Eastern Merced County is home to some of California’s rarest, most endangered animals and plants. Each species has specific adaptations that allows it to survive in these sparsely vegetated lands that receives only about 13 inches of rain in a year. The survival of many of these rare and endangered organisms is linked to the vernal pools - ephemeral wetlands that fill seasonally with rainfall and persist for only three to five months before drying. These pools are considered one of the most threatened ecosystems in California. Most have been lost as agriculture expanded across the Central Valley and to road building and urbanization.