 Since the Olson eruption , the Rogue River has eroded 90 percent of the solidified lava . Though the andesite prevented much erosion to the caps of the Table Rocks , the andesite @-@ capped cliffs eroded from the side as the softer sedimentary units of the Payne Cliffs Formation gave way . This erosion created expansive talus fields which surround the plateaus on all sides , creating slopes capable of supporting abundant plant and animal life . Upper and Lower Table Rock both stand 800 feet ( 240 m ) above the valley floor , and just over 2 @,@ 000 feet ( 610 m ) above sea level . There are approximately 300 acres ( 120 ha ) of level ground on Lower Table Rock , and 500 acres ( 200 ha ) on Upper Table Rock . 
