RE: Not one squirrel..
If there are oak trees and acorns there should be some squirrels around. Gray squirrels usually announce their presence by barking, which can be heard from a distance and they make a lot of noise when they hunt for those acorns on the forest floor when the leaves are dry. Squirrel hunting involves sitting in a spot and not moving for at least 45 minutes before moving on to another area. Patience is key, just like most of hunting.