Included are the raw results obtained by running the numerical models and analyzing the remote sensing maps. Also included are the input data and output data for all CHIM-XPT and SOLVEQ-XPT geochemical models, so the user may reproduce the results from the paper. Programs CHIM-XPT and SOLVEQ-XPT ((c) Mark H. Reed, University of Oregon) are required to run the geochemical models. Please refer to the paper for details on methodology, and get in touch if clarification is required ("Paleohydrology on Mars constrained by mass balance and mineralogy of pre-Amazonian sodium chloride lakes", by M. Melwani Daswani and E. S. Kite, published in the Journal of Geophysical Research: Planets Volume 122, Issue 9 (2017), https://doi.org/10.1002/2017JE005319). Please get in touch if you notice any mistakes too. All data are backed up by M. Melwani Daswani. A lot of data were generated for this project, and it is possible something may have been missed while uploading. Mohit Melwani Daswani, 20 June 2018 melwani.mohit@gmail.com EOM

We thank David P. Mayer for producing the HiRISE and CTX DTMs, for helpful discussions, and for help with GIS. We are grateful for comments and suggestions from reviewers John Bridges and M. R. El‐Maarry, which improved the manuscript. We thank Walter Kiefer, Timothy Glotch, and Cheng Ye for data that helped shape this work, and we also acknowledge discussions with and insights from Justin Filiberto, Benjamin Black, Mark Reed, Caleb Fassett, Thomas Bristow, Jim Palandri, Tim Bowling, and Monica Grady. We acknowledge the use of University of Chicago Research Computing Center computing resources ("Midway" cluster). The data used are listed in the references, tables, and the supporting information. This work was supported by NASA grant NNX16AG55G.