72 Pa. Stat. § 3774
The Revenue Commissioners and the Banking Commissioner, or a majority of them, shall designate three banks or trust companies in Dauphin County, two banks or trust companies in Philadelphia County, and two banks or trust companies in Allegheny County, to be known as active depositaries, in which shall be deposited a sufficient amount of the daily receipts of the State Treasury to transact the current business of the Commonwealth; and said Revenue Commissioners and the Banking Commissioner, or a majority of them, shall have power, if to them it seem necessary, to designate two other banks or trust companies, located in any of the counties above mentioned or in any other county of the Commonwealth, to be known as active depositaries, and to be used for the purposes above mentioned.
72 P.S. § 3774