National Geographic : 1950 Aug
. . .. 207 Leslie P. Greenhill Hikers Above the Clouds Don Sunglasses in the Glare of Great Aletsch Glacier Here, not far from Jungfraujoch (page 211), they see part of the 15-mile-long frozen sea moving slowly down the valley to help feed the River Rhone, which winds across southern France to the Mediterranean. Aletsch Glacier, the largest in the Alps, fills the valley between the Finsteraarhorn, Jungfrau, and Aletschhorn mountain groups.