Prairie Potholes
These freshwater marshes are found in the upper Midwestern prairies, especially the Dakotas and Minnesota. Depressions that were created by retreating glaciers about 10,000 years ago;, they fill with water during spring, providing important habitat for waterfowl and many other species. Indeed, the Prairie Pothole Region is often called America’s “duck factory� since around half of the continent’s ducks spend at least part of the year there. The prairie potholes are an important water source, and they help recharge underground aquifers.