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e e e 6.11 inches (National Oceanic and AtmosP1eric Administration, 1981, p. 6). Precipitation results from winter frontal storms, which generally CX?R'e from the west, and summer oonvection storms, which generally come fran the south. '!he convection storms produce local but intense rainfall whi~ generates rapid runoff and sediment transport. ' Rocks ranging in ag~ from Precambrian to Holocene ~re exposed in the Green River drainage basin above Green River, utah. Most of these rocks are shale, siltstone, mUcEtone, sandstone, and limestone of Tertiary age (Stoke~, 1964), '!be shale. siltstone, and mudstone probably are the most ea~ily eroded rocks in the basin, and they contribute a large p;lrt of the sediment 19ad in the Green Rive r. <DLLEC1'ION AND E.VALUATION OF REXDRIS Sampling to determine susp;!nded-sediment concentrations began in May 1930, and sampling to determine particle size ~gan in Ap~il 1951. Most qf the sampling for suspmded sediment at station 09313>00 was from a cab1eway about 0.25 mile oownstream from the stream gage or fran a highway bridge about SOO feet upstream from the gage. '!he samplin9 was oontj,nuous through September 1982. 1 ? ..I1i(1Y I?1M'f4/v or \-h~1' / I 1/ /1 . Prior to 1945, the sampling for sus{:ended sediment was by simple, i.pexact methods. Many samples were collected by dipping bottles or oth~r con~rs in the river. Various methods were used to weight the containers in an attempt to collect depth-integrated samples. some sampling devices {:ermitted the oontainer to beopmed below the surface of the water, and this tyI:e of sampler collected samples at specif j.c po~ts in the sampling vertical, It waS virtually impossible, however, to obtain Clccurate depth-integrated ~ples with this type of equipment. The U.q. D-43 susp;!nded-sediment sampler was develop;!d in 1943, and it was the first standard sampler designed to collect accurate, depth-integrated, suspended-sediment samples. With this and Slt>sequent samplers, accurate depth-integrated samples could be collected over a wide range of flow conditions, thus providing a more representative suspended-sediment record. The U.S. 0-43 sus{:ended-sediment sampler was first used at station 09315000 in October 1945. The development and use of suspended-sediment sampling equipment is described in a series of reports released by the U.s. Interagency Committee on Water Resources (l94la, 1 941b, 1948, 1952, 1 96 la, and 1961b). It is im{X>rtant to consider the reliability of available records before an analysis of the records is attempted. The sampling site also must be considered. Numerous changes have occurr~ d\lIing the 52 years in whidl data were collected at station 09315000. During that time th~re were numerous c.banges in sampling, lab:>ratory, streamflow-measuring and recording equipnent, all involved techniques. and ~rsonnel. 4