Lake Oahe is a massive reservoir created by the construction of Oahe Dam on the Missouri River, extending across North Dakota and South Dakota for hundreds of miles. Its long, winding shape follows the original river channel and flooded tributary valleys, turning former plains, farms, and river bottoms into open water. Today, it stands as one of the largest human-made lakes in North America, both in surface area and storage capacity. Geography plays a central role in how Lake Oahe functions. The