the river valley zones are subdivided into southeastern and northwestern areas. on the southeast side, the rivers fall steeply through volcanic ash deposits where vegetation has largely recolonized the areas devastated by the volcano's eruption. on the northwest side, the rivers are more gently sloped and the land is boggy with lush vegetation. the southeast coastal region is deeply indented, with coastal cliffs, headlands and islands. three large bays are the remnants of earlier volcanic craters. the two larger bays are aniakchak and amber bays, and the smaller is kejulik bay. all have cinder-covered beaches between the sea and large freshwater lagoons.