This geospatial dataset includes one point feature class file and associated FGDC-compliant metadata representing datasets to support development of ecological limit functions for the Cumberland Plateau in northeastern Middle Tennessee and southeastern Kentucky. Knight and others (2012, 2014) developed a methodology of relating fish species richness to changes in hydrologic conditions for sites within the Tennessee River Basin; this dataset applies this methodology to 138 sites within the the Cumberland Plateau. Information contained within this dataset represents values of basin characteristics (see Table II in Knight and others, 2012), estimates of streamflow characteristics (see Table I in Knight and others, 2012), measures of individual and cumulative departure of streamflow characteristics from reference hydrologic conditions, and fish species richness for 138 sites in the study area. Characteristics describing each basin were estimated and standardized (see Table III in Knight and others, 2012) and include: percent forest, percent agriculture, percent of basin in the Interior Plateau Level 3 Ecoregion, percent of basin in Blue Ridge Level 3 Ecoregion, mean basin elevation, index of Hortonian overland flow, soil factor, geologic factor, monthly mean precipitation, January precipitation deviation, August temperature deviation, temperature range, and rock depth as well as the interaction of soil factor, geologic factor, and rock depth with monthly mean precipitation. Basin characteristics were used as independent variables to estimate streamflow characteristics, also in standardized form, following Knight and others (2012). Estimated streamflow characteristics include measures of the magnitude, duration, frequency, timing, and rate of change of the annual hydrograph (Knight and others, 2012). Departure values for individual streamflow characteristics were determined by calculating the numerical distance (difference) outside the reference range for each streamflow characteristic. Reference hydrologic conditions for the study area were determined using methods presented in Knight and others (2012; 2014). Reference ranges are included in the metadata in the entity and attribute descriptions for the fields representing individual hydrologic departure values. Cumulative hydrologic departures represent the sum of individual departure values that were identified as statistically significant (p < 0.05) in quantile regression analysis based on Knight and others (2014), stratified by fish group. Fish species richness for 11 fish groups is presented for each site and represents trophic, taxonomic, reproductive, and habitat preferences (see Table I in Knight and others, 2014) as well as fishes that are considered as rare, threatened, or endangered by Withers (2009). Knight, R.R., Gain, W.S., and Wolfe, W.J., 2012, Modelling ecological flow regime: an example from the Tennessee and Cumberland River basins: Ecohydrology, v. 5, p. 613–627, http://dx.doi.org/10.1002/eco.246 Knight, R.R., Murphy, J.C., Wolfe, W.J., Saylor, C.F., and Wales, A.K., 2014, Ecological limit functions relating fish community response to hydrologic departures of the ecological flow regime in the Tennessee River basin, United States: Ecohydrology, v. 7, p. 1262–1280, http://dx.doi.org/10.1002/eco.1460 Withers, D., 2009, Tennessee Natural Heritage Program rare animals list: Division of Natural Areas, Tennessee Department of Environment and Conservation, Nashville, TN, 61 p, last accessed November 19, 2015, at https://www.tn.gov/assets/entities/environment/attachments/na_animal-list.pdf