Total dissolved solids (TDS) in surface waters affect water quality and useability and are of particular concern in the Colorado River Basin. Estimates of current and past TDS concentration and flux in rivers support appropriate management and salinity control measures. In this study we estimated the total dissolved solid concentration and flux at 11 sites on tributaries of the Colorado River, starting as early as 1938 until 2021. Of these sites, eight were not affected by dams. For these we estimated daily and water year flow normalized TDS concentration and flux using the Weighted Regressions on Time Discharge and Season (WRTDS) water quality modeling framework. For the three sites situated below dams, we used flow-weighted concentrations to estimate water year mean TDS concentrations. Along with these estimates, we include information about the timing of construction, and capacity of dams in the Lower Colorado River Basin.