The Katahdin Woods and Waters National Monument Seboeis Unit Vegetation Mapping Project was initiated in the fall of 2019 by a grant through the USGS Natural Resource Preservation Program to classify and map vegetation types of the Seboeis Unit thereby providing resource managers and biological researchers with useful baseline vegetation information. These data are the results of the field effort to collect vegetation plots data for testing the Katahdin Woods and Waters National Monument Seboeis Unit Vegetation Mapping Project vegetation map. Data collection was assisted by Jennifer Tibbetts and Jamie Attanasio. During summer 2019, botanists with the Maine Natural Areas Program collected data from 94 vegetation plots for plant community characterization. In addition to the ground data, site photos were collected at each vegetation plot for a total of 582 ground images. The sampling data were entered into the National Park Service PLOTS version 4.0 (National Park Service 2015) for analyses to characterize vegetation associations in the U.S. National Vegetation Classification.