel On September 13, 1859, Chief Justice of the California Supreme Court David S. Terry killed United States Senator David C. Broderick in a duel at the lake. See also 49-Mile Scenic Drive List of lakes in the San Francisco Bay Area Rancho Laguna de la Merced References External links Guide to San Francisco Bay Area Creeks – Lake Merced Lake Merced Flickr group – Pictures of Lake Merced on Flickr Merced Parks in San Francisco Merced Bay Area Ridge Trail