A rolling conveyor belt of storms this winter has left the Sierra Nevada blanketed in a thick layer of snow. The year started modestly, with the snowpack measuring around 70 percent of average on the first of the year. A robust January and February has brought the snowpack up to around 145 percent of normal for this time of year. April 1 typically marks the peak of Sierra snowpack accumulation and the start of the spring runoff. Move the sliders below to view the terrain before and after snowstorms.