TOURTELOTTE PARK SPECIAL MAP. 93 
Corresponding with the steepening toward the south of the easterly 
dipping beds on the western side of the fault is a steepening of the fault 
plane itself’ While in Keno Gulch it appears to be 45 or 50 degrees to the 
east, as shown in tunnels, in Queens Gulch it is as much as 80 or 90 
degrees to the east. At the extreme southern end of the district it has 
become nearly vertical, with still an easterly tendency. If we consider, as 
has been suggested, that at the southern end of the district are the roots of 
an original overthrown fold, which culminated in the faulting, then the 
gradual steepening of the fault plane toward the south shows that the main 
fault has a curved form, becoming steep and possibly overturning in depth, 
while in the higher formations it has a dip approximately corresponding 
with the main axis of the overthrust fold, and consequently with the dip of 
the strata. 
Saddle Rock fault— This name is given to the eastern of the two branches 
into which the Pride fault splits on West Aspen Mountain. The Pride 
fault itself, as has been stated, has a downthrow to the east of about 2,000 
feet, and is thus, since it has a very steep dip to the east, a normal fault. 
After it splits into two branches its throw is divided. The Saddle Rock 
fault is continuously traceable from the area of the Aspen special map into 
that of the Tourtelotte Park special map. 
In Section A, Tourtelotte Park special map (Atlas Sheet XIII), the 
throw of the Saddle Rock fault is shown to be about 500 feet; in Section 
B, farther south, it is about 300 feet; in Section C it is about 200 feet; in 
Section D about 100 feet, and in Section EK about the same. These figures 
show a constant diminution in throw, and it is probable that the fault dies 
out in the southern part of the area mapped or merges into the Castle 
Creek fault. The explanation of this diminution of throw in the Saddle 
Rock fault is the same as for the Castle Creek fault, namely, a differential 
movement consisting of a slight elevation of the southern end of the district 
on the east of the fault, and a marked depression on the west side. Thus, 
im going along the western side of the fault from the northern edge of the 
district toward the southern, we pass from the Archean granite up into 
the Cambrian quartzite, and from this into the Silurian dolomite. This 
dolomite outcrops in the neighborhood of the Saddle Rock shaft. On the 
eastern side of the fault, however, there is no change in formation in going 
this distance, so that while at the northern edge of the district the fault 
