-_ 
parallel with these has a general course from northwest to southeast. 
Itexteuds through seventeen degrees of latitude, reaching from the 
British Possessions to the Mexican boundary. Springing from elevated 
plains and plateaus, which range in altitude from 3,000 to 7,000 feet, 
the mountains of this system attain their greatest elevation in Colo- 
rado, reaching there an extreme height of 14,460 feet above the sea. 
The several parts of the system may be described briefly as follows: 
Commencing at the boundary line between British America and 
Montana, in the western part of the last-named Territory, the Main 
Range there takes a southeasterly course for a distance of about 200 
miles; then it turns sharply to the west and at the boundary of Idaho — 
is joined by the Bitter Root chain of mountains, which run in a south- 
easterly direction and form the middle portion of the dividing line 
between Montana and Idaho. The Coeur d’Alene Mountains, in north- 
ern Idaho, coustitute the northwest extension of the Bitter Root Moun- 
talus. ; : 
The Main Range, from the point where it is joined by the last-named 
mountains, continues in a southeasterly course on the line between the 
two Territories and enters northwestern Wyoming near the southwest- 
ern corner of the Yellowstone National Park. Continuing in the same 
direction, the Wind River Mountains form an important link in the 
great chain. At their southeastern extremity they meet the Sweet- 
water Mountains, a comparatively short range, trending eastward. The 
crest, or dividing line, there turns to the southeast and passes over an 
open country or high table-land for a distance of 75 to 100 miles; it 
then strikes the Sierra Madre Mountains, the northern extension of the 
Park Range of Colorado, which form a portion of the Main Range. In 
North and Central Wyoming, the Big Horn, the Laramie and Medicine 
Bow Mountains are the most notable adjacent ranges. 
The Colorado system commences on the north with the Park Range, 
which forms the western boundary of North Park. At the southwestern 
angle of the park the main divide turns directly eastward, separating 
Northaud Middle Parks, and is joined by the Medicine Bow Range at the 
northeast corner of the last-named park. The Main Range then bears 
to the southeast for a short distance, then turns southwestward and 
continues in that direetion until it crosses the Park Range a few miles 
north of Leadville. The northern extremity of the Saguache Range is 
here reached. This range takes a course a little east of south, and ter- 
minates about 40 miles southeast of the town of Gunnison, in south- 
western Colorado. A range called in part the “ Cochetopa Hills,” and 
running in a southwesterly direction, connects the Saguache with the 
San Juan Mountains. The iatter, bearing southeastward, terminate 
near the southern line of the State. 
The principal secondary range in Colorado is the Park Range, which 
constitutes the western boundaries of North, Middle, and South Parks, 
and is crossed, as before stated, by the Continental Divide. Other im- 

