National Geographic : 1941 Sep
(~ National Geographic Society Kodachrome by Richard H.Stewart Rising Out of the Flat Plain, a Volcano of Bubbling Mud Builds Up a Sun-cracked Cone Fifty years ago the phenomenon did not exist. Now the parched mud, overflowing from the crater, has covered several acres just ashort walk from the expedition camp at Cerro de las Mesas (Plate VI). The crater erupts vigorously during the rainy season. Warm mud oozes from seep holes inthesides ofthecone.