N.Y. State Law § 54

§ 54. Exemption of property from state taxation. The said property\nshall be and continue forever thereafter exonerated and discharged from\nall taxes, assessments and other charges, which may be levied or imposed\nunder the authority of this state; but the jurisdiction hereby ceded and\nthe exemption from taxation hereby granted, shall continue in respect to\nsaid property so long as the same shall remain the property of the\nUnited States, and be used for the purposes aforesaid, and no longer.\n