Technical Abstract: Loss of ecological integrity due to sediment is a major cause of water quality impairment in the United States. Numeric criteria for total maximum daily loads (TMDLs) must be generated and attained to regain ecological integrity of listed streams. Current assessment protocols lack a means to link temporally variable sediment transport rates with specific losses of ecological functions as loads increase. This study located in Northwestern Great Plains Ecoregion co-located 58 USGS gauging stations with existing flow and suspended sediment data, and fish data from federal and state agencies. Suspended sediment transport rates were quantified into exceedance frequencies of a given concentration, duration as the number of consecutive days a given concentration was equaled or exceeded, dosage as concentration x duration, and mean annual suspended sediment yields. Functional traits fish species present were used to investigate biological impairment. Twenty fish traits were organized into four main trait groups: preferred rearing habitat, trophic structure, feeding habits, and spawning behavior. Through the use of a functional traits analysis, ten traits were identified with possible impairment responses, and enumerated by either concentration frequency and duration, and dosage. Three principal responses were observed: 1) traits correlated with a broad range of concentration exceedance frequencies, 2) traits correlated at the upper range of concentration exceedance frequencies, i.e., 90 to 95% events occurring at moderate flows; and 3) traits correlated at the lower range of concentration exceedance frequencies, i.e., 0.01% to 10% events likely occurring during floods. Specific to these responses, impairment linked traits included habitat preferences for stream pool and river shallow waters; feeding generalist, omnivores, piscivores; and several spawning behaviors. These responses provide some evidence as to the potential loss of ecological function, related to fish, from elevated suspended-sediment loads. In addition, unstable channels, found to be greater in transported suspended sediment than stable channels over a range of concentration exceedance frequencies, likely influence physical habitat quality. Preferred habitat traits are likely co-impacted by habitat loss from morphological instabilities and elevated sediment loads. Overall, a functional traits approach was successful in identifying potential “thresholds” for biological impairment due to excessive suspended sediment, and will aid in developing sediment TMDLs.