The Bear Lake Plateau extends north-south across the north central corner of Utah and the southeastern corner of Idaho. North Eden Creek drains westward through part of the plateau and is crossaxial across both strikes of beds and other structures in the area. The formations in the area mapped are of Triassic, Jurassic, and Tertiary age, although only Jurassic and Tertiary rocks contribute sediments to North Eden Creek. The formations consist of sandstones (Nugget), limestones (Twin Creek), and conglomerates (Wasatch). A local extrusion of basalt occurs in the southwestern part of the drainage area. Particle-size analyses of 15 samples from pits dug along North Eden Creek and its tributaries and North Eden Delta show that mean and maximum particle sizes increase downstream due to additions by tributaries and mass-wasting from the coarse-grained, highly jointed Nugget Formation flanking lower parts of the stream. Mineralogic analyses of these samples show that quartzite and chert predominate in the gravel sizes and that quartz and calcite predominate in the sand and silt sizes; kaolinite is the dominant mineral in the clay sizes. Feldspar and dolomite also are present in small quantities. Amorphous material, a common constituent in the sediment of Bear Lake, is abundant in sizes < .00049 mm. The calcite supplied to Bear Lake as clay-sized particles indicates that claysized calcite in Bear Lake is at least partly detrital.