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Show 86 -- 82-- bar, which is practically a wash, and each slight change in the river washes the surface and cuts into the vertical slopes of the second bar. Now, that particular bar there had an elevation of six feet above the elevation of the water at the time when we made our examination. A rise of six feet will flood the second bar, change its surface and cut against the vertical, or nearly vertical, third bar, and an extraordinary flood of, say, 13 or 14 feet at that point, will fill the entire channel between the rock walls, and then tend to wash out all of the bar at that place, depending upon the size of the flood. " Now, the crossing bars, which are known to change here ( indicating) are apparently caused by the washing away of the sand and the soil on these bars, carrying them down the stream to a point where the river changes into a straight channel, where they are deposited and building and changing on account of the silt and sediment brought in from these bars, as well as the silt and sediment brought in from the main stream." R. 188- 189. The condition that he has related as shown on Plate 33- A is typical of numerous places between the mouth of the San Rafael and the junction of the Green with the Colorado River. R. 189 I surveyed four bars below the mouth of the San Rafael, one at Mile 84.5, one at Mile 80.5, one at Mile 72.2, and one at Mile 23.24, in order to show typical bar conditions along the Green River." R. 189- R. 190. He simply surveyed typical sidebars through the rivers with the idea of determining from a study of the surveys how |