At the juncture of the Great Egg Harbor and the South River is a point of fresh water tidal marsh. Named Catawba, for the small village on the eastern bank of the Great Egg Harbor River, this area has long been a favorite of fishermen. The marsh system is an historic location for several rare plants. Waterfowl continue to use the river as a local flyway and find good resting areas in the small tidal steams of the preserve.
Accessible only by boat, the preserve is best appreciated by visitors who walk the foot trails at the adjacent Estell Manor County Park. No hunting is permitted.