Some forty years after the aqueduct first began tapping the Owens Valley, L.A. leaders realized that the city needed still more water. They also realized that there was a wealth of unappropriated water in the next watershed up, just 200 miles further north – the Mono Lake Basin. This chapter explores the extension of the aqueduct to the Mono Basin in 1940 and the acceleration of Mono exports after the second barrel was built in 1970. It begins by introducing the extraordinary features of the Mono Lake ecosystem itself – the trillions of brine shrimp, clouds of alkali flies, and millions of migratory birds that depend on a hypersaline sea – suspended in a high-desert basin marked by dormant volcanism, geothermal activity, and limestone tufa towers rising from calcium laden springs entering Mono’s carbonate-rich waters. It also reviews the human communities of the Basin, including the indigenous Kutzadika’a Paiute and the European settlement that followed the California Gold Rush. Finally, it explores the human and environmental consequences that followed Los Angeles’s acquisition of rights to take water from the Basin, setting the stage for the legal controversy that would follow.