((a)) ** .—** The United States may bring a civil action in the courts of the United States against a person to whom land lying within a national military park has been leased that refuses to give up possession of the land to the United States after the termination of the lease, and after possession has been demanded for the United States by the park superintendent, or against a person retaining possession of land lying within the boundary of a national military park that the person has sold to the United States for park purposes and received payment therefor, after possession of the land has been demanded for the United States by the park superintendent, to recover possession of the land withheld. The civil action shall be brought according to the statutes of the State in which the national military park is situated.
((b)) ** .—** A person described in subsection (a) shall be guilty of trespass.