Lake Tahoe, nestled high in the mountains between California and Nevada, is one of America’s great natural wonders. But the lake faces a variety of threats -- some old, some new -- that scientists have spent years studying.Reporter: Saul Gonzalez, The California ReportA Bay Area Assemblymember wants to increase access to California's public parks and beaches, by overhauling the state's reservation system.Reporter: Keith Mizuguchi, The California Report Learn more about your ad choices. Visit megaphone.fm/adchoices