Major ecological changes occurred on Earth 66 million years ago, including the extinction of the non-avian dinosaurs. Detailed study of strata spanning this time in Montana reveal fundamental changes in the hydrologic cycle, including the size and geometry of river systems. Reconstructing the courses of these rivers would provide insight into the distribution of distinct environmental niches, and the nature of ecological change. We have thousands of measurements of the direction of ancient river flow in an area of approximately 5,000 km^2, but these are discrete measurements made with a sparse density of ~1/2 km^2. An ML and/or AI based approach to connect the vectors with continuous curves would serve to define the rivers' courses. The data can be resolved into time slices such that changes over approximately 1.5 million years could be quantified.
