3° 



The National Geographic Magazine 



struction of the principal engineering 

 work, a rock-fill dam. This structure 

 was located about 8 miles southwest of 

 Minidoka, at a point where the channel of 

 the river has been crossed by recurring 

 lava flows. A ridge of lava probably ex- 

 tended entirely across the river channel 

 at this point and the river cut a narrow 

 way through it. The purposes of the 

 dam are mainly control, diversion, and 

 power development. In constructing the 

 dam the diversion channel was first built. 

 Two separate masses of fill, the upper 

 one of earth and the lower one of rock, 

 about 150 feet apart, were extended 

 across the river from shore to shore. As 

 the natural channel was thus gradually 

 closed, the water was backed up and com- 

 pelled to flow through the diversion chan- 

 nel. The line of rock-fill was deposited 

 from a cable-way, the earth-fill being put 

 in place by means of dump-cars and 

 trestle-work. Between the two masses 

 of fill a concrete core wall, built up from 

 bed-rock, was extended across the river. 

 The headworks contain nine gates each 5 

 feet wide by 7 feet high, and the con- 

 trolling works contain five gates each 

 8 by 12 feet. The dam is 80 feet high 

 and 625 feet long; on top it is 25 feet 

 wide. Its volume is about 190,000 cubic 

 yards. It was completed in September, 

 1906. The natural conditions are favor- 

 able for the development of power, and 

 from 11,000 to 30,000 horse-power will be 

 available for the people who dwell under 

 the project, an asset the value of which 

 can scarcely be overestimated. The canal 

 system, to be in operation this year, is 

 more than 100 miles in length and will 

 cover 60,000 acres. 



THE WONDERFUL YAKIMA VALLEY 



Redlands and Riverside of southern 

 California have their rivals in the North- 

 west in the wonderful Yakima A^alley, in 

 Washington. Those M'ho find the per- 

 petual summer of the Southwest too ener- 

 vating will be attracted to this remarkable 

 region, which has so recently come into 

 prominence by reason of its surprising 



fertility and the diversity and superior 

 cjuality of its products. 



Naturally this region was not over- 

 looked by the Service. Today construc- 

 tion is under way which when fully con- 

 cluded will bring approximately 400,000 

 acres under ditch. The crop yields in 

 this valley are almost incredible, and, as a 

 result, agricultural lands have as high 

 average value here as anywhere in this 

 country, California orange lands not ex- 

 cepted. Two thousand dollars per acre 

 for orchard land is not an uncommon 

 price. We need not wonder at such sales 

 when these apple orchards frequently 

 yield 1,470 boxes per acre, which sell for 

 $1.25 per box, or $1,737 V^^ acre. The 

 hay crop is an important one. The val- 

 ley potatoes bring an annual income of 

 $1,000,000 to the farmers. Hops yield 

 from $300 to $600 per acre. Yakima ap- 

 ples and hops sell well in the New York 

 markets, and are exported in large quan- 

 tities. 



The Yakima project is in several units 

 which ultimately will be combined in one 

 great system, embracing 400,000 acres, 

 every acre of which, with an assured 

 water supply, will be worth not less than 

 $100. The government's plans involve 

 an expenditure of about $13,000,000 in 

 canals and ditches and in storage dams to 

 hold back the flood waters of the Yakima 

 drainage in several mountain lakes. 



Our desert region is the only section of 

 our imperial country wherein there is an 

 equality of opportunity. In no other part 

 of the nation are the rewards for indi- 

 vidual effort more certain and constant. 

 When these facts are more fully realized, 

 the wisdom of President Roosevelt's pol- 

 icy of safeguarding and conserving this 

 vast estate for the people will be appre- 

 ciated. America has furnished a safety- 

 valve against the overcrowding of the 

 great centers of population in the Old 

 World for 50 years. Is it not about time 

 to look to our problem and prepare 

 against the day when there shall be a 

 glut of population in our own cities? 

 Thoughtful men are predicting a popula- 



