Field and laboratory studies were conducted to characterize concentrations, factors determining concentrations, particle size composition, and presumed food quality of particulate organic matter (POM) transported by streams of four different orders in Oregon's Cascade Mountains. Devils Club Creek (first order) and Mack Creek (third order) as high gradient, heavily shaded headwater streams receive large amounts of forest debris. Lookout Creek (fifth order) and the McKenzie River (seventh order) have lower gradients and more organic inputs from in situ aquatic primary producers and organic matter drifting from upstream areas than from the adjacent forest. Concentration of particulate organic matter is low during periods of nonstorm discharge, and not significantly related to stream power or type of organic input. All streams transport a mean POM particle size < 12 μm. Over 70% of all particulate organic matter transported is very fine particulate organic matter (VPOM: 0.45–53 μm). Except for spring, the ratio of coarse (> 1 mm) to fine (0.45 μm–1 mm) organic matter (CPOM:FPOM) is near zero, but remains elevated for the McKenzie River during all seasons. As determined by the amount of chlorophyll, carbon to nitrogen (C:N) ratio, percentage of organic matter and respiration rate, the presumed food quality of drifting organic matter is potentially better in downstream reaches.Key words: food quality, detritus, organic matter, streams, rivers, watershed, drift, transport