During summer 2019, botanists with the Maine Natural Areas Program collected data from 94 vegetation plots for plant community characterization. The sampling data were entered into the National Park Service PLOTS version 4.0 (National Park Service 2018) for analyses to characterize vegetation associations in the U.S. National Vegetation Classification. An accuracy assessment was performed on the draft version of the vegetation map layer. During the summer of 2020, field crews collected data from 107 stratified and randomly selected sites for evaluating the accuracy of the vegetation map layer for those map classes representing U.S. National Vegetation Classification associations. The accuracy assessment field data were then compared to the vegetation map data. Results from the accuracy assessment study show an overall accuracy of 87.6% (kappa index of 87.0%) based on an analysis of data from 105 of the 107 accuracy assessment sites.