The primary purposes of Deer Creek Marsh Wildlife Management Area (WMA) are wildlife management, wildlife habitat management, and wildlife-dependent recreation.
Located in the northwest corner of Oswego County along the shore of Lake Ontario, this WMA totals 1,771 acres in size. Deer Creek Marsh WMA is a combination of wetland types
that includes open cattails and a bog. The prominent feature is an extensive barrier beach and sand dune system that separates and protects the marshland from the ravages of Lake Ontario.
The water elevation in the marsh is determined to a large extent by the level of Lake Ontario and whether the outlet of Deer Creek is plugged by sand or open to flow into Lake Ontario.