From above, the Dundas River winds through the landscape, gradually widening as it approaches a broad, shallow expanse of water that marks the beginnings of a river delta. These deltas form over time as glacial meltwater carries sediment downstream, depositing it where the river meets slower-moving tidal waters after glaciers retreat. The mixing of fresh river water with the salty Gulf of Alaska (visible in the upper right) creates nutrient-rich estuarine environments that support abundant plant and animal life, from plankton and fish to waterfowl and shorebirds. This dynamic zone illustrates the vital connection between inland freshwater systems and the open ocean, highlighting how glacial processes, sediment transport, and the meeting of two waters create biologically rich coastal ecosystems. Photographer: Sean Neilson