making it the highest dam in the United States. As an outlet 

 for the reservoir, a tunnel 450 feet long has heen constructed 

 through the canyon -wall around the point where one end of the 

 dam -will he huilt into the rock side wall. During construction 

 this tunnel -will carry the diverted -waters of the river so that 

 excavations for the foundations may go on uninterruptedly. 

 The tunnel is closed hy a series of six mammoth gates of steel, 

 weighing, -with their operating machinery, nearly 800,000 

 pounds, and which will regulate the emptying of the reservoir 

 water. 



To carry flood waters around the ends of the dam when the 

 reservoir is full, two spill-ways, each 200 feet in width, are cut 

 in the solid rock twenty feet lower than the crest of the dam. 

 Concrete steel arch hndges 200 feet long will span the spillways 

 and carry a road-way across the top of the dam. Behind the 

 dam will stretch the greatest artificial reservoir in the -world, 

 a hody of -water twenty-five miles long and with an average 



