Konwakiton Glacier was described and mapped by the early writers, but its lower portion as well as what is now Mud Creek Glacier were overlooked, apparently because they were covered with ash. At that time these glaciers must have been united and have extended from 1,000 to 1,500 ft. lower than the map indicated for Konwakiton Glacier. In 1924 profound changes occurred in these glaciers and their covering of ash largely disappeared. Between that year and 1933 the terminus of Mud Creek Glacier retreated 440 yds., which, according to the committee’s report, is believed to have “been occasioned more by the breaking down of the supporting wall of ash underneath the snout, which disintegrates with infiltration of water seeping through the glacial ice, rather than by the melting of the ice front.” The walls of the gorge below the present terminus have broken down to such an extent since 1924, that it is very difficult to identify the former positions of the terminus. In 1933 Konwakiton Glacier, which was formerly a tributary of Mud Greek Glacier, had become entirely separate.