the locations of buildings and trees can be represented, for many
purposes, by a single point, but unfortunately there is no common format for
distributing point data
USGS printed topographical maps ("topo quads") contain a black square
symbol for every building (outside of urban areas). This is sometimes
(rarely) also digitized as a point feature in the corresponding
DLG file. However, for the most part, the USGS does not distribute the
building locations in any digital point format - only as printed maps or
DRG (scanned printed maps)
building locations can be extracted from the DRGs with
BExtractor