This dataset presents the results of analysis of aquatic biota tissue samples, collected over multiple sampling events from in from 2007 to 2014 at three sites (Las Vegas Bay, Overton Arm, and Boulder Basin) in Lake Mead National Recreational Area. The tissue samples were analyzed for concentrations of Carbon 13 and Nitrogen 15 isotopes by the University of California, Davis in Davis, California. Data are presented in 1 spreadsheet worksheet that is organized by year, location, and taxa. General trophic level (Vander Zanden and Rasmussen, 1999) and calculations of benthic reliance (Umek and others, 2010) also are included. Combined data from sampling events in 2007 and 2008 previously were published in Umek and others, 2010. Common species names are used in the spreadsheet and scientific names can be found in the metadata.