Union Slough National Wildlife Refuge is an important place for wildlife in an area with extensive cropland. Two portions of the refuge, Schwob Marsh and Buffalo Creek Bottoms, are open for all state hunting seasons. During times of higher water, good numbers of mallards and other ducks use the floodplain and backwaters of Buffalo Creek Bottoms. Hunting spots may be accessed by foot or by boat depending on water levels. The middle section of the refuge is called the Core Area. This portion contains a large marsh that provides a resting place for birds during spring and fall migration. The Core Area is closed to all hunting – except for pheasant and gray partridge hunting during the last five days of the state-established pheasant hunting season. Pheasant hunting is especially popular on the refuge. Successful shotgunners during the late-season hunt know that the area of heavy cover and cattails along the marsh is where the birds are most plentiful.