Iowa is one of the most important wintering grounds for Bald Eagles with thousands of the huge raptors moving into the state from the north to join our resident breeding birds. Wisconsin, Minnesota and Michigan all have some of the highest densities of nesting Bald Eagles in the lower 48 states and many of those eagles, especially from MN and WI move into Iowa during the winter months and frequently gather in large numbers around areas of open water to feed and roost.