Different kinds of squirrels:
Western Gray...Sciurus griseus
Tassel-eared...Sciurus aberti
Eastern Gray...Sciurus carolinensis
Arizona Gray...Sciurus arizonensis
Eastern Fox....Sciurus niger A
pache Fox.....Sciurus apache
Red............Tamiasciurus hudsonicus
Chickaree......Tamiasciurus douglasi
Chipmunks:
Eastern.........Tamias striatus
Alpine..........Eutamias alpinus
Least...........Eutamias minimus
Townsend........Eutamias townsendi
Cliff...........Eutamias dorsalis
Sonoma..........Eutamias sonomae
Yellow Pine.....Eutamias amoenus
Merriam.........Eutamias merriami
Grayneck........Eutamias cinereicollis
Long-Eared......Eutamias quadrimaculatus
Redtail.........Eutamias ruficaudus
Colorado........Eutamias quadrivittatus
Uinta...........Eutamias umbrinus
Panamint........Eutamias panamintinus
Lodgepole.......Eutamias speciosus
Charleston Mtn..Eutamias palmeri
As i suspected, In most of Eastern North America only the Eastern Chipmunk is found. Also, the crucial difference between the "tree" squirrels and chipmunks is very simple, chipmunks, have cheek pouches. For food. To be honest i know nothing about squirrels and chipmunks. Just having some fun cuz i'm bored and this is the first thing that came to my mind. Enjoy reading