The series was created and edited by renowned ornithologist Roger Tory Peterson (1908–1996).
The PFG series utilized what became known as the Peterson Identification System, a practical method for field identification which highlights readily noticed visual features rather than focusing on the technical features of interest to scientists.
In many books in this series (especially older editions), a number of the plates are in black and white.
One source claims that the increased size of one of the new editions (Eastern reptiles/amphibians) was considered detrimental to its use as a field guide by its own author and was a publisher decision.
For example, the fourth edition of the mammals guide has an entirely new text and illustrations by new author Fiona Reid, because the author (William Burt) and illustrator (Richard Grossenheider) of previous editions are both deceased.
Both of these guides appeared in the Easton Press leather bound copies of the series.