Children under 16 years-old cannot operate an ATV on any land other than land owned or rented by their parent or guardian unless the child has a valid safety certificate or is under the supervision of a certified instructor during a safety training course. Children may not operate an ATV across highways, connecting streets or on state forest or park roads unless they have a valid safety certificate or are being directly supervised by an individual 18 years of age or older. Children under eight years-old are not eligible for a safety certificate and may only operate an ATV on private property. Children between the ages of eight and nine years-old may not exceed an engine size of 70cc.
Check out these Ashfield, PA ATV/OHV resources: