The jurisdiction ceded shall not vest until the United States shall have acquired the title of said lands by purchase, condemnation or otherwise; and so long as the said lands shall remain the property of the United States, when acquired as aforesaid, and no longer, the same shall be and continue exempt and exonerated from all state, county and municipal taxation, assessment, or other charges which may be levied or imposed under the authority of this state. R.L.1910, § 3192.
Oklahoma Legal Code