As Americans settled west of the Missouri River, access to abundant water proved a defining feature of an area’s habitability. Miners and other citizens laying claim to land asserted a kind of “first come, first serve” authority to any water access on their newly acquired property. Rivers proved a valuable commodity: Texas and New Mexico both laid claim to the Rio Grande; Colorado and Arkansas vied for the Arkansas River; and Colorado entered into another battle with Wyoming for control of the Platte River (Nadeau, Remi. “The Water War.” American Heritage, 1961). In California, however, the Los Angeles/Owens Valley conflict proved the most violent.

Between 1892 and 1904, California had a period of drought. Simultaneously, the city of Los Angeles experienced a population boom, and it became apparent that further growth wouldn’t be sustainable without a reliable water source. An Irish immigrant named William Mulholland was superintendent of the Los Angeles Department of Water and Power (and by 1911, he became its chief engineer). In 1904, Mulholland took a camping trip to the Sierra Nevada mountains, where he discovered that the snow runoff from the mountains filled Owens River below, making the Owens Valley lush and fertile.