Vegetation classification and mapping was conducted at Weir Farm National Historic Site during the fall of 2003 and the summers of 2004 and 2005, creating a current digital geospatial vegetation database for the park. There are nine natural vegetation types that occur in the park; four upland forest types, one upland non-vascular type, two forested wetland types, and two wetland shrub thicket types that reflected the soil moisture conditions of the site. In addition, four anthropogenic vegetation types occurred; one successional forest and three non-forested types (two in mowed upland fields, and one herbaceous wetland seep). Each of these is described in detail in this report.