N.Y. County Law § 532

§ 532. Retention and destruction of certain recorded instruments.\nAfter twenty years have elapsed from the date of recording a deed,\nlease, contract, agreement, mortgage or a release of part of mortgaged\npremises any such instrument so recorded which has not been returned to\nthe person presenting such instrument for recording or to some other\nperson authorized to receive the same, may be destroyed by the county\nclerk without the permission of the commissioner of education provided\nany such instrument is photographed, microphotographed or reproduced on\nfilm preserved for examination and use.\n