Aerial photo by Comisión de Estudios del Territorio Nacional (CETENAL), 1:25,000, 1978. Volcán Riveroll, seen here from the NE, is the northernmost of the southern group of cones of the San Quintín volcanic field. A broad crater truncates the summit of the cinder cone and is breached widely to the NW. A smaller nested crater, itself breached to the NW, was constructed within the original crater and is the youngest feature of the volcano.