Professional genealogists have recognized the importance of these atlases for many years. Although some of these atlases were reprinted during the 1970s, the fact is that many of these reprints are becoming as rare as the originals. McGill's Rare Books and Special Collections Division is fortunate in owning copies of many of the original atlases.

Begun in July 1998, the County Atlas pilot project initially encompassed ten atlases. Two subsequent Phases allowed the completion of the Ontario map, ultimately totalling forty-three atlases.

The County Atlas Digital Project is a searchable database of the property owners' names which appear on the township maps in the county atlases. Township maps, portraits and properties have been scanned, with links from the property owners' names in the database.