114 GUIDEBOOK OF THE WESTERN UNITED STATES. 
of the valley is composed mainly of rocks that overlie the quartzite, 
and if a trench were cut from the top to the bottom of the slope the 
rocks would appear as shown in figure 28. 
Fo 
: g 
« v 
W. < £ E 
o o 
rs = 
> 
> 3 
NAIF < © 
re oF oat " Vv 
AT SN Prd 9 a 
ANUS =z ; 
nets | oy Gh LN is me a as 
AZIZ NIN pe AY 
NT NTN he TENS DIAN RS 
NAVEUS ean tee tp tN ANSE INN > VSN INE CL 
SR aS P-L RUS Siew ot ONS Shy ERS Wt NST. 
7— [FN iio ras pe airy jd = Sie y aan J en 7 = 7 — ts 
Sistas A Me Ng Sai ag ole rns ES CES 
Fiecure 28.—Section across Eagle Park, showing the thin cap of quartzite on the west 
(left) and the same bed dipping into the base of the slope on the opposite side. The 
beds dip eastward, away from the Sawatch or Holy Cross anticline. 
Near milepost 286 the traveler has an unobstructed view to the 
east (right) up the valley of the East Fork of Eagle River almost 
into Fremont Pass. The width of this valley suggests that it has 
een occupied by a great river of ice that origi- 
nated in the high summits of the Mosquito 
Range north of Leadville and fiowed down | 
Eagle River valley to a point where the melt- 
ing exceeded the supply of ice from above, 
but the region has not been examined carefully 
enough to determine this point. 
In descending the west wall of the valley 
the traveler may look down upon the level sur- 
face of Eagle Park, and one of the features 
that may attract his attention is the crooked 
. 
course of Eagle River, which wends its way 
down the valley in many bends or meanders. 
These bends, as seen from a point midway be- 
tween mileposts 286 and 287, are shown in the 
accompanying sketch (fig. 29). Courses so 
crooked are not limited to streams in mountain 
regions but are characteristic of streams that 
Figure 29.—Meanders of flow on flat surfaces with a grade insufficient, 
pase River in Eagle to enable them to straighten their channels. 
ark near Deen. 
The cause of the flat surface here was a dam 
formed by a glacier in the valley at Pando. In the pond above this 
dam mud accumulated, and when the ice disappeared the valley was 
left with a flat mud bottom, which has since been covered with a thick 
layer of turf. . 
