The two largest rivers in Alaska, the Yukon and Kuskokwim Rivers, empty into the Bering Sea very near each other, creating a massive delta.  At over 50,000 square miles (roughly the size of Oregon), it is one of the world's largest deltas.  The delta is comprised of coastal wetlands and tundra and support one of the largest concentrations of water fowl in the world, with over 2 million ducks and geese breeding in the area annually.

Over 50 villages are located in the Y-K Delta, mostly along the banks of the Yukon and Kuskokwim Rivers or the Bering Sea coast. 25,000 people live in these communities. Approximately 85% of the population are Alaskan Native, primarily Yupik. A traditional subsistence lifestyle of hunting and fishing continues to be a major part of the area's culture.  Bethel is the area's main population center and regional hub.