A Common North American SquirrelThe Eastern Gray Suirrel (Sciurus carolinensis), is also sometimes just called the Grey Squirrel. It is a common native tree squirrel in the eastern United States and Canada. This squirrels range covers most of the deciduous forest belt of North America where it thrives. The only squirrel tht it is commonly mistaken for is the fox squirrel (Sciurus niger), which it sometimes overlaps ranges with.
There have been several accounts of Eastern Gray Squirrels being white. While generally rare, there are localized population of white squirrels throughout all parts of its range. Some are albininstic but most are white morphs of the Eastern Gray Squirrel.
Links:
[1] http://www.thewildclassroom.com/biomes/speciesprofile/deciduousforest.html