Blackwater Refuge contains one-third of Maryland's tidal wetlands, which makes it an ecologically important area within the state.Blackwater Refuge is recognized as a "Wetlands of International Importance" by the Ramsar Convention and was named a priority wetland in the North American Waterfowl Management Plan. A daily permit is required for all visitors Private vehicle - $3 Pedestrian, Bicyclist - $1 Commercial Van or Bus up to 20 passengers - $15 21 or more passengers - $25