
ROCKY MOUNTAINS—REVIEW OF SECTION. 67 

fault, occur at the north-eastern corner of the range. They were not 
closely examined, but may belong to Series B. 
143. Chief, or more properly Chief’s Mountain, which projects 
still further to the eastward, is one of the most remarkable mountain 
masses of this region. It is nearly isolated from the rest, though 
surrounded by rugged foot-hills, which are covered with dense woods 
and wind-fall, rendering it almost unapproachable. As seen from the 
eastward, it resembles the base of a broken column, and its outline was 
quite distinguishable from that of the remainder of the mountains, even 
from the Sweet Grass Hills, a distance of one hundred miles. On three 
sides, the central mass of the mountain is precipitous, and its bare rocky 
cliffs are of great height. To the west, it appears to slope more 
gradually, and its summit is cleft with deep ravines. It seems to owe its 
remarkable form to the peculiar weathering of the limestones of Series 
D., of which the perpendicular portion is composed. The rocks 
of the foot-hills are softer, and no doubt belong to Series C. Chief 
Mountain resembles in its structure the peak called Castle Mountain by 
Dr. Hector, each being formed of a huge quadrangular block of nearly 
horizontal limestone beds. 
Review of the Section. 
144. The total thickness of the beds seen in this part of the Rocky 
Mountains must be about 4,500 feet, though this can only be regarded 
as an approximation; as owing to the short time at my disposal, few 
of the beds were actually measured. The entire series arranged as a 
continuous section in descending order, is as follows :— 
H. Fawn-coloured flaggy beds, seen only at a distance, but probably 
composed of magnesian sandstones and limestones. 100 feet. 
G. Beds characterized by a predominent red colour, and chiefly red sand- 
stone, but including some thin greyish beds, and magnesian sand- 
stones, the whole generally thin-bedded, though sometimes 
rather massive. Ripple-marks, &c., Weathers to a steep rocky 
talus, where exposed in the mountain sides; and passes gradually 
down into the next series. 300 feet. 
F. Fawn-coloured flaggy beds of magnesian sandstone and limestone. 
Some red sandstones occur throughout, but are especially abundant 
toward the top. Apparently a continuation upward of the lime- 
stone D., and only separated from it by the trap overflow. 200 
feet. 

