74 Pa. Stat. § 120.125
Exclusive jurisdiction over the lands conveyed under the provisions of this act is hereby ceded to the United States of America by the Commonwealth of Pennsylvania and said lands shall be exempt from the payment of all taxes, State and local: Provided, That the Commonwealth of Pennsylvania shall retain a concurrent jurisdiction with the United States of America over the lands so acquired by the United States of America for the purpose of serving of all civil processes: And, provided further, That such criminal processes as may issue under the authority of the Commonwealth against any person or persons charged with crimes committed without the area so acquired may be executed therein in the same manner as though this cession had not been granted.
74 P.S. § 120.125