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I I I I I I I I I I I I I I I I I I I 001,),)6 sizes of the samples taken at the four locations 1 isted above. All samples contain less than 2 percent gravel or silt and clay. 2. Bank Materials The soils in the Cherry Creek valley in Arapahoe County were surveyed by the U.S. Department of Agriculture. Soil Conservation Service (Larson and Brown, 1971). Their maps indicate that in the study reach, the bank materials are mostly sandy and loamy alluvial soils. At the sharp bend immediately upstream from Arapahoe Road, Cherry Creek cuts into a high terrace escarpment composed of deep stratified calcareous clay and sand. In other locations, the stream is cutting laterally into the Nunn loam terraces of eolean and alluvial deposits generally grading coarse in the downward direction. Th e terrace soil s are usua lly more res i stant to eros i on than the newer alluvial soils. The sandy alluvial lands are mostly on the inside of bends and are the most recent alluvial deposits. 3. Suspended Sediment Numerous suspended sediment measurements were taken in Cherry Creek by the Denver District of the U.S. Army Corps of Engineers in the period between 1941 and 1951 (Stevens, 1983). Thereafter, the Denver District was disbanded and the measuring program ceased. The records of these measurements are in the archives of the Corps and are not readily available. At the Melvin streamgaging station at Arapahoe Road, 1,083 suspended sediment observations were made from July 1941 to October 1951. The catchment area upstream from the gage is 336 square miles. A minimum of one sample per week was taken. During changing stage. supplemental observations were made. The Corps of Engineers (Stevens, 1983) has computed the suspended sediment load of Cherry Creek at Me 1 vi n to be 722 tons per square mil e per yea r for the period 1942 to 1948. -14-