173 
14,408 feet in altitude, the highest peak of the Cascade Range, but 
this view gives him little idea of the magnitude and grandeur of the 
mountain. 
The great sheets of basalt that underlie the Yakima Valley are in 
places thrown into low folds by pressure in the crust of the earth 
exerted in a north-south direction, and consequently 
the folds trend at right angles to that direction, or 
nearly east and west. As these folds bring up ithe 
hard basalt, they make ridges or mountains across 
the country, the length of the ridge depending on the 
the extent of the fold. The big ridge lying to the south of the rail- 
way from Kennewick to Mabton is supposed to be of this character, 
although its structure has not been accurately determined. This 
broad upland, from its original cover of abundant and nutritious 
unch grass, is known as Horse Heaven. The next ridges to the 
north are Toppenish Ridge west of the river and Snipes Mountain on 
the east. These appear to be parts of one general line of disturbance 
but are separate folds. In Snipes Mountain the arch is so low that 
the basalt is scarcely visible under the cover of the Ellensburg 
formation. 
The next pcidhene to the north, which hes north of Toppenish, is 
known west of the river as Atanuni Ridge and east of the river as 
Rattlesnake Ridge. The Yakima has made a deep, 
THE NORTHERN PACIFIC ROUTE. 
Wapato. 
Elevation 865 feet. 
Population 400. 
St. Paul 1,729 miles. 
Parker. narrow cut, called Union Gap, through this ridge 
Elevation 930feet. north of Parker. At the south entrance to the gap 
Population 
the Northern Pacific crosses the North Yakima 
branch of the Oregon-Washington Railroad. The 
gap is about a mile in length, and the sheets of lava at the south 
entrance dip toward the south at an angle of about 20°. The oppo- 
site dip on the north side of the fold is not so apparent, for it is 
much steeper and in some places the layers are crushed and over- 
turned, so that the dip is toward the south. 
St. Paul 1,733 miles. 
high summits to mark its once even sur- 
face. When seen from a distant point, 
as from Toppenish, the tops fall into line 
and have ha appearance of an unbroken 
upland m 
At x Sag same time that the streams were 
on the platform of the range. As lava 
flow succeeded lava flow,.and showers of 
ash fell upon the area surrounding the 
vent, a cone was gradually built up, 
orming the present high peaks. These 
voleanic cones between Canada ‘and Co- 
lumbia River are Mount Baker, Glacier 
Peak, Mount Rainier (Tacoma), Mount 
Asians: and Mount St. Helens. 
The view from Alfalfa or Toppenish 
shows clearly that Mount Adams rests on 
the platform called the Cascade Range, 
but that it is not really a part of that 
range, but rather an excrescence upon the 
apparently rounded, tree-covered surface 
of the plateau. 
Ln) 
