The lush plains east of Yosemite National Park offer a window into a bygone California — a place where sage grouse welcome the arrival of spring with theatrical mating rituals and cattle graze on verdant pastures. For nearly a century, these lands have been made green thanks to annual flooding by the Los Angeles Department of Water and Power, helping maintain cattle forage and keeping alive a culture of ranching in southern Mono County. But those days may have come to an end in August.