- The Johnson/DeBay’s Slough Unit is comprised of agricultural fields, riparian forest, and freshwater wetlands. The unit was purchased in the late 1990’s to provide an undisturbed Game Reserve for trumpeter swans as well as to provide limited waterfowl hunting area. Public access in the Game Reserve area is limited to the parking/viewing area at the end of DeBay Island Road and the mowed grass field to the east of the Game Reserve parking area. Waterfowl hunting is allowed in the portion of DeBay’s Slough to the north of DeBay Island Road and the adjacent field to the east of DeBay’s Slough.