François Coulee threads through Lafayette’s Acadiana Park Nature Station, carving an ancient path originally etched by the Mississippi River. The little waterway, whose name echoes the French word for “flow,” drifts east beneath loess-capped bluffs, then slips into the Vermilion River. Walk its bridges and you cross two worlds: prairie terrace above, swampy floodplain below. Black, clay-rich soils—deposited when Ice Age torrents scoured deep trenches—still nourish oaks, sycamores, and the wildlife hiding in their shade.