For the more information about the air resources of the National Park Service, please visit http://www.nature.nps.gov/air/.
Dexter Marsh is a relatively undisturbed, extensive example of a large bay-head marsh complex at the eastern end of Lake Ontario.
Location: Jefferson County, NY
Year designated: 1973
Please remember, National Natural Landmarks (NNLs) are not national parks. NNL status does not indicate public ownership, and many sites are not open for visitation.
Last Updated: June 28, 2012