What type of snake
Thank you for your question. This looks like the Eastern Milksnake (Lampropeltis triangulum triangulum). It is a non-venomous species that is common throughout Pennsylvania. Length ranges from approximately 24 - 52 inches.
This species is found in open country, near human habitats, rocky hillsides, areas bordering bogs and deciduous forests. It is frequently found under cover objects like rocks, stumps, boards and logs.
It feeds primarily on other snakes, lizards and mice, but will also eat earthworms, insects and small frogs. The common name comes from the myth that this snake obtained food by milking cows and drinking the milk.
Here's a link to the Pennsylvania Herps website where you can find additional information on the Eastern Milksnake:
Hope this answers your question, and thank you for using Ask an Expert.