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O~275S estimates of annual suspended-sediment loads at sites 5 and 6 for water years 1975-82. 1\vo regressions were determined from correlations of measured annual sus- pended-sediment loads at sites 5 and 6 with measured annual suspended-sediment loads at site 4 for water years 1983-88. A second pair of regressions was determined from correlations of measured annual suspended-sediment loads at sites 5 and 6 (water years 1983-88) with annual stream discharge at sites 5 and 6 (water years 1983-88). Differences between regression values and measured values generally were less than 20 percent for the first pair of regressions and generally were less than 10 percent for the second pair of regres- sions. Regression estimates of annual suspended-sedi- ment loads at site 6 were increased by 130,000 tons during water year 1978. The adjustment is based on a daily value of 132,000 tons measured at station 09306300 above Rangely on September 8, 1978. The large daily suspended-sediment load at station 09306300 occurred 1 day after an intense storm in the Yellow Creek Basin. The storm caused about 290,000 tons of sediment to discharge to the White River between sites 5 and 6 (U.S. Geological Survey, 1978-86). Regression values from regression pairs of annual suspended-sediment loads at sites 5 and 6 for water years 1975-82 were compared with the measured annual suspended-sediment loads at site 4 and station 09306300 (table 5). Best estimates of annual sus- pended-sediment loads at site 5 for water years 1975- 82 and at site 6 for water years 1975, 1978-79, and 1982 were obtained from the second pair of regressions (suspended-sediment loads and annual stream dis- charge). Regression estimates of annual suspended- sediment loads at site 6 for water years 1976-77 and 1980-81 did not compare well with measured values at site 4 and station 09306300. The regression values were for years when annual stream discharges were less than 500,000 acre-ft and generally less than the stream-discharge range used in the regressions. Thus, for water years 1976-77 and 1980-81, the annual sus- pended-sediment loads at site 6 were obtained by aver- aging the annual suspended-sediment loads determined for site 5 and the measured annual suspended-sediment loads at station 09306300. Correlation of estimated and measured values of annual suspended-sediment loads for sites 5 and 6 and measured values of annual suspended-sediment loads at site 4 and station 09306300 with annual stream discharge are shown in figure 9. Maximum and minimum daily suspended- sediment loads and annual suspended-sediment loads for the White River for water years 1975-88 are listed in table 5; statistical summaries of annual suspended- sediment loads for sites 1-6 and for the combined loads of sites 1 and 2 (site 3A) are shown in figure 10. Annual suspended-sediment loads in the White River ranged from slightly more than 2,100 tons at sites 1 and 2 to about 2 million tons at site 6. Average annual sus- pended-sediment loads were least in the North Fork (site I, about 11,500 tons) and South Forks (site 2, about 11,100 tons) and greatest at site 6 (about 705,000 tons). A comparison of annual loads of sus- pended sediment in the main stem of the White River indicates that sediment loads increased gradually between sites 3A and 4 and increased greatly down- stream from site 4. The increases in sediment loads downstream from site 4 probably resulted from the intermittent inputs of fluvial sediment from semiarid basins and from the seasonal inputs of fluvial sediment from the perennial streams, Piceance and Yellow Creeks. Comparison of bar graphs of annual suspended- sediment loads (fig. 10) for the river segments (river subbasins) indicates that the subbasin between sites 4 and 5 generally was the principal source of fluvial sed- iment during years of moderate to low streamflow. Irrigation diversions that transported unmeasured quantities of suspended sediment from the White River upstream from site 3 probably caused an underestima- tion of suspended-sediment loads between sites 3 and 3A. During years of high stream discharge (water years 1983-86), precipitation in the low-elevation basins was extensive, and greater quantities of sedi- ment entered the White River between sites 5 and 6 than between sites 4 and 5. Although shales and silt- stones are the most common rocks in the river sub- basins between sites 3 and 6, the natural and agricul- tural vegetation cover is more extensive in the river subbasin between sites 3 and 4 than in the subbasins between sites 4 and 6. The vegetation cover in the subbasin between sites 3 and 4 probably decreased sediment erosion and transport compared with the downstream subbasins. In the high-elevation basins upstream from site 3, natural vegetation cover is even more extensive, and exposed rocks mo&t1y are indu- rated sandstones and siltstones, which substantially decreased sediment erosion and transport. SEDIMENT TRANSPORT 19