BOTANY OF THE ROUTE. 17 



the country becoming very mountainous, and therefore well wooded. Southward it is continuous 

 with the central plains of Oregon, through them with those of Utah, and through the South 

 Pass with the vast plains extending eastward to the Mississippi river. 



In order to show the peculiarities in the vegetation of the plain region, I have included the 

 plants collected there in a separate list. Though made at an unfavorable season, and few in 

 number, they show a marked dissimilarity from those obtained west of the mountains, yet many 

 of the latter belonging to the prairies west of the mountains are also known to be found on the 

 plains of the central districts. 



One peculiar group of shrubs represents in this region the forest trees, and are characteristic 

 of all the plain regions between the eastern base of the Rocky mountains and the Pacific. 

 (PursJiia tridentata, Artemisia tridentata, Linosyris albicaulis, L. viscidiflora, Sarcobatus ver- 

 micularis.) 



As the most characteristic animals, I refer to the badger, coyote, or barking wolf, cock of the 

 plains, or sage fowl ; sharp-tailed grouse, or prairie chicken, and other smaller kinds, mentioned 

 more particularly elsewhere. The antelope, buffalo, prairie dog, and some others found in other 

 parts of the plains, doubtless are sometimes to be met with in this Territory, though we neither 

 saw them nor heard of them as being common. 



The various divisions of the plains due to differences of elevations, soil, and moisture, have 

 each their peculiarities, which would require a long description, had my opportunities been 

 sufficient to make it complete. A short notice of the most striking may not be without interest 

 here. 



The high ridges forming spurs of the Cascade range, extending \vith a gradual slope from 

 the pine forests down to the Columbia on each side the Yakima valley, between its branches, are 

 too dry to serve as anything but a grazing region. Some portions near their summits are also 

 very rocky and barren, but these are comparatively small. The greatest obstacle to cultivation 

 is the absence of means of irrigation, but there can be little doubt of the success of winter 

 grains on many parts of these ridges. The Spokane plain, between that river and the Snake, 

 west of longitude 118, resembles, in soil and elevation, the lowest part of these ridges, being 

 from 500 to 2,500 feet in elevation. But being a great plateau, it has the advantage of retaining 

 moisture, and in many parts are tracts sufficiently irrigated naturally for general cultivation. 

 Alkaline lakes and marshes, and some very rocky portions, are all that cannot be made use of, 

 but these seem to occupy comparatively a small extent of it. 



On all the branches of the northern Columbia crossed by us we found valleys of various 

 extent, which form the best portion of the plain region. Terraces varying in height from five 

 to two hundred feet above the water border these valleys, and present various soils, from the 

 very dry gravel of the ridges down to the fertile alluvium of the river banks. The change in 

 the native vegetation from one to another of these is very remarkable, indicating an adaptation 

 for various crops. Long rank grass covers the moister portions of the bottoms, and there is 

 always some timber close to the water, except towards the mouth of the Yakima. Those valleys 

 north of latitude 48 are doubtless the best in soil and climate, crops doing admirably at Fort 

 Colville without any irrigation. 



The lands immediately along the Columbia itself, from just below the mouth of the Spokane 



to near the Dalles, and all the adjoining region below the elevation of about 2,000 feet, seem 



available only for grazing without the assistance of irrigation. But it has, as well as the higher 



valleys, great advantages for effecting this object in the terraces which often partially form a 



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