EXTINCT AND EXISTING GLACIERS OF COLORADO 57 



and noted evidence of two epochs, the ice of the last covering the 

 larger part of the surface of the mountains. The glaciers originated 

 at 11,000 feet usually and descended to 9,000 or less, the larger ones 

 reaching a depth of i ,000 feet. Emmons, in the Leadville Monograph 

 (pp. 94-95), says the Platte Glacier must have been about 2,000 feet 

 thick. All the main streams of the Mosquito Range head in glacial 

 cirques. Some, ten miles long, extended down into South Park, 

 according to Stone. Buckskin and Mosquito Gulches are worthy of 

 special mention. Tenmile Glacier extended some distance down 

 Eagle River, A lateral moraine at Clinton Gulch has been tunneled 

 to a distance of 300 feet without reaching solid rock, according to 

 Emmons {Tenmile Folio, p. 2). The southern part of Park Range 

 shows glaciation everywhere. According to Hay den {Seventh Ann. 

 Kept., p. 54) the Lake Creek Glacier was 1,500 feet in thickness. 

 There are great moraines everywhere along both east and west sides of 

 the Sawatch Range (Hayden, Seventh Ann. Rept., p. 51). Roches 

 Moutonnees Creek has been made famous as an illustration of glacier- 

 rounded rock knobs by Hayden and Dana. Hayden {Seventh Ann. 

 Rept., pp. 72, 76) also reports moraines and cirques as common in the 

 Blue River Range, and "great masses of snow, like glaciers." The 

 Elk Mountains are also heavily glaciated (Hayden, Seventh Ann. Rept., 

 p. 67). 



This great mountain mass, consisting of several ranges centering 

 near Leadville, abounds in cirques separated by serrated ridges, as 

 in the Northern Front Range region. The general elevation of the 

 Sawatch Range for 60 miles or more is from 13,000 to 14,000 feet. 



The Elk Mountains were heavily glaciated. Emmons^ says: 

 "Glacial drift is found over the whole district, although often stripped 



off by more recent erosion On top of Smuggler Mountain, 



which is 10,000 feet high, the thickness of moraine .... is about 



Mountains," U.S. Geol. Surv., Mon., Vol. XXXIV, pp. 338-54, 1899; Westgate, Lewis, C, "The Twin 

 Lakes Glaciated Area, Colorado," /owrn. Geol., Vol. XIH, pp. 285-312, 1905; Davis, W. M., "Glaciation of the 

 Sawatch Range, Colorado," Bull. Mus. Compar. Zool., Vol XLIX, pp. i-ii, 1905; "Glacial Erosion in the 

 Sawatch Range, Colorado," Appalachia, Vol. X, pp. 392-404, 1904; Capps, S. R., and Leffingwell, E. D. K., 

 "Pleistocene Geology of the Sawatch Range, Near Leadville, Colorado," Journ. Geol., Vol. XU, pp. 698-706, 

 1904. 



" Emmons, S. F., Geology of the Aspen Mining District, Colorado, U.S. Geol. Surv., Mon., Vol. XXXI, pp. 

 244-47, 1898. 



