Introduction 



The Weiser River joins the Snake River approximately 3h2 

 miles above the confluence of the Snake and Columbia Riverso Its 

 drainage area comprises approximately 1700 square miles of west- 

 central Idaho. The total stream length of the system, including all 

 major tributaries, is more than 600 miles o 



The Weiser River watershed embraces several rich agri- 

 cultural valleys, but the arid natiire of the region necessitates 

 the extensive use of irrigation facilities for the successful 

 production of crops. Water is consequently the dearest and most 

 contested resoijrce of the area. Water rights have been granted 

 for much more water than there is available dxiring periods of 

 normal flow. On several streams practically all of the water is 

 diverted at certain points during the su-nmer, leaving sections of 

 dry stream bed. Water is also transferred from one tributary'' to 

 another, and even brought in from the Little Salmon River water- 

 shed. There are I67 irrigation diversions in the system, not one 

 of ?*dch is screened to prevent the loss of fish. 



In the early days before the agricultural development of this 

 region, the Weiser River System was a valuable area for the reproduc- 

 tion of salmon. Large runs of Chinook salmon formerly utilized the 

 extensive spawning area in both the main stream and its principal tri- 

 butaries. These runs have gradually become depleted, the last fair- 

 sized run of chinooks being reported as occurring in 1931o A few 

 salmon continue to appear, spawning mainly in the upper Little Weiser 

 River early in September, A fairly good run of steelhead trout still 

 enters the river during the spring high water period and ascends the 

 tributaries to spawn. 



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