GENERAL TOPOGRAPHIC RELATIONS. 113 
imentary rocks. Mount Rainier, the largest and highest, holds its crater 
rim at 14,519 feet (4,426.5 meters) above tide. The ranges are profoundly 
dissected, with development of amphitheaters and acute culminating 
peaks such as are called by the French “ dents” or “ teeth.” The scenic 
type is that peculiar to a region which has long harbored valley glaciers 
below the culminating summits, as the Alps nowdo. The space between 
the foothills of these ranges is about 60 miles (100 kilometers), and from 
summit to summit about 100 miles (160 kilometers). 
THE EOCENE GEOSYNCLINE 
A wide geosyncline lies between them, extending from north to south, 
with southern pitch. South of the Olympics the trough widens westward 
to the Pacific ocean, but its main axis is prolonged to the Columbia river 
and continued in the Willamette valley in Oregon. In Eocene time this 
geosyncline was a basin in which fresh and brackish water sediments 
accumulated to a depth of 9,000 feet (2,700 meters) or more. It was more 
narrowly limited and defined by the orogenic uplifts of the mountain 
ranges, which, according to the evidence of fossil plants, cannot be dated 
farther back than the early Miocene. 
PUGET SOUND AND THE STRAITS 
Puget sound lies in the northern part of this trough. The application 
of the name has been variously defined. Vancouver originally gave it 
to the sound explored by Lieutenant Puget on a boat trip, and which is 
a branch of Admiralty inlet, beginning at the south end of Vashon island 
and extending thence south and west. As now almost universally used, 
the term includes all of Admiralty inlet, and is defined in the Pacific 
Coast Pilot in the broad acceptation of the term as lying between lati- 
tudes 47° 03’ and 48° 11’ and between longitudes 122° 10’ and 128° 10’. 
The latter definition does not appear to extend to Hoods canal, an im- 
portant member of the system, but in the phrase ‘‘ Puget Sound basin ” 
in this article the name is intended to cover all that complex maze of 
channels south of the strait of Juan de Fuca. Southeast of Vancouver 
island is an indefinite water body defined by the United States Coast 
Survey as the eastern end of the strait, which thus extends to Whidbey 
island. Puget sound opens from it. Vancouver called the eastern part 
of the strait part of the gulf of Georgia, but his usage has not prevailed. 
CLASSIFICATION OF TOPOGRAPHIC FEATURES 
‘The topographic features of the Puget Sound basin are readily classi- 
fied by magnitude as major and minor, The major features are (1) 
