374 REPORT UNITED STATES GEOLOGICAL SURVEY. 



The fourth patch is found near the junction of Yampa and Snake 

 Eivers, and is called Lily's Park. This park-valley is not very exten- 

 sive; it is not quite 5 miles in length, and is from ^ to 1 mile in width. 

 It is surrounded by the abruptly-rising spurs and benches of Pro- 

 montary Plateau and Junction Mountain, as well as by those that run 

 out from the high hills to the north of the park. This park represents 

 the last spot of agricultural laud on the Yampa Eiver, and together 

 "with a portion of the Snake Eiver Valley might give accommodations 

 to a few settlers. 



For the jremainder of its course, down to where the Green Eiver finally 

 absorbs its name, the Yampa flows, as already described, in an almost 

 vertical canon, wherein naturally even the smallest area of useful land 

 does not exist. 



The defile in which Williams Fork of the Yampa meanders can 

 scarcely be called a valley — it would be a misnomer, and, indeed, few 

 are the acres that could be found in it to be regarded as farming land. 



All over the Western Plateau region the same unfavorable conditions 

 prevail even to a greater degree than here, for we have in the district 

 already noted at least two prominent streams on which we would find 

 the necessary water to accomplish the irrigation which would be possi- 

 ble along their banks. 



Although this plateau region may be classed among the driest, it is 

 not absolutely destitute of rain ; only the regular periodical rains com- 

 mon in all moderate climates are wanting. The occasional rains that 

 fall are short in duration, but violent in action. Moderation in climati- 

 cal phenomena, we might say, does not exist throughout the far West, 

 and that it has been the case for ages is proved by the absence of a sod, 

 or a mantle of deep-rooted grass-vegetation. The rain-fall that occurred 

 several times during our sojourn in this region was violent in the ex- 

 treme but short in duration. The total absence of a well-connected sod 

 permitted the water to run oif suddenly, as if poured on a crust of terra 

 cotta. Every trace of moisture disappeared almost in as short a time 

 as the rain lasted. The nature of the ground is unfavorable for the 

 gradual absorption of the moisture, nor did we observe moderation in 

 the accompanying elements during or after the rain-fall. The rain was 

 generally accompanied by a very low temperature, so much so, that 

 bail and snow were generally associated with the rain. After the ces- 

 sation of rain followed either a piercing cold wind or an extreme heat, 

 which caused the recently- moist clay-ground to crack or break into 

 wrinkles. The water flows off rapidly, gathers in its natural drainage- 

 channels, through which it ploughs and digs deeper and deeper into 

 the soft material, each creek, large or small, producing thereby a perpen- 

 dicular deep fissure or small caiion, which have been seen in places as 

 much as 60 feet deep, with only a width of perhaps 20 feet from rim 

 to rim. 



Under the existing conditions we may arrive at the conclusion that 

 this plateau region cannot be made available for agricultural purposes, 

 and there is hardly a doubt that even the most desperate attempts of an 

 over-populated but industrious community would fail in the attempt to 

 change this country for the better. 



Through ages this plateau region seems to have possessed this dry 

 character during the greater number of months in the year ; the topo- 

 graphy as well as the vegetation bears testimony to this fact. 



There exists no gentle undulating ground anywhere except on the 

 very tops of the plateaus. The whole surface of the crust indicates the 

 violence of erosion during winter and a desert-like dryness during the 



