Lake Tahoe is one of the largest and deepest alpine lakes in the world. Human pressures on the lake and basin have increased since the 1960 Winter Olympics. Science has become a crucial tool for striking a balance between human impacts and preservation of the lake. The movie shows how scientists are monitoring water flows into and out of the lake, monitoring the lake water itself, mapping the lake floor, mapping the basin and using new land use models to better plan for the future.