22 CoE. SLE BENGIREVAL 
over 80 feet. ‘The slope of the ice surface is very steep, about 42°— 
quite too steep for climbing without alpinestock and_ice-creepers. 
Two embryonic terminal morainic ridges are visible, the lower and 
larger one some 400 feet below the present edge of visible ice. The 
ice, as will be noted, shows the characteristic upturned dirt bands 
looped concentrically about the point of supply, and the surface of 
the lower half of the glacier is for the most part covered with fine 
black gravelly dirt, residual from the dirt bands. Many small longitu- 
dinal rivulets have cut gullies down the otherwise notably smooth 
surface of the ice, exposing the banded ice beneath the dirt covering. 
The ice itself displays characteristic gletscherkérne about one-tenth inch 
in diameter. Because of the conformation of the pocket in which the 
ice accumulates, the production of crevasses is impossible, with the 
exception of a definite bergschrunde which marks the line where the 
upper edge of the ice pulls away from the rock wall in the wasting 
season. The precipice above and the steep face of the glacier cause 
loose fragments falling upon the ice to attain great velocity in their 
passage across if, so that examination of the glacier is attended by 
considerable danger from these flying rocks. 
The Blanca glaciers possess an added interest in being the southern- 
most existing glaciers yet reported in the Rocky Mountains, and, so 
far as known to the writer, the southernmost in the United States, 
Their latitude is 37° 35’ N., their longitude 105° 28’ W., and their 
elevation about 12,000 feet. 
Summary.—The various stream valleys heading against the crest 
of the Sangre de Cristo Range held Pleistocene glaciers, the morainic 
remains of which fall into two systems, showing the existence of 
two periods of glaciation. The moraines of both systems are com- 
paratively fresh-looking, and the outer, older ones are not noticeably 
more eroded than, or different topographically from, the inner, later 
ones. The inner moraines are sometimes lower, sometimes higher, 
than the outer ones, and while they usually are shorter than the older 
moraines, sometimes, as in Bear Creek valley, they transgress the 
older moraine and extend farther out upon the alluvial slope, these 
irregularities being due presumably to variable local conditions in 
Pleistocene time. 
