Flat Rock State Forest is a New York State Department of Environmental Conservation state forest property located in Altona, New York. It is home to a Sandstone Pavement Barrens. The Sandstone Pavement Barrens community is a narrow regional endemic that is possibly restricted to the northernmost counties of New York, north of the Adirondack Mountains in the northeastern portion of the Great Lakes Ecoregion, where the bedrock is sandstone. The Sandstone Pavement Barrens is concentrated in the Champlain Valley of Clinton and Essex Counties where it reaches large patch size. Several small patch occurrences are reported from the Eastern Ontario and St. Lawrence Lowlands including islands in the Thousand Islands Region. Additional occurrences are suspected from within Lake George.