In Hawkeye W.A. in northwest Johnson Co. Two fairly small wetlands straddle Greencastle Ave. directly south of Swan Lake Rd. The east side is always an open pond, and the west side is a grassy marsh with little or no open water. A few miles north of I-80, take the North Liberty/F-28 exit off I-380. Go west on F-28 about 3.5 miles to Greencastle Ave. Take Greencastle 1.5 miles north to the ponds.

This area has a large concentration of waterfowl and pelicans during migration. When water levels are right, large concentrations of shorebirds are found here during migration. The woodlands in the area produce significant numbers of migrating songbirds. Bald Eagle and Double-crested Cormorants nest in the area. There are large numbers of raptors in the area, some during migration and following the shorebirds, some nesting, and some wintering, such as Long and Short-eared Owls, Northern Harrier, and Rough-legged Hawk. There are heron rookeries, and large numbers of wading birds use the area during post breeding dispersal. The number of rare birds that have been found here over the years is quite large.

From highway 965 one and three-quarters miles north of North Liberty, go west on the Swan Lake Road to areas on the south side of Hawkeye WA. To reach areas on the north side, go west from highway 965 on the first road north of the reservoir (Amana Road).