The data provided in this repository is the source data for "Narrower Paleo-canyons Downsize Megafloods". The repository contains 3 main directories: 1) Hydro_Models (hydrodynamic modeling data), 2) Topo_Reconstruction (topographic reconstruction data), and 3) Analysis_Scripts (data analysis scripts). The Hydro_Models directory contains all inputs, outputs, and python scripts used for the ANUGA flood simulations. The Topo_Reconstruction directory contains all inputs, outputs, and Matlab scripts used in the artificial neural network analysis. The Analysis_Scripts folder contains Matlab scripts to analyze flood hydraulics and sediment routing, and to reproduce plots.