ABSTRACT The vascular flora of the North Chickamauga Creek Gorge State Natural Area (NCCG) was studied during three growing seasons from 2006 to 2008. NCCG is located in Hamilton and Sequatchie Counties, Tennessee, on the eastern edge of the Cumberland Plateau. Within the study area are 2,862 ha of eastern deciduous forest that contains 12 distinct habitat types. A survey of these habitat types yielded 110 families, 329 genera, and 604 species or lesser taxa, including 238 county records. Seventy-six introduced species were found, comprising 13% of the total flora. Eleven species with either a state or federal listing were documented: Castanea dentata, Diervilla lonicera, Diervilla rivularis, Glyceria acutifolia, Nestronia umbellula, Spiraea virginiana, Scutellaria montana, Sabatia capitata, Woodwardia virginica, Panax quinquefolium, and Viola tripartita. A species-area curve for the Cumberland Plateau of Tennessee was constructed from the current study and seven other similar studies of the plateau. Three family level species-area linear regression lines were also constructed, demonstrating that the natural area reaches or exceeds expectations for Asteraceae, Poaceae, and Cyperaceae.