The California Central Valley grasslands is a temperate grasslands, savannas, and shrublands ecoregion in California's Central Valley. It a diverse ecoregion containing areas of desert grassland (at the southern end), prairie, savanna, riparian forest, marsh, several types of seasonal vernal pools, and large lakes such as now-dry Tulare Lake (which was the largest freshwater lake in the United States west of the Mississippi), Buena Vista Lake, and Kern Lake.