The data and R scripts contained in this data release are provided as support for a manuscript titled, "Copula theory as a generalized framework for flow-duration curve based streamflow estimates in ungaged and partially gaged catchments" (Worland and others, 2019) submitted to Water Resources Research. The dv_input.csv contains the measured daily streamflow values for 37 streamgages in the Mobile-Tombigbee River Basin, 4-digit hydrologic unit code (HUC4) 0316, and 37 gages in the Trinity River Basin, HUC4 codes 1201, 1202, 1203, and 1204. The coord_input.csv contains the coordinates and the basin area (squared meters) for the gages in each basin. The R scripts generate daily streamflow estimates using 16 different estimation methods. Additionally, the R scripts also provide a function for estimating leave-one-out cross validated correlations between sites using an ordinary kriging approach. The dv_output.csv files contains the predicted daily streamflow values using the 16 streamflow estimation methods.