FOEMER GLACIATIOX OF THE ROCKY MOUNTAINS. 69 



have attracted numerous quasi-scientific government expeditions in that 

 direction. The earlier explorations of the Pacific Railroad Surveys were 

 extended through the northern part of the Rocky Mountains, but the pub- 

 lished reports give no infornuition in regard to the phenomena of ancient 

 glaciers in that region, which fact may be accounted for partly by the igno- 

 rance and inexperience of the observers, and partly on the ground that 

 details of this kind had not at that time attracted much attention in the Far 

 West, the routes of the explorers being almost exclusively limited to the 

 lower valleys ; their object was chiefly to get across the country as rapidly 

 and with as little trouble as possible. 



Some hints in regard to the existence of former glaciers in the more 

 northern portions of the Rocky Mountains, south of the United States 

 boundary, may be obtained from Dr. Hayden's reports. For instance, the 

 volume giving the results of the explorations of the year 1871, when the 

 Yellowstone region was visited, by way of Fort Hall in Idaho and Fort Ellis 

 in Montana, contains the following quotation, which refers to the vicinity 

 of the range of the Snowy Mountains " forming the great water-.shed be- 

 tween two portions of the Yellowstone River," a volcanic range rising to the 

 altitude of from 10,000 to 11,000 feet above the sea-level. Here Dr. Haj'den 

 describes great detrital accumulations resting against the flanks of the range, 

 and apparently exactly resembling in character the so-called " washes " of 

 the California ranges, of which mention has already been repeatedly made. 

 Of these piles of detritus he .says : " The little streams that flow down from 

 the mountain sides cut sections through this deposit, so that they are re- 

 vealed quite clearl}-. The upper portion is composed in part of the debris 

 from the mountains, but thei-e is all over the valley a vast deposit of what 

 I can call by no better name than local drift or detritus. In this detritus are 

 quite frequently masses of rock, or boulders, that have evidently been trans- 

 ported a considerable distance by a force not now in operation in this vicin- 

 ity. This fact points back to a time when we may suppose that there were 

 vast accumidations of snow and ice all over the valleys, but more especially 

 on the sides and summits of the mountains ; and as the temperature became 

 much warmer this snow and ice melted, producing rivers and torrents with 

 sufficient force, aided perhaps by the masses of ice, to move these immense 

 boulders from place to place. An important fact should be continually borne 

 in mind, that a critical examination of this detritus reveals no evidence of 

 the existence of rocks from any distant point outside of the river drainage 



