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Figure 1: — I-lississippi River approximately 2 miles south of La Crosse. VJi scons in, Miller Lake 

 is indicated by a line near the center of the photograph (aerial photo taken J'lly 28, 19L7). 



follows the east bank of the valley proper at 

 this location. West of the main channel the 

 broad river bottoms are dissected by lesser 

 meandering channels and it is in this region 

 that the two sampling areas are located. Nor- 

 mal level of the pool at the U.S. Corps of 

 Engineers Fountain City boatyard gauge is 

 650.50 feet. 



Area A covered 1.35 acres on July 6, 1948. 

 It had a maximum depth of 4.5 feet and an aver- 

 age depth of 2.4 feet with a water level of 650.61 

 feet at the Fountain City gauge. The bottom was 

 silt and except for a heavy stand of Sagittaria sp. 

 at the closed end of the backwater, aquatic vege- 

 tation was sparse. 



Area B covered 3.36 acres on July 7, 1948 

 (fig. 3) . It had a maximum depth of 9 feet and 

 an average depth of 5 .5 feet when the water level 

 at the Fountain City gauge was 650.65. The 

 silt bottom supported a more diversified and 

 abundant stand of aquatic vegetation than was 

 found in area A. Sagittaria sp. predominated, 

 Potamogeton natans was abundant, and there 

 was a scattering of Valli a ncri a sp. and Nymphaea 

 tuberosa . 



Water temperature and turbidity were not 

 determined in areas A and B on these dates but 

 maximum air temperature at Winona, Minnesota, 

 6 miles downstream, on both dates was 96-F. 

 The water in both cases was clear enough to 

 permit the bottom to be seen to depths of 

 approximately 3 feet. 



