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GUIDEBOOK OF THE WESTERN UNITED STATES. 



South of De Beque the railroad is built on a low terrace at some 

 distance from the river, but near the entrance to Palisade Canyon, 

 4^ miles south of De Beque, halfway between mileposts 48 and 49, it 

 reaches the river (on the left) in a shallow canyon cut into one of 

 the thick beds of sandstone near the top of the coal-bearing ]\lesa- 

 verde formation. As the beds rise gradually downstream the canyon 

 slowly increases in depth from its head to Palisade, where it ends. 

 At AJcin siding (milepost 51) the canyon walls are about 300 feet 

 high, and they show well the alternate bands of resistant sandstone 

 and soft, easily eroded shale. Here and there some of the beds of 

 sandstone are thick and massive ,and form cliffs 40 or 50 feet high, 

 but on the whole the alternation of shale and sandstone gives rise 

 to sloping banded walls which have a sameness in appearance that 

 soon becomes monotonous. 



At Tunnel siding (milepost 55) the walls of the canyon have in- 

 creased in height to 600 or TOO feet, but they have the same general 

 character, A mile west of this siding the train passes through a 

 tunnel which pierces a long spur (shaped in plan like a beaver's tail, 

 hence the name Beavertail tunnel) that projects from the right 

 wall of the canyon and then comes to a diversion dam which turns 

 some of the water of Colorado River into a canal on the other 

 side of the river. This canal is in sight throughout the length of 

 the canyon below this point, and its effects may be noted in the 

 crops and orchards on the high bench lands east of the river. 



JNIilepost 57 marks the largest diversion project in the canyon, 

 known as the Grand Valley or High Line project of the United 

 States Eeclamation Service, which is intended to furnish water 

 for the irrigation of the high bench lands on the north side of the 

 river from Palisade as far west as the western boundary of the 

 State. The diversion dam, shown in Plate LXVI, is completed, and 

 the canal is constructed as far west as Loma (see p. 153) and in the 

 near future will be extended to the State line.*' 



*'The Grand Valley project of the 

 United States Reclamation Service, 

 usually spoken of as the High Line 

 canal, provides for the irrigation of 

 45,000 acres of land in Mesa County, 

 Colo., comprising, as shown in figure 

 39, a strip along the northern border 

 of the valley above the old private 

 canals from 2 to 6 miles wide and 40 

 miles long. The water is taken from 

 Colorado River (formerly called Grand 

 River) by a diversion dam (shown in 

 PI. LXVI) 8 miles above Palisade, into 

 a main canal 65 miles in length, ex- 



tending to a point 6 miles northwest 

 of Mack. About 35.000 acres lies 

 under the main canal and will be sup- 

 plied by gravity, and 10.000 acres lies 

 above the level of the main canal and 

 will be supplied by electrically oper- 

 ated pumping plants. 



The most interesting engineering 

 works in this project are the diversion 

 dam and the first 6 miles of main 

 canal, which are in the canyon of 

 Colorado River. The dam, which is 

 unique in American engineering, con- 

 sists of a concrete weir, 546.5 feet in 



