All conservation futures on agricultural lands acquired pursuant to RCW
64.04.130 or
84.34.200 through
84.34.240, that are held by any nonprofit corporation or association, the primary purpose of which is conserving agricultural lands and preventing the conversion of such lands to nonagricultural uses, shall be exempt from ad valorem taxation if:
(1) The conservation futures are of an unlimited duration;
(2) The conservation futures are effectively restricted to preclude nonagricultural uses on such agricultural land; and
(3) The lands are classified as farm and agricultural lands under chapter
84.34 RCW: PROVIDED, That at such time as these property interests are not used for the purposes enumerated in RCW
84.34.210 and
64.04.130 the additional tax specified in *RCW
84.34.108(3) shall be imposed.