Delineating catchment boundaries is a required step in almost every analysis related to hydrology and water resources. Stand-alone proprietary GIS packages are commonly used for catchment delineation, which can hinder the development of integrated, reproducible workflows that can be run by analysts who lack access to the GIS package. The goal of this presentation is to illustrate how to perform catchment delineation and analysis using two free and open-source software applications, R and WhiteboxTools. The R language is a popular programming language for data analysis, and the latter was developed by the Geomorphometry and Hydrogeomatics Research Group at University of Guelph. Functions are available in the CSHShydRology package to simplify the application of WhiteboxTools functions from within an R script. The application of these functions will be illustrated in the context of a comparison of catchment delineations for the Upper Penticton Creek experimental catchments based on field surveys, the Canadian Digital Elevation Model (DEM) and a Lidar DEM.