16 U.S.C. § 41

The tract of land in the State of California known and described as township numbered 18 south, of range numbered 30 east, also township 18 south, range 31 east; and sections 31, 32, 33, and 34, township 17 south, range 30 east, all east of Mount Diablo meridian, is reserved and withdrawn from settlement, occupancy, or sale under the laws of the United States, and dedicated and set apart as a public park, or pleasure ground, for the benefit and enjoyment of the people; and all persons who shall locate or settle upon, or occupy the same or any part thereof except as provided in section 43 of this title , shall be considered trespassers and removed therefrom.