STEEP TRAILS 



and by evaporation on the parched desert 

 plains. The grand flood of the Columbia, now 

 from half a mile to a mile wide, sweeps on to 

 the westward, holding a nearly direct course 

 until it reaches the mouth of the Willamette, 

 where it turns to the northward and flows 

 fifty miles along the main valley between the 

 Coast and Cascade Ranges ere it again resumes 

 its westward course to the sea. In all its course 

 from the mouth of the Yakima to the sea, a 

 distance of three hundred miles, the only con- 

 siderable affluent from the northward is the 

 Cowlitz, which heads in the glaciers of Mount 

 Rainier. 



From the south and east it receives the 

 Walla-Walla and Umatilla, rather short and 

 dreary-looking streams, though the plains 

 they pass through have proved fertile, and 

 their upper tributaries in the Blue Moun- 

 tains, shaded with tall pines, firs, spruces, and 

 the beautiful Oregon larch {Larix brevifolia), 

 lead into a delightful region. The John Day 

 River also heads in the Blue Mountains, and 

 flows into the Columbia sixty miles below the 

 mouth of the Umatilla. Its valley is in great 

 part fertile, and is noted for the interesting 

 fossils discovered in it by Professor Condon 

 in sections cut by the river through the over- 

 lying lava-beds. 



338 



