Bayou Fountain once connected to the Mississippi River when spring flooding spilled over natural levees below downtown Baton Rouge into swamps east of the river along Nicholson Drive and through what is now Old South Baton Rouge, then either returned to the Mississippi through the area now occupied by Louisiana State University’s main campus or flowed southeast through Bayou Fountain to Bayou Manchac, Lake Pontchartrain, the Rigolets, and the Gulf. Beginning at the foot of the Baton Rouge Lakes just outside downtown Baton Rouge, it runs between the Mississippi River’s natural levee on the west and the Pleistocene terrace on the east. Bayous in Louisiana’s Mississippi and Atchafalaya deltas are typically slow-moving waterbodies in flat, low-lying areas, sometimes functioning as anabranches within braided river systems, and they support varied animal life. Bayou Fountain was once an important transportation route for American Indians and early colonial settlers, and its position near a high terrace made it favorable for settlement. In modern times, urban runoff, fallen trees, and trapped debris made the stream impassable and reduced its flood-carrying capacity, though community efforts in recent years have cleared several miles of log and trash jams from Highland Road Park to Bayou Manchac.