BECHLEK.] YAMPA EIVER. 371 



a straig^ht line. Eepeated changes ia its features are characteristic of 

 this stream. Basins, caiions, and caiion-valleys, with occasional spots of 

 well developed valley, constitute its main features. The valley form is, 

 for instance, decidedly expressed for 24 miles along that portion of the 

 river which terminates with the junction of Williams Fork, from which 

 point the stream flows for 10 miles, more or less, in a canon, which con- 

 tains not only some picturesque scenery, but in the river-bends occasional 

 small park areas. By repeated crossing we are enabled to make our 

 way with pack and saddle animals through this half caiion of the 

 Yampa. The river emerges from this semi-icaSon at the western terminus 

 of Sage Plateau, which is elsewhere described in these notes. The river 

 enters here a splendid bottom of five or six miles in extent, leaving 

 which, it forces a passage through a small canon situated near Yampa 

 Peak, in longitude 108°. (See Plate XXIV.) After passing this caiion 

 the stream meanders for 16 miles in a basin-shaped area, having the 

 name of West-axial Basin on the accompanying map. While in this 

 basin, the river flows on the north side near a girdle of not very high 

 but abruptly-rising bluft's. 



West-axial Basin constitutes principally a gently descending area of 

 terraces, covering from 50 to 60 square miles, which lie on the north side 

 of Citadel Plateau and Wampita Peak. 



A splendid patch of river bottom with rich grass distinguishes from 

 the remainder of the basin the lower or western end of the valley imme- 

 diately below Junction Mountain. There, where the most western mar- 

 gin of this grassy bottom meets Junction Mountain, there opens a 

 tremendous gorge with almost vertical walls of about 1,000 feet in height, 

 in which the river disappears (see Plate XXV,) but only to emerge again 

 2miles beyondmaprettylittle valley namedLily's Park. Here theSnake 

 Eiver joins the Yampa, and rich grass and cottonwood groves character- 

 ize this, which is, perhaps, the finest valley in the course of Yampa 

 Eiver (see Plate XXVI). This park is surrounded on all sides by eroded 

 terraces and plateau spurs which rise step by step to the divide on either 

 side. Promontory Plateau rises on the south side just opposite the 

 junction of Snake and Yampa Eiver, to a height of over 1,000 feet above 

 river-level, while Junction Mountain attains an altitude of 1,800 feet 

 above Lily's Park, or 7,800 feet above sea-level. 



The best portion of this small area of Lily's Park lies on the south side 

 of the river, and at a point where Vale Disappointment — a small, dry 

 valley — approaches Lily's Park the Yampa Eiver again enters a huge fis- 

 sure in the mountains. In this it remains with great persistency during 

 nearly its entire course down to i s junction with the Green Eiver. 



From Lily's Park to Green Eiver Junction, a distance of 26 miles in 

 air-line, the Yampa flows within narrow, precipitous walls, and only when 

 within a distance from 6 or 8 miles from Green Eiver does it come 

 out of the caiion, touching the margin of a basin (Eed Eock Basin) which 

 lies along the northern slope of the Great Yampa Plateau. It, however, 

 suddenly disappears again, as if showing a decided preference for a dark, 

 rocky inclosure rather than for freedom. There is no doubt that this 

 piece of drainage of the Yampa Eiver between Lily's Park and Green 

 Eiver Junction is one of the most remarkable on record. All along this 

 portion of the river, and only from 1 to 2 miles south of it, lies a basin- 

 like depression, to all appearances just molded for a valley, and, as far as 

 can be discovered by ordinary observation, seeming to be nothing else 

 else but the actual synclinal axis between the strata dipping from the 

 Yampa Plateau and those dipping from the opposite Escalante Hills. In 

 cousequence of this it would seem to be the proper course for the river, 



