Large river systems in mountain belts exert important controls on erosion, sediment flux to oceans, as well as the distribution and evolution, of species. These rivers are highly mobile systems and understanding the processes that modulate their development and evolution are fundamental questions in earth surface processes. This proposal will address the timing and factors that caused the growth of major longitudinal river systems in the northern Andes Mountains of Colombia by studying the modern and ancient sediment transported by these rivers. Data from this project will form the foundation for a new course at the University of Oklahoma. Exercises will be designed to introduce students to transferable skills including basic coding, plotting, and use of geospatial software. These exercises will be available online (at no charge) for others to use or modify in teaching or research. Additionally, this project will support and train undergraduate and graduate students and a postdoctoral scholar, and continue to enhance collaborations with international scientists. More specifically, this proposal will address growth of the Magdalena and Cauca Rivers in the northern Andes Mountains using combination of modern geomorphology, source characterization, and basin analysis. Geomorphic indices will be used to identify areas of modern drainage instability, and 10Be erosion rates will allow for assessment of along-strike variations of erosion rates over notable knick-points. Uniqu