Show CHAPTER XXI LAKE OSCILLATION During the past century the only century of observation the lake has remained at a relatively level when compared with the extensive changes in tion of its surface during geological times This imply however that there has been no oscillation water surface Between the lake constant the elevais not to of the high water mark of 1873 and the all-tilow of October 15 1940 there has been a fluctuation of more than seventeen feet This has had a all-ti- me me tremendous influence on the area of the lake because of the relatively shallow condition of it and the relatively flat lake bottom A few inches of rise extends the surface greatly Stansbury in 1850 found the lake to have an area of 1750 square miles the Fortieth Parallel survey of 1869 to be 2150 At its extreme low of 1935 the lake surface had an area of only 1420 square miles whereas at its all-tihigh of 1873 the area was 2250 square miles The 1873 area was 59$ greater than that of 1935 showed the area me This fluctuation in the lake level and area also has a marked influence on the relative salinity of the water When the lake is high the percentage of salt content decreases when it is low it increases This difference is noticeable even during any given year the flood season |