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GUIDEBOOK OF THE WESTERN" UNITED STATES. 



At milepost 379 the railroad crosses the river, and from this place 

 to Grand Junction the best views of the canyon may be obtained on 

 the left. In the upper end of the canyon the walls are composed of 

 variegated shale and sandstone of the Gunnison formation,^^ as 

 shown in Plate LXXVI, B. 



At first the only part of the Gunnison formation that is seen is the 

 upper shale, which gives to the canyon walls bands of rather strong 



color, but after watching these colors 

 for several miles one would welcome 

 any change from the ever-present 

 maroon and green. Although the 

 canyon is fairlj^ narrow and there is 

 not much land in it that can be irri- 

 gated, several attempts at irrigation 

 on a small scale have been made. 

 The method used employs no dams or 

 ditches but only a current wheel, 

 which is placed in the stream in such 

 a position that the current turns it, 

 and as it is provided with buckets, 

 a small quantity of water is at each 

 revolution lifted from the river to 

 the top of the wheel, where it is automatically dumped into a trough 

 that carries it to the land to be irrigated. Although this is a primi- 

 tive arrangement it is excellently adapted to the irrigation of small 

 tracts of land. A number of these wheels may be seen in the canj'on. 

 In general the canyon grows deeper downstream, and at Escalante 

 siding, milepost 385 (see sheet 7, p. 198), the second member of the 

 Gunnison formation — a hard sandstone — appears near the railroad 



Figure 47. — Rocks forming the canyon 

 wall near Bridgeport. 



^ The Gunnison formation liere is 

 composed of tliree parts, as shown in 

 figure 47. The upper part, which prob- 

 ably corresponds to the Morrison for- 

 mation of the east side of the range, is 

 visible where the walls are low. It is 

 about 250 feet thick and is made up 

 of variegated shale and soft sand- 

 stone. The colors are mostly maroon 

 and green, and in many places the 

 bands of color are very distinct. This 

 part is comparatively soft and conse- 

 quently forms slopes that lead down 

 from the more resistant sandstone 

 cliffs above. The middle part of the 

 formation is about 100 feet thick and 



is composed largely of sandstone that 

 is resistant to erosion and there- 

 fore stands out as buttresses on the 

 canyon wall with steep or precipitous 

 faces. Although not brightly colored, 

 it has many of the same tints as the 

 overlying shale. The lowest part of 

 the formation is about 130 feet thick 

 and is made up almost entirely of 

 shale, which in the upper part is of a 

 dull slate color but near the bottom 

 has many bands of strong maroon. 

 It is generally soft and forms slopes, 

 but the slopes are steeper than those 

 formed on the uppermost part of the 

 formation. 



