The United States of America is hereby empowered to acquire, by purchase or by making adequate compensation under condemnation proceedings, such lands in Pennsylvania as, in the opinion of the Federal Government, may be needed for the establishment of National Forest Reserves in this State, in accordance with an act of Congress, entitled “An act to enable any State to cooperate with any other State or States, or with the United States, for the protection of the watersheds of navigable streams, and to appoint a commission for the acquisition of lands for the purpose of conserving the navigability of navigable rivers,” approved the first day of March, one thousand nine hundred and eleven:¹ Provided, That the approval of the State Forestry Reservation Commission² and the Water Supply Commission³ shall be first had and obtained: Provided further, That the Commonwealth of Pennsylvania shall retain a concurrent jurisdiction with the United States in and over such lands so far that civil process in all cases and such criminal process as may issue under the authority of the Commonwealth of Pennsylvania against any persons charged with the commission of any crime, without or within said jurisdiction, may be executed thereon in like manner as if this act had not been passed.