Dams and their corresponding reservoirs have segmented river networks in the conterminous United States (CONUS) for centuries. This segmentation has altered natural streamflow dynamics, which has impacted aquatic species, sediment transport, and water quality. As a result, there have been loud calls for the removal of dams; however, many communities rely on dams for flood protection and water resources. This study aims to quantify and map historical reservoir storage change along river networks over the course of human development. The National Hydrography Dataset (NHD) and National Anthropogenic Barrier Dataset (NABD) developed by the United States Geologic Survey (USGS) were used to connect dam storage with their river networks. The aggregate amount of storage contained within each reservoir was quantified for each corresponding river network. The effects of segmentation could subsequently be identified and analyzed by comparing storage and streamflow. Stakeholders can use this research to understand the historical changes in storage to better predict the effects of dam removal and climate change on water resources.