28 GENERAL DESCRIPTION OF THE REGIONS EXAMINED. 



The system of drainage on this plateau is peculiar. There are numerous lakes, some ot 

 which have no known outlets, although they receive affluents. Wright and Rhett lakes were 

 visited by our party. The former is surrounded by low hills, and, as far as our observation 

 went, receives no tributary, although its waters are fresh. There may be, and doubtless are, 

 springs among the hills, from which it draws its supply. In the rainy season it discharges its 

 surplus waters by Lost river into Rhett lake, which has no known outlet. The level of this 

 lake is 470 feet below that of Wright lake, although the distance between them, in a right line, 

 is only about 6.5 miles. 



The chain of Klamath waters is an interesting feature of this region. The highest point 

 upon it visited by our party was near the northern end of Klamath marsh, but Colonel Fremont, 

 in his expedition of 1843-'44, crossed the principal tributary of this marsh. He describes it as 

 a stream thirty feet wide, and from two to four feet deep. It undoubtedly rises, as indicated 

 upon his map, among the mountains east of Upper Klamath lake, and after flowing towards 

 the north for a considerable distance, bends towards the south, and spreads out into Klamath 

 marsh. When it emerges again, it is a large, deep stream, with a sluggish current. After 

 passing through a canon, four miles in length, the highest points of the sides of which are 

 about 1,000 feet above the water surface, it again spreads out into a fine sheet of water, called 

 Upper Klamath lake. This lake receives several smaller tributaries. The river leaves it near 

 its southern point, and soon winds through a marsh, which forms the northern portion of 

 Lower Klamath lake. Lieut. Williamson, with a detached party, examined this portion of its 

 course, and his opinion was, that in seasons of high water the marsh is overflowed and the 

 river can properly be said to flow through the lake. In the summer, however, its bed is very 

 distinct, and it does not join the sheet of water forming the lake. After crossing the marsh it 

 soon enters the canon, by which it traverses the Cascade Range. Its subsequent course will be 

 described, in the latter part of this chapter, under the head of " Klamath river and its tribu- 

 taries." The portion of the plateau through which this chain of waters extends, is occasionally 

 fertile and valuable for agricultural purposes, but most of it is utterly worthless. 



DES CHUTES VALLEY. 



East of Diamond Peak, the general altitude of the great plateau bordering the Cascade Range 

 begins to diminish. There are many isolated hills and low ridges upon it, but in its general 

 character it now becomes an inclined plain, sloping towards the Columbia river. It is drained 

 by the Des Chutes river, which, flowing in a northerly direction near the foot hills, and receiving 

 many tributaries from the mountains, at length discharges itself into the Columbia. 



The Des Chutes river, near its source, flows through a narrow prairie, bordered by a forest of 

 pine, fir and cedar, which occasionally closes in upon its banks. The soil is of a light pumice- 

 stone character. This formation is changed to basalt in about latitude 44°. North of this point, 

 as far as its course is known, the river flows through a deep canon, broken by numerous rapids 

 which have given it the name of Des Chutes. Its average descent in this canon is about twenty- 

 five feet per mile. We did not find its tributaries sunk in canons until we reached about 

 latitude 44° 35', where we emerged from the foot-hills, and came upon the great basaltic 

 plain, through which the river had been flowing for many miles. This plain is formed by suc- 

 cessive layers of trap, of which I once counted as many as seven, interstratified with tufas and 

 conglomerates. Although this stone is exceedingly hard under the hammer, it disintegrates 

 rapidly when exposed to the weather. Not only have all the streams flowing through the plain 



