Question: Given the following context:  Four overlapping ecological regions have been identified on the Table Rocks, with considerable differences in the variety of wildlife found in each. From the outermost base of the rocks, three regions consisting of oak savanna, chaparral, and mixed woodland surround the relatively flat tops. The andesite cap is covered by the fourth region, mounded prairie. This region formed when the caps were slowly eroded by the freezing and thawing of water that seeped into the ground (ice erosion), which created layers of mounded soil. Vernal pools fill in from October to June in the mounded prairie area due to the andesite's impermeability. The pools support species of plants and animals. Over 340 species of plants grow on the rocks, including approximately 200 species of wildflowers. Some of the most common wildflowers are western buttercups, desert parsley, bicolor lupine, and California goldfields. Camas and death camas also grow on the rocks. Camas produces an edible bulb, while death camas is poisonous and was used by the Takelma as an anesthetic.More than 70 species of animals are known to live on the Table Rocks. Lizards such as the western fence lizard, southern alligator lizard, and western skink have been seen in all four regions of the Table Rocks. Western rattlesnakes and two species of garter snakes also live in all regions. Black-tailed deer, coyotes, and bobcats are some of the mammals that live on the Table Rocks. The rocks are also home to western black-legged ticks, although they are mainly found in the chaparral region. Many species of birds live on the rocks.The Table Rocks experience a Mediterranean climate. The average wind speed in the area is less than 6 miles per hour (10 km/h), and the annual precipitation is approximately 18 inches (460 mm) due to the rain shadow created by the Klamath Mountains. It rarely snows in the winter.  answer the following question:  What ecological region is not on the outermost base of the Table Rocks?
Answer:
mounded prairie